package httpapi

import (
	"database/sql"
	"encoding/json"
	"errors"
	"log"
	"net/http"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"github.com/go-chi/chi/v5"

	"github.com/benya/temporserv/internal/auth"
	"github.com/benya/temporserv/internal/config"
	"github.com/benya/temporserv/internal/library"
	"github.com/benya/temporserv/internal/playlist"
	"github.com/benya/temporserv/internal/scanner"
	"github.com/benya/temporserv/internal/subsonic"
)

type app struct {
	auth      *auth.Service
	library   *library.Service
	playlists *playlist.Service
	scanner   *scanner.Service
}

func NewRouter(cfg config.Config, database *sql.DB, scanService *scanner.Service) http.Handler {
	application := app{
		auth:      auth.NewService(database, cfg.EncryptionKey),
		library:   library.NewService(database),
		playlists: playlist.NewService(database),
		scanner:   scanService,
	}

	r := chi.NewRouter()
	r.Use(requestLogger)
	r.Use(recoverer)
	r.Use(cors(cfg.CORSOrigins))

	r.Get("/health", func(w http.ResponseWriter, r *http.Request) {
		writeJSON(w, http.StatusOK, map[string]any{
			"status": "ok",
			"time":   time.Now().UTC(),
			"env":    cfg.AppEnv,
		})
	})

	r.Route("/api", func(api chi.Router) {
		api.Post("/auth/login", application.login)
		api.Post("/auth/logout", application.logout)

		api.Group(func(private chi.Router) {
			private.Use(application.requireAuth)
			private.Get("/me", application.me)
			private.Get("/home", application.home)
			private.Get("/recently-played", application.recentlyPlayed)
			private.Get("/artists", application.artists)
			private.Get("/artists/{id}", application.artistByID)
			private.Get("/albums", application.albums)
			private.Get("/albums/{id}", application.albumByID)
			private.Get("/tracks", application.tracks)
			private.Get("/tracks/{id}", application.trackByID)
			private.Get("/search", application.search)
			private.Get("/favorites", application.favorites)
			private.Post("/favorites", application.starFavorites)
			private.Delete("/favorites", application.unstarFavorites)
			private.Get("/playlists", application.playlistsList)
			private.Post("/playlists", application.createPlaylist)
			private.Get("/playlists/{id}", application.playlistByID)
			private.Patch("/playlists/{id}", application.updatePlaylist)
			private.Delete("/playlists/{id}", application.deletePlaylist)
			private.Get("/admin/scan-status", application.scanStatus)
			private.Post("/admin/scan", application.scanLibrary)
			private.Post("/history/scrobble", application.recordPlayEvent)
		})

		api.Get("/cover-art/{id}", application.coverArt)
		api.Get("/stream/{id}", application.streamTrack)
	})

	r.Route("/rest", func(rest chi.Router) {
		rest.Get("/ping.view", func(w http.ResponseWriter, r *http.Request) {
			writeJSON(w, http.StatusOK, subsonic.PingResponse())
		})
		rest.Get("/getLicense.view", func(w http.ResponseWriter, r *http.Request) {
			writeJSON(w, http.StatusOK, subsonic.PingResponse())
		})
		rest.Group(func(authed chi.Router) {
			authed.Use(application.requireSubsonicAuth)
			authed.Get("/getArtists.view", application.subsonicArtists)
			authed.Get("/getArtist.view", application.subsonicArtistByID)
			authed.Get("/getAlbum.view", application.subsonicAlbumByID)
			authed.Get("/getSong.view", application.subsonicSongByID)
			authed.Get("/getRandomSongs.view", application.subsonicRandomSongs)
			authed.Get("/search3.view", application.subsonicSearch3)
			authed.Get("/getStarred2.view", application.subsonicStarred2)
			authed.Get("/star.view", application.subsonicStar)
			authed.Get("/unstar.view", application.subsonicUnstar)
			authed.Get("/getPlaylists.view", application.subsonicPlaylists)
			authed.Get("/getPlaylist.view", application.subsonicPlaylistByID)
			authed.Get("/createPlaylist.view", application.subsonicCreatePlaylist)
			authed.Get("/updatePlaylist.view", application.subsonicUpdatePlaylist)
			authed.Get("/getScanStatus.view", application.subsonicScanStatus)
			authed.Get("/startScan.view", application.subsonicStartScan)
			authed.Get("/getCoverArt.view", application.subsonicCoverArt)
			authed.Get("/stream.view", application.subsonicStream)
			authed.Get("/scrobble.view", application.subsonicScrobble)
		})
	})

