package subsonic

import (
	"context"
	"crypto/md5"
	"database/sql"
	"encoding/hex"
	"encoding/json"
	"encoding/xml"
	"io"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/mithral/vellum/internal/apitoken"
	"github.com/mithral/vellum/internal/auth"
	"github.com/mithral/vellum/internal/core"
	"github.com/mithral/vellum/internal/subsonic/dto"
	"github.com/mithral/vellum/migrations"
)

// fixture is one seeded Subsonic server.
type fixture struct {
	db     *sql.DB
	userID int64
	key    string
	libID  int64
	album  int64
	file   int64
	root   string
}

func testDB(t *testing.T) *sql.DB {
	t.Helper()
	db, err := core.OpenDB(filepath.Join(t.TempDir(), "subsonic.db"))
	if err != nil {
		t.Fatalf("OpenDB: %v", err)
	}
	t.Cleanup(func() { _ = db.Close() })
	if err := core.Migrate(context.Background(), db, migrations.FS, slog.New(slog.NewTextHandler(io.Discard, nil))); err != nil {
		t.Fatalf("Migrate: %v", err)
	}
	return db
}

// newFixture seeds one non-admin user with a granted music library holding a
// single three-track album, an artist credit and a cover.
func newFixture(t *testing.T) (*httptest.Server, *fixture) {
	t.Helper()
	db := testDB(t)
	ctx := context.Background()

	root := t.TempDir()
	for _, name := range []string{
		"Artist/Album/01 - One.mp3",
		"Artist/Album/02 - Two.mp3",
		"Artist/Album/03 - Three.mp3",
	} {
		p := filepath.Join(root, filepath.FromSlash(name))
		if err := os.MkdirAll(filepath.Dir(p), 0o755); err != nil {
			t.Fatal(err)
		}
		// 100 deterministic bytes so a Range read is verifiable.
		if err := os.WriteFile(p, []byte(strings.Repeat("v", 100)), 0o644); err != nil {
			t.Fatal(err)
		}
	}
	coverPath := filepath.Join(root, "cover.png")
	if err := os.WriteFile(coverPath, []byte("\x89PNG\r\n\x1a\ncoverbytes"), 0o644); err != nil {
		t.Fatal(err)
	}

	user, err := auth.CreateUser(ctx, db, "alice", "Alice", "password123", false)
	if err != nil {
		t.Fatalf("CreateUser: %v", err)
	}

	var libID int64
	if err := db.QueryRowContext(ctx,
		`INSERT INTO libraries (name, kind, root_path) VALUES ('Music','music',?) RETURNING id`,
		root).Scan(&libID); err != nil {
		t.Fatalf("insert library: %v", err)
	}
	if _, err := db.ExecContext(ctx,
		`INSERT INTO library_grants (user_id, library_id, can_read, can_download) VALUES (?,?,1,1)`,
		user.ID, libID); err != nil {
		t.Fatalf("grant: %v", err)
	}

	var albumID int64
	if err := db.QueryRowContext(ctx, `
		INSERT INTO media_items (library_id, kind, path, title, sort_title, year)
		VALUES (?, 'music', 'Artist/Album', 'Album', 'album', 2013) RETURNING id`,
		libID).Scan(&albumID); err != nil {
		t.Fatalf("insert album: %v", err)
	}

	var firstFile int64
	for i, name := range []string{
		"Artist/Album/01 - One.mp3",
		"Artist/Album/02 - Two.mp3",
		"Artist/Album/03 - Three.mp3",
	} {
		var id int64
		if err := db.QueryRowContext(ctx, `
			INSERT INTO media_files (item_id, path, size, container, duration_ms)
			VALUES (?,?,100,'mp3',60000) RETURNING id`,
			albumID, name).Scan(&id); err != nil {
			t.Fatalf("insert file: %v", err)
		}
		if i == 0 {
			firstFile = id
		}
	}

