import 'package:freezer/main.dart';
import 'package:sqflite/sqflite.dart';
import 'package:disk_space_plus/disk_space_plus.dart';
import 'package:filesize/filesize.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:fluttertoast/fluttertoast.dart';
import 'package:freezer/api/deezer.dart';
import 'package:freezer/api/definitions.dart';
import 'package:freezer/settings.dart';
import 'package:path_provider/path_provider.dart';
import 'package:path/path.dart' as p;
import 'package:permission_handler/permission_handler.dart';
import 'package:freezer/translations.i18n.dart';

import 'dart:io';
import 'dart:async';

final downloadManager = DownloadManager();

class DownloadManager {
  // DownloadManager currently only supports android
  static bool get isSupported => Platform.isAndroid;

  //Platform channels
  static MethodChannel platform = const MethodChannel('f.f.freezer/native');
  static EventChannel eventChannel =
      const EventChannel('f.f.freezer/downloads');

  bool running = false;
  int? queueSize = 0;

  StreamController serviceEvents = StreamController.broadcast();
  late String offlinePath;
  late Database db;

  //Start/Resume downloads
  Future start() async {
    if (!isSupported) return;

    //Returns whether service is bound or not, the delay is really shitty/hacky way, until i find a real solution
    await updateServiceSettings();
    await platform.invokeMethod('start');
  }

  //Stop/Pause downloads
  Future stop() async {
    if (!isSupported) return;

    await platform.invokeMethod('stop');
  }

  Future init() async {
    if (!isSupported) return;
    //Remove old DB
    File oldDbFile = File(p.join((await getDatabasesPath()), 'offline.db'));
    if (await oldDbFile.exists()) {
      await oldDbFile.delete();
    }

    String dbPath = p.join((await getDatabasesPath()), 'offline2.db');
    //Open db
    db = await openDatabase(dbPath, version: 1,
        onCreate: (Database db, int version) async {
      Batch b = db.batch();
      //Create tables, if doesn't exit
      b.execute("""CREATE TABLE Tracks (
        id TEXT PRIMARY KEY, title TEXT, album TEXT, artists TEXT, duration INTEGER, albumArt TEXT, trackNumber INTEGER, offline INTEGER, lyrics TEXT, favorite INTEGER, diskNumber INTEGER, explicit INTEGER)""");
      b.execute("""CREATE TABLE Albums (
        id TEXT PRIMARY KEY, title TEXT, artists TEXT, tracks TEXT, art TEXT, fans INTEGER, offline INTEGER, library INTEGER, type INTEGER, releaseDate TEXT)""");
      b.execute("""CREATE TABLE Artists (
        id TEXT PRIMARY KEY, name TEXT, albums TEXT, topTracks TEXT, picture TEXT, fans INTEGER, albumCount INTEGER, offline INTEGER, library INTEGER, radio INTEGER)""");
      b.execute("""CREATE TABLE Playlists (
        id TEXT PRIMARY KEY, title TEXT, tracks TEXT, image TEXT, duration INTEGER, userId TEXT, userName TEXT, fans INTEGER, library INTEGER, description TEXT)""");
      await b.commit();
    });

    //Create offline directory
    offlinePath =
        p.join((await getExternalStorageDirectory())!.path, 'offline/');
    await Directory(offlinePath).create(recursive: true);

    //Update settings
    await updateServiceSettings();

    //Listen to state change event
    eventChannel.receiveBroadcastStream().listen((e) {
      if (e['action'] == 'onStateChange') {
        running = e['running'];
        queueSize = e['queueSize'];
      }

      //Forward
      serviceEvents.add(e);
    });

    await platform.invokeMethod('loadDownloads');
  }

  //Get all downloads from db
  Future<List<Download>> getDownloads() async {
    if (!isSupported) return [];

    List raw = await platform.invokeMethod('getDownloads');
    return raw.map((d) => Download.fromJson(d)).toList();
  }