	if frontendRoot := detectFrontendRoot(); frontendRoot != "" {
		r.NotFound(spaHandler(frontendRoot))
	} else {
		log.Printf("frontend assets not found; API routes are available, but web UI is not being served")
	}

	return r
}

func (a app) login(w http.ResponseWriter, r *http.Request) {
	var payload struct {
		Username string `json:"username"`
		Password string `json:"password"`
	}

	if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid request body"})
		return
	}

	session, err := a.auth.Login(r.Context(), payload.Username, payload.Password)
	if err != nil {
		if errors.Is(err, auth.ErrInvalidCredentials) {
			writeJSON(w, http.StatusUnauthorized, map[string]string{"error": "invalid credentials"})
			return
		}
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "login failed"})
		return
	}

	writeJSON(w, http.StatusOK, session)
}

func (a app) logout(w http.ResponseWriter, r *http.Request) {
	token := strings.TrimSpace(strings.TrimPrefix(r.Header.Get("Authorization"), "Bearer "))
	if token == "" {
		var payload struct {
			Token string `json:"token"`
		}
		if err := json.NewDecoder(r.Body).Decode(&payload); err == nil {
			token = strings.TrimSpace(payload.Token)
		}
	}

	if err := a.auth.Logout(r.Context(), token); err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "logout failed"})
		return
	}

	writeJSON(w, http.StatusOK, map[string]any{"status": "ok"})
}

func (a app) me(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	writeJSON(w, http.StatusOK, user)
}

func (a app) home(w http.ResponseWriter, r *http.Request) {
	home, err := a.library.Home(r.Context())
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load home"})
		return
	}
	writeJSON(w, http.StatusOK, home)
}

func (a app) artists(w http.ResponseWriter, r *http.Request) {
	items, err := a.library.Artists(r.Context(), 500)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load artists"})
		return
	}
	writeJSON(w, http.StatusOK, map[string]any{"items": items})
}

func (a app) recentlyPlayed(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	items, err := a.library.RecentTracks(r.Context(), user.ID, 24)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load recent tracks"})
		return
	}
	writeJSON(w, http.StatusOK, map[string]any{"items": items})
}

func (a app) artistByID(w http.ResponseWriter, r *http.Request) {
	item, err := a.library.ArtistByID(r.Context(), chi.URLParam(r, "id"))
	if err != nil {
		if errors.Is(err, library.ErrNotFound) {
			writeJSON(w, http.StatusNotFound, map[string]string{"error": "artist not found"})
			return
		}
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load artist"})
		return
	}
	writeJSON(w, http.StatusOK, item)
}

func (a app) albums(w http.ResponseWriter, r *http.Request) {
	items, err := a.library.Albums(r.Context(), 1000)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load albums"})
		return
	}
	writeJSON(w, http.StatusOK, map[string]any{"items": items})
}

func (a app) albumByID(w http.ResponseWriter, r *http.Request) {
	item, err := a.library.AlbumByID(r.Context(), chi.URLParam(r, "id"))
	if err != nil {
		if errors.Is(err, library.ErrNotFound) {
			writeJSON(w, http.StatusNotFound, map[string]string{"error": "album not found"})
			return
		}
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load album"})
		return
	}
	writeJSON(w, http.StatusOK, item)
}