	var personID int64
	if err := db.QueryRowContext(ctx,
		`INSERT INTO people (name) VALUES ('The Artist') RETURNING id`).Scan(&personID); err != nil {
		t.Fatalf("insert person: %v", err)
	}
	if _, err := db.ExecContext(ctx,
		`INSERT INTO item_people (item_id, person_id, role, ord) VALUES (?,?,'author',0)`,
		albumID, personID); err != nil {
		t.Fatalf("insert credit: %v", err)
	}
	if _, err := db.ExecContext(ctx,
		`INSERT INTO assets (item_id, role, path, bytes) VALUES (?, 'cover', ?, 20)`,
		albumID, coverPath); err != nil {
		t.Fatalf("insert asset: %v", err)
	}

	key, err := apitoken.Mint(ctx, db, user.ID, apitoken.KindSubsonic, "test")
	if err != nil {
		t.Fatalf("Mint: %v", err)
	}

	authenticator := auth.NewAuthenticator(db, "vellum_session", 0, false, slog.New(slog.NewTextHandler(io.Discard, nil)))
	h := NewHandlers(db, slog.New(slog.NewTextHandler(io.Discard, nil)), authenticator)
	mux := http.NewServeMux()
	h.Register(mux)
	srv := httptest.NewServer(mux)
	t.Cleanup(srv.Close)

	return srv, &fixture{db: db, userID: user.ID, key: key, libID: libID, album: albumID, file: firstFile, root: root}
}

// authQuery is the preferred t=md5(key+salt) credential form.
func (f *fixture) authQuery() string {
	salt := "abc123"
	sum := md5.Sum([]byte(f.key + salt))
	return "u=alice&s=" + salt + "&t=" + hex.EncodeToString(sum[:]) + "&v=1.16.1&c=test"
}

// get performs a request and returns the recorder.
func get(t *testing.T, url string) *http.Response {
	t.Helper()
	resp, err := http.Get(url)
	if err != nil {
		t.Fatalf("GET %s: %v", url, err)
	}
	return resp
}

func readBody(t *testing.T, resp *http.Response) string {
	t.Helper()
	defer resp.Body.Close()
	b, err := io.ReadAll(resp.Body)
	if err != nil {
		t.Fatalf("read body: %v", err)
	}
	return string(b)
}

// jsonEnvelope decodes a Subsonic JSON response into the root object.
func jsonEnvelope(t *testing.T, body string) map[string]any {
	t.Helper()
	var out map[string]any
	if err := json.Unmarshal([]byte(body), &out); err != nil {
		t.Fatalf("decode json %q: %v", body, err)
	}
	root, ok := out["subsonic-response"].(map[string]any)
	if !ok {
		t.Fatalf("missing subsonic-response in %q", body)
	}
	return root
}

// ── auth ───────────────────────────────────────────────────────────────

// TestAuthTokenForm proves the preferred md5(key+salt) path succeeds.
func TestAuthTokenForm(t *testing.T) {
	srv, f := newFixture(t)
	body := readBody(t, get(t, srv.URL+"/rest/ping.view?"+f.authQuery()+"&f=json"))
	root := jsonEnvelope(t, body)
	if root["status"] != "ok" {
		t.Fatalf("status = %v, want ok; body=%s", root["status"], body)
	}
}

// TestAuthWrongTokenIsEnvelope pins the single most common integration failure:
// a bad token is HTTP 200 with status failed and error code 40, never a 401.
func TestAuthWrongTokenIsEnvelope(t *testing.T) {
	srv, _ := newFixture(t)
	resp := get(t, srv.URL+"/rest/ping.view?u=alice&s=abc123&t=deadbeef&v=1.16.1&c=test&f=json")
	if resp.StatusCode != http.StatusOK {
		t.Errorf("HTTP status = %d, want 200 (errors belong in the envelope)", resp.StatusCode)
	}
	body := readBody(t, resp)
	root := jsonEnvelope(t, body)
	if root["status"] != "failed" {
		t.Fatalf("status = %v, want failed; body=%s", root["status"], body)
	}
	errObj, ok := root["error"].(map[string]any)
	if !ok {
		t.Fatalf("missing error object; body=%s", body)
	}
	if code, _ := errObj["code"].(float64); int(code) != 40 {
		t.Errorf("error code = %v, want 40; body=%s", errObj["code"], body)
	}
}

