package api

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net"
	"net/http"
	"slices"
	"strconv"
	"strings"
	"tera-clone/services/tera-api/internal/startup"
	"time"

	"tera-clone/services/tera-api/internal/alarmdelivery"
	"tera-clone/services/tera-api/internal/authcaptcha"
	"tera-clone/services/tera-api/internal/domain"
	"tera-clone/services/tera-api/internal/hardware/greenled"
	"tera-clone/services/tera-api/internal/networkconfig"
	"tera-clone/services/tera-api/internal/portservice"
	"tera-clone/services/tera-api/internal/serial"
	"tera-clone/services/tera-api/internal/sessionhealth"
	"tera-clone/services/tera-api/internal/systemmetrics"
	"tera-clone/services/tera-api/internal/systemtime"
	"tera-clone/services/tera-api/internal/update"
)

type Router struct {
	clockBootstrap   *startup.ClockBootstrap
	store            domain.Store
	mux              *http.ServeMux
	corsAllowAll     bool
	corsAllowlist    map[string]struct{}
	maxRequestBytes  int64
	disableMockAuth  bool
	greenLEDs        greenled.Controller
	serialPorts      serial.Controller
	portServices     portservice.Controller
	sessions         sessionhealth.Controller
	network          networkconfig.Controller
	firmware         update.Controller
	systemMetrics    systemmetrics.Reader
	maxFirmwareBytes int64
	firmwareTimeout  time.Duration
	captcha          authcaptcha.Service
	commandsReady    func() bool
	startupStatus    func() startup.Status
	serialRuntime    serialRuntimeCache
}

type commandSpec struct {
	Action     string
	Target     string
	Permission string
}

type RouterOptions struct {
	ClockBootstrap        *startup.ClockBootstrap
	CORSAllowedOrigins    []string
	MaxRequestBytes       int64
	DisableMockActors     bool
	GreenLEDController    greenled.Controller
	SerialController      serial.Controller
	PortServiceController portservice.Controller
	SessionController     sessionhealth.Controller
	NetworkController     networkconfig.Controller
	FirmwareController    update.Controller
	SystemMetricsReader   systemmetrics.Reader
	MaxFirmwareBytes      int64
	FirmwareTimeout       time.Duration
	CaptchaService        authcaptcha.Service
	CommandsReady         func() bool
	StartupStatus         func() startup.Status
}

const (
	defaultMaxRequestBytes        int64 = 1 << 20
	defaultLogLimit                     = 100
	maxLogLimit                         = 500
	defaultMaxFirmwareBytes       int64 = 1280 << 20
	defaultFirmwareTimeout              = 30 * time.Minute
	failedLoginSafetyThreshold          = 5
	failedLoginSafetyMinutes            = 15
	serialApplyLeaseRetryInterval       = 25 * time.Millisecond
	serialApplyLeaseRetryCount          = 20
)

func NewRouter(store domain.Store) http.Handler {
	return NewRouterWithOptions(store, RouterOptions{
		MaxRequestBytes:  defaultMaxRequestBytes,
		SerialController: serial.MockController{},
	})
}

func NewRouterWithOptions(store domain.Store, options RouterOptions) http.Handler {
	greenLEDController := options.GreenLEDController
	if greenLEDController == nil {
		greenLEDController = greenled.UnavailableController{Reason: "tera-hwd is not connected"}
	}
	serialController := options.SerialController
	if serialController == nil {
		serialController = serial.UnavailableController{Reason: "tera-seriald is not connected"}
	}
	portServiceController := options.PortServiceController
	if portServiceController == nil {
		portServiceController = portservice.NoopController{}
	}
	sessionController := options.SessionController
	if sessionController == nil {
		sessionController = sessionhealth.UnavailableController{Reason: "tera-sessiond status is not connected"}
	}
	networkController := options.NetworkController
	if networkController == nil {
		networkController = &networkconfig.MockController{}
	}
	firmwareController := options.FirmwareController
	if firmwareController == nil {
		firmwareController = update.UnavailableController{Reason: "tera-updated is not connected"}
	}
	systemMetricsReader := options.SystemMetricsReader
	if systemMetricsReader == nil {
		systemMetricsReader = systemmetrics.UnavailableReader{}
	}
	maxFirmwareBytes := options.MaxFirmwareBytes
	if maxFirmwareBytes <= 0 {
		maxFirmwareBytes = defaultMaxFirmwareBytes
	}
	firmwareTimeout := options.FirmwareTimeout
	if firmwareTimeout <= 0 {
		firmwareTimeout = defaultFirmwareTimeout
	}
	captchaService := options.CaptchaService
	if captchaService == nil {
		captchaService = authcaptcha.New(authcaptcha.Options{})
	}
	router := &Router{
		store:            store,
		mux:              http.NewServeMux(),
		corsAllowlist:    make(map[string]struct{}),
		maxRequestBytes:  normalizeMaxRequestBytes(options.MaxRequestBytes),
		disableMockAuth:  options.DisableMockActors,
		greenLEDs:        greenLEDController,
		serialPorts:      serialController,
		portServices:     portServiceController,
		sessions:         sessionController,
		network:          networkController,
		firmware:         firmwareController,
		systemMetrics:    systemMetricsReader,
		maxFirmwareBytes: maxFirmwareBytes,
		firmwareTimeout:  firmwareTimeout,
		captcha:          captchaService,
		commandsReady:    options.CommandsReady,
		startupStatus:    options.StartupStatus,
		clockBootstrap:   options.ClockBootstrap,
	}
	for _, origin := range options.CORSAllowedOrigins {
		origin = strings.TrimSpace(origin)
		if origin == "" {
			continue
		}
		if origin == "*" {
			router.corsAllowAll = true
			router.corsAllowlist = nil
			break
		}
		router.corsAllowlist[origin] = struct{}{}
	}
	router.routes()
	return router
}

func normalizeMaxRequestBytes(value int64) int64 {
	if value > 0 {
		return value
	}
	return defaultMaxRequestBytes
}

func managementClientForRequest(req *http.Request) (string, string, int) {
	address := req.RemoteAddr
	if host, _, err := net.SplitHostPort(address); err == nil {
		address = host
	}
	protocol := "http"
	destinationPort := 80
	if req.TLS != nil {
		protocol, destinationPort = "https", 443
	}
	if _, portText, err := net.SplitHostPort(req.Host); err == nil {
		if port, parseErr := strconv.Atoi(portText); parseErr == nil && port >= 1 && port <= 65535 {
			destinationPort = port
		}
	}

	// The browser-facing tera-web process is the only trusted source of these
	// headers. Remote clients cannot spoof them because they are accepted only
	// when the API connection itself originates from loopback.
	if remoteIP := net.ParseIP(strings.Trim(address, "[]")); remoteIP != nil && remoteIP.IsLoopback() {
		forwardedIP := strings.TrimSpace(req.Header.Get("X-Tera-Client-IP"))
		if parsed := net.ParseIP(strings.Trim(forwardedIP, "[]")); parsed != nil {
			address = parsed.String()
		}
		forwardedProtocol := strings.ToLower(strings.TrimSpace(req.Header.Get("X-Tera-Client-Protocol")))
		if forwardedProtocol == "http" || forwardedProtocol == "https" {
			protocol = forwardedProtocol
		}
		if forwardedPort, err := strconv.Atoi(strings.TrimSpace(req.Header.Get("X-Tera-Client-Port"))); err == nil && forwardedPort >= 1 && forwardedPort <= 65535 {
			destinationPort = forwardedPort
		}
	}
	return address, protocol, destinationPort
}

func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	if req.Method != http.MethodGet && req.Method != http.MethodHead && req.URL.Path != "/api/v1/system/factory-reset" {
		if gate, ok := r.store.(interface{ BeginMutation() (func(), bool) }); ok {
			release, accepted := gate.BeginMutation()
			if !accepted {
				writeError(w, http.StatusServiceUnavailable, "factory_reset_rebooting", "factory reset completed; device is rebooting")
				return
			}
			defer release()
		}
	}

	req = req.WithContext(domain.WithCommandMetadata(req.Context(), domain.CommandMetadata{
		Surface: "web_api",
		Command: req.Method + " " + req.URL.Path,
	}))
	if authorizer, ok := r.store.(domain.ClientAddressAuthorizer); ok {
		address, protocol, destinationPort := managementClientForRequest(req)
		if err := authorizer.AuthorizeClient(req.Context(), address, protocol, destinationPort); err != nil {
			_, _ = r.store.RecordAudit(req.Context(), domain.AuditEvent{Actor: "anonymous", Action: "auth.address_filter", Target: address, Result: "authorization_denied", Message: err.Error()})
			writeError(w, http.StatusForbidden, "address_filter_denied", err.Error())
			return
		}
	}
	origin := req.Header.Get("Origin")
	corsAllowed := r.applyCORSHeaders(w, origin)
	if req.Method == http.MethodOptions {
		if origin != "" && !corsAllowed {
			writeError(w, http.StatusForbidden, "cors_origin_forbidden", "CORS origin is not allowed")
			return
		}
		w.WriteHeader(http.StatusNoContent)
		return
	}
	if r.commandsReady != nil && !r.commandsReady() && !commandAllowedDuringStartup(req) {
		w.Header().Set("Retry-After", "1")
		writeError(w, http.StatusServiceUnavailable, "service_initializing", "device runtime synchronization is still in progress")
		return
	}
	if req.Method == http.MethodPost && req.URL.Path == "/api/v1/firmware/packages" {
		deadline := time.Now().Add(r.firmwareTimeout)
		controller := http.NewResponseController(w)
		_ = controller.SetReadDeadline(deadline)
		_ = controller.SetWriteDeadline(deadline)
		req.Body = http.MaxBytesReader(w, req.Body, r.maxFirmwareBytes)
	} else {
		req.Body = http.MaxBytesReader(w, req.Body, r.maxRequestBytes)
	}
	r.mux.ServeHTTP(w, req)
}

func commandAllowedDuringStartup(req *http.Request) bool {
	switch req.Method {
	case http.MethodGet, http.MethodHead, http.MethodOptions:
		return true
	}
	if req.Method != http.MethodPost {
		return false
	}
	switch req.URL.Path {
	case "/api/v1/auth/logout", "/api/v1/auth/bootstrap-time":
		return true
	default:
		return false
	}
}

func decodeJSON(w http.ResponseWriter, req *http.Request, target any) bool {
	ok, _ := decodeJSONBody(w, req, target, false)
	return ok
}

func decodeOptionalJSON(w http.ResponseWriter, req *http.Request, target any) bool {
	ok, _ := decodeJSONBody(w, req, target, true)
	return ok
}

func decodeJSONBody(w http.ResponseWriter, req *http.Request, target any, allowEmpty bool) (bool, string) {
	decoder := json.NewDecoder(req.Body)
	decoder.DisallowUnknownFields()
	if err := decoder.Decode(target); err != nil {
		if errors.Is(err, io.EOF) {
			if allowEmpty {
				return true, ""
			}
			message := writeJSONDecodeError(w, err)
			return false, message
		}
		message := writeJSONDecodeError(w, err)
		return false, message
	}

	var extra any
	if err := decoder.Decode(&extra); !errors.Is(err, io.EOF) {
		if err != nil {
			message := writeJSONDecodeError(w, err)
			return false, message
		}
		message := "request body must contain a single JSON value"
		writeError(w, http.StatusBadRequest, "validation_failed", message)
		return false, message
	}
	return true, ""
}

func writeJSONDecodeError(w http.ResponseWriter, err error) string {
	var maxBytesErr *http.MaxBytesError
	if errors.As(err, &maxBytesErr) {
		message := "request body exceeds configured size limit"
		writeError(w, http.StatusRequestEntityTooLarge, "payload_too_large", message)
		return message
	}
	message := "invalid JSON body"
	writeError(w, http.StatusBadRequest, "validation_failed", message)
	return message
}

func (r *Router) decodeCommandJSON(w http.ResponseWriter, req *http.Request, ctx context.Context, spec commandSpec, target any) bool {
	ok, message := decodeJSONBody(w, req, target, false)
	if !ok {
		r.recordRejectedCommand(ctx, spec, message)
	}
	return ok
}

func (r *Router) decodeConfigRestoreJSON(w http.ResponseWriter, req *http.Request, ctx context.Context, spec commandSpec, target any) bool {
	ok, message := decodeConfigRestoreJSONBody(w, req, target)
	if !ok {
		r.recordRejectedCommand(ctx, spec, message)
	}
	return ok
}

func (r *Router) decodeOptionalCommandJSON(w http.ResponseWriter, req *http.Request, ctx context.Context, spec commandSpec, target any) bool {
	ok, message := decodeJSONBody(w, req, target, true)
	if !ok {
		r.recordRejectedCommand(ctx, spec, message)
	}
	return ok
}

func decodeConfigRestoreJSONBody(w http.ResponseWriter, req *http.Request, target any) (bool, string) {
	body, err := io.ReadAll(req.Body)
	if err != nil {
		message := writeJSONDecodeError(w, err)
		return false, message
	}

	var raw any
	if err := json.Unmarshal(body, &raw); err != nil {
		message := writeJSONDecodeError(w, err)
		return false, message
	}
	if key, ok := findConfigRestoreSecretField(raw); ok {
		message := "config restore must not include secret material field " + strconv.Quote(key)
		writeError(w, http.StatusBadRequest, "validation_failed", message)
		return false, message
	}
	decoder := json.NewDecoder(strings.NewReader(string(body)))
	decoder.DisallowUnknownFields()
	if err := decoder.Decode(target); err != nil {
		message := writeJSONDecodeError(w, err)
		return false, message
	}
	var extra any
	if err := decoder.Decode(&extra); !errors.Is(err, io.EOF) {
		message := writeJSONDecodeError(w, err)
		return false, message
	}
	return true, ""
}

func findConfigRestoreSecretField(value any) (string, bool) {
	switch typed := value.(type) {
	case map[string]any:
		for key, child := range typed {
			if isConfigRestoreSecretField(key) {
				return key, true
			}
			if found, ok := findConfigRestoreSecretField(child); ok {
				return found, true
			}
		}
	case []any:
		for _, child := range typed {
			if found, ok := findConfigRestoreSecretField(child); ok {
				return found, true
			}
		}
	}
	return "", false
}

func isConfigRestoreSecretField(key string) bool {
	normalized := strings.ToLower(strings.TrimSpace(key))
	switch normalized {
	case "password_stored",
		"secret_stored",
		"credential_stored",
		"private_key_stored",
		"auth_key_stored",
		"privacy_key_stored",
		"read_only_community_stored":
		return false
	case "password",
		"password_hash",
		"password_value",
		"smtp_password",
		"secret",
		"secret_value",
		"shared_secret",
		"credential",
		"credential_value",
		"private_key",
		"private_key_pem",
		"community_value",
		"auth_key",
		"auth_secret",
		"privacy_key",
		"privacy_secret":
		return true
	default:
		return strings.Contains(normalized, "password") ||
			strings.Contains(normalized, "shared_secret") ||
			strings.Contains(normalized, "private_key") ||
			strings.HasSuffix(normalized, "_secret")
	}
}

func (r *Router) recordRejectedCommand(ctx context.Context, spec commandSpec, message string) {
	_, _ = r.store.RecordAudit(ctx, domain.AuditEvent{
		Action:  spec.Action,
		Target:  spec.Target,
		Result:  "rejected",
		Message: message,
	})
}

func (r *Router) applyCORSHeaders(w http.ResponseWriter, origin string) bool {
	if r.corsAllowAll {
		w.Header().Set("Access-Control-Allow-Origin", "*")
		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PATCH, DELETE, OPTIONS")
		w.Header().Set("Access-Control-Allow-Headers", r.corsAllowedHeaders())
		return true
	}
	if origin == "" {
		return true
	}
	if _, ok := r.corsAllowlist[origin]; !ok {
		return false
	}
	w.Header().Set("Vary", "Origin")
	w.Header().Set("Access-Control-Allow-Origin", origin)
	w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PATCH, DELETE, OPTIONS")
	w.Header().Set("Access-Control-Allow-Headers", r.corsAllowedHeaders())
	return true
}

