package backup

import (
	"encoding/json"
	"log"
	"os"
	"path/filepath"
	"testing"
	"time"

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

// r487Provider knows exactly which stacks are deployed: GetStackComposePath answers ok for those and
// only those, which is the question ListRestorePoints and the restore ask.
type r487Provider struct{ floorProvider }

func (p *r487Provider) GetStackComposePath(name string) (string, bool) {
	for _, s := range p.stacks {
		if s == name {
			return filepath.Join(p.dir, "stacks", name, "docker-compose.yml"), true
		}
	}
	return "", false
}

func r487Manager(t *testing.T, sysPath string, deployed ...string) (*Manager, *settings.Settings) {
	t.Helper()
	sett, err := settings.Load(filepath.Join(t.TempDir(), "settings.json"), log.New(os.Stderr, "", 0))
	if err != nil {
		t.Fatal(err)
	}
	cfg := &config.Config{}
	cfg.Paths.SystemDataPath = sysPath
	m := NewManager(cfg, sett, log.New(os.Stderr, "", 0))
	m.SetStackProvider(&r487Provider{floorProvider{stacks: deployed, dir: t.TempDir()}})
	return m, sett
}

// writeR487Unit lays down a readable unit (manifest + one dump) for stack under nsRoot.
func writeR487Unit(t *testing.T, nsRoot, stack, display string, dumpAt time.Time) string {
	t.Helper()
	u := mkUnit(t, nsRoot, stack)
	man := RecoveryManifest{SchemaVersion: 2, AppName: stack, DisplayName: display, CreatedAt: "2026-09-12T02:15:29Z"}
	b, _ := json.Marshal(man)
	if err := os.WriteFile(UnitManifestFile(u), b, 0o644); err != nil {
		t.Fatal(err)
	}
	if err := os.MkdirAll(UnitDBDumpDir(u), 0o755); err != nil {
		t.Fatal(err)
	}
	dump := filepath.Join(UnitDBDumpDir(u), stack+".sql")
	if err := os.WriteFile(dump, []byte("-- dump"), 0o644); err != nil {
		t.Fatal(err)
	}
	if err := os.Chtimes(dump, dumpAt, dumpAt); err != nil {
		t.Fatal(err)
	}
	// the manifest is the OLDER artifact, as on a real box: it moves only when the definition changes
	older := dumpAt.Add(-24 * time.Hour)
	if err := os.Chtimes(UnitManifestFile(u), older, older); err != nil {
		t.Fatal(err)
	}
	return u
}

// R-487 — a removed app's kept unit is listed; a deployed app's is not; a unit on a registered DATA
// drive is found where it sits and carries that drive's label.
func TestR487_ListRemovedAppUnits_ListsKeptUnitsOfUndeployedApps(t *testing.T) {
	sys := t.TempDir()
	m, sett := r487Manager(t, sys, "kept-app")
	sysRoot := m.namespaceRoot(sys)
	writeR487Unit(t, sysRoot, "kept-app", "Kept", time.Now())
	writeR487Unit(t, sysRoot, "gone-app", "Gone", time.Now())
	drive := t.TempDir()
	if err := sett.AddStoragePath(settings.StoragePath{Path: drive, Label: "Külső HDD", Schedulable: true}); err != nil {
		t.Fatal(err)
	}
	writeR487Unit(t, m.namespaceRoot(drive), "drive-app", "On the drive", time.Now())
	// a bare directory without a manifest is NOT an offer
	if err := os.MkdirAll(RecoveryUnitPath(sysRoot, "hollow"), 0o755); err != nil {
		t.Fatal(err)
	}

	got := m.ListRemovedAppUnits()
	if len(got) != 2 || got[0].StackName != "drive-app" || got[1].StackName != "gone-app" {
		t.Fatalf("want [drive-app gone-app], got %+v", got)
	}
	if got[0].DriveLabel != "Külső HDD" || got[1].DriveLabel != systemDriveLabel {
		t.Errorf("drive labels: %q / %q", got[0].DriveLabel, got[1].DriveLabel)
	}
	if got[1].DisplayName != "Gone" || got[0].UnitDir != RecoveryUnitPath(m.namespaceRoot(drive), "drive-app") {
		t.Errorf("display/unit dir: %+v", got)
	}
	for _, u := range got {
		if u.StackName == "kept-app" || u.StackName == "hollow" {
			t.Errorf("%s must not be listed", u.StackName)
		}
	}
}

// R-487 — the restore picker's snapshot list answers for a removed app instead of 404.
func TestR487_ListRestorePointsFindsARemovedAppsUnit(t *testing.T) {
	sys := t.TempDir()
	m, _ := r487Manager(t, sys)
	at := time.Date(2026, 9, 13, 0, 30, 0, 0, time.UTC)
	writeR487Unit(t, m.namespaceRoot(sys), "gone-app", "Gone", at)

	pts, found := m.ListRestorePoints("gone-app")
	if !found || len(pts) != 1 {
		t.Fatalf("want found with one point, got found=%v pts=%+v", found, pts)
	}
	if pts[0].ShortID != restorePointShortID || pts[0].Tier != 1 || pts[0].Time != at.Format(time.RFC3339) {
		t.Errorf("point %+v", pts[0])
	}
	if _, found := m.ListRestorePoints("never-existed"); found {
		t.Error("an app with no unit anywhere must still be not-found")
	}
}

// R-487 — a removed app's unit kept on a DATA drive is the one the restore opens, not the system
// path the drive fallback would name.
func TestR487_PrimaryUnitDirForNamesTheRemovedUnitWhereItSits(t *testing.T) {
	sys := t.TempDir()
	m, sett := r487Manager(t, sys)
	drive := t.TempDir()
	if err := sett.AddStoragePath(settings.StoragePath{Path: drive, Label: "HDD", Schedulable: true}); err != nil {
		t.Fatal(err)
	}
	want := writeR487Unit(t, m.namespaceRoot(drive), "drive-app", "D", time.Now())
	if got := m.primaryUnitDirFor("drive-app"); got != want {
		t.Errorf("unit dir: got %s want %s", got, want)
	}
}