  //Insert track and metadata to DB
  Future<Batch> _addTrackToDB(
      Batch batch, Track track, bool overwriteTrack) async {
    batch.insert('Tracks', track.toSQL(off: true),
        conflictAlgorithm: overwriteTrack
            ? ConflictAlgorithm.replace
            : ConflictAlgorithm.ignore);
    batch.insert('Albums', track.album!.toSQL(off: false),
        conflictAlgorithm: ConflictAlgorithm.ignore);
    //Artists
    for (Artist a in track.artists!) {
      batch.insert('Artists', a.toSQL(off: false),
          conflictAlgorithm: ConflictAlgorithm.ignore);
    }
    return batch;
  }

  //Quality selector for custom quality
  Future<AudioQuality?> qualitySelect(BuildContext context) {
    return showModalBottomSheet<AudioQuality>(
        context: context,
        builder: (context) {
          return Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Padding(
                padding: const EdgeInsets.fromLTRB(0, 12, 0, 2),
                child: Text(
                  'Quality'.i18n,
                  style: const TextStyle(
                      fontWeight: FontWeight.bold, fontSize: 20.0),
                ),
              ),
              ListTile(
                title: const Text('MP3 128kbps'),
                onTap: () => Navigator.pop(context, AudioQuality.MP3_128),
              ),
              ListTile(
                title: const Text('MP3 320kbps'),
                onTap: () => Navigator.pop(context, AudioQuality.MP3_320),
              ),
              ListTile(
                title: const Text('FLAC'),
                onTap: () => Navigator.pop(context, AudioQuality.FLAC),
              )
            ],
          );
        });
  }

  Future<bool> addOfflineTrack(Track track,
      {bool private = true,
      BuildContext? context,
      bool isSingleton = false}) async {
    if (!isSupported) return false;
    //Permission
    if (!private && !(await checkPermission())) return false;

    //Ask for quality
    AudioQuality? quality;
    if (!private && settings.downloadQuality == AudioQuality.ASK) {
      quality = await qualitySelect(context!);
      if (quality == null) return false;
    }

    //Fetch track if missing meta
    if (track.artists == null ||
        track.artists!.isEmpty ||
        track.album == null) {
      track = await deezerAPI.track(track.id);
    }

    //Add to DB
    if (private) {
      Batch b = db.batch();
      b = await _addTrackToDB(b, track, true);
      await b.commit();

      //Cache art
      cacheManager.getSingleFile(track.albumArt!.thumb);
      cacheManager.getSingleFile(track.albumArt!.full);
    }

    //Get path
    String? path = _generatePath(track, private, isSingleton: isSingleton);
    await platform.invokeMethod('addDownloads', [
      await Download.jsonFromTrack(track, path,
          private: private, quality: quality)
    ]);
    await start();
    return true;
  }

  Future addOfflineAlbum(Album? album,
      {private = true, BuildContext? context}) async {
    //Permission
    if (!private && !(await checkPermission())) return;

    //Ask for quality
    AudioQuality? quality;
    if (!private && settings.downloadQuality == AudioQuality.ASK) {
      quality = await qualitySelect(context!);
      if (quality == null) return false;
    }

    //Get from API if no tracks
    if (album!.tracks == null || album.tracks!.isEmpty) {
      album = await deezerAPI.album(album.id);
    }

    //Add to DB
    if (private) {
      //Cache art
      cacheManager.getSingleFile(album.art!.thumb);
      cacheManager.getSingleFile(album.art!.full);

      Batch b = db.batch();
      b.insert('Albums', album.toSQL(off: true),
          conflictAlgorithm: ConflictAlgorithm.replace);
      for (Track? t in album.tracks!) {
        b = await (_addTrackToDB(b, t!, false));
      }
      await b.commit();
    }

    //Create downloads
    List<Map> out = [];
    for (Track? t in album.tracks!) {
      out.add(await Download.jsonFromTrack(t!, _generatePath(t, private),
          private: private, quality: quality));
    }
    await platform.invokeMethod('addDownloads', out);
    await start();
  }

  Future addOfflinePlaylist(Playlist? playlist,
      {private = true, BuildContext? context, AudioQuality? quality}) async {
    if (!isSupported) return false;

    //Permission
    if (!private && !(await checkPermission())) return;

