using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using NLog;
using Sony.Filtr.Buzz;
using Sony.Filtr.Contracts.Definitions;
using Sony.Filtr.Contracts.Entities;
using Sony.Filtr.Core.EditorialPlaylists;
using Sony.Filtr.DeezerAPI;
using Sony.Filtr.DeezerAPI.Model;
using Sony.Filtr.Playlists;
using Sony.Filtr.Playlists.Deezer;
using Sony.Filtr.Utility;
using Sony.Filtr.Utility.Extensions;

namespace Sony.Filtr.Tasks.Tasks.Deezer
{
    public class DeezerImportPlaylistsTask : IScheduledTask
    {
        private readonly EditorialPlaylistManager _editorialPlaylistManager;
        private readonly EditorialPlaylistImportManager _editorialPlaylistImportManager;
        private readonly DeezerApi _deezerApi;
        private readonly DeezerPlaylistManager _deezerPlaylistManager;
        private readonly EditorialPlaylistManagerNew _editorialPlaylistManagerNew;
        private readonly BuzzAccountManager _buzzAccountManager;
        private Logger _logger;

        public DeezerImportPlaylistsTask(EditorialPlaylistManager editorialPlaylistManager, EditorialPlaylistImportManager editorialPlaylistImportManager, DeezerApi deezerApi,
            DeezerPlaylistManager deezerPlaylistManager, EditorialPlaylistManagerNew editorialPlaylistManagerNew, BuzzAccountManager buzzAccountManager)
        {
            _editorialPlaylistManager = editorialPlaylistManager;
            _editorialPlaylistImportManager = editorialPlaylistImportManager;
            _deezerApi = deezerApi;
            _deezerPlaylistManager = deezerPlaylistManager;
            _editorialPlaylistManagerNew = editorialPlaylistManagerNew;
            _buzzAccountManager = buzzAccountManager;

            _logger = NLog.LogManager.GetLogger("DeezerImportPlaylistsTask");
        }

        public async Task<ScheduledTaskLog> ExecuteAsync(Guid scheduledTaskLogId)
        {
            var editorialPlaylistImportUsers = _editorialPlaylistImportManager.GetDeezerImportUsers();
            var deezerBuzzUsers = await _buzzAccountManager.GetBuzzUsersAsync(musicServiceId: (int)MusicService.Deezer);

            var deezerBuzzUserIds = deezerBuzzUsers.Select(d => Maybe.ToLongOrDefault(d.Username)).FilterNull();

            var allDeezerUserIds = editorialPlaylistImportUsers.Select(u => u.UserId).Union(deezerBuzzUserIds).Distinct().ToList();

            _logger.Info("Begin fetching all playlists for {0} users", allDeezerUserIds.Count);

            var existingPlaylists = _deezerPlaylistManager.GetPlaylists();
            var existingPlaylistDic = existingPlaylists.ToDictionary(k => k.DeezerId, v => v);

            await allDeezerUserIds.ForEachAsync(5, async userId =>
            {
                try
                {
                    var playlists = await _deezerApi.GetAllUsersPlaylistsAsync(userId);
                    _logger.Debug("Fetching all playlists for {0}.", userId);
                    if (playlists != null)
                    {
                        var ownPublicPlaylists = playlists.Where(p => !p.is_loved_track && p.creator.id == userId).ToList();
                        if (ownPublicPlaylists.Any())
                        {
                            _logger.Debug("Found {0} playlists for user {1}.", ownPublicPlaylists.Count, userId);

                            var mappedPlaylists = ownPublicPlaylists.Select(MapDeezerPlaylist).Where(p => ShouldAddOrUpdate(p, existingPlaylistDic));

                            await mappedPlaylists.ForEachAsync(5, async playlist =>
                            {
                                try
                                {
                                    _logger.Debug("Saving {0}.", playlist.DeezerId);
                                    _deezerPlaylistManager.AddOrUpdateDeezerPlaylist(playlist);
                                }
                                catch (Exception ex)
                                {
                                    _logger.Error(ex, "Could not save playlist!");
                                }
                            });
                        }
                    }
                }
                catch(Exception ex)
                {
                    _logger.Error(ex, $"Could not import playlists for user {userId}!");
                }
                
            });
            
            _logger.Info("Done fetching all playlists for {0} deezer users.", allDeezerUserIds.Count);

            return null;
        }

        private bool ShouldAddOrUpdate(DeezerPlaylist deezerPlaylist, Dictionary<long, DeezerPlaylist> existingPlaylistDic)
        {
            DeezerPlaylist existingPlaylist;
            if (existingPlaylistDic.TryGetValue(deezerPlaylist.DeezerId, out existingPlaylist))
            {
                var different = deezerPlaylist.DeezerId != existingPlaylist.DeezerId
                       || deezerPlaylist.Title != existingPlaylist.Title
                       || deezerPlaylist.Description != existingPlaylist.Description
                       || deezerPlaylist.Rating != existingPlaylist.Rating
                       || deezerPlaylist.Link != existingPlaylist.Link
                       || deezerPlaylist.Picture != existingPlaylist.Picture
                       || deezerPlaylist.CreatorId != existingPlaylist.CreatorId
                       || deezerPlaylist.CreatorName != existingPlaylist.CreatorName
                       || deezerPlaylist.Duration != existingPlaylist.Duration
                       || deezerPlaylist.TrackCount != existingPlaylist.TrackCount;
                return different;
            }
            return true; //New playlist
        }

        private Contracts.Entities.DeezerPlaylist MapDeezerPlaylist(UserDeezerPlaylist playlist)
        {
            return new Contracts.Entities.DeezerPlaylist()
            {
                DeezerId = playlist.id,
                CreatorId = playlist.creator.id,
                CreatorName = playlist.creator.name,
                //Description = playlist.description,
                Duration = playlist.duration,
                Link = playlist.link,
                Picture = playlist.picture,
                Rating = playlist.rating,
                Title = playlist.title,
                //TrackCount = playlist.tr
            };
        }
    }
}