package backup

import (
	"io"
	"log"
	"os"
	"path/filepath"
	"testing"
	"time"

	"gitea.dooplex.hu/admin/felhom-controller/internal/settings"
)

// newRestorePointsManager builds a Manager over a tempdir unit layout for the ListRestorePoints
// tests. drive is the in-guest namespace root (≠ systemDataPath ⇒ treated as a user-data drive).
func newRestorePointsManager(t *testing.T, drive string, sett *settings.Settings) *Manager {
	t.Helper()
	return &Manager{
		logger:         log.New(io.Discard, "", 0),
		settings:       sett,
		systemDataPath: filepath.Join(t.TempDir(), "sys"),
		stackProvider:  &fakeRecoveryProvider{hdd: drive},
	}
}

// TestListRestorePoints_UnitOnDisk proves the F1 endpoint's data source: a recovery unit on disk
// yields EXACTLY ONE tier-1 point whose Time is the NEWEST artifact mtime (here: a db-dump made
// fresher than the manifest — the nightly-dump-vs-checksum-skipped-manifest case). This is the
// half a hollow "returns []" handler could never pass; the companion below is the same layout
// with the manifest deleted.
func TestListRestorePoints_UnitOnDisk(t *testing.T) {
	drive := filepath.Join(t.TempDir(), "drive")
	mustWrite(t, RecoveryUnitManifestPath(drive, "app"), "{}")
	dumpPath := filepath.Join(AppDBDumpPath(drive, "app"), "app-postgres.sql")
	mustWrite(t, dumpPath, "dump")
	// Make the dump decisively newer than the manifest (mtime granularity safety).
	dumpTime := time.Now().Add(1 * time.Hour).Truncate(time.Second)
	if err := os.Chtimes(dumpPath, dumpTime, dumpTime); err != nil {
		t.Fatal(err)
	}

	m := newRestorePointsManager(t, drive, nil)
	points, found := m.ListRestorePoints("app")
	if !found {
		t.Fatal("stack should be found")
	}
	if len(points) != 1 {
		t.Fatalf("want exactly 1 restore point, got %d (%v)", len(points), points)
	}
	p := points[0]
	if p.Tier != 1 {
		t.Errorf("tier = %d, want 1 (tier-2 copies are not restorable via /backup/restore)", p.Tier)
	}
	if p.ShortID != "helyi" {
		t.Errorf("short_id = %q, want %q", p.ShortID, "helyi")
	}
	if want := dumpTime.UTC().Format(time.RFC3339); p.Time != want {
		t.Errorf("time = %q, want newest artifact mtime %q (the db-dump, not the older manifest)", p.Time, want)
	}
}

// COMPANION red-proof for the above: the SAME layout minus the manifest must yield an EMPTY list
// (found=true — "no backup yet" is a valid answer, not an error). Together the pair kills the
// hollow implementations: always-[] fails the first test, always-1-entry fails this one.
func TestListRestorePoints_NoUnitYet(t *testing.T) {
	drive := filepath.Join(t.TempDir(), "drive")
	// db-dump exists but there is NO manifest — the unit is what makes an app restorable.
	mustWrite(t, filepath.Join(AppDBDumpPath(drive, "app"), "app-postgres.sql"), "dump")

	m := newRestorePointsManager(t, drive, nil)
	points, found := m.ListRestorePoints("app")
	if !found {
		t.Fatal("a known stack without a unit is still found")
	}
	if len(points) != 0 {
		t.Errorf("want empty list without a recovery unit, got %v", points)
	}
}

// TestListRestorePoints_DriveLabel proves drive_label resolution: a registered storage path's
// label for drive-resident apps, and EMPTY for the SSD system-data fallback (not a bogus basename).
func TestListRestorePoints_DriveLabel(t *testing.T) {
	sett, err := settings.Load(filepath.Join(t.TempDir(), "settings.json"), log.New(io.Discard, "", 0))
	if err != nil {
		t.Fatal(err)
	}

	t.Run("registered drive → label", func(t *testing.T) {
		drive := filepath.Join(t.TempDir(), "usb")
		if err := sett.AddStoragePath(settings.StoragePath{Path: drive, Label: "Tárhely (usb)"}); err != nil {
			t.Fatal(err)
		}
		mustWrite(t, RecoveryUnitManifestPath(drive, "app"), "{}")
		m := newRestorePointsManager(t, drive, sett)
		points, _ := m.ListRestorePoints("app")
		if len(points) != 1 || points[0].DriveLabel != "Tárhely (usb)" {
			t.Errorf("drive label: %v", points)
		}
	})

	t.Run("SSD fallback → empty label", func(t *testing.T) {
		sys := filepath.Join(t.TempDir(), "sysdata")
		nsRoot := NamespaceRoot(sys, false) // system path appends felhom-data
		mustWrite(t, RecoveryUnitManifestPath(nsRoot, "app"), "{}")
		m := &Manager{
			logger:         log.New(io.Discard, "", 0),
			settings:       sett,
			systemDataPath: sys,
			stackProvider:  &fakeRecoveryProvider{hdd: ""}, // no HDD_PATH → falls back to systemDataPath
		}
		points, found := m.ListRestorePoints("app")
		if !found || len(points) != 1 {
			t.Fatalf("points: %v found=%v", points, found)
		}
		if points[0].DriveLabel != "" {
			t.Errorf("SSD fallback drive_label = %q, want empty", points[0].DriveLabel)
		}
	})
}

// TestListRestorePoints_UnknownStack proves the found=false path (the handler's 404).
func TestListRestorePoints_UnknownStack(t *testing.T) {
	m := &Manager{
		logger:         log.New(io.Discard, "", 0),
		systemDataPath: t.TempDir(),
		stackProvider:  &unknownStackProvider{},
	}
	if _, found := m.ListRestorePoints("ghost"); found {
		t.Error("unknown stack must report found=false")
	}
	// No provider wired at all → also not found (nothing is restorable).
	m.stackProvider = nil
	if _, found := m.ListRestorePoints("ghost"); found {
		t.Error("nil provider must report found=false")
	}
}

// unknownStackProvider is a fakeRecoveryProvider whose stacks never resolve.
type unknownStackProvider struct{ fakeRecoveryProvider }

func (u *unknownStackProvider) GetStackComposePath(string) (string, bool) { return "", false }
