using Mapster;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using Roadie.Library;
using Roadie.Library.Caching;
using Roadie.Library.Configuration;
using Roadie.Library.Encoding;
using Roadie.Library.Enums;
using Roadie.Library.Extensions;
using Roadie.Library.Models;
using Roadie.Library.Models.Pagination;
using Roadie.Library.Models.Playlists;
using Roadie.Library.Models.Users;
using Roadie.Library.Utility;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Linq.Dynamic.Core;
using System.Threading.Tasks;
using data = Roadie.Library.Data;

namespace Roadie.Api.Services
{
    public class PlaylistService : ServiceBase, IPlaylistService
    {
        private IBookmarkService BookmarkService { get; } = null;

        public PlaylistService(IRoadieSettings configuration,
                             IHttpEncoder httpEncoder,
                             IHttpContext httpContext,
                             data.IRoadieDbContext dbContext,
                             ICacheManager cacheManager,
                             ILogger<PlaylistService> logger,
                             IBookmarkService bookmarkService)
            : base(configuration, httpEncoder, dbContext, cacheManager, logger, httpContext)
        {
            this.BookmarkService = bookmarkService;
        }

        public async Task<OperationResult<PlaylistList>> AddNewPlaylist(User user, Playlist model)
        {
            var playlist = new data.Playlist
            {
                IsPublic = model.IsPublic,
                Description = model.Description,
                Name = model.Name,
                UserId = user.Id
            };
            this.DbContext.Playlists.Add(playlist);
            await this.DbContext.SaveChangesAsync();
            var r = await this.AddTracksToPlaylist(playlist, model.Tracks.OrderBy(x => x.ListNumber).Select(x => x.Track.Id));
            var request = new PagedRequest
            {
                FilterToPlaylistId = playlist.RoadieId
            };
            var result = await this.List(request, user);
            return new OperationResult<PlaylistList>
            {
                Data = result.Rows.First(),
                IsSuccess = true
            };
        }

        public async Task<OperationResult<bool>> AddTracksToPlaylist(data.Playlist playlist, IEnumerable<Guid> trackIds)
        {
            var sw = new Stopwatch();
            sw.Start();

            var result = false;
            var now = DateTime.UtcNow;

            var existingTracksForPlaylist = (from plt in this.DbContext.PlaylistTracks
                                             join t in this.DbContext.Tracks on plt.TrackId equals t.Id
                                             where plt.PlayListId == playlist.Id
                                             select t);
            var newTracksForPlaylist = (from t in this.DbContext.Tracks
                                        where (from x in trackIds select x).Contains(t.RoadieId)
                                        where !(from x in existingTracksForPlaylist select x.RoadieId).Contains(t.RoadieId)
                                        select t).ToArray();
            foreach (var newTrackForPlaylist in newTracksForPlaylist)
            {
                this.DbContext.PlaylistTracks.Add(new data.PlaylistTrack
                {
                    TrackId = newTrackForPlaylist.Id,
                    PlayListId = playlist.Id
                });
            }
            playlist.LastUpdated = now;
            await this.DbContext.SaveChangesAsync();
            result = true;

            var r = await this.ReorderPlaylist(playlist);
            result = result && r.IsSuccess;

            await base.UpdatePlaylistCounts(playlist.Id, now);

            sw.Stop();

            return new OperationResult<bool>
            {
                IsSuccess = result,
                Data = result,
                OperationTime = sw.ElapsedMilliseconds
            };
        }

        public async Task<OperationResult<bool>> DeletePlaylist(User user, Guid id)
        {
            var sw = new Stopwatch();
            sw.Start();
            var playlist = this.DbContext.Playlists.FirstOrDefault(x => x.RoadieId == id);
            if (playlist == null)
            {
                return new OperationResult<bool>(true, string.Format("Playlist Not Found [{0}]", id));
            }
            if(!user.IsAdmin || user.Id != playlist.UserId)
            {
                this.Logger.LogWarning("User `{0}` attempted to delete Playlist `{1}`", user, playlist);
                return new OperationResult<bool>("Access Denied")
                {
                    IsAccessDeniedResult = true
                };
            }
            this.DbContext.Playlists.Remove(playlist);
            await this.DbContext.SaveChangesAsync();
            this.Logger.LogInformation("User `{0}` deleted Playlist `{1}]`", user, playlist);
            this.CacheManager.ClearRegion(playlist.CacheRegion);
            sw.Stop();
            return new OperationResult<bool>
            {
                IsSuccess = true,
                Data = true,
                OperationTime = sw.ElapsedMilliseconds
            };
        }