    //Ask for quality
    if (!private &&
        settings.downloadQuality == AudioQuality.ASK &&
        quality == null) {
      quality = await qualitySelect(context!);
      if (quality == null) return false;
    }

    //Get tracks if missing
    if (playlist!.tracks == null ||
        playlist.tracks!.length < playlist.trackCount!) {
      playlist = await deezerAPI.fullPlaylist(playlist.id);
    }

    //Add to DB
    if (private) {
      Batch b = db.batch();
      b.insert('Playlists', playlist.toSQL(),
          conflictAlgorithm: ConflictAlgorithm.replace);
      for (Track? t in playlist.tracks!) {
        b = await _addTrackToDB(b, t!, false);
        //Cache art
        cacheManager.getSingleFile(t.albumArt!.thumb);
        cacheManager.getSingleFile(t.albumArt!.full);
      }
      await b.commit();
    }

    //Generate downloads
    List<Map> out = [];
    for (int i = 0; i < playlist.tracks!.length; i++) {
      Track t = playlist.tracks![i];
      out.add(await Download.jsonFromTrack(
          t,
          _generatePath(
            t,
            private,
            playlistName: playlist.title,
            playlistTrackNumber: i,
          ),
          private: private,
          quality: quality));
    }
    await platform.invokeMethod('addDownloads', out);
    await start();
  }

  //Get track and meta from offline DB
  Future<Track?> getOfflineTrack(String? id,
      {Album? album, List<Artist>? artists}) async {
    List tracks = await db.query('Tracks', where: 'id == ?', whereArgs: [id]);
    if (tracks.isEmpty) return null;
    Track track = Track.fromSQL(tracks[0]);

    //Get album
    if (album == null) {
      List rawAlbums = await db
          .query('Albums', where: 'id == ?', whereArgs: [track.album?.id]);
      if (rawAlbums.isNotEmpty) track.album = Album.fromSQL(rawAlbums[0]);
    } else {
      track.album = album;
    }

    //Get artists
    if (artists == null) {
      List<Artist> newArtists = [];
      for (Artist artist in track.artists!) {
        List rawArtist =
            await db.query('Artists', where: 'id == ?', whereArgs: [artist.id]);
        if (rawArtist.isNotEmpty) newArtists.add(Artist.fromSQL(rawArtist[0]));
      }
      if (newArtists.isNotEmpty) track.artists = newArtists;
    } else {
      track.artists = artists;
    }
    return track;
  }

  //Get offline library tracks
  Future<List<Track?>> getOfflineTracks() async {
    List rawTracks = await db.query('Tracks',
        where: 'library == 1 AND offline == 1', columns: ['id']);
    List<Track?> out = [];
    //Load track meta individually
    for (Map rawTrack in rawTracks as Iterable<Map<dynamic, dynamic>>) {
      out.add(await getOfflineTrack(rawTrack['id']));
    }
    return out;
  }

  //Get all offline available tracks
  Future<List<Track?>> allOfflineTracks() async {
    if (!isSupported) return [];

    List rawTracks =
        await db.query('Tracks', where: 'offline == 1', columns: ['id']);
    List<Track?> out = [];
    //Load track meta individually
    for (Map rawTrack in rawTracks as Iterable<Map<dynamic, dynamic>>) {
      out.add(await getOfflineTrack(rawTrack['id']));
    }
    return out;
  }

  //Get all offline albums
  Future<List<Album>> getOfflineAlbums() async {
    if (!isSupported) return [];

    List rawAlbums =
        await db.query('Albums', where: 'offline == 1', columns: ['id']);
    List<Album> out = [];
    //Load each album
    for (Map rawAlbum in rawAlbums as Iterable<Map<dynamic, dynamic>>) {
      out.add(await getOfflineAlbum(rawAlbum['id']));
    }
    return out;
  }

  //Get offline album with meta
  Future<Album> getOfflineAlbum(String id) async {
    List rawAlbums =
        await db.query('Albums', where: 'id == ?', whereArgs: [id]);
    if (rawAlbums.isEmpty) throw Exception();
    Album album = Album.fromSQL(rawAlbums[0]);