func (r *Router) corsAllowedHeaders() string {
	if r.disableMockAuth {
		return "Authorization, Content-Type, X-Tera-Filename"
	}
	return "Authorization, Content-Type, X-Mock-Actor, X-Tera-Filename"
}

func (r *Router) routes() {
	r.mux.HandleFunc("GET /api/v1/system/status", r.handleSystemStatus)
	r.mux.HandleFunc("GET /api/v1/system/services", r.handleServiceHealth)
	r.mux.HandleFunc("POST /api/v1/system/reboot", r.handleSystemReboot)
	r.mux.HandleFunc("POST /api/v1/system/factory-reset", r.handleFactoryReset)
	r.mux.HandleFunc("POST /api/v1/auth/login", r.handleAuthLogin)
	r.mux.HandleFunc("GET /api/v1/auth/login-policy", r.handleAuthLoginPolicy)
	r.mux.HandleFunc("GET /api/v1/auth/startup", r.handleStartupStatus)
	r.mux.HandleFunc("POST /api/v1/auth/bootstrap-time", r.handleBootstrapTime)
	r.mux.HandleFunc("POST /api/v1/auth/captcha", r.handleAuthCaptcha)
	r.mux.HandleFunc("POST /api/v1/auth/logout", r.handleAuthLogout)
	r.mux.HandleFunc("GET /api/v1/auth/me", r.handleAuthMe)
	r.mux.HandleFunc("PATCH /api/v1/auth/password", r.handleOwnPassword)
	r.mux.HandleFunc("GET /api/v1/auth/sessions", r.handleAuthSessions)
	r.mux.HandleFunc("DELETE /api/v1/auth/sessions/", r.handleAuthSessionSubtree)
	r.mux.HandleFunc("GET /api/v1/auth/tokens", r.handleAuthTokens)
	r.mux.HandleFunc("POST /api/v1/auth/tokens", r.handleCreateAuthToken)
	r.mux.HandleFunc("DELETE /api/v1/auth/tokens/", r.handleAuthTokenSubtree)
	r.mux.HandleFunc("GET /api/v1/auth/users", r.handleAuthUsers)
	r.mux.HandleFunc("POST /api/v1/auth/users", r.handleCreateAuthUser)
	r.mux.HandleFunc("PATCH /api/v1/auth/users/", r.handleAuthUserSubtree)
	r.mux.HandleFunc("DELETE /api/v1/auth/users/", r.handleAuthUserSubtree)
	r.mux.HandleFunc("GET /api/v1/auth/external", r.handleExternalAuth)
	r.mux.HandleFunc("PATCH /api/v1/auth/external", r.handleUpdateExternalAuth)
	r.mux.HandleFunc("GET /api/v1/auth/groups", r.handleAuthGroups)
	r.mux.HandleFunc("POST /api/v1/auth/groups", r.handleCreateAuthGroup)
	r.mux.HandleFunc("PATCH /api/v1/auth/groups/", r.handleAuthGroupSubtree)
	r.mux.HandleFunc("DELETE /api/v1/auth/groups/", r.handleAuthGroupSubtree)
	r.mux.HandleFunc("GET /api/v1/auth/permissions", r.handleAuthPermissions)
	r.mux.HandleFunc("GET /api/v1/network", r.handleNetwork)
	r.mux.HandleFunc("PATCH /api/v1/network/running", r.handleUpdateNetwork)
	r.mux.HandleFunc("POST /api/v1/network/apply", r.handleApplyNetwork)
	r.mux.HandleFunc("GET /api/v1/network/apply-status", r.handleNetworkApplyStatus)
	r.mux.HandleFunc("POST /api/v1/network/confirm", r.handleConfirmNetwork)
	r.mux.HandleFunc("POST /api/v1/network/rollback", r.handleRollbackNetwork)
	r.mux.HandleFunc("GET /api/v1/snmp/agent", r.handleSNMPAgent)
	r.mux.HandleFunc("PATCH /api/v1/snmp/agent", r.handleUpdateSNMPAgent)
	r.mux.HandleFunc("GET /api/v1/time/settings", r.handleTimeSettings)
	r.mux.HandleFunc("PATCH /api/v1/time/settings", r.handleUpdateTimeSettings)
	r.mux.HandleFunc("GET /api/v1/security/management-access", r.handleManagementAccess)
	r.mux.HandleFunc("PATCH /api/v1/security/management-access", r.handleUpdateManagementAccess)
	r.mux.HandleFunc("GET /api/v1/security/tls-certificate", r.handleTLSCertificate)
	r.mux.HandleFunc("PATCH /api/v1/security/tls-certificate", r.handleUpdateTLSCertificate)
	r.mux.HandleFunc("GET /api/v1/security/tls-certificates", r.handleTLSCertificates)
	r.mux.HandleFunc("POST /api/v1/security/tls-certificates", r.handleCreateTLSCertificate)
	r.mux.HandleFunc("POST /api/v1/security/tls-certificates/import", r.handleImportTLSCertificate)
	r.mux.HandleFunc("POST /api/v1/security/tls-certificates/", r.handleTLSCertificateSubtree)
	r.mux.HandleFunc("DELETE /api/v1/security/tls-certificates/", r.handleTLSCertificateSubtree)
	r.mux.HandleFunc("GET /api/v1/security/address-filters", r.handleAddressFilters)
	r.mux.HandleFunc("PUT /api/v1/security/address-filters", r.handleUpdateAddressFilters)
	r.mux.HandleFunc("GET /api/v1/ports/runtime-status", r.handlePortRuntimeStatus)
	r.mux.HandleFunc("GET /api/v1/ports", r.handlePorts)
	r.mux.HandleFunc("PATCH /api/v1/ports", r.handlePorts)
	r.mux.HandleFunc("POST /api/v1/ports/restart", r.handleBulkPortRestart)
	r.mux.HandleFunc("GET /api/v1/ports/", r.handlePortSubtree)
	r.mux.HandleFunc("PATCH /api/v1/ports/", r.handlePortSubtree)
	r.mux.HandleFunc("POST /api/v1/ports/", r.handlePortSubtree)
	r.mux.HandleFunc("GET /api/v1/hardware/serial-ports", r.handleSerialPorts)
	r.mux.HandleFunc("GET /api/v1/alarms/rules", r.handleAlarmRules)
	r.mux.HandleFunc("GET /api/v1/alarms/rules/", r.handleAlarmRuleSubtree)
	r.mux.HandleFunc("PATCH /api/v1/alarms/rules/", r.handleAlarmRuleSubtree)
	r.mux.HandleFunc("GET /api/v1/alarms/delivery-policy", r.handleAlarmDeliveryPolicy)
	r.mux.HandleFunc("PATCH /api/v1/alarms/delivery-policy", r.handleUpdateAlarmDeliveryPolicy)
	r.mux.HandleFunc("POST /api/v1/alarms/delivery-test", r.handleAlarmDeliveryTest)
	r.mux.HandleFunc("GET /api/v1/alarms/email-settings", r.handleEmailNotification)
	r.mux.HandleFunc("PATCH /api/v1/alarms/email-settings", r.handleUpdateEmailNotification)
	r.mux.HandleFunc("GET /api/v1/alarms/snmp-trap-targets", r.handleSNMPTrapTargets)
	r.mux.HandleFunc("PATCH /api/v1/alarms/snmp-trap-targets", r.handleUpdateSNMPTrapTargets)
	r.mux.HandleFunc("GET /api/v1/config/status", r.handleConfigStatus)
	r.mux.HandleFunc("GET /api/v1/config/export", r.handleConfigExport)
	r.mux.HandleFunc("POST /api/v1/config/export/encrypted", r.handleEncryptedConfigExport)
	r.mux.HandleFunc("POST /api/v1/config/restore", r.handleRestoreConfig)
	r.mux.HandleFunc("POST /api/v1/config/restore/encrypted", r.handleEncryptedConfigRestore)
	r.mux.HandleFunc("POST /api/v1/config/apply", r.handleApplyConfig)
	r.mux.HandleFunc("POST /api/v1/config/save", r.handleSaveConfig)
	r.mux.HandleFunc("POST /api/v1/config/save-and-apply", r.handleSaveAndApplyConfig)
	r.mux.HandleFunc("POST /api/v1/config/discard", r.handleDiscardConfig)
	r.mux.HandleFunc("POST /api/v1/config/save-and-restart", r.handleSaveAndRestart)
	r.mux.HandleFunc("POST /api/v1/direct/", r.handleDirectSubtree)
	r.mux.HandleFunc("DELETE /api/v1/direct/", r.handleDirectSubtree)
	r.mux.HandleFunc("POST /api/v1/time/sync-browser", r.handleSyncBrowserTime)
	r.mux.HandleFunc("POST /api/v1/time/sync-ntp", r.handleSyncNTPTime)
	r.mux.HandleFunc("GET /api/v1/diagnostics/support-bundles/", r.handleSupportBundleDownload)
	r.mux.HandleFunc("POST /api/v1/diagnostics/", r.handleDiagnosticsSubtree)
	r.mux.HandleFunc("GET /api/v1/logs/audit", r.handleAuditEvents)
	r.mux.HandleFunc("GET /api/v1/logs/system", r.handleSystemLogEvents)
	r.mux.HandleFunc("GET /api/v1/logs/port", r.handlePortLogEvents)
	r.mux.HandleFunc("POST /api/v1/logs/port/clear", r.handleClearPortLogs)
	r.mux.HandleFunc("POST /api/v1/logs/system/clear", r.handleClearSystemLogs)
	r.mux.HandleFunc("POST /api/v1/logs/links/clear", r.handleClearLinkLogs)
	r.mux.HandleFunc("GET /api/v1/logs/links", r.handleLinkLogEvents)
	r.mux.HandleFunc("GET /api/v1/logs/policy", r.handleLogPolicy)
	r.mux.HandleFunc("GET /api/v1/logs/storage", r.handleLogStorageStatus)
	r.mux.HandleFunc("GET /api/v1/logs/remote-syslog/status", r.handleRemoteSyslogStatus)
	r.mux.HandleFunc("GET /api/v1/logs/retention", r.handleLogRetention)
	r.mux.HandleFunc("PATCH /api/v1/logs/retention", r.handleUpdateLogRetention)
	r.mux.HandleFunc("GET /api/v1/logs/remote-syslog", r.handleRemoteSyslog)
	r.mux.HandleFunc("PATCH /api/v1/logs/remote-syslog", r.handleUpdateRemoteSyslog)
	r.mux.HandleFunc("POST /api/v1/logs/export", r.handleExportLogs)
	r.mux.HandleFunc("POST /api/v1/logs/export/download", r.handleDownloadLogs)
	r.mux.HandleFunc("GET /api/v1/operations", r.handleOperations)
	r.mux.HandleFunc("GET /api/v1/operations/", r.handleOperation)
	r.mux.HandleFunc("GET /api/v1/firmware/status", r.handleFirmwareStatus)
	r.mux.HandleFunc("POST /api/v1/firmware/packages", r.handleFirmwareUpload)
	r.mux.HandleFunc("POST /api/v1/firmware/apply", r.handleFirmwareApply)
}

func (r *Router) handleSystemStatus(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "system.read", Target: "system", Permission: "system.read"}); !ok {
		return
	}
	status, err := r.store.SystemStatus(req.Context())
	if err == nil {
		networkState, _ := r.store.NetworkState(req.Context())
		metrics := r.systemMetrics.Read(req.Context(), networkState.Interfaces)
		status.BuildNumber = metrics.BuildNumber
		if status.BuildNumber != "" {
			status.FirmwareVersion = status.BuildNumber
		} else {
			status.BuildNumber = status.FirmwareVersion
		}
		status.DeviceID = metrics.DeviceID
		status.SystemTime = metrics.SystemTime
		status.UptimeSeconds = metrics.UptimeSeconds
		status.TemperatureCelsius = metrics.TemperatureCelsius
		status.LoadAverages = metrics.LoadAverages
		status.CPUUsagePercent = metrics.CPUUsagePercent
		status.MemoryTotalBytes = metrics.MemoryTotalBytes
		status.MemoryUsedBytes = metrics.MemoryUsedBytes
		status.MemoryAvailableBytes = metrics.MemoryAvailableBytes
		status.MemoryUsagePercent = metrics.MemoryUsagePercent
		status.Storage = metrics.Storage
		status.NetworkInterfaces = metrics.NetworkInterfaces
		runtime := r.readSerialRuntime(req.Context())
		status.SerialPortCount = runtime.availablePorts()
		if runtime.sessionErr == nil {
			status.ActiveSessions = runtime.session.Broker.TotalAttachments
			status.ActivePortCount = runtime.session.Broker.ActiveChannels
			status.MostUsedPort = "-"
			for _, channel := range runtime.session.Serial.Channels {
				status.TotalSerialRXBytes += channel.RXBytes
				status.TotalSerialTXBytes += channel.TXBytes
				total := channel.RXBytes + channel.TXBytes
				if total > status.MostUsedPortBytes || (total == status.MostUsedPortBytes && total > 0 && (status.MostUsedPort == "-" || channel.Channel < status.MostUsedPort)) {
					status.MostUsedPort = channel.Channel
					status.MostUsedPortBytes = total
				}
			}
		} else {
			status.ActiveSessions = 0
			status.MostUsedPort = "-"
		}
	}
	writeResult(w, status, err)
}

func (r *Router) handleServiceHealth(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "system.service.read", Target: "services", Permission: "system.read"}); !ok {
		return
	}
	limit, offset, ok := parsePagination(w, req)
	if !ok {
		return
	}
	health, err := r.store.ServiceHealth(req.Context())
	health = r.withRuntimeHealth(req.Context(), health)
	health = r.withFirmwareHealth(req.Context(), health)
	health = windowServiceHealth(health, limit, offset)
	writeResult(w, health, err)
}

func (r *Router) withFirmwareHealth(ctx context.Context, health []domain.ServiceHealth) []domain.ServiceHealth {
	status, statusErr := r.firmware.Status(ctx)
	for index := range health {
		if health[index].Service != "tera-updated" {
			continue
		}
		if statusErr != nil {
			health[index].Status = "degraded"
			health[index].Detail = "validation-only updater unavailable: " + statusErr.Error()
			return health
		}
		health[index].Status = "ok"
		pressure := status.Capacity.Pressure
		if pressure == "critical" || pressure == "emergency" {
			health[index].Status = "degraded"
		}
		if pressure == "" {
			pressure = "unknown"
		}
		health[index].Detail = fmt.Sprintf("validation-only updater reachable; state=%s; storage_pressure=%s", status.State, pressure)
		return health
	}
	return health
}

func (r *Router) handleSystemReboot(w http.ResponseWriter, req *http.Request) {
	ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "system.reboot", Target: "system", Permission: "system.reboot"})
	if !ok {
		return
	}
	operation, err := r.store.RebootSystem(ctx)
	writeResult(w, operation, err)
}

func (r *Router) handleFactoryReset(w http.ResponseWriter, req *http.Request) {
	ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "system.factory_reset", Target: "system", Permission: "system.factory_reset"})
	if !ok {
		return
	}
	operation, err := r.store.FactoryReset(ctx)
	writeResult(w, operation, err)
}

func (r *Router) handleAuthMe(w http.ResponseWriter, req *http.Request) {
	actor, ok := r.authenticateActor(w, req)
	if !ok {
		return
	}
	writeJSON(w, http.StatusOK, authProfile(actor))
}