        public async Task<OperationResult<Playlist>> ById(User roadieUser, Guid id, IEnumerable<string> includes = null)
        {
            var sw = Stopwatch.StartNew();
            sw.Start();
            var cacheKey = string.Format("urn:playlist_by_id_operation:{0}:{1}", id, includes == null ? "0" : string.Join("|", includes));
            var result = await this.CacheManager.GetAsync<OperationResult<Playlist>>(cacheKey, async () =>
            {
                return await this.PlaylistByIdAction(id, includes);
            }, data.Artist.CacheRegionUrn(id));
            sw.Stop();
            if (result?.Data != null && roadieUser != null)
            {
                if (result?.Data?.Tracks != null)
                {
                    var user = this.GetUser(roadieUser.UserId);
                    foreach (var track in result.Data.Tracks)
                    {
                        track.Track.TrackPlayUrl = this.MakeTrackPlayUrl(user, track.Track.DatabaseId, track.Track.Id);
                    }
                }

                result.Data.UserCanEdit = result.Data.Maintainer.Id == roadieUser.UserId || roadieUser.IsAdmin;
                var userBookmarkResult = await this.BookmarkService.List(roadieUser, new PagedRequest(), false, BookmarkType.Playlist);
                if (userBookmarkResult.IsSuccess)
                {
                    result.Data.UserBookmarked = userBookmarkResult?.Rows?.FirstOrDefault(x => x.Bookmark.Text == result.Data.Id.ToString()) != null;
                }
            }
            return new OperationResult<Playlist>(result.Messages)
            {
                Data = result?.Data,
                IsNotFoundResult = result?.IsNotFoundResult ?? false,
                Errors = result?.Errors,
                IsSuccess = result?.IsSuccess ?? false,
                OperationTime = sw.ElapsedMilliseconds
            };
        }

        public Task<Library.Models.Pagination.PagedResult<PlaylistList>> List(PagedRequest request, User roadieUser = null)
        {
            var sw = new Stopwatch();
            sw.Start();

            int[] playlistWithArtistTrackIds = new int[0];
            if (request.FilterToArtistId.HasValue)
            {
                playlistWithArtistTrackIds = (from pl in this.DbContext.Playlists
                                              join pltr in this.DbContext.PlaylistTracks on pl.Id equals pltr.PlayListId
                                              join t in this.DbContext.Tracks on pltr.TrackId equals t.Id
                                              join rm in this.DbContext.ReleaseMedias on t.ReleaseMediaId equals rm.Id
                                              join r in this.DbContext.Releases on rm.ReleaseId equals r.Id
                                              join a in this.DbContext.Artists on r.ArtistId equals a.Id
                                              where a.RoadieId == request.FilterToArtistId
                                              select pl.Id
                                         ).ToArray();
            }
            int[] playlistReleaseTrackIds = new int[0];
            if (request.FilterToReleaseId.HasValue)
            {
                playlistReleaseTrackIds = (from pl in this.DbContext.Playlists
                                           join pltr in this.DbContext.PlaylistTracks on pl.Id equals pltr.PlayListId
                                           join t in this.DbContext.Tracks on pltr.TrackId equals t.Id
                                           join rm in this.DbContext.ReleaseMedias on t.ReleaseMediaId equals rm.Id
                                           join r in this.DbContext.Releases on rm.ReleaseId equals r.Id
                                           where r.RoadieId == request.FilterToReleaseId
                                           select pl.Id
                                         ).ToArray();
            }

            var result = (from pl in this.DbContext.Playlists
                          join u in this.DbContext.Users on pl.UserId equals u.Id
                          where (request.FilterToPlaylistId == null || pl.RoadieId == request.FilterToPlaylistId)
                          where (request.FilterToArtistId == null || playlistWithArtistTrackIds.Contains(pl.Id))
                          where (request.FilterToReleaseId == null || playlistReleaseTrackIds.Contains(pl.Id))
                          where ((roadieUser == null && pl.IsPublic) || (roadieUser != null && u.RoadieId == roadieUser.UserId || pl.IsPublic))
                          where (request.FilterValue.Length == 0 || (request.FilterValue.Length > 0 && (pl.Name != null && pl.Name.Contains(request.FilterValue))))
                          select PlaylistList.FromDataPlaylist(pl, u, this.MakePlaylistThumbnailImage(pl.RoadieId), this.MakeUserThumbnailImage(u.RoadieId)));
            var sortBy = string.IsNullOrEmpty(request.Sort) ? request.OrderValue(new Dictionary<string, string> { { "Playlist.Text", "ASC" } }) : request.OrderValue(null);
            var rowCount = result.Count();
            var rows = result.OrderBy(sortBy).Skip(request.SkipValue).Take(request.LimitValue).ToArray();
            sw.Stop();
            return Task.FromResult(new Library.Models.Pagination.PagedResult<PlaylistList>
            {
                TotalCount = rowCount,
                CurrentPage = request.PageValue,
                TotalPages = (int)Math.Ceiling((double)rowCount / request.LimitValue),
                OperationTime = sw.ElapsedMilliseconds,
                Rows = rows
            });
        }