    List<Track> tracks = [];
    //Load tracks
    for (int i = 0; i < album.tracks!.length; i++) {
      tracks.add((await getOfflineTrack(album.tracks![i].id, album: album))!);
    }
    album.tracks = tracks;
    //Load artists
    List<Artist> artists = [];
    for (int i = 0; i < album.artists!.length; i++) {
      artists.add(
          (await getOfflineArtist(album.artists![i].id)) ?? album.artists![i]);
    }
    album.artists = artists;

    return album;
  }

  //Get offline artist METADATA, not tracks
  Future<Artist?> getOfflineArtist(String? id) async {
    List rawArtists =
        await db.query("Artists", where: 'id == ?', whereArgs: [id]);
    if (rawArtists.isEmpty) return null;
    return Artist.fromSQL(rawArtists[0]);
  }

  //Get all offline playlists
  Future<List<Playlist>> getOfflinePlaylists() async {
    if (!isSupported) return [];
    final rawPlaylists = await db.query('Playlists', columns: ['id']);
    final out = <Playlist>[];
    for (final rawPlaylist in rawPlaylists) {
      out.add(await getPlaylist(rawPlaylist));
    }
    return out;
  }

  Future<Playlist?> getPlaylistFromId(String id) async {
    final rawPlaylists =
        await db.query('Playlists', where: 'id == ?', whereArgs: [id]);
    if (rawPlaylists.isEmpty) return null;

    return await getPlaylist(rawPlaylists[0]);
  }

  //Get offline playlist
  Future<Playlist> getPlaylist(Map<String, Object?> rawPlaylist) async {
    // List rawPlaylists =
    //     await db.query('Playlists', where: 'id == ?', whereArgs: [id]);
    Playlist playlist = Playlist.fromSQL(rawPlaylist);
    //Load tracks
    List<Track> tracks = [];
    for (Track t in playlist.tracks!) {
      tracks.add((await getOfflineTrack(t.id))!);
    }
    playlist.tracks = tracks;
    return playlist;
  }

  Future removeOfflineTracks(List<Track> tracks) async {
    for (Track t in tracks) {
      //Check if library
      List rawTrack = await db.query('Tracks',
          where: 'id == ?', whereArgs: [t.id], columns: ['favorite']);
      if (rawTrack.isNotEmpty) {
        //Count occurrences in playlists and albums
        List albums = await db
            .rawQuery('SELECT (id) FROM Albums WHERE tracks LIKE "%${t.id}%"');
        List playlists = await db.rawQuery(
            'SELECT (id) FROM Playlists WHERE tracks LIKE "%${t.id}%"');
        if (albums.isEmpty &&
            playlists.isEmpty &&
            rawTrack[0]['favorite'] == 0) {
          //Safe to remove
          await db.delete('Tracks', where: 'id == ?', whereArgs: [t.id]);
        } else {
          await db.update('Tracks', {'offline': 0},
              where: 'id == ?', whereArgs: [t.id]);
        }
      }

      //Remove file
      try {
        File(p.join(offlinePath, t.id)).delete();
      } catch (e) {
        print(e);
      }
    }
  }

  Future removeOfflineAlbum(String? id) async {
    //Get album
    List rawAlbums =
        await db.query('Albums', where: 'id == ?', whereArgs: [id]);
    if (rawAlbums.isEmpty) return;
    Album album = Album.fromSQL(rawAlbums[0]);
    //Remove album
    await db.delete('Albums', where: 'id == ?', whereArgs: [id]);
    //Remove tracks
    await removeOfflineTracks(album.tracks!);
  }

  Future removeOfflinePlaylist(String? id) async {
    if (!isSupported) return;
    //Fetch playlist
    List rawPlaylists =
        await db.query('Playlists', where: 'id == ?', whereArgs: [id]);
    if (rawPlaylists.isEmpty) return;
    Playlist playlist = Playlist.fromSQL(rawPlaylists[0]);
    //Remove playlist
    await db.delete('Playlists', where: 'id == ?', whereArgs: [id]);
    await removeOfflineTracks(playlist.tracks!);
  }