func (a app) tracks(w http.ResponseWriter, r *http.Request) {
	items, err := a.library.Tracks(r.Context(), 200)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load tracks"})
		return
	}
	writeJSON(w, http.StatusOK, map[string]any{"items": items})
}

func (a app) trackByID(w http.ResponseWriter, r *http.Request) {
	item, err := a.library.TrackByID(r.Context(), chi.URLParam(r, "id"))
	if err != nil {
		if errors.Is(err, library.ErrNotFound) {
			writeJSON(w, http.StatusNotFound, map[string]string{"error": "track not found"})
			return
		}
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load track"})
		return
	}
	writeJSON(w, http.StatusOK, item)
}

func (a app) search(w http.ResponseWriter, r *http.Request) {
	query := strings.TrimSpace(r.URL.Query().Get("q"))
	if query == "" {
		writeJSON(w, http.StatusOK, library.SearchResults{})
		return
	}

	results, err := a.library.Search(r.Context(), query, 20)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "search failed"})
		return
	}
	writeJSON(w, http.StatusOK, results)
}

func (a app) favorites(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	results, err := a.library.Starred(r.Context(), user.ID)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load favorites"})
		return
	}
	writeJSON(w, http.StatusOK, results)
}

func (a app) starFavorites(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	var payload struct {
		TrackIDs  []string `json:"trackIds"`
		AlbumIDs  []string `json:"albumIds"`
		ArtistIDs []string `json:"artistIds"`
	}
	if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid request body"})
		return
	}
	if err := a.library.Star(r.Context(), user.ID, payload.TrackIDs, payload.AlbumIDs, payload.ArtistIDs); err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to star favorites"})
		return
	}
	results, err := a.library.Starred(r.Context(), user.ID)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load favorites"})
		return
	}
	writeJSON(w, http.StatusOK, results)
}

func (a app) unstarFavorites(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	var payload struct {
		TrackIDs  []string `json:"trackIds"`
		AlbumIDs  []string `json:"albumIds"`
		ArtistIDs []string `json:"artistIds"`
	}
	if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid request body"})
		return
	}
	if err := a.library.Unstar(r.Context(), user.ID, payload.TrackIDs, payload.AlbumIDs, payload.ArtistIDs); err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to unstar favorites"})
		return
	}
	results, err := a.library.Starred(r.Context(), user.ID)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load favorites"})
		return
	}
	writeJSON(w, http.StatusOK, results)
}

func (a app) playlistsList(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	items, err := a.playlists.List(r.Context(), user.ID)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load playlists"})
		return
	}
	writeJSON(w, http.StatusOK, map[string]any{"items": items})
}

func (a app) playlistByID(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	item, err := a.playlists.ByID(r.Context(), user.ID, chi.URLParam(r, "id"))
	if err != nil {
		if errors.Is(err, playlist.ErrNotFound) {
			writeJSON(w, http.StatusNotFound, map[string]string{"error": "playlist not found"})
			return
		}
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load playlist"})
		return
	}
	writeJSON(w, http.StatusOK, item)
}

func (a app) createPlaylist(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	var payload playlist.CreateInput
	if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid request body"})
		return
	}

	item, err := a.playlists.Create(r.Context(), user.ID, payload)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to create playlist"})
		return
	}
	writeJSON(w, http.StatusCreated, item)
}

func (a app) updatePlaylist(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	var payload playlist.UpdateInput
	if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid request body"})
		return
	}

	item, err := a.playlists.Update(r.Context(), user.ID, chi.URLParam(r, "id"), payload)
	if err != nil {
		if errors.Is(err, playlist.ErrNotFound) {
			writeJSON(w, http.StatusNotFound, map[string]string{"error": "playlist not found"})
			return
		}
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to update playlist"})
		return
	}
	writeJSON(w, http.StatusOK, item)
}