// TestAuthPlainKey proves p=<key> is accepted (Navidrome compatibility).
func TestAuthPlainKey(t *testing.T) {
	srv, f := newFixture(t)
	body := readBody(t, get(t, srv.URL+"/rest/ping.view?u=alice&p="+f.key+"&v=1.16.1&c=test&f=json"))
	if root := jsonEnvelope(t, body); root["status"] != "ok" {
		t.Fatalf("p=<key> status = %v, want ok; body=%s", root["status"], body)
	}
}

// TestAuthUnknownUserIsCode40 proves an unknown user is the same envelope error.
func TestAuthUnknownUserIsCode40(t *testing.T) {
	srv, _ := newFixture(t)
	body := readBody(t, get(t, srv.URL+"/rest/ping.view?u=nobody&p=x&v=1.16.1&c=test&f=json"))
	root := jsonEnvelope(t, body)
	if root["status"] != "failed" {
		t.Fatalf("unknown user status = %v, want failed", root["status"])
	}
	if code, _ := root["error"].(map[string]any)["code"].(float64); int(code) != 40 {
		t.Errorf("unknown user code = %v, want 40", root["error"])
	}
}

// ── system / browse ────────────────────────────────────────────────────

func TestPingJSONAndXML(t *testing.T) {
	srv, f := newFixture(t)

	jroot := jsonEnvelope(t, readBody(t, get(t, srv.URL+"/rest/ping.view?"+f.authQuery()+"&f=json")))
	if jroot["status"] != "ok" || jroot["version"] != dto.ProtocolVersion || jroot["type"] != dto.ServerType {
		t.Errorf("json envelope = %v", jroot)
	}

	xmlBody := readBody(t, get(t, srv.URL+"/rest/ping.view?"+f.authQuery()+"&f=xml"))
	var parsed struct {
		XMLName xml.Name `xml:"subsonic-response"`
		Status  string   `xml:"status,attr"`
		Version string   `xml:"version,attr"`
	}
	if err := xml.Unmarshal([]byte(xmlBody), &parsed); err != nil {
		t.Fatalf("xml parse: %v; body=%s", err, xmlBody)
	}
	if parsed.Status != "ok" || parsed.Version != dto.ProtocolVersion {
		t.Errorf("xml envelope = %+v", parsed)
	}
}

func TestGetMusicFolders(t *testing.T) {
	srv, f := newFixture(t)
	body := readBody(t, get(t, srv.URL+"/rest/getMusicFolders.view?"+f.authQuery()+"&f=json"))
	root := jsonEnvelope(t, body)
	folders, ok := root["musicFolders"].(map[string]any)
	if !ok {
		t.Fatalf("missing musicFolders; body=%s", body)
	}
	list, ok := folders["musicFolder"].([]any)
	if !ok || len(list) != 1 {
		t.Fatalf("musicFolder = %v, want one entry; body=%s", folders["musicFolder"], body)
	}
	if list[0].(map[string]any)["name"] != "Music" {
		t.Errorf("folder = %v", list[0])
	}
}

func TestGetIndexesAndArtists(t *testing.T) {
	srv, f := newFixture(t)

	body := readBody(t, get(t, srv.URL+"/rest/getArtists.view?"+f.authQuery()+"&f=json"))
	root := jsonEnvelope(t, body)
	artists := root["artists"].(map[string]any)
	indexes := artists["index"].([]any)
	if len(indexes) != 1 {
		t.Fatalf("indexes = %v", indexes)
	}
	first := indexes[0].(map[string]any)
	if first["name"] != "A" {
		t.Errorf("index name = %v, want A (The Artist)", first["name"])
	}
	if first["artist"].([]any)[0].(map[string]any)["name"] != "The Artist" {
		t.Errorf("artist = %v", first["artist"])
	}