func (r *Router) handleAuthLogin(w http.ResponseWriter, req *http.Request) {
	w.Header().Set("Cache-Control", "no-store")
	var loginRequest domain.AuthLoginRequest
	if ok, message := decodeJSONBody(w, req, &loginRequest, false); !ok {
		_, _ = r.store.RecordAudit(req.Context(), domain.AuditEvent{
			Actor:   "anonymous",
			Action:  "auth.login",
			Target:  "auth",
			Result:  "rejected",
			Message: message,
		})
		return
	}
	settings, err := r.store.ManagementAccess(req.Context())
	if err != nil {
		writeResult(w, nil, err)
		return
	}
	if settings.CaptchaEnabled && !r.captcha.Verify(requestPeerSubject(req), loginRequest.CaptchaID, loginRequest.CaptchaAnswer) {
		loginRequest.Password = ""
		loginRequest.CaptchaAnswer = ""
		_, _ = r.store.RecordAudit(req.Context(), domain.AuditEvent{
			Actor:   "anonymous",
			Action:  "auth.captcha.verify",
			Target:  "auth",
			Result:  "rejected",
			Message: "login automation challenge rejected",
		})
		writeError(w, http.StatusUnauthorized, "captcha_failed", "login verification failed")
		return
	}
	loginRequest.CaptchaID = ""
	loginRequest.CaptchaAnswer = ""
	session, err := r.store.Login(req.Context(), loginRequest)
	if err != nil {
		writeError(w, http.StatusUnauthorized, "authentication_failed", "invalid username or password")
		return
	}
	writeJSON(w, http.StatusOK, session)
}

func (r *Router) handleAuthLoginPolicy(w http.ResponseWriter, req *http.Request) {
	w.Header().Set("Cache-Control", "no-store")
	settings, err := r.store.ManagementAccess(req.Context())
	if err != nil {
		writeResult(w, nil, err)
		return
	}
	writeJSON(w, http.StatusOK, domain.AuthLoginPolicy{
		CaptchaEnabled:       settings.CaptchaEnabled,
		DetectionMinutes:     settings.LoginDetectionMinutes,
		SecurityHitCount:     settings.LoginSecurityHitCount,
		FixedSafetyThreshold: failedLoginSafetyThreshold,
		FixedSafetyMinutes:   failedLoginSafetyMinutes,
	})
}

func (r *Router) handleAuthCaptcha(w http.ResponseWriter, req *http.Request) {
	w.Header().Set("Cache-Control", "no-store")
	settings, err := r.store.ManagementAccess(req.Context())
	if err != nil {
		writeResult(w, nil, err)
		return
	}
	if !settings.CaptchaEnabled {
		writeError(w, http.StatusConflict, "captcha_disabled", "login verification challenge is disabled")
		return
	}
	challenge, err := r.captcha.Create(requestPeerSubject(req))
	if err != nil {
		writeError(w, http.StatusServiceUnavailable, "captcha_unavailable", "login verification challenge is unavailable")
		return
	}
	writeJSON(w, http.StatusOK, challenge)
}

func requestPeerSubject(req *http.Request) string {
	address := strings.TrimSpace(req.RemoteAddr)
	if host, _, err := net.SplitHostPort(address); err == nil {
		address = host
	}
	peerIP := net.ParseIP(address)
	if peerIP != nil && peerIP.IsLoopback() {
		forwarded := strings.TrimSpace(req.Header.Get("X-Forwarded-For"))
		if !strings.Contains(forwarded, ",") {
			if forwardedIP := net.ParseIP(forwarded); forwardedIP != nil {
				return forwardedIP.String()
			}
		}
	}
	if peerIP != nil {
		return peerIP.String()
	}
	if address == "" {
		return "unknown"
	}
	return address
}

func (r *Router) handleAuthLogout(w http.ResponseWriter, req *http.Request) {
	token := bearerToken(req.Header.Get("Authorization"))
	if token == "" {
		_, _ = r.store.RecordAudit(req.Context(), domain.AuditEvent{
			Actor:   "anonymous",
			Action:  "auth.logout",
			Target:  "auth",
			Result:  "authentication_failed",
			Message: "authentication required",
		})
		writeError(w, http.StatusUnauthorized, "authentication_required", "authentication required")
		return
	}
	if err := r.store.Logout(req.Context(), token); err != nil {
		_, _ = r.store.RecordAudit(req.Context(), domain.AuditEvent{
			Actor:   "anonymous",
			Action:  "auth.logout",
			Target:  "auth",
			Result:  "authentication_failed",
			Message: "invalid session token",
		})
		writeError(w, http.StatusUnauthorized, "authentication_required", "invalid session token")
		return
	}
	writeJSON(w, http.StatusOK, map[string]string{
		"result":  "logged_out",
		"message": "session revoked",
	})
}

func (r *Router) handleAuthUsers(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeAuthRead(w, req, "auth.users.read"); !ok {
		return
	}
	limit, offset, ok := parsePagination(w, req)
	if !ok {
		return
	}
	users, err := r.store.AuthUsers(req.Context())
	users = windowAuthUsers(users, limit, offset)
	writeResult(w, users, err)
}

func (r *Router) handleAuthSessions(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeAuthRead(w, req, "auth.sessions.read"); !ok {
		return
	}
	limit, offset, ok := parsePagination(w, req)
	if !ok {
		return
	}
	sessions, err := r.store.AuthSessions(req.Context())
	sessions = windowAuthSessions(sessions, limit, offset)
	writeResult(w, sessions, err)
}

func (r *Router) handleAuthSessionSubtree(w http.ResponseWriter, req *http.Request) {
	sessionID := strings.Trim(strings.TrimPrefix(req.URL.Path, "/api/v1/auth/sessions/"), "/")
	if sessionID == "" || req.Method != http.MethodDelete {
		writeError(w, http.StatusNotFound, "not_found", "auth session route not found")
		return
	}
	ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "auth.session.revoke", Target: sessionID, Permission: "auth.write"})
	if !ok {
		return
	}
	result, err := r.store.RevokeAuthSession(ctx, sessionID)
	writeResult(w, result, err)
}

func (r *Router) handleAuthTokens(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeAuthRead(w, req, "auth.tokens.read"); !ok {
		return
	}
	limit, offset, ok := parsePagination(w, req)
	if !ok {
		return
	}
	tokens, err := r.store.AuthTokens(req.Context())
	tokens = windowAuthTokens(tokens, limit, offset)
	writeResult(w, tokens, err)
}

func (r *Router) handleCreateAuthToken(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "auth.token.create", Target: "auth", Permission: "auth.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var createRequest domain.AuthTokenCreateRequest
	if !r.decodeCommandJSON(w, req, ctx, spec, &createRequest) {
		return
	}
	token, err := r.store.CreateAuthToken(ctx, createRequest)
	writeResult(w, token, err)
}

func (r *Router) handleAuthTokenSubtree(w http.ResponseWriter, req *http.Request) {
	tokenID := strings.Trim(strings.TrimPrefix(req.URL.Path, "/api/v1/auth/tokens/"), "/")
	if tokenID == "" || req.Method != http.MethodDelete {
		writeError(w, http.StatusNotFound, "not_found", "auth token route not found")
		return
	}
	ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "auth.token.revoke", Target: tokenID, Permission: "auth.write"})
	if !ok {
		return
	}
	result, err := r.store.RevokeAuthToken(ctx, tokenID)
	writeResult(w, result, err)
}

func (r *Router) handleExternalAuth(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeAuthRead(w, req, "auth.external.read"); !ok {
		return
	}
	settings, err := r.store.ExternalAuth(req.Context())
	writeResult(w, settings, err)
}

func (r *Router) handleUpdateExternalAuth(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "auth.external.update", Target: "external_auth", Permission: "auth.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var update domain.ExternalAuthUpdate
	if !r.decodeCommandJSON(w, req, ctx, spec, &update) {
		return
	}
	result, err := r.store.UpdateExternalAuth(ctx, update)
	writeResult(w, result, err)
}

func (r *Router) handleAddressFilters(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeAuthRead(w, req, "auth.address_filter.read"); !ok {
		return
	}
	settings, err := r.store.AddressFilters(req.Context())
	writeResult(w, settings, err)
}

func (r *Router) handleUpdateAddressFilters(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "auth.address_filter.update", Target: "address_filters", Permission: "auth.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var settings domain.AddressFilterSettings
	if !r.decodeCommandJSON(w, req, ctx, spec, &settings) {
		return
	}
	result, err := r.store.UpdateAddressFilters(ctx, settings)
	writeResult(w, result, err)
}

func (r *Router) handleCreateAuthUser(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "auth.user.create", Target: "auth", Permission: "auth.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var createRequest domain.AuthUserCreateRequest
	if !r.decodeCommandJSON(w, req, ctx, spec, &createRequest) {
		return
	}
	user, err := r.store.CreateAuthUser(ctx, createRequest)
	writeResult(w, user, err)
}

func (r *Router) handleOwnPassword(w http.ResponseWriter, req *http.Request) {
	actor, ok := r.authenticateActor(w, req)
	if !ok {
		return
	}
	ctx := domain.WithActor(req.Context(), actor)
	spec := commandSpec{Action: "auth.password.change", Target: actor.Name, Permission: ""}
	var update domain.AuthSelfPasswordUpdateRequest
	if !r.decodeCommandJSON(w, req, ctx, spec, &update) {
		return
	}
	user, err := r.store.ChangeOwnPassword(ctx, update)
	writeResult(w, user, err)
}

func (r *Router) handleCreateAuthGroup(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "auth.group.create", Target: "auth", Permission: "auth.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var create domain.AuthGroupCreateRequest
	if !r.decodeCommandJSON(w, req, ctx, spec, &create) {
		return
	}
	group, err := r.store.CreateAuthGroup(ctx, create)
	writeResult(w, group, err)
}

func (r *Router) handleAuthUserSubtree(w http.ResponseWriter, req *http.Request) {
	rest := strings.Trim(strings.TrimPrefix(req.URL.Path, "/api/v1/auth/users/"), "/")
	parts := strings.Split(rest, "/")
	if len(parts) == 0 || parts[0] == "" {
		writeError(w, http.StatusNotFound, "not_found", "auth user route not found")
		return
	}

	username := parts[0]
	switch {
	case req.Method == http.MethodDelete && len(parts) == 1:
		ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "auth.user.delete", Target: strings.ToLower(username), Permission: "auth.write"})
		if !ok {
			return
		}
		result, err := r.store.DeleteAuthUser(ctx, username)
		writeResult(w, result, err)
	case req.Method == http.MethodPatch && len(parts) == 1:
		spec := commandSpec{Action: "auth.user.update", Target: strings.ToLower(username), Permission: "auth.write"}
		ctx, ok := r.authorizeCommand(w, req, spec)
		if !ok {
			return
		}
		var updateRequest domain.AuthUserUpdateRequest
		if !r.decodeCommandJSON(w, req, ctx, spec, &updateRequest) {
			return
		}
		user, err := r.store.UpdateAuthUser(ctx, username, updateRequest)
		writeResult(w, user, err)
	case req.Method == http.MethodPatch && len(parts) == 2 && parts[1] == "password":
		spec := commandSpec{Action: "auth.user.password.update", Target: strings.ToLower(username), Permission: "auth.write"}
		ctx, ok := r.authorizeCommand(w, req, spec)
		if !ok {
			return
		}
		var updateRequest domain.AuthUserPasswordUpdateRequest
		if !r.decodeCommandJSON(w, req, ctx, spec, &updateRequest) {
			return
		}
		user, err := r.store.UpdateAuthUserPassword(ctx, username, updateRequest)
		writeResult(w, user, err)
	default:
		writeError(w, http.StatusNotFound, "not_found", "auth user route not found")
	}
}

func (r *Router) handleAuthGroups(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeAuthRead(w, req, "auth.groups.read"); !ok {
		return
	}
	limit, offset, ok := parsePagination(w, req)
	if !ok {
		return
	}
	groups, err := r.store.AuthGroups(req.Context())
	groups = windowAuthGroups(groups, limit, offset)
	writeResult(w, groups, err)
}

func (r *Router) handleAuthGroupSubtree(w http.ResponseWriter, req *http.Request) {
	groupID := strings.Trim(strings.TrimPrefix(req.URL.Path, "/api/v1/auth/groups/"), "/")
	if groupID == "" {
		writeError(w, http.StatusNotFound, "not_found", "auth group route not found")
		return
	}
	if req.Method == http.MethodDelete {
		ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "auth.group.delete", Target: strings.ToLower(groupID), Permission: "auth.write"})
		if !ok {
			return
		}
		result, err := r.store.DeleteAuthGroup(ctx, groupID)
		writeResult(w, result, err)
		return
	}
	if req.Method != http.MethodPatch {
		writeError(w, http.StatusNotFound, "not_found", "auth group route not found")
		return
	}

	spec := commandSpec{Action: "auth.group.update", Target: strings.ToLower(groupID), Permission: "auth.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var updateRequest domain.AuthGroupUpdateRequest
	if !r.decodeCommandJSON(w, req, ctx, spec, &updateRequest) {
		return
	}
	group, err := r.store.UpdateAuthGroup(ctx, groupID, updateRequest)
	writeResult(w, group, err)
}

func (r *Router) handleAuthPermissions(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeAuthRead(w, req, "auth.permissions.read"); !ok {
		return
	}
	limit, offset, ok := parsePagination(w, req)
	if !ok {
		return
	}
	permissions, err := r.store.AuthPermissions(req.Context())
	permissions = windowAuthPermissions(permissions, limit, offset)
	writeResult(w, permissions, err)
}

func (r *Router) handleNetwork(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "network.read", Target: "network", Permission: "network.read"}); !ok {
		return
	}
	network, err := r.store.NetworkState(req.Context())
	if err == nil {
		status, statusErr := r.network.Status(req.Context())
		if statusErr == nil {
			if reconcileErr := r.reconcileRolledBackNetwork(req.Context(), status); reconcileErr != nil {
				err = reconcileErr
			} else if strings.HasPrefix(status.State, "rolled_back") {
				network, err = r.store.NetworkState(req.Context())
			}
			mergeNetworkStatus(&network, status)
		} else if networkconfig.IsUnavailable(statusErr) {
			network.Apply = &domain.NetworkApplyStatus{State: "unavailable"}
		} else {
			err = statusErr
		}
	}
	writeResult(w, network, err)
}

func (r *Router) handleUpdateNetwork(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "network.update", Target: "network", Permission: "network.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var update domain.NetworkUpdate
	if !r.decodeCommandJSON(w, req, ctx, spec, &update) {
		return
	}
	result, err := r.store.UpdateNetwork(ctx, update)
	writeResult(w, result, err)
}

func (r *Router) handleNetworkApplyStatus(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "network.apply_status.read", Target: "network", Permission: "network.read"}); !ok {
		return
	}
	status, err := r.network.Status(req.Context())
	if err == nil {
		err = r.reconcileRolledBackNetwork(req.Context(), status)
	}
	writeResult(w, networkApplyStatus(status), err)
}