func (a app) deletePlaylist(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	err := a.playlists.Delete(r.Context(), user.ID, chi.URLParam(r, "id"))
	if err != nil {
		if errors.Is(err, playlist.ErrNotFound) {
			writeJSON(w, http.StatusNotFound, map[string]string{"error": "playlist not found"})
			return
		}
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to delete playlist"})
		return
	}
	w.WriteHeader(http.StatusNoContent)
}

func (a app) subsonicArtists(w http.ResponseWriter, r *http.Request) {
	artists, err := a.library.Artists(r.Context(), 1000)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, subsonic.PingResponse())
		return
	}
	writeJSON(w, http.StatusOK, subsonic.ArtistsResponse(artists))
}

func (a app) subsonicRandomSongs(w http.ResponseWriter, r *http.Request) {
	size := 20
	if raw := strings.TrimSpace(r.URL.Query().Get("size")); raw != "" {
		if parsed := parsePositiveInt(raw); parsed > 0 {
			size = parsed
		}
	}
	tracks, err := a.library.Tracks(r.Context(), size)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, subsonic.PingResponse())
		return
	}
	writeJSON(w, http.StatusOK, subsonic.RandomSongsResponse(tracks))
}

func (a app) subsonicSearch3(w http.ResponseWriter, r *http.Request) {
	query := strings.TrimSpace(r.URL.Query().Get("query"))
	if query == "" {
		writeJSON(w, http.StatusOK, subsonic.Search3Response(library.SearchResults{}))
		return
	}

	count := parsePositiveInt(r.URL.Query().Get("songCount"))
	if count == 0 {
		count = 20
	}

	results, err := a.library.Search(r.Context(), query, count)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, subsonic.ErrorResponse(0, "search failed"))
		return
	}
	writeJSON(w, http.StatusOK, subsonic.Search3Response(results))
}

func (a app) subsonicStarred2(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	results, err := a.library.Starred(r.Context(), user.ID)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, subsonic.ErrorResponse(0, "failed to load starred items"))
		return
	}
	writeJSON(w, http.StatusOK, subsonic.Starred2Response(results))
}

func (a app) subsonicStar(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	if err := a.library.Star(r.Context(), user.ID, readMultiValue(r, "id"), readMultiValue(r, "albumId"), readMultiValue(r, "artistId")); err != nil {
		writeJSON(w, http.StatusInternalServerError, subsonic.ErrorResponse(0, "failed to star items"))
		return
	}
	writeJSON(w, http.StatusOK, subsonic.PingResponse())
}

func (a app) subsonicUnstar(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	if err := a.library.Unstar(r.Context(), user.ID, readMultiValue(r, "id"), readMultiValue(r, "albumId"), readMultiValue(r, "artistId")); err != nil {
		writeJSON(w, http.StatusInternalServerError, subsonic.ErrorResponse(0, "failed to unstar items"))
		return
	}
	writeJSON(w, http.StatusOK, subsonic.PingResponse())
}

func (a app) subsonicPlaylists(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	items, err := a.playlists.List(r.Context(), user.ID)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, subsonic.ErrorResponse(0, "failed to load playlists"))
		return
	}
	writeJSON(w, http.StatusOK, subsonic.PlaylistsResponse(user.Username, items))
}

func (a app) subsonicPlaylistByID(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	item, err := a.playlists.ByID(r.Context(), user.ID, strings.TrimSpace(r.URL.Query().Get("id")))
	if err != nil {
		if errors.Is(err, playlist.ErrNotFound) {
			writeJSON(w, http.StatusNotFound, subsonic.ErrorResponse(70, "playlist not found"))
			return
		}
		writeJSON(w, http.StatusInternalServerError, subsonic.ErrorResponse(0, "failed to load playlist"))
		return
	}
	writeJSON(w, http.StatusOK, subsonic.PlaylistResponse(user.Username, item))
}

