package backup

import (
	"archive/zip"
	"context"
	"errors"
	"io"
	"log/slog"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"github.com/cdnutter/playlink/internal/store"
)

var ctx = context.Background()

func setup(t *testing.T) (*store.Store, *Manager, string) {
	t.Helper()
	dir := t.TempDir()
	st, err := store.Open(dir)
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { st.DB.Close() })
	return st, New(st, dir, "test", slog.New(slog.NewTextHandler(io.Discard, nil))), dir
}

func TestCreateListDownloadPath(t *testing.T) {
	st, m, _ := setup(t)
	st.SetSetting(ctx, "marker", "before")
	b, err := m.Create(ctx, TypeManual, "manual")
	if err != nil {
		t.Fatal(err)
	}
	list, _ := m.List(ctx)
	if len(list) != 1 || list[0].Name != b.Name || list[0].Type != TypeManual || list[0].Size == 0 {
		t.Fatalf("list: %+v", list)
	}
	p, err := m.Path(ctx, b.Name)
	if err != nil {
		t.Fatal(err)
	}
	zr, err := zip.OpenReader(p)
	if err != nil {
		t.Fatal(err)
	}
	names := []string{}
	for _, f := range zr.File {
		names = append(names, f.Name)
	}
	zr.Close()
	if strings.Join(names, ",") != "playlink.db,backup.json" {
		t.Fatalf("zip contents: %v", names)
	}
	for _, bad := range []string{"../playlink.db", "evil.zip", "playlink_backup_manual_x.zip", "playlink_backup_manual_2026.01.01_00.00.00.zip/../../x"} {
		if _, err := m.Path(ctx, bad); !errors.Is(err, ErrBadName) {
			t.Errorf("%q must be refused, got %v", bad, err)
		}
	}
}

func TestRestoreRoundTrip(t *testing.T) {
	st, m, dir := setup(t)
	st.SetSetting(ctx, "marker", "before")
	b, _ := m.Create(ctx, TypeManual, "manual")
	st.SetSetting(ctx, "marker", "after")
	p, _ := m.Path(ctx, b.Name)
	if err := m.Stage(ctx, p, store.SchemaVersion()); err != nil {
		t.Fatal(err)
	}
	st.DB.Close()
	if err := ApplyStaged(dir, slog.New(slog.NewTextHandler(io.Discard, nil))); err != nil {
		t.Fatal(err)
	}
	st2, err := store.Open(dir)
	if err != nil {
		t.Fatal(err)
	}
	defer st2.DB.Close()
	if got := st2.Setting(ctx, "marker", ""); got != "before" {
		t.Fatalf("restore should bring back the old value, got %q", got)
	}
	kept, _ := filepath.Glob(filepath.Join(dir, "playlink.db.pre-restore-*"))
	if len(kept) == 0 {
		t.Fatal("the replaced database must be kept")
	}
}

func TestStageRejectsBadBackups(t *testing.T) {
	_, m, dir := setup(t)
	notZip := filepath.Join(dir, "x.zip")
	os.WriteFile(notZip, []byte("nope"), 0o644)
	if err := m.Stage(ctx, notZip, store.SchemaVersion()); err == nil {
		t.Error("a non-zip must be rejected")
	}
	mk := func(name string, content []byte) string {
		p := filepath.Join(dir, name)
		f, _ := os.Create(p)
		zw := zip.NewWriter(f)
		w, _ := zw.Create("playlink.db")
		w.Write(content)
		zw.Close()
		f.Close()
		return p
	}
	if err := m.Stage(ctx, mk("junk.zip", []byte("not a database")), store.SchemaVersion()); err == nil {
		t.Error("a damaged database must be rejected")
	}
	b, _ := m.Create(ctx, TypeManual, "manual")
	p, _ := m.Path(ctx, b.Name)
	if err := m.Stage(ctx, p, 1); err == nil || !strings.Contains(err.Error(), "newer version") {
		t.Errorf("a backup from a newer schema must be rejected, got %v", err)
	}
	if _, err := os.Stat(filepath.Join(dir, stagedName)); err == nil {
		t.Error("nothing may be staged after a rejected backup")
	}
}

func TestRetentionScheduleAndBeforeAction(t *testing.T) {
	_, m, _ := setup(t)
	cfg := m.Config(ctx)
	if cfg.IntervalDays != 7 || cfg.RetentionDays != 28 || cfg.BeforeActions {
		t.Fatalf("defaults: %+v", cfg)
	}
	// Off by default: no backup before actions.
	if err := m.BeforeAction(ctx, "link"); err != nil {
		t.Fatal(err)
	}
	if l, _ := m.List(ctx); len(l) != 0 {
		t.Fatal("no action backup while the option is off")
	}
	cfg.BeforeActions = true
	if err := m.SetConfig(ctx, cfg); err != nil {
		t.Fatal(err)
	}
	for i := 0; i < 12; i++ {
		if err := m.BeforeAction(ctx, "link"); err != nil {
			t.Fatal(err)
		}
	}
	l, _ := m.List(ctx)
	if len(l) != keepActions {
		t.Fatalf("only the newest %d action backups are kept, got %d", keepActions, len(l))
	}
	// An old scheduled backup is removed by retention; Due makes a new one.
	old := filepath.Join(cfg.Folder, "playlink_backup_scheduled_"+time.Now().AddDate(0, 0, -60).Format("2006.01.02_15.04.05")+".zip")
	os.WriteFile(old, []byte("x"), 0o644)
	m.Due(ctx)
	if _, err := os.Stat(old); !errors.Is(err, os.ErrNotExist) {
		t.Error("scheduled backups past retention must be removed")
	}
	sched := 0
	l, _ = m.List(ctx)
	for _, b := range l {
		if b.Type == TypeScheduled {
			sched++
		}
	}
	m.Due(ctx) // not due again yet
	l2, _ := m.List(ctx)
	if sched != 1 || len(l2) != len(l) {
		t.Fatalf("want exactly one scheduled backup, got %d (then %d total vs %d)", sched, len(l2), len(l))
	}
	if err := m.SetConfig(ctx, Config{Folder: "relative/path", IntervalDays: 1, RetentionDays: 1}); err == nil {
		t.Error("a relative backup folder must be rejected")
	}
}