using System;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Windows.Media;

namespace MusicPlayer
{
    internal class Backend
    {
        public MediaPlayer Player;
        public ObservableCollection<Song> Playlist;
        private bool _isPlaying;

        public Backend()
        {
            Player = new MediaPlayer();
            Playlist = new ObservableCollection<Song>();
            Playing = 0;
            _isPlaying = false;
            Player.MediaEnded += Next;
        }

        public int Playing { get; set; }

        public void Play()
        {
            var path = new Uri(Playlist[Playing].Path);
            if (Player.Source != path)
                Player.Open(path);
            Player.Play();
            _isPlaying = true;
            Playlist[Playing].BackgroundColor = Colors.Red;
        }

        public void Next(object sender, EventArgs e)
        {
            Next();
        }

        public void Next()
        {
            ChangeTrack(Playing + 1);
        }

        public void Previous()
        {
            Playlist[Playing].Title = "Played";
            ChangeTrack(Playing - 1);
        }

        public void ChangeTrack(int changeTo)
        {
            if (changeTo >= Playlist.Count || changeTo < 0)
                return;
            Playlist[Playing].BackgroundColor = Colors.White;
            Playing = changeTo;
            Playlist[Playing].BackgroundColor = Colors.Red;

            if (_isPlaying)
            {
                Play();
            }
        }

        public void Pause()
        {
            Player.Pause();
            _isPlaying = false;
        }

        public void Stop()
        {
            Player.Stop();
            _isPlaying = false;
            Playlist[Playing].BackgroundColor = Colors.White;
        }
    }

    internal class Song : INotifyPropertyChanged
    {
        private Color _backgroundColor;
        private string _title;

        public Song(string path)
        {
            Path = path;
            Title = path;
            BackgroundColor = Colors.White;
        }

        public string Path { get; set; }

        public string Title
        {
            get { return _title; }
            set
            {
                NotifyPropertyChanged("Title");
                _title = value;
            }
        }

        public int Track { get; set; }

        public Color BackgroundColor
        {
            get { return _backgroundColor; }
            set
            {
                NotifyPropertyChanged("BackgroundColor");
                _backgroundColor = value;
            }
        }

        #region INotifyPropertyChanged Members

        public event PropertyChangedEventHandler PropertyChanged;

        #endregion

        private void NotifyPropertyChanged(String info)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(info));
            }
        }


        public override string ToString()
        {
            return Title;
        }
    }
}