package server

import (
	"io"
	"net/http"
	"net/http/httptest"
	"net/url"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"strings"
	"testing"

	"vidarchive/internal/config"
	"vidarchive/internal/database"
	"vidarchive/internal/handler"
	"vidarchive/internal/repository"
	"vidarchive/internal/service"
	"vidarchive/internal/worker"
)

func setupTestServer(t *testing.T) (*Server, *config.Config, func()) {
	t.Helper()
	dataDir := t.TempDir()
	t.Setenv("VIDARCHIVE_DATA_DIR", dataDir)

	cfg := config.New()
	if err := os.MkdirAll(cfg.LibraryDir, 0755); err != nil {
		t.Fatalf("create library dir: %v", err)
	}
	if err := os.MkdirAll(cfg.TempDir, 0755); err != nil {
		t.Fatalf("create temp dir: %v", err)
	}

	db, err := database.New(cfg)
	if err != nil {
		t.Fatalf("init db: %v", err)
	}

	presetRepo := repository.NewPresetRepository(db)
	downloadRepo := repository.NewDownloadRepository(db)
	settingsRepo := repository.NewSettingsRepository(db)

	presetSvc := service.NewPresetService(presetRepo)
	librarySvc := service.NewLibraryService(cfg.LibraryDir)
	settingsSvc := service.NewSettingsService(settingsRepo)
	downloadSvc := service.NewDownloadService(downloadRepo, librarySvc, presetSvc, settingsSvc, cfg)
	workerPool := worker.New(downloadSvc, cfg.Workers)

	h, err := handler.New(cfg, presetSvc, downloadSvc, librarySvc, settingsSvc, workerPool)
	if err != nil {
		t.Fatalf("init handler: %v", err)
	}

	srv := New(cfg, h)
	cleanup := func() {
		workerPool.Stop()
		db.Close()
	}
	return srv, cfg, cleanup
}

func createItem(t *testing.T, libraryDir, relPath, name string, files map[string]string) {
	t.Helper()
	itemDir := filepath.Join(libraryDir, relPath)
	if err := os.MkdirAll(itemDir, 0755); err != nil {
		t.Fatalf("create item dir: %v", err)
	}
	marker := filepath.Join(itemDir, ".vidarchive-item.toml")
	if err := os.WriteFile(marker, []byte("name = \""+name+"\"\nduration = -1\n"), 0644); err != nil {
		t.Fatalf("write marker: %v", err)
	}
	for filename, content := range files {
		path := filepath.Join(itemDir, filename)
		if err := os.WriteFile(path, []byte(content), 0644); err != nil {
			t.Fatalf("write file %s: %v", filename, err)
		}
	}
}

func TestNestedLibraryItem(t *testing.T) {
	srv, cfg, cleanup := setupTestServer(t)
	defer cleanup()

	createItem(t, cfg.LibraryDir, "test/My Item [id]", "My Item", map[string]string{
		"My Item [id].mp4": "dummy video",
	})

	router := srv.Router()

	req := httptest.NewRequest("GET", "/library/item/test/My%20Item%20%5Bid%5D", nil)
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)
	if w.Code != http.StatusOK {
		body, _ := io.ReadAll(w.Body)
		t.Errorf("expected 200, got %d: %s", w.Code, string(body))
	}
}

// A directory whose name contains a literal '+' must round-trip: in a URL path
// '+' is a literal plus (not a space), reachable raw or percent-encoded.
func TestLiteralPlusInPathSegment(t *testing.T) {
	srv, cfg, cleanup := setupTestServer(t)
	defer cleanup()

	createItem(t, cfg.LibraryDir, "C++ Tutorial", "C++ Tutorial", map[string]string{
		"C++ Tutorial.mp4": "dummy video",
	})

	router := srv.Router()
	for _, path := range []string{
		"/library/item/C++%20Tutorial",
		"/library/item/C%2B%2B%20Tutorial",
	} {
		req := httptest.NewRequest("GET", path, nil)
		w := httptest.NewRecorder()
		router.ServeHTTP(w, req)
		if w.Code != http.StatusOK {
			body, _ := io.ReadAll(w.Body)
			t.Errorf("%s: expected 200, got %d: %s", path, w.Code, string(body))
		}
	}
}

func TestMediaFileQueryDecoding(t *testing.T) {
	srv, cfg, cleanup := setupTestServer(t)
	defer cleanup()

	createItem(t, cfg.LibraryDir, "My Item [id]", "My Item", map[string]string{
		"My Item [id].mp4": "dummy video",
		"My+Other.mp4":     "dummy video plus",
	})

