package e2e

import (
	"bytes"
	"context"
	"database/sql"
	"image"
	"image/color"
	"image/png"
	"io/fs"
	"path/filepath"
	"testing"
	"time"

	assets "galo"
	"galo/internal/albums"
	"galo/internal/auth"
	"galo/internal/db"
	"galo/internal/photos"
	"galo/internal/settings"
	"galo/internal/sse"
	"galo/internal/storage"
	"galo/internal/store"
)

func makePNG(t *testing.T) []byte {
	t.Helper()
	img := image.NewRGBA(image.Rect(0, 0, 4, 4))
	for x := 0; x < 4; x++ {
		for y := 0; y < 4; y++ {
			img.Set(x, y, color.RGBA{R: uint8(x * 40), G: uint8(y * 40), B: 128, A: 255})
		}
	}
	var buf bytes.Buffer
	if err := png.Encode(&buf, img); err != nil {
		t.Fatalf("encode png: %v", err)
	}
	return buf.Bytes()
}

type stack struct {
	db     *sql.DB
	photos *photos.Service
	albums *albums.Service
	auth   *auth.Service
	hub    *sse.Hub
}

// openStack opens a migrated SQLite database at path and builds the services.
func openStack(t *testing.T, path, blobRoot string) (*stack, func()) {
	t.Helper()
	migFS, err := fs.Sub(assets.Migrations, "migrations/sqlite")
	if err != nil {
		t.Fatalf("migrations fs: %v", err)
	}
	if err := db.MigrateSQLite(path, migFS); err != nil {
		t.Fatalf("migrate: %v", err)
	}
	database, err := db.OpenSQLite(path)
	if err != nil {
		t.Fatalf("open: %v", err)
	}
	repos := store.NewSQLite(database)
	hub := sse.NewHub(1)
	signer, err := storage.NewSigner("http://app.test", "secret", time.Hour, 10*time.Minute)
	if err != nil {
		t.Fatalf("signer: %v", err)
	}
	blob, err := storage.NewFS(blobRoot, signer)
	if err != nil {
		t.Fatalf("fs: %v", err)
	}
	authSvc := auth.NewService(repos.Auth, auth.NewTokenManager("secret", 15*time.Minute, time.Hour))
	albumsSvc := albums.NewService(repos.Albums, repos.Members, hub, blob)
	photosSvc := photos.NewService(repos.Photos, albumsSvc, blob, hub)
	return &stack{db: database, photos: photosSvc, albums: albumsSvc, auth: authSvc, hub: hub}, func() { database.Close() }
}

func TestUploadSetsDefaultCover(t *testing.T) {
	ctx := context.Background()
	path := filepath.Join(t.TempDir(), "galo.db")
	st, closeDB := openStack(t, path, t.TempDir())
	defer closeDB()

	user, _, err := st.auth.Register(ctx, "cover@test.local", "password123", "C")
	if err != nil {
		t.Fatalf("register: %v", err)
	}
	album, err := st.albums.Create(ctx, user.ID, albums.CreateInput{Title: "Cover"})
	if err != nil {
		t.Fatalf("create album: %v", err)
	}

	first, err := st.photos.Upload(ctx, photos.UploadInput{
		AlbumID: album.ID, UserID: user.ID, Filename: "a.png", Data: makePNG(t),
	})
	if err != nil {
		t.Fatalf("upload first: %v", err)
	}
	got, _, err := st.albums.Get(ctx, album.ID, user.ID)
	if err != nil {
		t.Fatalf("get album: %v", err)
	}
	if got.CoverPhotoID == nil || *got.CoverPhotoID != first.ID {
		t.Fatalf("cover = %v, want first photo %s", got.CoverPhotoID, first.ID)
	}

	second, err := st.photos.Upload(ctx, photos.UploadInput{
		AlbumID: album.ID, UserID: user.ID, Filename: "b.png", Data: makePNG(t),
	})
	if err != nil {
		t.Fatalf("upload second: %v", err)
	}
	got, _, err = st.albums.Get(ctx, album.ID, user.ID)
	if err != nil {
		t.Fatalf("get album after second: %v", err)
	}
	if got.CoverPhotoID == nil || *got.CoverPhotoID != first.ID {
		t.Fatalf("cover changed to %v, want still first %s (second=%s)", got.CoverPhotoID, first.ID, second.ID)
	}
}