	// getIndexes returns the same index but a leaner artist element.
	body = readBody(t, get(t, srv.URL+"/rest/getIndexes.view?"+f.authQuery()+"&f=json"))
	root = jsonEnvelope(t, body)
	if _, ok := root["indexes"]; !ok {
		t.Fatalf("missing indexes; body=%s", body)
	}
}

func TestSearch3(t *testing.T) {
	srv, f := newFixture(t)
	body := readBody(t, get(t, srv.URL+"/rest/search3.view?"+f.authQuery()+"&query=Artist&f=json"))
	root := jsonEnvelope(t, body)
	result := root["searchResult3"].(map[string]any)

	albums := result["album"].([]any)
	if len(albums) != 1 {
		t.Fatalf("albums = %v, want one; body=%s", albums, body)
	}
	if albums[0].(map[string]any)["name"] != "Album" {
		t.Errorf("album = %v", albums[0])
	}
	if len(result["song"].([]any)) != 3 {
		t.Errorf("songs = %v, want three", result["song"])
	}
	if len(result["artist"].([]any)) != 1 {
		t.Errorf("artists = %v, want one", result["artist"])
	}
}

func TestGetAlbumList2Newest(t *testing.T) {
	srv, f := newFixture(t)
	body := readBody(t, get(t, srv.URL+"/rest/getAlbumList2.view?"+f.authQuery()+"&type=newest&f=json"))
	root := jsonEnvelope(t, body)
	list := root["albumList2"].(map[string]any)
	albums := list["album"].([]any)
	if len(albums) != 1 {
		t.Fatalf("albums = %v; body=%s", albums, body)
	}
	if albums[0].(map[string]any)["songCount"].(float64) != 3 {
		t.Errorf("songCount = %v, want 3", albums[0].(map[string]any)["songCount"])
	}
}

func TestGetAlbumAndSong(t *testing.T) {
	srv, f := newFixture(t)

	body := readBody(t, get(t, srv.URL+"/rest/getAlbum.view?"+f.authQuery()+"&id="+dto.AlbumID(f.album)+"&f=json"))
	root := jsonEnvelope(t, body)
	album := root["album"].(map[string]any)
	if len(album["song"].([]any)) != 3 {
		t.Errorf("getAlbum songs = %v", album["song"])
	}

	body = readBody(t, get(t, srv.URL+"/rest/getSong.view?"+f.authQuery()+"&id="+dto.FileID(f.file)+"&f=json"))
	root = jsonEnvelope(t, body)
	song := root["song"].(map[string]any)
	if song["album"] != "Album" || song["artist"] != "The Artist" {
		t.Errorf("song = %v", song)
	}
}

func TestGetMusicDirectory(t *testing.T) {
	srv, f := newFixture(t)
	body := readBody(t, get(t, srv.URL+"/rest/getMusicDirectory.view?"+f.authQuery()+"&id="+dto.FolderID(f.libID)+"&f=json"))
	root := jsonEnvelope(t, body)
	dir := root["directory"].(map[string]any)
	children := dir["child"].([]any)
	if len(children) != 1 || children[0].(map[string]any)["isDir"] != true {
		t.Fatalf("root children = %v; body=%s", children, body)
	}
	// Drill into the album directory and confirm its songs appear.
	body = readBody(t, get(t, srv.URL+"/rest/getMusicDirectory.view?"+f.authQuery()+"&id="+dto.AlbumID(f.album)+"&f=json"))
	root = jsonEnvelope(t, body)
	dir = root["directory"].(map[string]any)
	if len(dir["child"].([]any)) != 3 {
		t.Errorf("album directory children = %v", dir["child"])
	}
}

func TestGetUser(t *testing.T) {
	srv, f := newFixture(t)
	body := readBody(t, get(t, srv.URL+"/rest/getUser.view?"+f.authQuery()+"&f=json"))
	root := jsonEnvelope(t, body)
	user := root["user"].(map[string]any)
	if user["username"] != "alice" {
		t.Errorf("username = %v", user["username"])
	}
	if user["adminRole"] != false || user["streamRole"] != true {
		t.Errorf("roles = %v", user)
	}
}

func TestGetPlaylistsEmpty(t *testing.T) {
	srv, f := newFixture(t)
	body := readBody(t, get(t, srv.URL+"/rest/getPlaylists.view?"+f.authQuery()+"&f=json"))
	root := jsonEnvelope(t, body)
	pl, ok := root["playlists"].(map[string]any)
	if !ok {
		t.Fatalf("missing playlists; body=%s", body)
	}
	if list, ok := pl["playlist"].([]any); !ok || len(list) != 0 {
		t.Errorf("playlist = %v, want empty array", pl["playlist"])
	}
}