  //Check if album, track or playlist is offline
  Future<bool> checkOffline(
      {Album? album, Track? track, Playlist? playlist}) async {
    if (!isSupported) return false;

    //Track
    if (track != null) {
      List res = await db.query('Tracks',
          where: 'id == ? AND offline == 1', whereArgs: [track.id]);
      if (res.isEmpty) return false;
      return true;
    }
    //Album
    if (album != null) {
      List res = await db.query('Albums',
          where: 'id == ? AND offline == 1', whereArgs: [album.id]);
      if (res.isEmpty) return false;
      return true;
    }
    //Playlist
    if (playlist != null) {
      List res = await db
          .query('Playlists', where: 'id == ?', whereArgs: [playlist.id]);
      if (res.isEmpty) return false;
      return true;
    }
    return false;
  }

  //Offline search
  Future<SearchResults> search(String? query) async {
    SearchResults results =
        SearchResults(tracks: [], albums: [], artists: [], playlists: []);
    //Tracks
    List tracksData = await db.rawQuery(
        'SELECT * FROM Tracks WHERE offline == 1 AND title like "%$query%"');
    for (Map trackData in tracksData as Iterable<Map<dynamic, dynamic>>) {
      results.tracks!.add((await getOfflineTrack(trackData['id']))!);
    }
    //Albums
    List albumsData = await db.rawQuery(
        'SELECT (id) FROM Albums WHERE offline == 1 AND title like "%$query%"');
    for (Map rawAlbum in albumsData as Iterable<Map<dynamic, dynamic>>) {
      results.albums!.add((await getOfflineAlbum(rawAlbum['id'])));
    }
    //Playlists

    List playlists = await db.query("Playlists",
        where: "title like '%' || ? || '%'", whereArgs: [query]);
    for (Map playlist in playlists as Iterable<Map<dynamic, dynamic>>) {
      results.playlists!.add((await getPlaylist(playlist['id'])));
    }
    return results;
  }

  //Sanitize filename
  String sanitize(String input) {
    RegExp sanitize = RegExp(r'[\/\\\?\%\*\:\|\"\<\>]');
    return input.replaceAll(sanitize, '');
  }

  //Generate track download path
  String? _generatePath(Track? track, bool private,
      {String? playlistName,
      int? playlistTrackNumber,
      bool isSingleton = false}) {
    String? path;
    if (private) {
      // TODO: add extension
      return p.join(offlinePath, track!.id);
    }

    //Download path
    path = settings.downloadPath;

    if (settings.playlistFolder && playlistName != null) {
      path = p.join(path!, sanitize(playlistName));
    }

    if (settings.artistFolder) path = p.join(path!, '%albumArtist%');

    //Album folder / with disk number
    if (settings.albumFolder) {
      if (settings.albumDiscFolder) {
        path = p.join(path!, '%album% - Disk ${track!.diskNumber ?? 1}');
      } else {
        path = p.join(path!, '%album%');
      }
    }
    //Final path
    path = p.join(path!,
        isSingleton ? settings.singletonFilename : settings.downloadFilename);
    //Playlist track number variable (not accessible in service)
    if (playlistTrackNumber != null) {
      path = path.replaceAll(
          '%playlistTrackNumber%', playlistTrackNumber.toString());
      path = path.replaceAll('%0playlistTrackNumber%',
          playlistTrackNumber.toString().padLeft(2, '0'));
    } else {
      path = path.replaceAll('%playlistTrackNumber%', '');
      path = path.replaceAll('%0playlistTrackNumber%', '');
    }

