package update

import (
	"context"
	"errors"
	"io"
	"time"

	"tera-clone/services/tera-api/internal/storage/capacity"
)

const (
	ApplyCapabilityValidationOnly = "validation-only"
	ApplyCapabilityRecoveryV1     = "recovery-v1"
	RecoveryCapabilityOfflineV1   = "offline-resumable-v1"

	StateIdle          = "idle"
	StateReceiving     = "receiving"
	StateStaged        = "staged"
	StateValidating    = "validating"
	StateValidated     = "validated"
	StateApplyPending  = "apply_pending"
	StateRebootPending = "reboot_pending"
	StateApplying      = "applying"
	StateVerifying     = "verifying"
	StateSucceeded     = "succeeded"
	StateFailed        = "failed"
)

type Payload struct {
	Name            string `json:"name"`
	Path            string `json:"path"`
	Class           string `json:"class"`
	Size            int64  `json:"size"`
	SHA256          string `json:"sha256"`
	TargetPartition string `json:"target_partition,omitempty"`
	Encoding        string `json:"encoding,omitempty"`
	ExpandedSize    int64  `json:"expanded_size,omitempty"`
	ExpandedSHA256  string `json:"expanded_sha256,omitempty"`
}

type Manifest struct {
	FormatVersion         int       `json:"format_version"`
	PackageID             string    `json:"package_id"`
	Product               string    `json:"product"`
	HardwareProfile       string    `json:"hardware_profile"`
	Version               string    `json:"version"`
	MinimumCurrentVersion string    `json:"minimum_current_version,omitempty"`
	AllowDowngrade        bool      `json:"allow_downgrade"`
	CreatedAt             time.Time `json:"created_at"`
	SigningKeyID          string    `json:"signing_key_id"`
	Payloads              []Payload `json:"payloads"`
	Apply                 struct {
		Capability     string `json:"capability"`
		RebootRequired bool   `json:"reboot_required"`
	} `json:"apply"`
	Recovery struct {
		Capability   string `json:"capability"`
		Instructions string `json:"instructions"`
	} `json:"recovery"`
}

type Status struct {
	FormatVersion   int       `json:"format_version"`
	OperationID     string    `json:"operation_id,omitempty"`
	State           string    `json:"state"`
	Message         string    `json:"message"`
	Filename        string    `json:"filename,omitempty"`
	DeviceVersion   string    `json:"device_version,omitempty"`
	BytesReceived   int64     `json:"bytes_received"`
	BytesTotal      int64     `json:"bytes_total"`
	ProgressPercent int       `json:"progress_percent"`
	PackagePath     string    `json:"-"`
	Manifest        *Manifest `json:"manifest,omitempty"`
	SignerKeyID     string    `json:"signer_key_id,omitempty"`
	// ApplyPolicy is persisted by field firmware; retain it across upgrades.
	ApplyPolicy          string            `json:"apply_policy,omitempty"`
	ApplyEnabled         bool              `json:"apply_enabled"`
	ApplyDisabledReason  string            `json:"apply_disabled_reason,omitempty"`
	RecoveryInstructions string            `json:"recovery_instructions,omitempty"`
	FailureCode          string            `json:"failure_code,omitempty"`
	FailureReason        string            `json:"failure_reason,omitempty"`
	RecoveryStep         string            `json:"recovery_step,omitempty"`
	RecoveryAttempt      int               `json:"recovery_attempt,omitempty"`
	Capacity             capacity.Snapshot `json:"capacity"`
	CreatedAt            time.Time         `json:"created_at,omitempty"`
	UpdatedAt            time.Time         `json:"updated_at"`
}

type UploadRequest struct {
	Filename      string
	ContentLength int64
	Actor         string
	Body          io.Reader
}

type ApplyRequest struct {
	Actor       string
	OperationID string
}

type Controller interface {
	Status(context.Context) (Status, error)
	Upload(context.Context, UploadRequest) (Status, error)
	Apply(context.Context, ApplyRequest) (Status, error)
}

type Error struct {
	Code    string
	Message string
}

func (e *Error) Error() string { return e.Message }

func Code(err error) string {
	var updateErr *Error
	if errors.As(err, &updateErr) {
		return updateErr.Code
	}
	return ""
}

type UnavailableController struct{ Reason string }

func (u UnavailableController) unavailable() error {
	reason := u.Reason
	if reason == "" {
		reason = "tera-updated is unavailable"
	}
	return &Error{Code: "update_unavailable", Message: reason}
}

func (u UnavailableController) Status(context.Context) (Status, error) {
	return Status{}, u.unavailable()
}
func (u UnavailableController) Upload(context.Context, UploadRequest) (Status, error) {
	return Status{}, u.unavailable()
}
func (u UnavailableController) Apply(context.Context, ApplyRequest) (Status, error) {
	return Status{}, u.unavailable()
}

type FactoryResetter interface{ FactoryReset(context.Context) error }