func (a app) subsonicCreatePlaylist(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	item, err := a.playlists.Create(r.Context(), user.ID, playlist.CreateInput{
		Name:     strings.TrimSpace(r.URL.Query().Get("name")),
		TrackIDs: readMultiValue(r, "songId"),
	})
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, subsonic.ErrorResponse(0, "failed to create playlist"))
		return
	}
	writeJSON(w, http.StatusOK, subsonic.PlaylistResponse(user.Username, item))
}

func (a app) subsonicUpdatePlaylist(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	item, err := a.playlists.Update(r.Context(), user.ID, strings.TrimSpace(r.URL.Query().Get("playlistId")), playlist.UpdateInput{
		Name:            optionalString(r.URL.Query().Get("name")),
		Comment:         optionalString(r.URL.Query().Get("comment")),
		Public:          optionalBool(r.URL.Query().Get("public")),
		AddTrackIDs:     readMultiValue(r, "songIdToAdd"),
		RemovePositions: playlist.ParseIndices(readMultiValue(r, "songIndexToRemove")),
	})
	if err != nil {
		if errors.Is(err, playlist.ErrNotFound) {
			writeJSON(w, http.StatusNotFound, subsonic.ErrorResponse(70, "playlist not found"))
			return
		}
		writeJSON(w, http.StatusInternalServerError, subsonic.ErrorResponse(0, "failed to update playlist"))
		return
	}
	writeJSON(w, http.StatusOK, subsonic.PlaylistResponse(user.Username, item))
}

func (a app) subsonicArtistByID(w http.ResponseWriter, r *http.Request) {
	item, err := a.library.ArtistByID(r.Context(), r.URL.Query().Get("id"))
	if err != nil {
		if errors.Is(err, library.ErrNotFound) {
			writeJSON(w, http.StatusNotFound, subsonic.ErrorResponse(70, "artist not found"))
			return
		}
		writeJSON(w, http.StatusInternalServerError, subsonic.ErrorResponse(0, "failed to load artist"))
		return
	}
	writeJSON(w, http.StatusOK, subsonic.ArtistResponse(item))
}

func (a app) subsonicAlbumByID(w http.ResponseWriter, r *http.Request) {
	item, err := a.library.AlbumByID(r.Context(), r.URL.Query().Get("id"))
	if err != nil {
		if errors.Is(err, library.ErrNotFound) {
			writeJSON(w, http.StatusNotFound, subsonic.ErrorResponse(70, "album not found"))
			return
		}
		writeJSON(w, http.StatusInternalServerError, subsonic.ErrorResponse(0, "failed to load album"))
		return
	}
	writeJSON(w, http.StatusOK, subsonic.AlbumResponse(item))
}

func (a app) subsonicSongByID(w http.ResponseWriter, r *http.Request) {
	item, err := a.library.TrackByID(r.Context(), r.URL.Query().Get("id"))
	if err != nil {
		if errors.Is(err, library.ErrNotFound) {
			writeJSON(w, http.StatusNotFound, subsonic.ErrorResponse(70, "song not found"))
			return
		}
		writeJSON(w, http.StatusInternalServerError, subsonic.ErrorResponse(0, "failed to load song"))
		return
	}
	writeJSON(w, http.StatusOK, subsonic.SongResponse(item))
}

func (a app) scanLibrary(w http.ResponseWriter, r *http.Request) {
	result, err := a.scanner.Scan(r.Context())
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, result)
}

func (a app) recordPlayEvent(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	var payload struct {
		TrackID    string `json:"trackId"`
		Submission bool   `json:"submission"`
		Time       int64  `json:"time"`
		ClientName string `json:"clientName"`
	}
	if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid request body"})
		return
	}
	if strings.TrimSpace(payload.TrackID) == "" {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "trackId is required"})
		return
	}

	playedAt := time.Now().UTC()
	if payload.Time > 0 {
		playedAt = time.UnixMilli(payload.Time).UTC()
	}
	eventType := "play"
	if payload.Submission {
		eventType = "scrobble"
	}

	if err := a.library.RecordPlayEvent(r.Context(), user.ID, payload.TrackID, eventType, payload.ClientName, playedAt, payload.Submission); err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to record play event"})
		return
	}

