import 'dart:async';

import 'package:flutter/material.dart';
import 'package:freezer/api/deezer.dart';
import 'package:freezer/api/definitions.dart';
import 'package:freezer/api/download.dart';

Importer importer = Importer();

class Importer {
  //Options
  bool download = false;

  //Preserve context
  BuildContext? context;
  String? title;
  String? description;
  late List<ImporterTrack> tracks;
  String? playlistId;
  Playlist? playlist;

  bool done = false;
  bool busy = false;
  Future? _future;
  late StreamController _streamController;

  Stream get updateStream => _streamController.stream;
  int get ok =>
      tracks.fold(0, (v, t) => (t.state == TrackImportState.OK) ? v + 1 : v);
  int get error =>
      tracks.fold(0, (v, t) => (t.state == TrackImportState.ERROR) ? v + 1 : v);

  Importer();

  //Start importing wrapper
  Future<void> start(BuildContext context, String? title, String? description,
      List<ImporterTrack> tracks) async {
    //Save variables
    this.playlist = null;
    this.context = context;
    this.title = title;
    this.description = description ?? '';
    this.tracks = tracks.map((t) {
      t.state = TrackImportState.NONE;
      return t;
    }).toList();

    //Create playlist
    playlistId =
        await deezerAPI.createPlaylist(title, description: description);

    busy = true;
    done = false;
    _streamController = StreamController.broadcast();
    _future = _start();
  }

  //Start importer
  Future _start() async {
    for (int i = 0; i < tracks.length; i++) {
      try {
        String? id = await _searchTrack(tracks[i]);
        //Not found
        if (id == null) {
          tracks[i].state = TrackImportState.ERROR;
          _streamController.add(tracks[i]);
          continue;
        }
        //Add to playlist
        await deezerAPI.addToPlaylist(id, playlistId);
        tracks[i].state = TrackImportState.OK;
      } catch (_) {
        //Error occurred, mark as error
        tracks[i].state = TrackImportState.ERROR;
      }
      _streamController.add(tracks[i]);
    }
    //Get full playlist
    playlist = await deezerAPI.playlist(playlistId, nb: 10000);
    playlist!.library = true;

    //Download
    if (download) {
      await downloadManager.addOfflinePlaylist(playlist,
          private: false, context: context);
    }

    //Mark as done
    done = true;
    busy = false;
    //To update UI
    _streamController.add(null);
    _streamController.close();
  }

  //Find track on Deezer servers
  Future<String?> _searchTrack(ImporterTrack track) async {
    //Try by ISRC
    if (track.isrc != null && track.isrc!.length == 12) {
      Map deezer = (await deezerAPI.callPublicApi('track/isrc:' + track.isrc!));
      if (deezer["id"] != null) {
        return deezer["id"].toString();
      }
    }

    //Search
    String cleanedTitle = track.title!
        .trim()
        .toLowerCase()
        .replaceAll("-", "")
        .replaceAll("&", "")
        .replaceAll("+", "");
    SearchResults results =
        await deezerAPI.search("${track.artists![0]} $cleanedTitle");
    for (Track t in results.tracks!) {
      //Match title
      if (_cleanMatching(t.title!) == _cleanMatching(track.title!)) {
        //Match artist
        if (_matchArtists(
            track.artists!, t.artists!.map((a) => a.name) as List<String?>)) {
          return t.id;
        }
      }
    }
  }

  //Clean title for matching
  String _cleanMatching(String t) {
    return t
        .toLowerCase()
        .replaceAll(",", "")
        .replaceAll("-", "")
        .replaceAll(" ", "")
        .replaceAll("&", "")
        .replaceAll("+", "")
        .replaceAll("/", "");
  }

  String _cleanArtist(String? a) {
    return a!.toLowerCase().replaceAll(" ", "").replaceAll(",", "");
  }

  //Match at least 1 artist
  bool _matchArtists(List<String?> a, List<String?> b) {
    //Clean
    List<String> _a = a.map(_cleanArtist).toList();
    List<String> _b = b.map(_cleanArtist).toList();

    for (String artist in _a) {
      if (_b.contains(artist)) {
        return true;
      }
    }
    return false;
  }
}

class ImporterTrack {
  String? title;
  List<String?>? artists;
  String? isrc;
  TrackImportState state;

  ImporterTrack(this.title, this.artists,
      {this.isrc, this.state = TrackImportState.NONE});
}

enum TrackImportState { NONE, ERROR, OK }

extension TrackImportStateExtension on TrackImportState {
  Widget get icon {
    switch (this) {
      case TrackImportState.ERROR:
        return Icon(
          Icons.error,
          color: Colors.red,
        );
      case TrackImportState.OK:
        return Icon(Icons.done, color: Colors.green);
      default:
        return Container(width: 0, height: 0);
    }
  }
}