// handleApplyNetwork applies only the pending network section. Other staged
// sections (ports, alarms, and so on) remain pending and are never activated by
// a network form submission.
func (r *Router) handleApplyNetwork(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "network.apply", Target: "network", Permission: "network.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	applyStore, ok := r.store.(networkPendingConfigApplier)
	if !ok {
		writeResult(w, nil, errors.New("network-only configuration apply is unavailable"))
		return
	}
	// Reconfiguring the management interface can close the HTTP connection that
	// initiated the operation. Keep the authenticated operation values, but do
	// not let that expected disconnect cancel confirmation and persistence.
	operationCtx, cancelOperation := context.WithTimeout(context.WithoutCancel(ctx), 2*time.Minute)
	defer cancelOperation()
	networkApply, err := r.applyPendingNetworkConfig(operationCtx)
	if err != nil {
		r.recordHardwareFailure(operationCtx, spec, err)
		writeResult(w, nil, err)
		return
	}
	result, err := applyStore.ApplyPendingNetwork(operationCtx)
	if err != nil && networkApply != nil {
		r.rollbackAppliedNetwork(networkApply)
	}
	if err == nil && networkApply != nil {
		status, confirmErr := r.network.Confirm(operationCtx, networkApply.TransactionID)
		if confirmErr != nil {
			r.rollbackAppliedNetwork(networkApply)
			err = confirmErr
		} else if confirmer, ok := r.store.(networkRuntimeConfirmer); ok {
			err = confirmer.ConfirmNetworkRuntime(operationCtx, networkApply.TransactionID)
		}
		if err == nil {
			if saver, ok := r.store.(networkRunningConfigSaver); ok {
				err = saver.SaveRunningNetwork(operationCtx)
			}
		}
		if err == nil {
			r.recordNetworkTransaction(operationCtx, "network.confirm", networkApply.TransactionID, "succeeded", "confirmed by immediate network apply")
			status.State = "confirmed"
			result.NetworkApply = networkApplyStatus(status)
		}
	}
	if err == nil && networkApply == nil {
		result.NetworkApply = domainNetworkApplyResult(nil)
	}
	writeResult(w, result, err)
}

func (r *Router) handleConfirmNetwork(w http.ResponseWriter, req *http.Request) {
	r.handleNetworkTransaction(w, req, "network.confirm", r.network.Confirm)
}

func (r *Router) handleRollbackNetwork(w http.ResponseWriter, req *http.Request) {
	r.handleNetworkTransaction(w, req, "network.rollback", r.network.Rollback)
}

func (r *Router) handleNetworkTransaction(w http.ResponseWriter, req *http.Request, action string, command func(context.Context, string) (networkconfig.Status, error)) {
	spec := commandSpec{Action: action, Target: "network", Permission: "network.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var request domain.NetworkTransactionRequest
	if !r.decodeCommandJSON(w, req, ctx, spec, &request) {
		return
	}
	request.TransactionID = strings.TrimSpace(request.TransactionID)
	if !validNetworkTransactionID(request.TransactionID) {
		err := errors.New("transaction_id must contain 1 to 128 letters, digits, or hyphens")
		r.recordNetworkTransaction(ctx, action, "", "failed", err.Error())
		writeResult(w, nil, err)
		return
	}
	status, err := command(ctx, request.TransactionID)
	if err != nil {
		r.recordNetworkTransaction(ctx, action, request.TransactionID, "failed", err.Error())
		writeResult(w, nil, err)
		return
	}
	if action == "network.rollback" {
		if err := r.reconcileRolledBackNetwork(ctx, status); err != nil {
			r.recordNetworkTransaction(ctx, action, request.TransactionID, "failed", err.Error())
			writeResult(w, nil, err)
			return
		}
	} else if action == "network.confirm" {
		if confirmer, ok := r.store.(networkRuntimeConfirmer); ok {
			if err := confirmer.ConfirmNetworkRuntime(ctx, request.TransactionID); err != nil {
				r.recordNetworkTransaction(ctx, action, request.TransactionID, "failed", err.Error())
				writeResult(w, nil, err)
				return
			}
		}
		if saver, ok := r.store.(networkRunningConfigSaver); ok {
			if err := saver.SaveRunningNetwork(ctx); err != nil {
				r.recordNetworkTransaction(ctx, action, request.TransactionID, "failed", err.Error())
				writeResult(w, nil, err)
				return
			}
		}
	}
	auditID := r.recordNetworkTransaction(ctx, action, request.TransactionID, "succeeded", status.State)
	writeResult(w, domain.CommandResult{
		Result:       action,
		Message:      status.State,
		AuditID:      auditID,
		NetworkApply: networkApplyStatus(status),
	}, nil)
}

func validNetworkTransactionID(value string) bool {
	if len(value) == 0 || len(value) > 128 {
		return false
	}
	for _, char := range value {
		if (char >= 'a' && char <= 'z') || (char >= 'A' && char <= 'Z') || (char >= '0' && char <= '9') || char == '-' {
			continue
		}
		return false
	}
	return true
}

type networkTransactionAuditRecorder interface {
	RecordNetworkTransaction(context.Context, string, string, string, string) (string, error)
}

func (r *Router) recordNetworkTransaction(ctx context.Context, action, transactionID, result, message string) string {
	recorder, ok := r.store.(networkTransactionAuditRecorder)
	if !ok {
		return ""
	}
	auditID, _ := recorder.RecordNetworkTransaction(ctx, action, transactionID, result, message)
	return auditID
}

func mergeNetworkStatus(state *domain.NetworkState, status networkconfig.Status) {
	state.RoutingMode = status.RoutingMode
	state.DefaultRoute = status.DefaultRoute
	state.Apply = networkApplyStatus(status)
	state.OOB.PrimaryInterface = status.OOB.PrimaryInterface
	state.OOB.FallbackInterface = status.OOB.FallbackInterface
	state.OOB.PrimaryLink = status.OOB.PrimaryLink
	state.OOB.FallbackAvailable = status.OOB.FallbackAvailable
	state.OOB.FallbackActive = status.OOB.FallbackActive
	state.OOB.FailoverReason = status.OOB.FailoverReason
	state.OOB.LastFailoverAt = status.OOB.LastFailoverAt
	for index := range state.Interfaces {
		for _, actual := range status.Interfaces {
			if actual.Device != state.Interfaces[index].Device {
				continue
			}
			state.Interfaces[index].Link = actual.Link
			if actual.Speed != "" {
				state.Interfaces[index].Speed = actual.Speed
			}
			if len(actual.Addresses) > 0 {
				state.Interfaces[index].Address = actual.Addresses[0]
			}
			break
		}
	}
}

func networkApplyStatus(status networkconfig.Status) *domain.NetworkApplyStatus {
	return &domain.NetworkApplyStatus{
		TransactionID: status.TransactionID,
		State:         status.State,
		Deadline:      status.Deadline,
	}
}

type networkRuntimeReconciler interface {
	ReconcileNetworkRuntime(context.Context, networkconfig.Config) error
}

type networkRuntimePreparer interface {
	PrepareNetworkRuntimeApply(context.Context, string) error
}

type networkRuntimeConfirmer interface {
	ConfirmNetworkRuntime(context.Context, string) error
}

type networkRuntimeRollbacker interface {
	RollbackNetworkRuntime(context.Context) (bool, error)
}

type networkPendingConfigApplier interface {
	ApplyPendingNetwork(context.Context) (domain.CommandResult, error)
}

type networkRunningConfigSaver interface {
	SaveRunningNetwork(context.Context) error
}

func (r *Router) reconcileRolledBackNetwork(ctx context.Context, status networkconfig.Status) error {
	if !strings.HasPrefix(status.State, "rolled_back") {
		return nil
	}
	if rollbacker, ok := r.store.(networkRuntimeRollbacker); ok {
		restored, err := rollbacker.RollbackNetworkRuntime(ctx)
		if err != nil || restored {
			return err
		}
	}
	if status.Current == nil {
		return nil
	}
	reconciler, ok := r.store.(networkRuntimeReconciler)
	if !ok {
		return nil
	}
	return reconciler.ReconcileNetworkRuntime(ctx, *status.Current)
}

func (r *Router) handleSNMPAgent(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "snmp.agent.read", Target: "snmp_agent", Permission: "config.read"}); !ok {
		return
	}
	settings, err := r.store.SNMPAgent(req.Context())
	writeResult(w, settings, err)
}

func (r *Router) handleUpdateSNMPAgent(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "snmp.agent.update", Target: "snmp_agent", Permission: "config.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var update domain.SNMPAgentUpdate
	if !r.decodeCommandJSON(w, req, ctx, spec, &update) {
		return
	}
	result, err := r.store.UpdateSNMPAgent(ctx, update)
	writeResult(w, result, err)
}

func (r *Router) handleTimeSettings(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "time.settings.read", Target: "time", Permission: "config.read"}); !ok {
		return
	}
	settings, err := r.store.TimeSettings(req.Context())
	writeResult(w, settings, err)
}

func (r *Router) handleUpdateTimeSettings(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "time.settings.update", Target: "time", Permission: "config.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var update domain.TimeSettingsUpdate
	if !r.decodeCommandJSON(w, req, ctx, spec, &update) {
		return
	}
	result, err := r.store.UpdateTimeSettings(ctx, update)
	writeResult(w, result, err)
}

func (r *Router) handleManagementAccess(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "security.management_access.read", Target: "management_access", Permission: "config.read"}); !ok {
		return
	}
	settings, err := r.store.ManagementAccess(req.Context())
	writeResult(w, settings, err)
}

func (r *Router) handleUpdateManagementAccess(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "security.management_access.update", Target: "management_access", Permission: "config.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var update domain.ManagementAccessUpdate
	if !r.decodeCommandJSON(w, req, ctx, spec, &update) {
		return
	}
	result, err := r.store.UpdateManagementAccess(ctx, update)
	writeResult(w, result, err)
}

func (r *Router) handleTLSCertificate(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "security.tls_certificate.read", Target: "tls_certificate", Permission: "config.read"}); !ok {
		return
	}
	settings, err := r.store.TLSCertificate(req.Context())
	writeResult(w, settings, err)
}

func (r *Router) handleUpdateTLSCertificate(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "security.tls_certificate.update", Target: "tls_certificate", Permission: "config.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var update domain.TLSCertificateUpdate
	if !r.decodeCommandJSON(w, req, ctx, spec, &update) {
		return
	}
	result, err := r.store.UpdateTLSCertificate(ctx, update)
	writeResult(w, result, err)
}

func (r *Router) handleTLSCertificates(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "security.tls_certificate.list", Target: "tls_certificate", Permission: "config.read"}); !ok {
		return
	}
	inventory, err := r.store.TLSCertificates(req.Context())
	writeResult(w, inventory, err)
}

func (r *Router) handleCreateTLSCertificate(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "security.tls_certificate.create", Target: "tls_certificate", Permission: "config.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var request domain.TLSCertificateCreateRequest
	if !r.decodeCommandJSON(w, req, ctx, spec, &request) {
		return
	}
	entry, err := r.store.CreateTLSCertificate(ctx, request)
	writeResult(w, entry, err)
}

func (r *Router) handleImportTLSCertificate(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "security.tls_certificate.import", Target: "tls_certificate", Permission: "config.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var request domain.TLSCertificateImportRequest
	if !r.decodeCommandJSON(w, req, ctx, spec, &request) {
		return
	}
	entry, err := r.store.ImportTLSCertificate(ctx, request)
	request.Password, request.PrivateKeyPEM = "", ""
	writeResult(w, entry, err)
}

func (r *Router) handleTLSCertificateSubtree(w http.ResponseWriter, req *http.Request) {
	path := strings.Trim(strings.TrimPrefix(req.URL.Path, "/api/v1/security/tls-certificates/"), "/")
	parts := strings.Split(path, "/")
	if len(parts) == 1 && req.Method == http.MethodDelete {
		spec := commandSpec{Action: "security.tls_certificate.delete", Target: parts[0], Permission: "config.write"}
		ctx, ok := r.authorizeCommand(w, req, spec)
		if !ok {
			return
		}
		result, err := r.store.DeleteTLSCertificate(ctx, parts[0])
		writeResult(w, result, err)
		return
	}
	if len(parts) == 2 && parts[1] == "csr" && req.Method == http.MethodPost {
		spec := commandSpec{Action: "security.tls_certificate.csr", Target: parts[0], Permission: "config.write"}
		ctx, ok := r.authorizeCommand(w, req, spec)
		if !ok {
			return
		}
		var request domain.TLSCSRRequest
		if !r.decodeOptionalCommandJSON(w, req, ctx, spec, &request) {
			return
		}
		artifact, err := r.store.ExportTLSCSR(ctx, parts[0], request)
		writeResult(w, artifact, err)
		return
	}
	writeError(w, http.StatusNotFound, "not_found", "TLS certificate endpoint not found")
}

func (r *Router) handlePorts(w http.ResponseWriter, req *http.Request) {
	if req.Method == http.MethodPatch {
		spec := commandSpec{Action: "port.bulk_update", Target: "ports", Permission: "port.write"}
		ctx, ok := r.authorizeCommand(w, req, spec)
		if !ok {
			return
		}
		var update domain.PortBulkUpdate
		if !r.decodeCommandJSON(w, req, ctx, spec, &update) {
			return
		}
		for _, channel := range update.Channels {
			if !r.requirePortAccess(w, ctx, strings.ToUpper(channel), "write", spec) {
				return
			}
		}
		result, err := r.store.UpdatePorts(ctx, update.Channels, update.Update)
		writeResult(w, result, err)
		return
	}
	ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "port.read", Target: "ports", Permission: "port.read"})
	if !ok {
		return
	}
	limit, offset, ok := parsePagination(w, req)
	if !ok {
		return
	}
	ports, err := r.store.Ports(req.Context())
	if err == nil {
		if req.URL.Query().Get("runtime") != "false" {
			ports = r.overlayPortRuntime(ports, r.readSerialRuntime(req.Context()))
		} else {
			// Configuration reads must not wait for hardware/session telemetry.
			// Never expose unobserved store defaults as a live link state.
			for i := range ports {
				ports[i].Status = "unknown"
				ports[i].Runtime = nil
				ports[i].ConnectedUsers = 0
				ports[i].Writer = ""
			}
		}
		ports = r.filterAuthorizedPorts(ctx, ports, "read")
	}
	ports = windowPorts(ports, limit, offset)
	writeResult(w, ports, err)
}

func (r *Router) handlePortRuntimeStatus(w http.ResponseWriter, req *http.Request) {
	ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "port.read", Target: "ports", Permission: "port.read"})
	if !ok {
		return
	}
	ports, err := r.store.Ports(req.Context())
	if err == nil {
		ports = r.overlayPortRuntime(ports, r.readSerialRuntime(req.Context()))
		ports = r.filterAuthorizedPorts(ctx, ports, "read")
	}
	writeResult(w, compactPortRuntimeStatuses(ports), err)
}

func (r *Router) handlePortSubtree(w http.ResponseWriter, req *http.Request) {
	rest := strings.TrimPrefix(req.URL.Path, "/api/v1/ports/")
	parts := strings.Split(strings.Trim(rest, "/"), "/")
	if len(parts) == 0 || parts[0] == "" {
		writeError(w, http.StatusNotFound, "not_found", "port route not found")
		return
	}

	channel := strings.ToUpper(parts[0])
	switch {
	case req.Method == http.MethodGet && len(parts) == 1:
		ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "port.read", Target: channel, Permission: "port.read"})
		if !ok || !r.requirePortAccess(w, ctx, channel, "read", commandSpec{Action: "port.read", Target: channel}) {
			return
		}
		port, err := r.store.Port(req.Context(), channel)
		if err == nil {
			ports := r.overlayPortRuntime([]domain.Port{port}, r.readSerialRuntime(req.Context()))
			port = ports[0]
		}
		writeResult(w, port, err)
	case req.Method == http.MethodPatch && len(parts) == 1:
		spec := commandSpec{Action: "port.update", Target: channel, Permission: "port.write"}
		ctx, ok := r.authorizeCommand(w, req, spec)
		if !ok || !r.requirePortAccess(w, ctx, channel, "write", spec) {
			return
		}
		var update domain.PortUpdate
		if !r.decodeCommandJSON(w, req, ctx, spec, &update) {
			return
		}
		result, err := r.store.UpdatePort(ctx, channel, update)
		writeResult(w, result, err)
	case req.Method == http.MethodPost && len(parts) == 2 && parts[1] == "restart":
		spec := commandSpec{Action: "port.restart", Target: channel, Permission: "port.restart"}
		ctx, ok := r.authorizeCommand(w, req, spec)
		if !ok || !r.requirePortAccess(w, ctx, channel, "write", spec) {
			return
		}
		port, err := r.store.Port(ctx, channel)
		if err != nil {
			r.recordRejectedCommand(ctx, spec, err.Error())
			writeResult(w, nil, err)
			return
		}
		if err := r.applySerialPortConfig(ctx, port); err != nil {
			r.recordHardwareFailure(ctx, spec, err)
			writeResult(w, nil, err)
			return
		}
		operation, err := r.store.RestartPort(ctx, channel)
		writeResult(w, operation, err)
	default:
		writeError(w, http.StatusNotFound, "not_found", "port route not found")
	}
}