	writeJSON(w, http.StatusOK, map[string]any{"status": "ok"})
}

func (a app) scanStatus(w http.ResponseWriter, r *http.Request) {
	writeJSON(w, http.StatusOK, a.scanner.Status())
}

func (a app) coverArt(w http.ResponseWriter, r *http.Request) {
	token := r.URL.Query().Get("token")
	if token == "" {
		token = strings.TrimSpace(strings.TrimPrefix(r.Header.Get("Authorization"), "Bearer "))
	}
	if _, err := a.auth.CurrentUserByToken(r.Context(), token); err != nil {
		writeJSON(w, http.StatusUnauthorized, map[string]string{"error": "unauthorized"})
		return
	}
	a.serveCoverArtByID(w, r, chi.URLParam(r, "id"))
}

func (a app) streamTrack(w http.ResponseWriter, r *http.Request) {
	token := r.URL.Query().Get("token")
	if token == "" {
		token = strings.TrimSpace(strings.TrimPrefix(r.Header.Get("Authorization"), "Bearer "))
	}

	if _, err := a.auth.CurrentUserByToken(r.Context(), token); err != nil {
		writeJSON(w, http.StatusUnauthorized, map[string]string{"error": "unauthorized"})
		return
	}
	a.serveTrackByID(w, r, chi.URLParam(r, "id"))
}

func (a app) subsonicScanStatus(w http.ResponseWriter, r *http.Request) {
	writeJSON(w, http.StatusOK, subsonic.ScanStatusResponse(a.scanner.Status()))
}

func (a app) subsonicStartScan(w http.ResponseWriter, r *http.Request) {
	if started := a.scanner.ScanAsync(r.Context()); !started {
		writeJSON(w, http.StatusConflict, subsonic.ErrorResponse(0, "scan already running"))
		return
	}
	writeJSON(w, http.StatusOK, subsonic.ScanStatusResponse(a.scanner.Status()))
}

func (a app) subsonicCoverArt(w http.ResponseWriter, r *http.Request) {
	a.serveCoverArtByID(w, r, r.URL.Query().Get("id"))
}

func (a app) subsonicStream(w http.ResponseWriter, r *http.Request) {
	a.serveTrackByID(w, r, r.URL.Query().Get("id"))
}

func (a app) subsonicScrobble(w http.ResponseWriter, r *http.Request) {
	user := currentUserFromContext(r)
	trackIDs := readMultiValue(r, "id")
	if len(trackIDs) == 0 {
		writeJSON(w, http.StatusBadRequest, subsonic.ErrorResponse(10, "missing track id"))
		return
	}

	submission := false
	if value := strings.TrimSpace(r.URL.Query().Get("submission")); value != "" {
		submission = value == "true" || value == "1"
	}
	timestamp := time.Now().UTC()
	if raw := strings.TrimSpace(r.URL.Query().Get("time")); raw != "" {
		if parsed, err := strconv.ParseInt(raw, 10, 64); err == nil && parsed > 0 {
			// Subsonic sends seconds since epoch.
			timestamp = time.Unix(parsed, 0).UTC()
		}
	}

	for _, trackID := range trackIDs {
		eventType := "play"
		if submission {
			eventType = "scrobble"
		}
		if err := a.library.RecordPlayEvent(r.Context(), user.ID, trackID, eventType, "subsonic", timestamp, submission); err != nil {
			writeJSON(w, http.StatusInternalServerError, subsonic.ErrorResponse(0, "failed to record scrobble"))
			return
		}
	}

	writeJSON(w, http.StatusOK, subsonic.PingResponse())
}

func (a app) serveCoverArtByID(w http.ResponseWriter, r *http.Request, id string) {
	path, err := a.library.CoverArtPathByEntityID(r.Context(), id)
	if err != nil {
		if errors.Is(err, library.ErrNotFound) {
			writeJSON(w, http.StatusNotFound, map[string]string{"error": "cover art not found"})
			return
		}
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load cover art"})
		return
	}