func TestCoverClearedWhenCoverPhotoLeaves(t *testing.T) {
	ctx := context.Background()
	path := filepath.Join(t.TempDir(), "galo.db")
	st, closeDB := openStack(t, path, t.TempDir())
	defer closeDB()

	user, _, err := st.auth.Register(ctx, "clear@test.local", "password123", "C")
	if err != nil {
		t.Fatalf("register: %v", err)
	}
	albumA, err := st.albums.Create(ctx, user.ID, albums.CreateInput{Title: "A"})
	if err != nil {
		t.Fatalf("create A: %v", err)
	}
	albumB, err := st.albums.Create(ctx, user.ID, albums.CreateInput{Title: "B"})
	if err != nil {
		t.Fatalf("create B: %v", err)
	}

	cover, err := st.photos.Upload(ctx, photos.UploadInput{
		AlbumID: albumA.ID, UserID: user.ID, Filename: "cover.png", Data: makePNG(t),
	})
	if err != nil {
		t.Fatalf("upload cover: %v", err)
	}

	// Trashing the cover clears it.
	if err := st.photos.Delete(ctx, cover.ID, user.ID); err != nil {
		t.Fatalf("delete cover: %v", err)
	}
	goal, _, _ := st.albums.Get(ctx, albumA.ID, user.ID)
	if goal.CoverPhotoID != nil {
		t.Fatalf("cover not cleared on delete: %v", goal.CoverPhotoID)
	}

	// A fresh upload becomes the cover, and moving it out clears it again.
	next, err := st.photos.Upload(ctx, photos.UploadInput{
		AlbumID: albumA.ID, UserID: user.ID, Filename: "next.png", Data: makePNG(t),
	})
	if err != nil {
		t.Fatalf("upload next: %v", err)
	}
	goal, _, _ = st.albums.Get(ctx, albumA.ID, user.ID)
	if goal.CoverPhotoID == nil || *goal.CoverPhotoID != next.ID {
		t.Fatalf("cover = %v, want %s", goal.CoverPhotoID, next.ID)
	}
	if _, err := st.photos.MoveBatch(ctx, []string{next.ID}, user.ID, albumB.ID); err != nil {
		t.Fatalf("move: %v", err)
	}
	goal, _, _ = st.albums.Get(ctx, albumA.ID, user.ID)
	if goal.CoverPhotoID != nil {
		t.Fatalf("cover not cleared on move: %v", goal.CoverPhotoID)
	}
}

func TestWorkerPublishesPhotoUpdated(t *testing.T) {
	ctx := context.Background()
	path := filepath.Join(t.TempDir(), "galo.db")
	st, closeDB := openStack(t, path, t.TempDir())
	defer closeDB()

	worker := photos.NewWorker(st.photos, 20*time.Millisecond, 10, time.Minute, 2)
	wctx, cancel := context.WithCancel(ctx)
	defer cancel()
	go worker.Run(wctx)

	user, _, err := st.auth.Register(ctx, "evt@test.local", "password123", "E")
	if err != nil {
		t.Fatalf("register: %v", err)
	}
	album, err := st.albums.Create(ctx, user.ID, albums.CreateInput{Title: "Trip"})
	if err != nil {
		t.Fatalf("create album: %v", err)
	}

	sub := st.hub.SubscribeAlbum(album.ID)
	defer sub.Close()

	if _, err := st.photos.Upload(ctx, photos.UploadInput{
		AlbumID: album.ID, UserID: user.ID, Filename: "a.png", Data: makePNG(t),
	}); err != nil {
		t.Fatalf("upload: %v", err)
	}

	select {
	case ev := <-sub.Events():
		if ev.Type != "photo.updated" {
			t.Fatalf("variant-ready event = %q, want photo.updated", ev.Type)
		}
	case <-time.After(5 * time.Second):
		t.Fatalf("no photo.updated event published for generated variants")
	}
}

func TestSQLiteEndToEndWithRestart(t *testing.T) {
	ctx := context.Background()
	path := filepath.Join(t.TempDir(), "galo.db")
	blobs := t.TempDir()

	st, closeDB := openStack(t, path, blobs)
	worker := photos.NewWorker(st.photos, 20*time.Millisecond, 10, time.Minute, 2)
	wctx, cancel := context.WithCancel(ctx)
	go worker.Run(wctx)