func (r *Router) handleBulkPortRestart(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "port.bulk_restart", Target: "ports", Permission: "port.restart"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var request domain.PortBulkRestart
	if !r.decodeCommandJSON(w, req, ctx, spec, &request) {
		return
	}
	if len(request.Channels) == 0 || len(request.Channels) > serial.ChannelCount {
		err := errors.New("channels must include 1 through 48 unique channels")
		r.recordRejectedCommand(ctx, spec, err.Error())
		writeResult(w, nil, err)
		return
	}
	ports := make([]domain.Port, 0, len(request.Channels))
	seen := make(map[string]bool, len(request.Channels))
	for index, requested := range request.Channels {
		channel := strings.ToUpper(strings.TrimSpace(requested))
		if seen[channel] {
			err := errors.New("channels must not include duplicates")
			r.recordRejectedCommand(ctx, spec, err.Error())
			writeResult(w, nil, err)
			return
		}
		seen[channel] = true
		request.Channels[index] = channel
		if !r.requirePortAccess(w, ctx, channel, "write", spec) {
			return
		}
		port, err := r.store.Port(ctx, channel)
		if err != nil {
			r.recordRejectedCommand(ctx, spec, err.Error())
			writeResult(w, nil, err)
			return
		}
		ports = append(ports, port)
	}
	if err := r.applySerialPortsConfig(ctx, ports); err != nil {
		r.recordHardwareFailure(ctx, spec, err)
		writeResult(w, nil, err)
		return
	}
	operation, err := r.store.RestartPorts(ctx, request.Channels)
	writeResult(w, operation, err)
}

func (r *Router) handleSerialPorts(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "hardware.serial.read", Target: "serial_ports", Permission: "hardware.read"}); !ok {
		return
	}
	states, err := r.serialPorts.States(req.Context())
	if serial.IsUnavailable(err) {
		states, _ = serial.UnavailableController{Reason: err.Error()}.States(req.Context())
		err = nil
	}
	writeResult(w, states, err)
}

func (r *Router) handleGreenLEDs(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "hardware.green_led.read", Target: "green_leds", Permission: "hardware.read"}); !ok {
		return
	}
	states, err := r.greenLEDs.States(req.Context())
	if greenled.IsUnavailable(err) {
		states, _ = greenled.UnavailableController{Reason: err.Error()}.States(req.Context())
		err = nil
	}
	writeResult(w, states, err)
}

type greenLEDCommandResponse struct {
	greenled.State
	AuditID string `json:"audit_id"`
	Message string `json:"message"`
}

func (r *Router) handleGreenLEDSubtree(w http.ResponseWriter, req *http.Request) {
	rest := strings.Trim(strings.TrimPrefix(req.URL.Path, "/api/v1/hardware/green-leds/"), "/")
	parts := strings.Split(rest, "/")
	if len(parts) == 0 || parts[0] == "" {
		writeError(w, http.StatusNotFound, "not_found", "green LED route not found")
		return
	}
	channel := strings.ToUpper(parts[0])
	spec := commandSpec{Action: "hardware.green_led.set", Target: channel, Permission: "hardware.write"}

	switch {
	case req.Method == http.MethodPut && len(parts) == 1:
		ctx, ok := r.authorizeCommand(w, req, spec)
		if !ok || !r.requirePortAccess(w, ctx, channel, "write", spec) {
			return
		}
		var command domain.GreenLEDForceRequest
		if !r.decodeCommandJSON(w, req, ctx, spec, &command) {
			return
		}
		if command.Force == nil {
			message := "force must be provided"
			r.recordRejectedCommand(ctx, spec, message)
			writeError(w, http.StatusBadRequest, "validation_failed", message)
			return
		}
		state, err := r.greenLEDs.SetForce(ctx, channel, *command.Force)
		action := "hardware.green_led.release"
		message := channel + " green LED released to RX activity"
		if *command.Force {
			action = "hardware.green_led.force"
			message = channel + " green LED forced on"
		}
		r.writeGreenLEDCommandResult(w, ctx, action, channel, message, state, err)
	case req.Method == http.MethodPost && len(parts) == 2 && parts[1] == "pulse":
		ctx, ok := r.authorizeCommand(w, req, spec)
		if !ok {
			return
		}
		var command domain.GreenLEDPulseRequest
		if !r.decodeCommandJSON(w, req, ctx, spec, &command) {
			return
		}
		state, err := r.greenLEDs.Pulse(ctx, channel, time.Duration(command.DwellMilliseconds)*time.Millisecond)
		message := fmt.Sprintf("%s green LED forced on for %d ms then released to RX activity", channel, command.DwellMilliseconds)
		r.writeGreenLEDCommandResult(w, ctx, "hardware.green_led.pulse", channel, message, state, err)
	default:
		writeError(w, http.StatusNotFound, "not_found", "green LED route not found")
	}
}

func (r *Router) writeGreenLEDCommandResult(w http.ResponseWriter, ctx context.Context, action, channel, message string, state greenled.State, commandErr error) {
	if commandErr != nil {
		_, _ = r.store.RecordAudit(ctx, domain.AuditEvent{
			Action:  action,
			Target:  channel,
			Result:  "failed",
			Message: commandErr.Error(),
		})
		writeResult(w, nil, commandErr)
		return
	}
	auditID, err := r.store.RecordAudit(ctx, domain.AuditEvent{
		Action:  action,
		Target:  channel,
		Result:  "succeeded",
		Message: message,
	})
	if err != nil {
		writeResult(w, nil, err)
		return
	}
	writeJSON(w, http.StatusOK, greenLEDCommandResponse{
		State:   state,
		AuditID: auditID,
		Message: message,
	})
}

func (r *Router) handleConfigStatus(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "config.read", Target: "config", Permission: "config.read"}); !ok {
		return
	}
	status, err := r.store.ConfigStatus(req.Context())
	writeResult(w, status, err)
}

func (r *Router) handleConfigExport(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "config.export", Target: "config", Permission: "config.read"}); !ok {
		return
	}
	export, err := r.store.ConfigExport(req.Context())
	writeResult(w, export, err)
}

func (r *Router) handleEncryptedConfigExport(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "config.export.encrypted", Target: "config", Permission: "config.read"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var request encryptedConfigExportRequest
	if !r.decodeCommandJSON(w, req, ctx, spec, &request) {
		return
	}
	export, err := r.store.ConfigExport(ctx)
	if err != nil {
		request.Key = ""
		writeResult(w, nil, err)
		return
	}
	content, err := encryptConfigEnvelope(export, request.Key)
	request.Key = ""
	if err != nil {
		writeResult(w, nil, err)
		return
	}
	stamp := export.GeneratedAt.UTC().Format("20060102T150405Z")
	writeJSON(w, http.StatusOK, encryptedConfigExportResponse{
		Filename: "tera-core-x48-pro-config-" + stamp + ".tera-config.json",
		Content:  content,
		Summary:  export.Summary,
	})
}

func (r *Router) handleRestoreConfig(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "config.restore", Target: "config", Permission: "config.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var snapshot domain.ConfigExport
	if !r.decodeConfigRestoreJSON(w, req, ctx, spec, &snapshot) {
		return
	}
	result, err := r.store.RestoreConfig(ctx, snapshot)
	writeResult(w, result, err)
}

func (r *Router) handleEncryptedConfigRestore(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "config.restore.encrypted", Target: "config", Permission: "config.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var request encryptedConfigRestoreRequest
	if !r.decodeCommandJSON(w, req, ctx, spec, &request) {
		return
	}
	snapshot, err := decryptConfigEnvelope(request.Content, request.Key)
	request.Key = ""
	request.Content = ""
	if err != nil {
		writeResult(w, nil, err)
		return
	}
	if !request.IncludeNetwork {
		current, exportErr := r.store.ConfigExport(ctx)
		if exportErr != nil {
			writeResult(w, nil, exportErr)
			return
		}
		// A restore that excludes networking must preserve the interfaces that
		// are serving the current management connection. RestoreConfig stages
		// only values that differ from this running state, so this also removes
		// any unrelated network transaction that was pending before restore.
		snapshot.Persistent.Network = current.Running.Network
	}
	result, err := r.store.RestoreConfig(ctx, snapshot)
	writeResult(w, result, err)
}

func (r *Router) handleAlarmRules(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "alarm.rule.read", Target: "alarms", Permission: "alarm.read"}); !ok {
		return
	}
	limit, offset, ok := parsePagination(w, req)
	if !ok {
		return
	}
	rules, err := r.store.AlarmRules(req.Context())
	rules = windowAlarmRules(rules, limit, offset)
	writeResult(w, rules, err)
}

func (r *Router) handleAlarmRuleSubtree(w http.ResponseWriter, req *http.Request) {
	rest := strings.TrimPrefix(req.URL.Path, "/api/v1/alarms/rules/")
	parts := strings.Split(strings.Trim(rest, "/"), "/")
	if len(parts) == 0 || parts[0] == "" {
		writeError(w, http.StatusNotFound, "not_found", "alarm rule route not found")
		return
	}

	ruleID := strings.ToLower(parts[0])
	switch {
	case req.Method == http.MethodGet && len(parts) == 1:
		if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "alarm.rule.read", Target: ruleID, Permission: "alarm.read"}); !ok {
			return
		}
		rule, err := r.store.AlarmRule(req.Context(), ruleID)
		writeResult(w, rule, err)
	case req.Method == http.MethodPatch && len(parts) == 1:
		spec := commandSpec{Action: "alarm.rule.update", Target: ruleID, Permission: "alarm.write"}
		ctx, ok := r.authorizeCommand(w, req, spec)
		if !ok {
			return
		}
		var update domain.AlarmRuleUpdate
		if !r.decodeCommandJSON(w, req, ctx, spec, &update) {
			return
		}
		result, err := r.store.UpdateAlarmRule(ctx, ruleID, update)
		writeResult(w, result, err)
	default:
		writeError(w, http.StatusNotFound, "not_found", "alarm rule route not found")
	}
}

func (r *Router) handleAlarmDeliveryPolicy(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "alarm.delivery_policy.read", Target: "alarm_delivery", Permission: "alarm.read"}); !ok {
		return
	}
	policy, err := r.store.AlarmDeliveryPolicy(req.Context())
	writeResult(w, policy, err)
}

func (r *Router) handleUpdateAlarmDeliveryPolicy(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "alarm.delivery_policy.update", Target: "alarm_delivery", Permission: "alarm.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var update domain.AlarmDeliveryPolicyUpdate
	if !r.decodeCommandJSON(w, req, ctx, spec, &update) {
		return
	}
	result, err := r.store.UpdateAlarmDeliveryPolicy(ctx, update)
	writeResult(w, result, err)
}

func (r *Router) handleAlarmDeliveryTest(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "alarm.delivery.test", Target: "alarm_delivery", Permission: "alarm.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var request domain.AlarmDeliveryTestRequest
	if !r.decodeOptionalCommandJSON(w, req, ctx, spec, &request) {
		return
	}
	operation, err := r.store.TestAlarmDelivery(ctx, request)
	writeResult(w, operation, err)
}

func (r *Router) handleEmailNotification(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "alarm.email.read", Target: "email_notification", Permission: "alarm.read"}); !ok {
		return
	}
	settings, err := r.store.EmailNotification(req.Context())
	writeResult(w, settings, err)
}

func (r *Router) handleUpdateEmailNotification(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "alarm.email.update", Target: "email_notification", Permission: "alarm.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var update domain.EmailNotificationUpdate
	if !r.decodeCommandJSON(w, req, ctx, spec, &update) {
		return
	}
	result, err := r.store.UpdateEmailNotification(ctx, update)
	writeResult(w, result, err)
}

func (r *Router) handleSNMPTrapTargets(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "alarm.snmp_trap.read", Target: "snmp_trap_targets", Permission: "alarm.read"}); !ok {
		return
	}
	targets, err := r.store.SNMPTrapTargets(req.Context())
	writeResult(w, targets, err)
}

func (r *Router) handleUpdateSNMPTrapTargets(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "alarm.snmp_trap.update", Target: "snmp_trap_targets", Permission: "alarm.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var update domain.SNMPTrapTargetUpdate
	if !r.decodeCommandJSON(w, req, ctx, spec, &update) {
		return
	}
	result, err := r.store.UpdateSNMPTrapTargets(ctx, update)
	writeResult(w, result, err)
}

func (r *Router) handleAuditEvents(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "audit.read", Target: "audit", Permission: "audit.read"}); !ok {
		return
	}
	limit, offset, ok := parsePagination(w, req)
	if !ok {
		return
	}
	from, to, ok := parseLogTimeRange(w, req)
	if !ok {
		return
	}
	order := strings.ToLower(strings.TrimSpace(req.URL.Query().Get("order")))
	if order == "" {
		order = "asc"
	}
	if order != "asc" && order != "desc" {
		writeError(w, http.StatusBadRequest, "validation_failed", "order must be asc or desc")
		return
	}
	events, err := r.store.AuditEvents(req.Context())
	events = filterAuditEvents(events, req.URL.Query().Get("actor"), req.URL.Query().Get("keyword"), from, to)
	if order == "desc" {
		reverseAuditEvents(events)
	}
	events = windowAuditEvents(events, limit, offset)
	writeResult(w, events, err)
}

func (r *Router) handleSystemLogEvents(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "log.read", Target: "logs", Permission: "log.read"}); !ok {
		return
	}
	limit, offset, ok := parsePagination(w, req)
	if !ok {
		return
	}
	from, to, ok := parseLogTimeRange(w, req)
	if !ok {
		return
	}
	filter := domain.SystemLogFilter{
		Category: req.URL.Query().Get("category"),
		Severity: req.URL.Query().Get("severity"),
		Keyword:  req.URL.Query().Get("keyword"),
		From:     from,
		To:       to,
		Limit:    limit,
		Offset:   offset,
	}
	events, err := r.store.SystemLogEvents(req.Context(), filter)
	writeResult(w, events, err)
}

func (r *Router) handlePortLogEvents(w http.ResponseWriter, req *http.Request) {
	ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "log.port.read", Target: "logs", Permission: "log.read"})
	if !ok {
		return
	}
	limit, offset, ok := parsePagination(w, req)
	if !ok {
		return
	}
	from, to, ok := parseLogTimeRange(w, req)
	if !ok {
		return
	}
	filter := domain.PortLogFilter{
		Channel:   req.URL.Query().Get("channel"),
		Keyword:   req.URL.Query().Get("keyword"),
		EventType: req.URL.Query().Get("event_type"),
		Direction: req.URL.Query().Get("direction"),
		Actor:     req.URL.Query().Get("actor"),
		From:      from,
		To:        to,
		Limit:     limit,
		Offset:    offset,
	}
	if filter.Channel != "" && !r.requirePortAccess(w, ctx, strings.ToUpper(filter.Channel), "read", commandSpec{Action: "log.port.read", Target: filter.Channel}) {
		return
	}
	events, err := r.store.PortLogEvents(ctx, filter)
	writeResult(w, events, err)
}

func (r *Router) handleLinkLogEvents(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "log.read", Target: "logs", Permission: "log.read"}); !ok {
		return
	}
	limit, offset, ok := parsePagination(w, req)
	if !ok {
		return
	}
	from, to, ok := parseLogTimeRange(w, req)
	if !ok {
		return
	}
	events, err := r.store.LinkLogEvents(req.Context(), domain.LinkLogFilter{
		Kind: req.URL.Query().Get("kind"), Resource: req.URL.Query().Get("resource"),
		State: req.URL.Query().Get("state"), EventType: req.URL.Query().Get("event_type"),
		Keyword: req.URL.Query().Get("keyword"), From: from, To: to, Limit: limit, Offset: offset,
	})
	writeResult(w, events, err)
}

func (r *Router) handleLogPolicy(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "log.policy.read", Target: "logs", Permission: "log.read"}); !ok {
		return
	}
	policy, err := r.store.LogPolicy(req.Context())
	writeResult(w, policy, err)
}

func parsePagination(w http.ResponseWriter, req *http.Request) (int, int, bool) {
	limit, ok := parseOptionalNonNegativeInt(w, req.URL.Query().Get("limit"), "limit")
	if !ok {
		return 0, 0, false
	}
	if limit == 0 {
		limit = defaultLogLimit
	}
	if limit > maxLogLimit {
		writeError(w, http.StatusBadRequest, "validation_failed", "limit must be at most 500")
		return 0, 0, false
	}
	offset, ok := parseOptionalNonNegativeInt(w, req.URL.Query().Get("offset"), "offset")
	if !ok {
		return 0, 0, false
	}
	return limit, offset, true
}

