using MySql.Data.MySqlClient;
using Sony.Filtr.AppleMusic.BestOfTheWeek.Caching;
using Sony.Filtr.AppleMusic.BestOfTheWeek.Caching.Models;
using Sony.Filtr.AppleMusic.BestOfTheWeek.Entities;
using Sony.Filtr.Database;
using Sony.Filtr.Utility.Extensions;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace Sony.Filtr.AppleMusic.BestOfTheWeek
{
    public class BestOfTheWeekManager
    {
        private readonly BestOfTheWeekCacheProvider _cacheProvider;
        private readonly BestOfTheWeekFactory _botwFactory;

        public BestOfTheWeekManager(BestOfTheWeekCacheProvider cacheProvider, BestOfTheWeekFactory botwFactory)
        {
            _cacheProvider = cacheProvider;
            _botwFactory = botwFactory;
        }

        public bool IsTrackListChanged(IList<AppleMusicBestOfTheWeekPlaylistTrack> existingTracklist, IList<AppleMusicBestOfTheWeekPlaylistTrack> newTracks)
        {
            if (existingTracklist.Count != newTracks.Count)
                return true;

            existingTracklist = existingTracklist.OrderBy(x => x.PlaylistIndex).ToList();
            newTracks = newTracks.OrderBy(x => x.PlaylistIndex).ToList();

            for (int playlistIndex = 0; playlistIndex < existingTracklist.Count; playlistIndex++)
            {
                var oldTrack = existingTracklist[playlistIndex];
                var newTrack = newTracks[playlistIndex];
                if (oldTrack.SongId != newTrack.SongId)
                    return true;
            }

            return false;
        }

        public async Task<IDictionary<BestOfTheWeekPlaylistReference, List<BestOfTheWeekPlaylistTrackCacheModel>>> GetTracklistsAsync(IList<BestOfTheWeekPlaylistReference> playlists, DateTime date)
        {
            var playlistCollections = new ConcurrentDictionary<BestOfTheWeekPlaylistReference, List<BestOfTheWeekPlaylistTrackCacheModel>>();

            await playlists.ForEachAsync(20, async playlist =>
            {
                var tracks = await GetPlaylistTracksAsync(playlist, date);

                playlistCollections.TryAdd(playlist, tracks);
            });

            return playlistCollections;
        }

        private async Task<List<BestOfTheWeekPlaylistTrackCacheModel>> GetPlaylistTracksAsync(BestOfTheWeekPlaylistReference playlist, DateTime date)
        {
            var playlistCollection = _cacheProvider.GetPlaylistCollection(playlist, date);
            if (playlistCollection == null)
            {
                playlistCollection = await _botwFactory.GetPlaylistTracksAsync(playlist, date);
                _cacheProvider.SetPlaylistCollection(playlist, date, playlistCollection);
            }

            return playlistCollection;
        }

        public async Task<IList<BestOfTheWeekPlaylistReference>> GetPlaylistReferenceCacheItems()
        {
            var playlistReferences = _cacheProvider.GetPlaylistReferences();
            if (playlistReferences == null)
            {
                playlistReferences = new List<BestOfTheWeekPlaylistReference>();

                const string sql = "SELECT DISTINCT pl.Id, botwpl.Storefront, pl.Name, pl.Artwork FROM tblAppleMusicBestOfTheWeekPlaylist AS botwpl " +
                                   "INNER JOIN tblAppleMusicPlaylist AS pl ON pl.Id = botwpl.PlaylistId";
                using (var conn = await DatabaseHandler.GetOpenReadOnlyConnectionAsync())
                using (var command = new MySqlCommand(sql, conn))
                using (var reader = await command.ExecuteReaderAsync())
                {
                    while (await reader.ReadAsync())
                    {
                        playlistReferences.Add(new BestOfTheWeekPlaylistReference()
                        {
                            PlaylistId = reader.GetString("Id"),
                            Storefront = reader.GetString("Storefront")
                        });
                    }
                }

                _cacheProvider.SetPlaylistReferences(playlistReferences);
            }

            return playlistReferences;
        }

        public async Task<IList<DateTime>> GetAvailableFridays()
        {
            var dates = new List<DateTime>();
            const string sql = "SELECT DISTINCT Date FROM tblAppleMusicBestOfTheWeekPlaylistTrack ORDER BY Date DESC";

            using (var conn = await DatabaseHandler.GetOpenReadOnlyConnectionAsync())
            using (var command = new MySqlCommand(sql, conn))
            using (var reader = await command.ExecuteReaderAsync())
            {
                while (reader.Read())
                {
                    dates.Add(reader.GetDateTime("Date"));
                }
            }

            return dates;
        }
    }
}