	user, _, err := st.auth.Register(ctx, "e2e@test.local", "password123", "E2E")
	if err != nil {
		t.Fatalf("register: %v", err)
	}
	album, err := st.albums.Create(ctx, user.ID, albums.CreateInput{Title: "Trip"})
	if err != nil {
		t.Fatalf("create album: %v", err)
	}
	p, err := st.photos.Upload(ctx, photos.UploadInput{AlbumID: album.ID, UserID: user.ID, Filename: "a.png", Data: makePNG(t)})
	if err != nil {
		t.Fatalf("upload: %v", err)
	}
	waitFor(t, "variants of first photo", func() bool {
		got, err := st.photos.Get(ctx, p.ID, user.ID)
		return err == nil && got.ThumbURL != "" && got.PreviewURL != ""
	})

	if err := st.photos.PermanentDelete(ctx, p.ID, user.ID); err != nil {
		t.Fatalf("permanent delete: %v", err)
	}
	waitFor(t, "garbage collection", func() bool {
		var n int
		return st.db.QueryRowContext(ctx, `SELECT count(*) FROM objects`).Scan(&n) == nil && n == 0
	})

	// Stop the worker, then queue another upload whose variant job must survive
	// the restart and be processed by a fresh worker over the same file.
	cancel()
	time.Sleep(50 * time.Millisecond)

	p2, err := st.photos.Upload(ctx, photos.UploadInput{AlbumID: album.ID, UserID: user.ID, Filename: "b.png", Data: makePNG(t)})
	if err != nil {
		t.Fatalf("upload p2: %v", err)
	}
	got2, _ := st.photos.Get(ctx, p2.ID, user.ID)
	if got2.PreviewURL != "" {
		t.Fatalf("variants generated before restart")
	}
	closeDB()

	st2, close2 := openStack(t, path, blobs)
	defer close2()
	worker2 := photos.NewWorker(st2.photos, 20*time.Millisecond, 10, time.Minute, 2)
	wctx2, cancel2 := context.WithCancel(ctx)
	defer cancel2()
	go worker2.Run(wctx2)

	waitFor(t, "variants of second photo after restart", func() bool {
		got, err := st2.photos.Get(ctx, p2.ID, user.ID)
		return err == nil && got.ThumbURL != "" && got.PreviewURL != ""
	})
}

func TestJWTSecretPersistsAcrossRestart(t *testing.T) {
	ctx := context.Background()
	path := filepath.Join(t.TempDir(), "galo.db")
	migFS, err := fs.Sub(assets.Migrations, "migrations/sqlite")
	if err != nil {
		t.Fatalf("migrations fs: %v", err)
	}

	open := func() (*sql.DB, store.Repos) {
		t.Helper()
		if err := db.MigrateSQLite(path, migFS); err != nil {
			t.Fatalf("migrate: %v", err)
		}
		database, err := db.OpenSQLite(path)
		if err != nil {
			t.Fatalf("open: %v", err)
		}
		return database, store.NewSQLite(database)
	}

	db1, repos1 := open()
	secret1, err := repos1.Settings.Ensure(ctx, settings.JWTSecretKey, settings.GenerateSecret)
	if err != nil || secret1 == "" {
		t.Fatalf("ensure secret: %v %q", err, secret1)
	}
	tm1 := auth.NewTokenManager(secret1, 15*time.Minute, time.Hour)
	token, err := tm1.GenerateAccess("user-1", "u@test.local")
	if err != nil {
		t.Fatalf("generate: %v", err)
	}
	_ = db1.Close()

	db2, repos2 := open()
	defer db2.Close()
	secret2, err := repos2.Settings.Ensure(ctx, settings.JWTSecretKey, settings.GenerateSecret)
	if err != nil {
		t.Fatalf("ensure after restart: %v", err)
	}
	if secret2 != secret1 {
		t.Fatalf("secret changed across restart")
	}
	tm2 := auth.NewTokenManager(secret2, 15*time.Minute, time.Hour)
	if _, err := tm2.ParseAccess(token); err != nil {
		t.Fatalf("token issued before restart not valid after: %v", err)
	}
}

func waitFor(t *testing.T, what string, cond func() bool) {
	t.Helper()
	deadline := time.Now().Add(10 * time.Second)
	for time.Now().Before(deadline) {
		if cond() {
			return
		}
		time.Sleep(20 * time.Millisecond)
	}
	t.Fatalf("timed out waiting for %s", what)
}