func parseOptionalNonNegativeInt(w http.ResponseWriter, value, field string) (int, bool) {
	if strings.TrimSpace(value) == "" {
		return 0, true
	}
	parsed, err := strconv.Atoi(value)
	if err != nil || parsed < 0 {
		writeError(w, http.StatusBadRequest, "validation_failed", field+" must be a non-negative integer")
		return 0, false
	}
	return parsed, true
}

func parseLogTimeRange(w http.ResponseWriter, req *http.Request) (time.Time, time.Time, bool) {
	from, ok := parseOptionalRFC3339(w, req.URL.Query().Get("from"), "from")
	if !ok {
		return time.Time{}, time.Time{}, false
	}
	to, ok := parseOptionalRFC3339(w, req.URL.Query().Get("to"), "to")
	if !ok {
		return time.Time{}, time.Time{}, false
	}
	if !from.IsZero() && !to.IsZero() && from.After(to) {
		writeError(w, http.StatusBadRequest, "validation_failed", "from must not be after to")
		return time.Time{}, time.Time{}, false
	}
	return from, to, true
}

func parseOptionalRFC3339(w http.ResponseWriter, value, field string) (time.Time, bool) {
	value = strings.TrimSpace(value)
	if value == "" {
		return time.Time{}, true
	}
	parsed, err := time.Parse(time.RFC3339, value)
	if err != nil {
		writeError(w, http.StatusBadRequest, "validation_failed", field+" must be an RFC3339 timestamp")
		return time.Time{}, false
	}
	return parsed, true
}

func filterAuditEvents(events []domain.AuditEvent, actor, keyword string, from, to time.Time) []domain.AuditEvent {
	actor = strings.ToLower(strings.TrimSpace(actor))
	keyword = strings.ToLower(strings.TrimSpace(keyword))
	filtered := make([]domain.AuditEvent, 0, len(events))
	for _, event := range events {
		if !from.IsZero() && event.Timestamp.Before(from) || !to.IsZero() && event.Timestamp.After(to) {
			continue
		}
		if actor != "" && !strings.Contains(strings.ToLower(event.Actor), actor) {
			continue
		}
		searchable := strings.ToLower(event.AuditID + " " + event.Actor + " " + event.Action + " " + event.Target + " " + event.Command + " " + event.ReturnValue + " " + event.Message)
		if keyword != "" && !strings.Contains(searchable, keyword) {
			continue
		}
		filtered = append(filtered, event)
	}
	return filtered
}

func reverseAuditEvents(events []domain.AuditEvent) {
	for left, right := 0, len(events)-1; left < right; left, right = left+1, right-1 {
		events[left], events[right] = events[right], events[left]
	}
}

func windowAuditEvents(events []domain.AuditEvent, limit, offset int) []domain.AuditEvent {
	if offset >= len(events) {
		return []domain.AuditEvent{}
	}
	end := offset + limit
	if end > len(events) {
		end = len(events)
	}
	return events[offset:end]
}

func windowOperations(operations []domain.Operation, limit, offset int) []domain.Operation {
	if offset >= len(operations) {
		return []domain.Operation{}
	}
	end := offset + limit
	if end > len(operations) {
		end = len(operations)
	}
	return operations[offset:end]
}

func windowAuthSessions(sessions []domain.AuthSessionInfo, limit, offset int) []domain.AuthSessionInfo {
	if offset >= len(sessions) {
		return []domain.AuthSessionInfo{}
	}
	end := offset + limit
	if end > len(sessions) {
		end = len(sessions)
	}
	return sessions[offset:end]
}

func windowAuthTokens(tokens []domain.AuthTokenInfo, limit, offset int) []domain.AuthTokenInfo {
	if offset >= len(tokens) {
		return []domain.AuthTokenInfo{}
	}
	end := offset + limit
	if end > len(tokens) {
		end = len(tokens)
	}
	return tokens[offset:end]
}

func windowAuthUsers(users []domain.AuthUser, limit, offset int) []domain.AuthUser {
	if offset >= len(users) {
		return []domain.AuthUser{}
	}
	end := offset + limit
	if end > len(users) {
		end = len(users)
	}
	return users[offset:end]
}

func windowAuthGroups(groups []domain.AuthGroup, limit, offset int) []domain.AuthGroup {
	if offset >= len(groups) {
		return []domain.AuthGroup{}
	}
	end := offset + limit
	if end > len(groups) {
		end = len(groups)
	}
	return groups[offset:end]
}

func windowAuthPermissions(permissions []domain.AuthPermission, limit, offset int) []domain.AuthPermission {
	if offset >= len(permissions) {
		return []domain.AuthPermission{}
	}
	end := offset + limit
	if end > len(permissions) {
		end = len(permissions)
	}
	return permissions[offset:end]
}

func windowPorts(ports []domain.Port, limit, offset int) []domain.Port {
	if offset >= len(ports) {
		return []domain.Port{}
	}
	end := offset + limit
	if end > len(ports) {
		end = len(ports)
	}
	return ports[offset:end]
}

func windowAlarmRules(rules []domain.AlarmRule, limit, offset int) []domain.AlarmRule {
	if offset >= len(rules) {
		return []domain.AlarmRule{}
	}
	end := offset + limit
	if end > len(rules) {
		end = len(rules)
	}
	return rules[offset:end]
}

func windowServiceHealth(health []domain.ServiceHealth, limit, offset int) []domain.ServiceHealth {
	if offset >= len(health) {
		return []domain.ServiceHealth{}
	}
	end := offset + limit
	if end > len(health) {
		end = len(health)
	}
	return health[offset:end]
}

func (r *Router) handleLogRetention(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "log.retention.read", Target: "logs", Permission: "log.read"}); !ok {
		return
	}
	settings, err := r.store.LogRetention(req.Context())
	writeResult(w, settings, err)
}

func (r *Router) handleUpdateLogRetention(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "log.retention.update", Target: "logs", Permission: "config.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var update domain.LogRetentionUpdate
	if !r.decodeCommandJSON(w, req, ctx, spec, &update) {
		return
	}
	result, err := r.store.UpdateLogRetention(ctx, update)
	writeResult(w, result, err)
}

func (r *Router) handleRemoteSyslog(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "log.remote_syslog.read", Target: "remote_syslog", Permission: "log.read"}); !ok {
		return
	}
	settings, err := r.store.RemoteSyslog(req.Context())
	writeResult(w, settings, err)
}

func (r *Router) handleUpdateRemoteSyslog(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "log.remote_syslog.update", Target: "remote_syslog", Permission: "config.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var update domain.RemoteSyslogUpdate
	if !r.decodeCommandJSON(w, req, ctx, spec, &update) {
		return
	}
	result, err := r.store.UpdateRemoteSyslog(ctx, update)
	writeResult(w, result, err)
}

func (r *Router) handleExportLogs(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "log.export", Target: "logs", Permission: "log.export"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var exportRequest domain.LogExportRequest
	if !r.decodeOptionalCommandJSON(w, req, ctx, spec, &exportRequest) {
		return
	}
	if exportRequest.Channel != "" && !r.requirePortAccess(w, ctx, strings.ToUpper(exportRequest.Channel), "read", spec) {
		return
	}

	operation, err := r.store.ExportLogs(ctx, exportRequest)
	writeResult(w, operation, err)
}

type streamingLogExporter interface {
	StreamLogExport(context.Context, domain.LogExportRequest, io.Writer) (domain.Operation, error)
}

type logAttachmentWriter struct {
	http.ResponseWriter
	filename  string
	committed bool
}

func (writer *logAttachmentWriter) commit() {
	if writer.committed {
		return
	}
	contentType := "application/x-ndjson"
	if strings.HasSuffix(writer.filename, ".csv") {
		contentType = "text/csv; charset=utf-8"
	}
	if strings.HasSuffix(writer.filename, ".json") {
		contentType = "application/json"
	}
	writer.Header().Set("Content-Type", contentType)
	writer.Header().Set("Cache-Control", "no-store")
	writer.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, writer.filename))
	writer.Header().Set("X-Content-Type-Options", "nosniff")
	writer.WriteHeader(http.StatusOK)
	writer.committed = true
}

func (writer *logAttachmentWriter) Write(payload []byte) (int, error) {
	writer.commit()
	return writer.ResponseWriter.Write(payload)
}

func (r *Router) handleDownloadLogs(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "log.export", Target: "logs", Permission: "log.export"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var exportRequest domain.LogExportRequest
	if !r.decodeOptionalCommandJSON(w, req, ctx, spec, &exportRequest) {
		return
	}
	if exportRequest.Channel != "" && !r.requirePortAccess(w, ctx, strings.ToUpper(exportRequest.Channel), "read", spec) {
		return
	}

	exporter, ok := r.store.(streamingLogExporter)
	if !ok {
		writeError(w, http.StatusServiceUnavailable, "service_unavailable", "streaming log export is unavailable")
		return
	}
	logType := strings.ToLower(strings.TrimSpace(exportRequest.LogType))
	if logType == "" {
		logType = "port"
	}
	format := strings.ToLower(strings.TrimSpace(exportRequest.Format))
	if format == "" {
		format = "jsonl"
	}
	if format != "jsonl" && format != "json" && format != "csv" {
		writeError(w, http.StatusBadRequest, "invalid_request", "format must be csv, json, or jsonl")
		return
	}
	filename := fmt.Sprintf("tera-%s-logs-%s.%s", logType, time.Now().UTC().Format("20060102T150405Z"), format)
	attachment := &logAttachmentWriter{ResponseWriter: w, filename: filename}
	if _, err := exporter.StreamLogExport(ctx, exportRequest, attachment); err != nil {
		if !attachment.committed {
			writeResult(w, domain.Operation{}, err)
		}
		return
	}
	attachment.commit()
}

func (r *Router) handleSyncBrowserTime(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "time.sync_browser", Target: "time", Permission: "time.sync"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var syncRequest domain.BrowserTimeSyncRequest
	if !r.decodeCommandJSON(w, req, ctx, spec, &syncRequest) {
		return
	}
	operation, err := r.store.SyncBrowserTime(ctx, syncRequest)
	writeResult(w, operation, err)
}

func (r *Router) handleSyncNTPTime(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "time.sync_ntp", Target: "time", Permission: "time.sync"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	operation, err := r.store.SyncNTPTime(ctx)
	writeResult(w, operation, err)
}

func (r *Router) handleDiagnosticsSubtree(w http.ResponseWriter, req *http.Request) {
	kind := strings.Trim(strings.TrimPrefix(req.URL.Path, "/api/v1/diagnostics/"), "/")
	if kind != "network-test" && kind != "support-bundle" {
		writeError(w, http.StatusNotFound, "not_found", "diagnostics route not found")
		return
	}

	action := "diagnostics." + strings.ReplaceAll(strings.ToLower(kind), "-", "_")
	spec := commandSpec{Action: action, Target: "diagnostics", Permission: "diagnostics.run"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	var diagnosticsRequest domain.DiagnosticsRequest
	if !r.decodeOptionalCommandJSON(w, req, ctx, spec, &diagnosticsRequest) {
		return
	}
	operation, err := r.store.RunDiagnostics(ctx, kind, diagnosticsRequest)
	writeResult(w, operation, err)
}

func (r *Router) handleSupportBundleDownload(w http.ResponseWriter, req *http.Request) {
	bundleID := strings.Trim(strings.TrimPrefix(req.URL.Path, "/api/v1/diagnostics/support-bundles/"), "/")
	if bundleID == "" || strings.Contains(bundleID, "/") {
		writeError(w, http.StatusNotFound, "not_found", "support bundle route not found")
		return
	}
	spec := commandSpec{Action: "diagnostics.support_bundle.download", Target: bundleID, Permission: "diagnostics.run"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	artifact, err := r.store.SupportBundle(ctx, bundleID)
	if err != nil {
		writeResult(w, nil, err)
		return
	}
	w.Header().Set("Content-Type", "application/zip")
	w.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=%q", artifact.Filename))
	w.Header().Set("Content-Length", strconv.Itoa(len(artifact.Content)))
	w.Header().Set("Cache-Control", "no-store")
	w.Header().Set("X-Content-Type-Options", "nosniff")
	w.Header().Set("X-Checksum-SHA256", artifact.SHA256)
	w.WriteHeader(http.StatusOK)
	_, _ = w.Write(artifact.Content)
}

func (r *Router) handleDirectSubtree(w http.ResponseWriter, req *http.Request) {
	rest := strings.TrimPrefix(req.URL.Path, "/api/v1/direct/")
	parts := strings.Split(strings.Trim(rest, "/"), "/")
	if len(parts) < 2 || parts[0] == "" {
		writeError(w, http.StatusNotFound, "not_found", "direct route not found")
		return
	}

	channel := strings.ToUpper(parts[0])
	switch {
	case req.Method == http.MethodPost && len(parts) == 2 && parts[1] == "sessions":
		spec := commandSpec{Action: "direct.session.open", Target: channel, Permission: "direct.view"}
		ctx, ok := r.authorizeCommand(w, req, spec)
		if !ok {
			return
		}
		var sessionRequest domain.DirectSessionRequest
		if !r.decodeOptionalCommandJSON(w, req, ctx, spec, &sessionRequest) {
			return
		}
		if strings.EqualFold(sessionRequest.Access, "writer") {
			spec.Permission = "direct.write"
			ctx, ok = r.authorizeCommand(w, req, spec)
			if !ok {
				return
			}
		}
		if !r.requirePortAccess(w, ctx, channel, directAccessForRequest(sessionRequest), spec) {
			return
		}
		if strings.EqualFold(sessionRequest.Access, "writer") && !r.requireDirectPortConnected(w, ctx, channel, spec) {
			return
		}
		session, err := r.store.OpenDirectSession(ctx, channel, sessionRequest)
		writeResult(w, session, err)
	case req.Method == http.MethodDelete && len(parts) == 3 && parts[1] == "sessions" && parts[2] != "":
		sessionID := parts[2]
		ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "direct.session.close", Target: channel, Permission: "direct.view"})
		if !ok || !r.requirePortAccess(w, ctx, channel, "read", commandSpec{Action: "direct.session.close", Target: channel}) {
			return
		}
		session, err := r.store.CloseDirectSession(ctx, channel, sessionID)
		writeResult(w, session, err)
	case req.Method == http.MethodPost && len(parts) == 2 && parts[1] == "writer":
		ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "direct.writer.claim", Target: channel, Permission: "direct.write"})
		if !ok || !r.requirePortAccess(w, ctx, channel, "write", commandSpec{Action: "direct.writer.claim", Target: channel}) {
			return
		}
		session, err := r.store.ClaimDirectWriter(ctx, channel)
		writeResult(w, session, err)
	case req.Method == http.MethodDelete && len(parts) == 2 && parts[1] == "writer":
		ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "direct.writer.release", Target: channel, Permission: "direct.write"})
		if !ok || !r.requirePortAccess(w, ctx, channel, "write", commandSpec{Action: "direct.writer.release", Target: channel}) {
			return
		}
		session, err := r.store.ReleaseDirectWriter(ctx, channel)
		writeResult(w, session, err)
	default:
		writeError(w, http.StatusNotFound, "not_found", "direct route not found")
	}
}

func (r *Router) handleApplyConfig(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "config.apply", Target: "config", Permission: "config.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	if err := r.applyPendingSerialConfig(ctx); err != nil {
		r.recordHardwareFailure(ctx, spec, err)
		writeResult(w, nil, err)
		return
	}
	networkApply, err := r.applyPendingNetworkConfig(ctx)
	if err != nil {
		r.recordHardwareFailure(ctx, spec, err)
		writeResult(w, nil, err)
		return
	}
	result, err := r.store.ApplyConfig(ctx)
	if err != nil && networkApply != nil {
		r.rollbackAppliedNetwork(networkApply)
	}
	if err == nil {
		result.NetworkApply = domainNetworkApplyResult(networkApply)
	}
	writeResult(w, result, err)
}