	router := srv.Router()

	tests := []struct {
		path     string
		expected int
	}{
		{"/media/item/My%20Item%20%5Bid%5D?file=My+Item+%5Bid%5D.mp4", http.StatusOK},
		{"/media/item/My%20Item%20%5Bid%5D?file=My%20Item%20%5Bid%5D.mp4", http.StatusOK},
		{"/media/item/My%20Item%20%5Bid%5D?file=My%2BOther.mp4", http.StatusOK},
		{"/media/item/My%20Item%20%5Bid%5D?file=missing.mp4", http.StatusNotFound},
	}
	for _, tc := range tests {
		req := httptest.NewRequest("GET", tc.path, nil)
		w := httptest.NewRecorder()
		router.ServeHTTP(w, req)
		if w.Code != tc.expected {
			body, _ := io.ReadAll(w.Body)
			t.Errorf("%s: expected %d, got %d: %s", tc.path, tc.expected, w.Code, string(body))
		}
	}
}

func TestPathTraversalBlocked(t *testing.T) {
	srv, cfg, cleanup := setupTestServer(t)
	defer cleanup()

	outside := filepath.Join(cfg.DataDir, "secret")
	if err := os.MkdirAll(outside, 0755); err != nil {
		t.Fatalf("create outside dir: %v", err)
	}
	marker := filepath.Join(outside, ".vidarchive-item.toml")
	if err := os.WriteFile(marker, []byte("name = \"secret\"\nduration = -1\n"), 0644); err != nil {
		t.Fatalf("write marker: %v", err)
	}

	router := srv.Router()

	req := httptest.NewRequest("GET", "/library/item/../secret", nil)
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)
	if w.Code != http.StatusNotFound {
		t.Errorf("expected 404 for path traversal, got %d", w.Code)
	}
}

func TestPerFileExistingThumbnailServed(t *testing.T) {
	srv, cfg, cleanup := setupTestServer(t)
	defer cleanup()

	// A pre-existing per-file thumbnail (<stem>.thumbnail.webp) is served for the
	// matching ?file= request without re-extraction.
	createItem(t, cfg.LibraryDir, "thumb-item", "Thumb Item", map[string]string{
		"video.mp4":            "dummy video",
		"video.thumbnail.webp": "GENERATED-THUMB",
	})

	router := srv.Router()
	req := httptest.NewRequest("GET", "/media/item/thumb-item/thumbnail?file=video.mp4", nil)
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)
	if w.Code != http.StatusOK {
		body, _ := io.ReadAll(w.Body)
		t.Fatalf("expected 200, got %d: %s", w.Code, string(body))
	}
	if body, _ := io.ReadAll(w.Body); string(body) != "GENERATED-THUMB" {
		t.Errorf("expected the existing per-file thumbnail, got %q", string(body))
	}
}

func TestAudioThumbnailPlaceholder(t *testing.T) {
	srv, cfg, cleanup := setupTestServer(t)
	defer cleanup()

	createItem(t, cfg.LibraryDir, "audio-item", "Audio Item", map[string]string{
		"song.mp3": "dummy audio",
	})

	router := srv.Router()
	req := httptest.NewRequest("GET", "/media/item/audio-item/thumbnail", nil)
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)
	if w.Code != http.StatusOK {
		body, _ := io.ReadAll(w.Body)
		t.Fatalf("expected 200, got %d: %s", w.Code, string(body))
	}
	body, _ := io.ReadAll(w.Body)
	if len(body) == 0 {
		t.Errorf("placeholder thumbnail body was empty")
	}
}

func TestMultiFileCardThumbnailURLsDecodeToFilenames(t *testing.T) {
	srv, cfg, cleanup := setupTestServer(t)
	defer cleanup()

	// Filenames with spaces are the case that broke: the template must emit a
	// query value that the handler decodes back to the exact filename (the bug
	// was double-escaping spaces to %2b, which decodes to '+').
	files := map[string]string{
		"01 - Color Bars.mp4":   "v",
		"02 - Test Pattern.mp4": "v",
	}
	createItem(t, cfg.LibraryDir, "multi", "Multi", files)

	req := httptest.NewRequest("GET", "/library", nil)
	w := httptest.NewRecorder()
	srv.Router().ServeHTTP(w, req)
	body, _ := io.ReadAll(w.Body)