    return path;
  }

  //Get stats for library screen
  Future<List<String>> getStats() async {
    //Get offline counts
    int? trackCount =
        (await db.rawQuery('SELECT COUNT(*) FROM Tracks WHERE offline == 1'))[0]
            ['COUNT(*)'] as int?;
    int? albumCount =
        (await db.rawQuery('SELECT COUNT(*) FROM Albums WHERE offline == 1'))[0]
            ['COUNT(*)'] as int?;
    int? playlistCount = (await db
        .rawQuery('SELECT COUNT(*) FROM Playlists'))[0]['COUNT(*)'] as int?;
    //Free space
    double diskSpace =
        await DiskSpacePlus.getFreeDiskSpace.then((value) => value ?? 0.0);
    //Used space
    List<FileSystemEntity> offlineStat =
        await Directory(offlinePath).list().toList();
    int offlineSize = 0;
    for (var fs in offlineStat) {
      offlineSize += (await fs.stat()).size;
    }
    //Return in list, //TODO: Make into class in future
    return ([
      trackCount.toString(),
      albumCount.toString(),
      playlistCount.toString(),
      filesize(offlineSize),
      filesize((diskSpace * 1000000).floor())
    ]);
  }

  //Send settings to download service
  Future updateServiceSettings() async {
    if (!isSupported) return;
    await platform.invokeMethod(
        'updateSettings', settings.getServiceSettings());
  }

  //Check storage permission
  Future<bool> checkPermission() async {
    if (await Permission.storage.request().isGranted) {
      return true;
    } else {
      Fluttertoast.showToast(
          msg: 'Storage permission denied!'.i18n,
          toastLength: Toast.LENGTH_SHORT,
          gravity: ToastGravity.BOTTOM);
      return false;
    }
  }

  //Remove download from queue/finished
  Future removeDownload(int? id) async {
    if (!isSupported) return;

    await platform.invokeMethod('removeDownload', {'id': id});
  }

  //Restart failed downloads
  Future retryDownloads() async {
    if (!isSupported) return;

    await platform.invokeMethod('retryDownloads');
  }

  //Delete downloads by state
  Future removeDownloads(DownloadState state) async {
    if (!isSupported) return;

    await platform.invokeMethod(
        'removeDownloads', {'state': DownloadState.values.indexOf(state)});
  }

  static Future<String?> getDirectory(String title) =>
      platform.invokeMethod('getDirectory', <String, String>{'title': title});
}

class Download {
  int id;
  String path;
  bool private;
  String trackId;
  String? md5origin;
  String? mediaVersion;
  String title;
  String image;
  int quality;
  //Dynamic
  DownloadState state;
  int? received;
  int? filesize;

  Download({
    required this.id,
    required this.path,
    required this.private,
    required this.trackId,
    required this.title,
    required this.image,
    required this.state,
    required this.quality,
    this.md5origin,
    this.mediaVersion,
    this.received,
    this.filesize,
  });

  //Get progress between 0 - 1
  double get progress {
    return ((received?.toDouble() ?? 0.0) / (filesize?.toDouble() ?? 1.0))
        .toDouble();
  }

  factory Download.fromJson(Map<dynamic, dynamic> data) {
    return Download(
        path: data['path'],
        image: data['image'],
        private: data['private'],
        trackId: data['trackId'],
        id: data['id'],
        state: DownloadState.values[data['state']],
        title: data['title'],
        quality: data['quality']);
  }

  //Change values from "update json"
  void updateFromJson(Map<dynamic, dynamic> data) {
    quality = data['quality'];
    received = data['received'] ?? 0;
    state = DownloadState.values[data['state']];
    //Prevent null division later
    filesize = ((data['filesize'] ?? 0) <= 0) ? 1 : (data['filesize'] ?? 1);
  }

  //Track to download JSON for service
  static Future<Map> jsonFromTrack(Track t, String? path,
      {private = true, AudioQuality? quality}) async {
    //Get download info
    if (t.playbackDetails == null || t.playbackDetails == []) {
      t = await deezerAPI.track(t.id);
    }
    return {
      "private": private,
      "trackId": t.id,
      "md5origin": t.playbackDetails![0],
      "mediaVersion": t.playbackDetails![1],
      "quality": private
          ? settings.offlineQuality.toDeezerQualityInt()
          : (quality ?? settings.downloadQuality).toDeezerQualityInt(),
      "title": t.title,
      "path": path,
      "image": t.albumArt?.thumb
    };
  }
}

//Has to be same order as in java
enum DownloadState { NONE, DOWNLOADING, POST, DONE, DEEZER_ERROR, ERROR }