func (r *Router) handleSaveConfig(w http.ResponseWriter, req *http.Request) {
	ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "config.save", Target: "config", Permission: "config.write"})
	if !ok {
		return
	}
	result, err := r.store.SaveConfig(ctx)
	writeResult(w, result, err)
}

func (r *Router) handleSaveAndApplyConfig(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "config.save_and_apply", Target: "config", Permission: "config.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	if err := r.applyPendingSerialConfig(ctx); err != nil {
		r.recordHardwareFailure(ctx, spec, err)
		writeResult(w, nil, err)
		return
	}
	networkApply, err := r.applyPendingNetworkConfig(ctx)
	if err != nil {
		r.recordHardwareFailure(ctx, spec, err)
		writeResult(w, nil, err)
		return
	}
	result, err := r.store.SaveAndApplyConfig(ctx)
	if err != nil && networkApply != nil {
		r.rollbackAppliedNetwork(networkApply)
	}
	if err == nil {
		result.NetworkApply = domainNetworkApplyResult(networkApply)
	}
	writeResult(w, result, err)
}

func (r *Router) handleDiscardConfig(w http.ResponseWriter, req *http.Request) {
	ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "config.discard", Target: "config", Permission: "config.write"})
	if !ok {
		return
	}
	result, err := r.store.DiscardConfig(ctx)
	writeResult(w, result, err)
}

func (r *Router) handleSaveAndRestart(w http.ResponseWriter, req *http.Request) {
	spec := commandSpec{Action: "config.save_and_restart", Target: "config", Permission: "config.write"}
	ctx, ok := r.authorizeCommand(w, req, spec)
	if !ok {
		return
	}
	if err := r.applyPendingSerialConfig(ctx); err != nil {
		r.recordHardwareFailure(ctx, spec, err)
		writeResult(w, nil, err)
		return
	}
	networkApply, err := r.applyPendingNetworkConfig(ctx)
	if err != nil {
		r.recordHardwareFailure(ctx, spec, err)
		writeResult(w, nil, err)
		return
	}
	operation, err := r.store.SaveAndRestart(ctx)
	if err != nil && networkApply != nil {
		r.rollbackAppliedNetwork(networkApply)
	}
	if err == nil && networkApply != nil {
		status, confirmErr := r.network.Confirm(ctx, networkApply.TransactionID)
		if confirmErr != nil {
			writeResult(w, nil, confirmErr)
			return
		}
		if confirmer, ok := r.store.(networkRuntimeConfirmer); ok {
			if confirmErr := confirmer.ConfirmNetworkRuntime(ctx, networkApply.TransactionID); confirmErr != nil {
				writeResult(w, nil, confirmErr)
				return
			}
		}
		r.recordNetworkTransaction(ctx, "network.confirm", networkApply.TransactionID, "succeeded", "confirmed before save-and-restart")
		if operation.Result == nil {
			operation.Result = make(map[string]any)
		}
		operation.Result["network_apply"] = networkApplyStatus(status)
	}
	if err == nil {
		rebootOperation, rebootErr := r.store.RebootSystem(ctx)
		if rebootErr != nil {
			writeResult(w, nil, fmt.Errorf("configuration was saved but device reboot could not be scheduled: %w", rebootErr))
			return
		}
		if operation.Result == nil {
			operation.Result = make(map[string]any)
		}
		operation.Result["reboot_scheduled"] = true
		operation.Result["reboot_operation_id"] = rebootOperation.OperationID
		operation.Message = strings.TrimSpace(operation.Message + "; device reboot scheduled")
	}
	writeResult(w, operation, err)
}

func (r *Router) rollbackAppliedNetwork(networkApply *networkconfig.ApplyResult) {
	if networkApply == nil || networkApply.TransactionID == "" {
		return
	}
	status, err := r.network.Rollback(context.Background(), networkApply.TransactionID)
	if err == nil {
		_ = r.reconcileRolledBackNetwork(context.Background(), status)
	}
}

func (r *Router) applyPendingNetworkConfig(ctx context.Context) (*networkconfig.ApplyResult, error) {
	config, pending, err := r.pendingNetworkConfig(ctx)
	if err != nil || !pending {
		return nil, err
	}
	if err := r.confirmReachablePendingNetworkTransaction(ctx); err != nil {
		return nil, err
	}
	result, err := r.network.Apply(ctx, config)
	if err != nil {
		return nil, err
	}
	if preparer, ok := r.store.(networkRuntimePreparer); ok {
		if err := preparer.PrepareNetworkRuntimeApply(ctx, result.TransactionID); err != nil {
			_, _ = r.network.Rollback(context.Background(), result.TransactionID)
			return nil, err
		}
	}
	return &result, nil
}

// confirmReachablePendingNetworkTransaction settles a previous guarded
// network apply before starting another one. Reaching an authenticated config
// command proves that the management API is still reachable through the
// currently active network configuration, which is the same condition used by
// the Web UI's explicit confirmation flow.
func (r *Router) confirmReachablePendingNetworkTransaction(ctx context.Context) error {
	status, err := r.network.Status(ctx)
	if err != nil {
		return err
	}
	if status.State != "pending_confirmation" || status.TransactionID == "" {
		return nil
	}
	confirmed, err := r.network.Confirm(ctx, status.TransactionID)
	if err != nil {
		r.recordNetworkTransaction(ctx, "network.confirm", status.TransactionID, "failed", err.Error())
		return err
	}
	r.recordNetworkTransaction(ctx, "network.confirm", status.TransactionID, "succeeded", "confirmed by reachable configuration command before replacement")
	if confirmed.State == "pending_confirmation" {
		return errors.New("network transaction remains pending after confirmation")
	}
	return nil
}

func (r *Router) pendingNetworkConfig(ctx context.Context) (networkconfig.Config, bool, error) {
	snapshot, err := r.store.ConfigExport(ctx)
	if err != nil {
		return networkconfig.Config{}, false, err
	}

	hasPendingNetwork := snapshot.Pending.Network != nil
	hasPendingInterfaces := len(snapshot.Pending.NetworkInterfaces) > 0

	if !hasPendingNetwork && !hasPendingInterfaces {
		return networkconfig.Config{}, false, nil
	}

	interfaces := make(map[string]domain.NetworkInterface, len(snapshot.Running.Network.Interfaces))

	for _, item := range snapshot.Running.Network.Interfaces {
		interfaces[item.Name] = item
	}

	for _, item := range snapshot.Pending.NetworkInterfaces {
		interfaces[item.Name] = item
	}

	global := snapshot.Running.Network

	if snapshot.Pending.Network != nil {
		pending := snapshot.Pending.Network

		if pending.HostName != "" {
			global.HostName = pending.HostName
		}
		if pending.OperatingMode != "" {
			global.OperatingMode = pending.OperatingMode
		}
		global.Advanced = pending.Advanced
		global.DDNS = pending.DDNS
		if pending.OOB.PrimaryInterface != "" {
			global.OOB.PrimaryInterface = pending.OOB.PrimaryInterface
		}
		if pending.OOB.FallbackInterface != "" {
			global.OOB.FallbackInterface = pending.OOB.FallbackInterface
		}
		if pending.OOB.HealthCheckTarget != "" {
			global.OOB.HealthCheckTarget = pending.OOB.HealthCheckTarget
		}
		if pending.OOB.HealthCheckIntervalSecond != 0 {
			global.OOB.HealthCheckIntervalSecond = pending.OOB.HealthCheckIntervalSecond
		}
		if pending.OOB.FailureThreshold != 0 {
			global.OOB.FailureThreshold = pending.OOB.FailureThreshold
		}
	}
	config := networkconfig.Config{
		HostName:      global.HostName,
		OperatingMode: global.OperatingMode,
		Advanced: networkconfig.AdvancedConfig{
			Mode: global.Advanced.Mode, BondMode: global.Advanced.BondMode,
			BondMii: global.Advanced.BondMii, BridgeSTP: global.Advanced.BridgeSTP,
		},
		DDNS: networkconfig.DDNSConfig{
			Enabled: global.DDNS.Enabled, Provider: global.DDNS.Provider,
			IPv4Enabled: global.DDNS.IPv4Enabled, IPv6Enabled: global.DDNS.IPv6Enabled,
			Username: global.DDNS.Username, Password: global.DDNS.Password,
			IPv4Domain: global.DDNS.IPv4Domain, IPv6Domain: global.DDNS.IPv6Domain,
			CheckIPURL: global.DDNS.CheckIPURL, CustomProvider: global.DDNS.CustomProvider,
			CustomPath: global.DDNS.CustomPath,
		},
		OOBPrimaryInterface:   global.OOB.PrimaryInterface,
		OOBFallbackInterface:  global.OOB.FallbackInterface,
		OOBHealthCheckTarget:  global.OOB.HealthCheckTarget,
		OOBHealthCheckSecond:  global.OOB.HealthCheckIntervalSecond,
		OOBFailureThreshold:   global.OOB.FailureThreshold,
		RoutingMode:           global.OperatingMode,
		RollbackTimeoutSecond: global.RollbackTimeoutSeconds,
		Interfaces:            make([]networkconfig.Interface, 0, len(interfaces)),
	}
	if config.RollbackTimeoutSecond == 0 {
		config.RollbackTimeoutSecond = networkconfig.DefaultRollbackSecond
	}
	for _, item := range interfaces {
		config.Interfaces = append(config.Interfaces, networkconfig.Interface{
			Name: item.Name, Device: item.Device, Role: item.Role, AddressMode: item.AddressMode,
			Address: item.Address, Gateway: item.Gateway, DNSServers: append([]string(nil), item.DNSServers...),
			IPv6Mode: item.IPv6Mode, IPv6Address: item.IPv6Address, IPv6Gateway: item.IPv6Gateway,
			IPv6DNSServers: append([]string(nil), item.IPv6DNSServers...), Weight: item.Weight,
		})
	}
	normalized, err := networkconfig.Normalize(config)
	if err != nil {
		return networkconfig.Config{}, false, err
	}
	return normalized, true, nil
}

func domainNetworkApplyResult(result *networkconfig.ApplyResult) *domain.NetworkApplyStatus {
	if result == nil {
		return nil
	}
	deadline := result.Deadline
	return &domain.NetworkApplyStatus{
		TransactionID: result.TransactionID,
		State:         result.State,
		Deadline:      &deadline,
	}
}

func (r *Router) applyPendingSerialConfig(ctx context.Context) error {
	snapshot, err := r.store.ConfigExport(ctx)
	if err != nil {
		return err
	}
	running := make(map[string]domain.Port, len(snapshot.Running.Ports))
	for _, port := range snapshot.Running.Ports {
		running[strings.ToUpper(port.Channel)] = port
	}
	configs := make([]serial.ChannelConfig, 0, len(snapshot.Pending.Ports))
	captures := make([]serial.CaptureConfig, 0, len(snapshot.Pending.Ports))
	operationChanged := false
	for _, pending := range snapshot.Pending.Ports {
		current, ok := running[strings.ToUpper(pending.Channel)]
		if !ok {
			return fmt.Errorf("serial configuration is missing running %s", pending.Channel)
		}
		if pending.BaudRate != current.BaudRate || pending.DataBits != current.DataBits || pending.Parity != current.Parity || pending.StopBits != current.StopBits || pending.FlowControl != current.FlowControl {
			configs = append(configs, serial.ChannelConfig{
				Channel: pending.Channel, BaudRate: pending.BaudRate, DataBits: pending.DataBits,
				Parity: pending.Parity, StopBits: pending.StopBits, StopBitsMode: pending.StopBitsMode,
				FlowControl: pending.FlowControl, RTSControl: pending.RTSControl, DTRControl: pending.DTRControl,
				IgnoreJammed: pending.IgnoreJammed,
			})
		}
		if pending.DataLogMode != current.DataLogMode || pending.DataPackage != current.DataPackage || pending.DataLog != current.DataLog {
			captures = append(captures, captureConfigFromPort(pending))
		}
		if pending.Operation1 != current.Operation1 || pending.Operation2 != current.Operation2 || !slices.Equal(pending.RedirectTo, current.RedirectTo) {
			operationChanged = true
		}
	}
	if len(configs) > 0 {
		if err := r.applySerialLineConfig(ctx, configs); err != nil {
			return err
		}
	}
	if len(captures) > 0 {
		controller, ok := r.serialPorts.(serial.CaptureController)
		if !ok {
			return &serial.UnavailableError{Reason: "serial payload capture control is unavailable"}
		}
		if err := controller.ApplyCapture(ctx, captures); err != nil {
			return err
		}
	}
	if operationChanged {
		servicePorts := snapshot.Pending.Ports
		if provider, ok := r.store.(domain.PortServiceCredentialProvider); ok {
			servicePorts, err = provider.ResolvePortServiceCredentials(ctx, "pending", servicePorts)
			if err != nil {
				return err
			}
		}
		if err := r.portServices.Apply(ctx, servicePorts); err != nil {
			return err
		}
	}
	return nil
}

// applySerialLineConfig absorbs the short exclusive lease held by the
// automatic CR response probe. A real debug/session lease remains active and
// still fails after this bounded wait, so line settings are never changed
// underneath an operator's live connection.
func (r *Router) applySerialLineConfig(ctx context.Context, configs []serial.ChannelConfig) error {
	for attempt := 0; ; attempt++ {
		_, err := r.serialPorts.Apply(ctx, configs)
		if err == nil {
			return nil
		}
		if !errors.Is(err, serial.ErrStreamLeaseBusy) || attempt >= serialApplyLeaseRetryCount {
			return err
		}
		timer := time.NewTimer(serialApplyLeaseRetryInterval)
		select {
		case <-ctx.Done():
			timer.Stop()
			return ctx.Err()
		case <-timer.C:
		}
	}
}

func (r *Router) applySerialPortConfig(ctx context.Context, port domain.Port) error {
	return r.applySerialPortsConfig(ctx, []domain.Port{port})
}

func (r *Router) applySerialPortsConfig(ctx context.Context, ports []domain.Port) error {
	if len(ports) == 0 {
		return errors.New("port restart requires at least one channel")
	}
	configs := make([]serial.ChannelConfig, 0, len(ports))
	captures := make([]serial.CaptureConfig, 0, len(ports))
	for _, port := range ports {
		configs = append(configs, serial.ChannelConfig{
			Channel: port.Channel, BaudRate: port.BaudRate, DataBits: port.DataBits,
			Parity: port.Parity, StopBits: port.StopBits, StopBitsMode: port.StopBitsMode,
			FlowControl: port.FlowControl, RTSControl: port.RTSControl, DTRControl: port.DTRControl,
			IgnoreJammed: port.IgnoreJammed,
		})
		captures = append(captures, captureConfigFromPort(port))
	}
	if err := r.applySerialLineConfig(ctx, configs); err != nil {
		return err
	}
	controller, ok := r.serialPorts.(serial.CaptureController)
	if !ok {
		return &serial.UnavailableError{Reason: "serial payload capture control is unavailable"}
	}
	return controller.ApplyCapture(ctx, captures)
}

func captureConfigFromPort(port domain.Port) serial.CaptureConfig {
	return serial.CaptureConfig{
		Channel: port.Channel,
		Mode:    port.DataLogMode,
		DataPackage: serial.CapturePackageConfig{
			Mode: port.DataPackage.Mode, Length: port.DataPackage.Length, TimeoutMillis: port.DataPackage.TimeoutMillis,
			DelimiterProcess: port.DataPackage.DelimiterProcess, Delimiter1: port.DataPackage.Delimiter1, Delimiter2: port.DataPackage.Delimiter2,
		},
		DataLog: serial.CaptureLogConfig{
			Read: port.DataLog.Read, Send: port.DataLog.Send, ShowTimestamp: port.DataLog.ShowTimestamp,
			ShowDirection: port.DataLog.ShowDirection, ShowUsername: port.DataLog.ShowUsername,
			ShowIPAddress: port.DataLog.ShowIPAddress, ShowPort: port.DataLog.ShowPort, Format: port.DataLog.Format,
			ReadTrigger: serial.CaptureTriggerConfig{
				Length: port.DataLog.ReadTrigger.Length, TimeoutMillis: port.DataLog.ReadTrigger.TimeoutMillis,
				Process: port.DataLog.ReadTrigger.Process, Character1: port.DataLog.ReadTrigger.Character1, Character2: port.DataLog.ReadTrigger.Character2,
			},
			SendTrigger: serial.CaptureTriggerConfig{
				Length: port.DataLog.SendTrigger.Length, TimeoutMillis: port.DataLog.SendTrigger.TimeoutMillis,
				Process: port.DataLog.SendTrigger.Process, Character1: port.DataLog.SendTrigger.Character1, Character2: port.DataLog.SendTrigger.Character2,
			},
		},
	}
}

