package systemmetrics

import (
	"context"
	"errors"
	"math"
	"tera-clone/services/tera-api/internal/domain"
	"testing"
)

func TestStorageMetricsDistinguishUsedAvailableAndReserved(t *testing.T) {
	m, err := storageMetrics("/userdata", 1000, 750, 700, 4096)
	if err != nil || m.TotalBytes != 4096000 || m.UsedBytes != 1024000 || m.AvailableBytes != 2867200 || m.ReservedBytes != 204800 || m.UsagePercent != 25 {
		t.Fatalf("metrics=%+v,%v", m, err)
	}
	for _, v := range [][4]uint64{{0, 0, 0, 4096}, {10, 11, 0, 1}, {10, 4, 5, 1}, {1, 0, 0, 0}, {math.MaxUint64, 0, 0, 2}} {
		if _, err := storageMetrics("/userdata", v[0], v[1], v[2], v[3]); err == nil {
			t.Fatalf("accepted %v", v)
		}
	}
}

func TestStorageReadFailureIsUnknownNotZeroUsage(t *testing.T) {
	root := t.TempDir()
	r := NewLinuxReader(LinuxReaderOptions{ProcRoot: root, SysRoot: root, EtcRoot: root, StorageReader: func(path string) (*domain.StorageMetrics, error) {
		if path != "/userdata" {
			t.Fatalf("path=%s", path)
		}
		return nil, errors.New("offline")
	}})
	if got := r.Read(context.Background(), nil); got.Storage != nil {
		t.Fatal("failed read was fabricated")
	}
	r.storageReader = func(path string) (*domain.StorageMetrics, error) { return storageMetrics(path, 100, 80, 75, 4096) }
	if got := r.Read(context.Background(), nil); got.Storage == nil || got.Storage.UsagePercent != 20 {
		t.Fatalf("storage=%+v", got.Storage)
	}
}