        public async Task<OperationResult<bool>> ReorderPlaylist(data.Playlist playlist)
        {
            var sw = new Stopwatch();
            sw.Start();

            var result = false;
            var now = DateTime.UtcNow;

            if (playlist != null)
            {
                var looper = 0;
                foreach (var playlistTrack in this.DbContext.PlaylistTracks.Where(x => x.PlayListId == playlist.Id).OrderBy(x => x.CreatedDate))
                {
                    looper++;
                    playlistTrack.ListNumber = looper;
                    playlistTrack.LastUpdated = now;
                }
                await this.DbContext.SaveChangesAsync();
                result = true;
            }

            return new OperationResult<bool>
            {
                IsSuccess = result,
                Data = result
            };
        }

        private Task<OperationResult<Playlist>> PlaylistByIdAction(Guid id, IEnumerable<string> includes = null)
        {
            var sw = Stopwatch.StartNew();
            sw.Start();

            var playlist = this.GetPlaylist(id);

            if (playlist == null)
            {
                return Task.FromResult(new OperationResult<Playlist>(true, string.Format("Playlist Not Found [{0}]", id)));
            }

            var result = playlist.Adapt<Playlist>();
            result.AlternateNames = playlist.AlternateNames;
            result.Tags = playlist.Tags;
            result.URLs = playlist.URLs;
            var maintainer = this.DbContext.Users.Include(x => x.UserRoles).Include("UserRoles.Role").FirstOrDefault(x => x.Id == playlist.UserId);
            result.Maintainer = UserList.FromDataUser(maintainer, this.MakeUserThumbnailImage(maintainer.RoadieId));
            result.Thumbnail = this.MakePlaylistThumbnailImage(playlist.RoadieId);
            result.MediumThumbnail = base.MakeThumbnailImage(id, "playlist", this.Configuration.MediumImageSize.Width, this.Configuration.MediumImageSize.Height);
            if (includes != null && includes.Any())
            {
                var playlistTracks = (from pl in this.DbContext.Playlists
                                      join pltr in this.DbContext.PlaylistTracks on pl.Id equals pltr.PlayListId
                                      join t in this.DbContext.Tracks on pltr.TrackId equals t.Id
                                      where pl.Id == playlist.Id
                                      select new { t, pltr });

                if (includes.Contains("stats"))
                {
                    result.Statistics = new Library.Models.Statistics.ReleaseGroupingStatistics
                    {
                        ReleaseCount = result.ReleaseCount,
                        TrackCount = result.TrackCount,
                        TrackSize = result.DurationTime,
                        FileSize = playlistTracks.Sum(x => (long?)x.t.FileSize).ToFileSize()
                    };
                }
                if (includes.Contains("tracks"))
                {
                    result.Tracks = (from plt in playlistTracks
                                     join rm in this.DbContext.ReleaseMedias on plt.t.ReleaseMediaId equals rm.Id
                                     join r in this.DbContext.Releases on rm.ReleaseId equals r.Id
                                     join releaseArtist in this.DbContext.Artists on r.ArtistId equals releaseArtist.Id
                                     join trackArtist in this.DbContext.Artists on plt.t.ArtistId equals trackArtist.Id into tas
                                     from trackArtist in tas.DefaultIfEmpty()
                                     select new PlaylistTrack
                                     {
                                         ListNumber = plt.pltr.ListNumber,
                                         Track = TrackList.FromDataTrack(null,
                                                                         plt.t,
                                                                         rm.MediaNumber,
                                                                         r,
                                                                         releaseArtist,
                                                                         trackArtist,
                                                                         this.HttpContext.BaseUrl,
                                                                         this.MakeTrackThumbnailImage(plt.t.RoadieId),
                                                                         this.MakeReleaseThumbnailImage(r.RoadieId),
                                                                         this.MakeArtistThumbnailImage(releaseArtist.RoadieId),
                                                                         this.MakeArtistThumbnailImage(trackArtist == null ? null : (Guid?)trackArtist.RoadieId))
                                     }).ToArray();
                }
            }

            sw.Stop();
            return Task.FromResult(new OperationResult<Playlist>
            {
                Data = result,
                IsSuccess = result != null,
                OperationTime = sw.ElapsedMilliseconds
            });
        }
    }
}