func (r *Router) recordHardwareFailure(ctx context.Context, spec commandSpec, commandErr error) {
	_, _ = r.store.RecordAudit(ctx, domain.AuditEvent{
		Action:  spec.Action,
		Target:  spec.Target,
		Result:  "failed",
		Message: commandErr.Error(),
	})
}

func (r *Router) handleOperations(w http.ResponseWriter, req *http.Request) {
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "operation.read", Target: "operations", Permission: "operation.read"}); !ok {
		return
	}
	limit, offset, ok := parsePagination(w, req)
	if !ok {
		return
	}
	operations, err := r.store.Operations(req.Context())
	operations = windowOperations(operations, limit, offset)
	writeResult(w, operations, err)
}

func (r *Router) handleOperation(w http.ResponseWriter, req *http.Request) {
	operationID := strings.Trim(strings.TrimPrefix(req.URL.Path, "/api/v1/operations/"), "/")
	if operationID == "" {
		writeError(w, http.StatusNotFound, "not_found", "operation route not found")
		return
	}
	if _, ok := r.authorizeCommand(w, req, commandSpec{Action: "operation.read", Target: operationID, Permission: "operation.read"}); !ok {
		return
	}
	operation, err := r.store.Operation(req.Context(), operationID)
	writeResult(w, operation, err)
}

func (r *Router) handleFirmwareStatus(w http.ResponseWriter, req *http.Request) {
	ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "firmware.read", Target: "firmware", Permission: "firmware.read"})
	if !ok {
		return
	}
	status, err := r.firmware.Status(ctx)
	writeUpdateResult(w, status, err)
}

func (r *Router) handleFirmwareUpload(w http.ResponseWriter, req *http.Request) {
	ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "firmware.upload", Target: "firmware", Permission: "firmware.upload"})
	if !ok {
		return
	}
	filename := strings.TrimSpace(req.Header.Get("X-Tera-Filename"))
	if req.ContentLength <= 0 || req.ContentLength > r.maxFirmwareBytes {
		writeError(w, http.StatusRequestEntityTooLarge, "update_size_invalid", "firmware package content length is missing or exceeds the configured maximum")
		return
	}
	if mediaType := strings.TrimSpace(strings.SplitN(req.Header.Get("Content-Type"), ";", 2)[0]); mediaType != "application/octet-stream" {
		writeError(w, http.StatusUnsupportedMediaType, "update_media_type_invalid", "firmware upload must use application/octet-stream")
		return
	}
	status, err := r.firmware.Upload(ctx, update.UploadRequest{
		Filename: filename, ContentLength: req.ContentLength, Actor: domain.ActorName(ctx), Body: req.Body,
	})
	result := "succeeded"
	message := "signed local firmware package validated"
	if err != nil {
		result = "failed"
		message = err.Error()
	}
	_, _ = r.store.RecordAudit(ctx, domain.AuditEvent{Action: "firmware.upload", Target: filename, Result: result, Message: message})
	writeUpdateResult(w, status, err)
}

func (r *Router) handleFirmwareApply(w http.ResponseWriter, req *http.Request) {
	ctx, ok := r.authorizeCommand(w, req, commandSpec{Action: "firmware.apply", Target: "firmware", Permission: "firmware.apply"})
	if !ok {
		return
	}
	status, err := r.firmware.Apply(ctx, update.ApplyRequest{Actor: domain.ActorName(ctx), OperationID: req.Header.Get("X-Tera-Operation-ID")})
	result := "succeeded"
	message := "firmware apply accepted"
	if err != nil {
		result = "rejected"
		message = err.Error()
	}
	_, _ = r.store.RecordAudit(ctx, domain.AuditEvent{Action: "firmware.apply", Target: status.OperationID, Result: result, Message: message})
	writeUpdateResult(w, status, err)
}

func (r *Router) authorizeCommand(w http.ResponseWriter, req *http.Request, spec commandSpec) (context.Context, bool) {
	actor, ok := r.authenticateActor(w, req)
	if !ok {
		_, _ = r.store.RecordAudit(req.Context(), domain.AuditEvent{
			Actor:   "anonymous",
			Action:  spec.Action,
			Target:  spec.Target,
			Result:  "authentication_failed",
			Message: "authentication required",
		})
		return req.Context(), false
	}
	if actor.MustChangePassword && spec.Action != "auth.password.change" {
		writeError(w, http.StatusForbidden, "password_change_required", "password must be changed before using this function")
		return req.Context(), false
	}

	if actor.Role == "port_operator" && strings.HasPrefix(spec.Action, "log.") {
		writeError(w, http.StatusForbidden, "authorization_denied", "port operators cannot access logs")
		return req.Context(), false
	}
	if !actor.Permissions[spec.Permission] {
		_, _ = r.store.RecordAudit(domain.WithActor(req.Context(), actor), domain.AuditEvent{
			Action:  spec.Action,
			Target:  spec.Target,
			Result:  "authorization_denied",
			Message: "actor is not authorized for " + spec.Permission,
		})
		writeError(w, http.StatusForbidden, "authorization_denied", "actor is not authorized for "+spec.Permission)
		return req.Context(), false
	}

	return domain.WithActor(req.Context(), actor), true
}

func directAccessForRequest(request domain.DirectSessionRequest) string {
	if strings.EqualFold(request.Access, "writer") {
		return "write"
	}
	return "read"
}

const directRecentRXWindowMilliseconds int64 = 10_000

func directPortConnected(port domain.Port) bool {
	runtime := port.Runtime
	if runtime == nil || !runtime.HardwareAvailable {
		return false
	}
	if runtime.SessionActive || runtime.CRProbeUp {
		return true
	}
	return runtime.LastRXAt != nil && runtime.RXAgeMillis >= 0 && runtime.RXAgeMillis <= directRecentRXWindowMilliseconds
}

func (r *Router) requireDirectPortConnected(w http.ResponseWriter, ctx context.Context, channel string, spec commandSpec) bool {
	port, err := r.store.Port(ctx, channel)
	if err != nil {
		writeResult(w, nil, err)
		return false
	}
	ports := r.overlayPortRuntime([]domain.Port{port}, r.readSerialRuntime(ctx))
	if len(ports) == 1 && directPortConnected(ports[0]) {
		return true
	}
	message := channel + " is not connected; Direct Mode writer requires an UP port"
	_, _ = r.store.RecordAudit(ctx, domain.AuditEvent{
		Action:  spec.Action,
		Target:  channel,
		Result:  "rejected",
		Message: message,
	})
	writeError(w, http.StatusConflict, "port_not_connected", message)
	return false
}

func (r *Router) requirePortAccess(w http.ResponseWriter, ctx context.Context, channel, access string, spec commandSpec) bool {
	if !isAPIChannel(channel) {
		return true
	}
	authorizer, ok := r.store.(domain.PortAuthorizer)
	if !ok {
		return true
	}
	actor, ok := domain.ActorFromContext(ctx)
	if !ok {
		return false
	}
	if err := authorizer.AuthorizePort(ctx, actor, channel, access); err != nil {
		_, _ = r.store.RecordAudit(ctx, domain.AuditEvent{Action: spec.Action, Target: channel, Result: "authorization_denied", Message: err.Error()})
		writeError(w, http.StatusForbidden, "port_authorization_denied", err.Error())
		return false
	}
	return true
}

func isAPIChannel(channel string) bool {
	if len(channel) != 4 || !strings.HasPrefix(channel, "CH") {
		return false
	}
	index, err := strconv.Atoi(channel[2:])
	return err == nil && index >= 1 && index <= 48
}

func (r *Router) filterAuthorizedPorts(ctx context.Context, ports []domain.Port, access string) []domain.Port {
	authorizer, ok := r.store.(domain.PortAuthorizer)
	actor, actorOK := domain.ActorFromContext(ctx)
	if !ok || !actorOK {
		return ports
	}
	result := make([]domain.Port, 0, len(ports))
	for _, port := range ports {
		if authorizer.AuthorizePort(ctx, actor, port.Channel, access) == nil {
			result = append(result, port)
		}
	}
	return result
}

func (r *Router) authorizeAuthRead(w http.ResponseWriter, req *http.Request, action string) (context.Context, bool) {
	actor, ok := r.authenticateActor(w, req)
	if !ok {
		_, _ = r.store.RecordAudit(req.Context(), domain.AuditEvent{
			Actor:   "anonymous",
			Action:  action,
			Target:  "auth",
			Result:  "authentication_failed",
			Message: "authentication required",
		})
		return req.Context(), false
	}
	if !actor.Permissions["auth.read"] {
		_, _ = r.store.RecordAudit(domain.WithActor(req.Context(), actor), domain.AuditEvent{
			Action:  action,
			Target:  "auth",
			Result:  "authorization_denied",
			Message: "actor is not authorized for auth.read",
		})
		writeError(w, http.StatusForbidden, "authorization_denied", "actor is not authorized for auth.read")
		return req.Context(), false
	}
	return domain.WithActor(req.Context(), actor), true
}

func writeResult(w http.ResponseWriter, value any, err error) {
	if err != nil {
		status := http.StatusInternalServerError
		code := "internal_error"
		if errors.Is(err, errNotFound{}) || strings.Contains(err.Error(), "not found") {
			status = http.StatusNotFound
			code = "not_found"
		} else if systemtime.IsUnavailable(err) {
			status = http.StatusServiceUnavailable
			code = "time_unavailable"
		} else if networkconfig.IsUnavailable(err) {
			status = http.StatusServiceUnavailable
			code = "network_unavailable"
		} else if strings.Contains(err.Error(), "support bundle service is unavailable") {
			status = http.StatusServiceUnavailable
			code = "diagnostics_unavailable"
		} else if alarmdelivery.IsUnavailable(err) {
			status = http.StatusServiceUnavailable
			code = "alarm_delivery_unavailable"
		} else if greenled.IsUnavailable(err) || serial.IsUnavailable(err) {
			status = http.StatusServiceUnavailable
			code = "hardware_unavailable"
		} else if strings.Contains(err.Error(), "owned by another actor") {
			status = http.StatusForbidden
			code = "authorization_denied"
		} else if strings.Contains(err.Error(), "category") {
			status = http.StatusBadRequest
			code = "validation_failed"
		} else if strings.Contains(err.Error(), "alarm delivery queue is full") || strings.Contains(err.Error(), "already owned") || strings.Contains(err.Error(), "auth token limit") || strings.Contains(err.Error(), "viewer limit") || strings.Contains(err.Error(), "already exists") || strings.Contains(err.Error(), "last enabled administrator") {
			status = http.StatusConflict
			code = "conflict"
		} else if strings.Contains(err.Error(), "CH01 through CH48") || strings.Contains(err.Error(), "address") || strings.Contains(err.Error(), "alarm delivery") || strings.Contains(err.Error(), "auth group name") || strings.Contains(err.Error(), "auth token") || strings.Contains(err.Error(), "auth_key_stored") || strings.Contains(err.Error(), "audit_days") || strings.Contains(err.Error(), "baud_rate") || strings.Contains(err.Error(), "browser_time") || strings.Contains(err.Error(), "channels") || strings.Contains(err.Error(), "community_stored") || strings.Contains(err.Error(), "config file") || strings.Contains(err.Error(), "config restore") || strings.Contains(err.Error(), "credential_stored") || strings.Contains(err.Error(), "data_bits") || strings.Contains(err.Error(), "data_log_mode") || strings.Contains(err.Error(), "delivery") || strings.Contains(err.Error(), "diagnostic max_hops") || strings.Contains(err.Error(), "diagnostic port") || strings.Contains(err.Error(), "diagnostic target") || strings.Contains(err.Error(), "direct access") || strings.Contains(err.Error(), "direction") || strings.Contains(err.Error(), "dwell_ms") || strings.Contains(err.Error(), "email notification") || strings.Contains(err.Error(), "enabled") || strings.Contains(err.Error(), "encrypted config") || strings.Contains(err.Error(), "external auth") || strings.Contains(err.Error(), "flow_control") || strings.Contains(err.Error(), "format_version") || strings.Contains(err.Error(), "from") || strings.Contains(err.Error(), "gateway") || strings.Contains(err.Error(), "idle_timeout_minutes") || strings.Contains(err.Error(), "interface") || strings.Contains(err.Error(), "interval_minutes") || strings.Contains(err.Error(), "limit") || strings.Contains(err.Error(), "log export") || strings.Contains(err.Error(), "log retention") || strings.Contains(err.Error(), "management access") || strings.Contains(err.Error(), "max_output_bytes") || strings.Contains(err.Error(), "mode must be") || strings.Contains(err.Error(), "network") || strings.Contains(err.Error(), "ntp") || strings.Contains(err.Error(), "offset") || strings.Contains(err.Error(), "operation_") || strings.Contains(err.Error(), "parity") || strings.Contains(err.Error(), "password") || strings.Contains(err.Error(), "password_stored") || strings.Contains(err.Error(), "pending_queue_limit") || strings.Contains(err.Error(), "port_days") || strings.Contains(err.Error(), "preserve_on_factory_reset") || strings.Contains(err.Error(), "primary_method") || strings.Contains(err.Error(), "privacy_key_stored") || strings.Contains(err.Error(), "protected_usage_warning_pct") || strings.Contains(err.Error(), "remote syslog") || strings.Contains(err.Error(), "retry_count") || strings.Contains(err.Error(), "retry_interval_seconds") || strings.Contains(err.Error(), "role") || strings.Contains(err.Error(), "session_id") || strings.Contains(err.Error(), "severity") || strings.Contains(err.Error(), "smtp") || strings.Contains(err.Error(), "snmp agent") || strings.Contains(err.Error(), "snmp trap") || strings.Contains(err.Error(), "stop_bits") || strings.Contains(err.Error(), "support bundle id") || strings.Contains(err.Error(), "system_days") || strings.Contains(err.Error(), "target_id") || strings.Contains(err.Error(), "time mode") || strings.Contains(err.Error(), "time settings") || strings.Contains(err.Error(), "timeout_seconds") || strings.Contains(err.Error(), "timezone") || strings.Contains(err.Error(), "tls certificate") || strings.Contains(err.Error(), "token") || strings.Contains(err.Error(), "trigger") || strings.Contains(err.Error(), "username") {
			status = http.StatusBadRequest
			code = "validation_failed"
		}
		writeError(w, status, code, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, value)
}

func writeUpdateResult(w http.ResponseWriter, status update.Status, err error) {
	if err == nil {
		writeJSON(w, http.StatusOK, status)
		return
	}
	code := update.Code(err)
	httpStatus := http.StatusInternalServerError
	switch code {
	case "update_unavailable":
		httpStatus = http.StatusServiceUnavailable
	case "update_capacity_failed":
		httpStatus = http.StatusInsufficientStorage
	case "update_conflict", "update_apply_unsupported":
		httpStatus = http.StatusConflict
	case "update_size_invalid":
		httpStatus = http.StatusRequestEntityTooLarge
	case "update_validation_failed", "update_receive_failed", "update_media_type_invalid":
		httpStatus = http.StatusBadRequest
	}
	if code == "" {
		code = "update_failed"
	}
	writeError(w, httpStatus, code, err.Error())
}

func writeJSON(w http.ResponseWriter, status int, value any) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	_ = json.NewEncoder(w).Encode(value)
}

func writeError(w http.ResponseWriter, status int, code, message string) {
	writeJSON(w, status, domain.ErrorResponse{
		Error: domain.ErrorBody{
			Code:    code,
			Message: message,
		},
	})
}

type errNotFound struct{}

func (errNotFound) Error() string { return "not found" }