	re := regexp.MustCompile(`thumbnail\?file=([^"]+)`)
	matches := re.FindAllStringSubmatch(string(body), -1)
	if len(matches) != len(files) {
		t.Fatalf("expected %d per-file thumbnail URLs in the card, got %d", len(files), len(matches))
	}
	for _, m := range matches {
		vals, err := url.ParseQuery("file=" + m[1])
		if err != nil {
			t.Fatalf("bad query %q: %v", m[1], err)
		}
		got := vals.Get("file")
		if _, ok := files[got]; !ok {
			t.Errorf("thumbnail file=%q decodes to %q, which is not a real filename (double-encoding regression)", m[1], got)
		}
	}
}

func TestListingDoesNotExtractThumbnails(t *testing.T) {
	srv, cfg, cleanup := setupTestServer(t)
	defer cleanup()

	createItem(t, cfg.LibraryDir, "novid", "No Thumb", map[string]string{
		"video.mp4": "dummy video",
	})

	router := srv.Router()
	req := httptest.NewRequest("GET", "/library", nil)
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)
	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", w.Code)
	}

	// Rendering the listing must not have created any thumbnail file.
	entries, err := os.ReadDir(filepath.Join(cfg.LibraryDir, "novid"))
	if err != nil {
		t.Fatal(err)
	}
	for _, e := range entries {
		if strings.Contains(e.Name(), ".thumbnail.") {
			t.Errorf("listing extracted a thumbnail (%q) — should happen on request only", e.Name())
		}
	}
}

func TestGeneratedThumbnailServedOverIcon(t *testing.T) {
	srv, cfg, cleanup := setupTestServer(t)
	defer cleanup()

	createItem(t, cfg.LibraryDir, "gen", "Gen", map[string]string{
		"video.mp4":            "dummy video",
		"video.thumbnail.webp": "WEBPDATA",
	})

	router := srv.Router()
	req := httptest.NewRequest("GET", "/media/item/gen/thumbnail?file=video.mp4", nil)
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)
	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", w.Code)
	}
	if body, _ := io.ReadAll(w.Body); string(body) != "WEBPDATA" {
		t.Errorf("expected generated thumbnail contents, got %q", string(body))
	}
}

func TestThumbnailExtractedOnRequest(t *testing.T) {
	if _, err := exec.LookPath("ffmpeg"); err != nil {
		t.Skip("ffmpeg not on PATH")
	}
	srv, cfg, cleanup := setupTestServer(t)
	defer cleanup()

	itemDir := filepath.Join(cfg.LibraryDir, "realvid")
	createItem(t, cfg.LibraryDir, "realvid", "Real", nil)
	cmd := exec.Command("ffmpeg", "-hide_banner", "-loglevel", "error",
		"-f", "lavfi", "-i", "testsrc=duration=3:size=64x64:rate=5",
		"-pix_fmt", "yuv420p", filepath.Join(itemDir, "realvid.mp4"), "-y")
	if out, err := cmd.CombinedOutput(); err != nil {
		t.Fatalf("make test video: %v\n%s", err, out)
	}

	router := srv.Router()
	req := httptest.NewRequest("GET", "/media/item/realvid/thumbnail?file=realvid.mp4", nil)
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)
	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", w.Code)
	}
	if ct := w.Header().Get("Content-Type"); !strings.HasPrefix(ct, "image/") {
		t.Errorf("expected image content-type, got %q", ct)
	}
	body, _ := io.ReadAll(w.Body)
	if len(body) == 0 {
		t.Error("served thumbnail body was empty")
	}

	// A real thumbnail file should now exist on disk, with no temp leftovers.
	entries, _ := os.ReadDir(itemDir)
	var found bool
	for _, e := range entries {
		if strings.Contains(e.Name(), ".thumbnail.") {
			found = true
		}
		if strings.Contains(e.Name(), ".tmp") {
			t.Errorf("leftover temp file %q", e.Name())
		}
	}
	if !found {
		t.Error("no thumbnail file written to disk after request")
	}
}

func TestLibraryPageIsFast(t *testing.T) {
	srv, cfg, cleanup := setupTestServer(t)
	defer cleanup()

	for i := 0; i < 50; i++ {
		createItem(t, cfg.LibraryDir, "item-"+string(rune('a'+i)), "Item", map[string]string{
			"video.mp4": "dummy",
		})
	}

	router := srv.Router()
	req := httptest.NewRequest("GET", "/library", nil)
	w := httptest.NewRecorder()
	router.ServeHTTP(w, req)
	if w.Code != http.StatusOK {
		body, _ := io.ReadAll(w.Body)
		t.Fatalf("expected 200, got %d: %s", w.Code, string(body))
	}
}