	file, err := os.Open(path)
	if err != nil {
		writeJSON(w, http.StatusNotFound, map[string]string{"error": "cover art file not available"})
		return
	}
	defer file.Close()

	info, err := file.Stat()
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to stat cover art"})
		return
	}

	w.Header().Set("Content-Type", detectImageContentType(path))
	http.ServeContent(w, r, info.Name(), info.ModTime(), file)
}

func (a app) serveTrackByID(w http.ResponseWriter, r *http.Request, id string) {
	track, err := a.library.TrackByID(r.Context(), id)
	if err != nil {
		if errors.Is(err, library.ErrNotFound) {
			writeJSON(w, http.StatusNotFound, map[string]string{"error": "track not found"})
			return
		}
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to load track"})
		return
	}

	file, err := os.Open(track.FilePath)
	if err != nil {
		writeJSON(w, http.StatusNotFound, map[string]string{"error": "audio file not available"})
		return
	}
	defer file.Close()

	info, err := file.Stat()
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to stat file"})
		return
	}

	w.Header().Set("Content-Type", track.ContentType)
	http.ServeContent(w, r, info.Name(), info.ModTime(), file)
}

func detectImageContentType(path string) string {
	lower := strings.ToLower(path)
	switch {
	case strings.HasSuffix(lower, ".jpg"), strings.HasSuffix(lower, ".jpeg"):
		return "image/jpeg"
	case strings.HasSuffix(lower, ".png"):
		return "image/png"
	default:
		return "application/octet-stream"
	}
}

func writeJSON(w http.ResponseWriter, status int, payload any) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	_ = json.NewEncoder(w).Encode(payload)
}

func readMultiValue(r *http.Request, key string) []string {
	values := r.URL.Query()[key]
	if len(values) > 0 {
		return values
	}
	if single := strings.TrimSpace(r.URL.Query().Get(key)); single != "" {
		return []string{single}
	}
	return nil
}

func parsePositiveInt(raw string) int {
	value, err := strconv.Atoi(strings.TrimSpace(raw))
	if err != nil || value < 1 {
		return 0
	}
	return value
}

func optionalString(raw string) *string {
	if strings.TrimSpace(raw) == "" {
		return nil
	}
	value := strings.TrimSpace(raw)
	return &value
}

func optionalBool(raw string) *bool {
	value := strings.ToLower(strings.TrimSpace(raw))
	switch value {
	case "true", "1":
		result := true
		return &result
	case "false", "0":
		result := false
		return &result
	default:
		return nil
	}
}

func spaHandler(root string) http.HandlerFunc {
	fileServer := http.FileServer(http.Dir(root))
	indexPath := filepath.Join(root, "index.html")

	return func(w http.ResponseWriter, r *http.Request) {
		if strings.HasPrefix(r.URL.Path, "/api") || strings.HasPrefix(r.URL.Path, "/rest") || strings.HasPrefix(r.URL.Path, "/health") {
			http.NotFound(w, r)
			return
		}

		cleanPath := filepath.Clean(strings.TrimPrefix(r.URL.Path, "/"))
		if cleanPath == "." {
			http.ServeFile(w, r, indexPath)
			return
		}

		fullPath := filepath.Join(root, cleanPath)
		if info, err := os.Stat(fullPath); err == nil && !info.IsDir() {
			fileServer.ServeHTTP(w, r)
			return
		}

		http.ServeFile(w, r, indexPath)
	}
}

func detectFrontendRoot() string {
	candidates := []string{
		"./apps/web/dist",
		"./web",
		filepath.Join(".", "apps", "web", "dist"),
		filepath.Join(".", "web"),
	}

	for _, candidate := range candidates {
		info, err := os.Stat(candidate)
		if err == nil && info.IsDir() {
			return candidate
		}
	}

	return ""
}