// ── media ──────────────────────────────────────────────────────────────

func TestStreamRawAndRange(t *testing.T) {
	srv, f := newFixture(t)

	resp := get(t, srv.URL+"/rest/stream.view?"+f.authQuery()+"&id="+dto.FileID(f.file)+"&format=raw")
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("stream status = %d, want 200", resp.StatusCode)
	}
	if got := readBody(t, resp); len(got) != 100 {
		t.Fatalf("stream body length = %d, want 100", len(got))
	}

	req, _ := http.NewRequest(http.MethodGet,
		srv.URL+"/rest/stream.view?"+f.authQuery()+"&id="+dto.FileID(f.file)+"&format=raw", nil)
	req.Header.Set("Range", "bytes=0-9")
	rangeResp, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatalf("range request: %v", err)
	}
	defer rangeResp.Body.Close()
	if rangeResp.StatusCode != http.StatusPartialContent {
		t.Fatalf("range status = %d, want 206", rangeResp.StatusCode)
	}
	if cr := rangeResp.Header.Get("Content-Range"); cr != "bytes 0-9/100" {
		t.Errorf("Content-Range = %q, want bytes 0-9/100", cr)
	}
	body, _ := io.ReadAll(rangeResp.Body)
	if len(body) != 10 {
		t.Errorf("range body length = %d, want 10", len(body))
	}
}

// TestStreamRejectsTranscode proves a non-raw format is refused honestly rather
// than silently served untranscoded.
func TestStreamRejectsTranscode(t *testing.T) {
	srv, f := newFixture(t)
	body := readBody(t, get(t, srv.URL+"/rest/stream.view?"+f.authQuery()+"&id="+dto.FileID(f.file)+"&format=mp3&f=json"))
	root := jsonEnvelope(t, body)
	if root["status"] != "failed" {
		t.Fatalf("format=mp3 status = %v, want failed; body=%s", root["status"], body)
	}
	if !strings.Contains(root["error"].(map[string]any)["message"].(string), "transcod") {
		t.Errorf("error message = %v, want a transcoding refusal", root["error"])
	}
}

func TestGetCoverArt(t *testing.T) {
	srv, f := newFixture(t)
	resp := get(t, srv.URL+"/rest/getCoverArt.view?"+f.authQuery()+"&id="+dto.AlbumID(f.album))
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("cover status = %d, want 200", resp.StatusCode)
	}
	if got := readBody(t, resp); !strings.HasPrefix(got, "\x89PNG") {
		t.Errorf("cover bytes = %q", got)
	}
}

// TestScrobbleWritesProgress proves scrobble lands in the progress store.
func TestScrobbleWritesProgress(t *testing.T) {
	srv, f := newFixture(t)
	body := readBody(t, get(t, srv.URL+"/rest/scrobble.view?"+f.authQuery()+
		"&id="+dto.FileID(f.file)+"&submission=true&position=30000&f=json"))
	if root := jsonEnvelope(t, body); root["status"] != "ok" {
		t.Fatalf("scrobble status = %v; body=%s", root["status"], body)
	}

	var position, duration int64
	if err := f.db.QueryRow(
		`SELECT position, duration FROM progress WHERE user_id = ? AND item_id = ? AND file_id = ?`,
		f.userID, f.album, f.file).Scan(&position, &duration); err != nil {
		t.Fatalf("progress row: %v", err)
	}
	if position != 30000 || duration != 60000 {
		t.Errorf("progress = (%d,%d), want (30000,60000)", position, duration)
	}
}

// TestAccessScopedToGrants proves a user without a grant cannot stream.
func TestAccessScopedToGrants(t *testing.T) {
	srv, f := newFixture(t)
	// Revoke the grant, then request the same file.
	if _, err := f.db.Exec(`DELETE FROM library_grants WHERE user_id = ?`, f.userID); err != nil {
		t.Fatal(err)
	}
	body := readBody(t, get(t, srv.URL+"/rest/stream.view?"+f.authQuery()+"&id="+dto.FileID(f.file)+"&format=raw&f=json"))
	root := jsonEnvelope(t, body)
	if root["status"] != "failed" {
		t.Fatalf("revoked grant stream status = %v, want failed; body=%s", root["status"], body)
	}
}