using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using Jellyfin.Api.Constants;
using Jellyfin.Api.Extensions;
using Jellyfin.Api.ModelBinders;
using Jellyfin.Data.Enums;
using Jellyfin.Extensions;
using MediaBrowser.Controller.Dto;
using MediaBrowser.Controller.Entities;
using MediaBrowser.Controller.Entities.TV;
using MediaBrowser.Controller.Library;
using MediaBrowser.Controller.TV;
using MediaBrowser.Model.Dto;
using MediaBrowser.Model.Entities;
using MediaBrowser.Model.Querying;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;

namespace Jellyfin.Api.Controllers
{
    /// <summary>
    /// The tv shows controller.
    /// </summary>
    [Route("Shows")]
    [Authorize(Policy = Policies.DefaultAuthorization)]
    public class TvShowsController : BaseJellyfinApiController
    {
        private readonly IUserManager _userManager;
        private readonly ILibraryManager _libraryManager;
        private readonly IDtoService _dtoService;
        private readonly ITVSeriesManager _tvSeriesManager;

        /// <summary>
        /// Initializes a new instance of the <see cref="TvShowsController"/> class.
        /// </summary>
        /// <param name="userManager">Instance of the <see cref="IUserManager"/> interface.</param>
        /// <param name="libraryManager">Instance of the <see cref="ILibraryManager"/> interface.</param>
        /// <param name="dtoService">Instance of the <see cref="IDtoService"/> interface.</param>
        /// <param name="tvSeriesManager">Instance of the <see cref="ITVSeriesManager"/> interface.</param>
        public TvShowsController(
            IUserManager userManager,
            ILibraryManager libraryManager,
            IDtoService dtoService,
            ITVSeriesManager tvSeriesManager)
        {
            _userManager = userManager;
            _libraryManager = libraryManager;
            _dtoService = dtoService;
            _tvSeriesManager = tvSeriesManager;
        }

        /// <summary>
        /// Gets a list of next up episodes.
        /// </summary>
        /// <param name="userId">The user id of the user to get the next up episodes for.</param>
        /// <param name="startIndex">Optional. The record index to start at. All items with a lower index will be dropped from the results.</param>
        /// <param name="limit">Optional. The maximum number of records to return.</param>
        /// <param name="fields">Optional. Specify additional fields of information to return in the output.</param>
        /// <param name="seriesId">Optional. Filter by series id.</param>
        /// <param name="parentId">Optional. Specify this to localize the search to a specific item or folder. Omit to use the root.</param>
        /// <param name="enableImages">Optional. Include image information in output.</param>
        /// <param name="imageTypeLimit">Optional. The max number of images to return, per image type.</param>
        /// <param name="enableImageTypes">Optional. The image types to include in the output.</param>
        /// <param name="enableUserData">Optional. Include user data.</param>
        /// <param name="nextUpDateCutoff">Optional. Starting date of shows to show in Next Up section.</param>
        /// <param name="enableTotalRecordCount">Whether to enable the total records count. Defaults to true.</param>
        /// <param name="disableFirstEpisode">Whether to disable sending the first episode in a series as next up.</param>
        /// <param name="rewatching">Whether to get a rewatching next up instead of standard next up.</param>
        /// <returns>A <see cref="QueryResult{BaseItemDto}"/> with the next up episodes.</returns>
        [HttpGet("NextUp")]
        [ProducesResponseType(StatusCodes.Status200OK)]
        public ActionResult<QueryResult<BaseItemDto>> GetNextUp(
            [FromQuery] Guid? userId,
            [FromQuery] int? startIndex,
            [FromQuery] int? limit,
            [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] ItemFields[] fields,
            [FromQuery] string? seriesId,
            [FromQuery] Guid? parentId,
            [FromQuery] bool? enableImages,
            [FromQuery] int? imageTypeLimit,
            [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] ImageType[] enableImageTypes,
            [FromQuery] bool? enableUserData,
            [FromQuery] DateTime? nextUpDateCutoff,
            [FromQuery] bool enableTotalRecordCount = true,
            [FromQuery] bool disableFirstEpisode = false,
            [FromQuery] bool rewatching = false)
        {
            var options = new DtoOptions { Fields = fields }
                .AddClientFields(Request)
                .AddAdditionalDtoOptions(enableImages, enableUserData, imageTypeLimit, enableImageTypes);

            var result = _tvSeriesManager.GetNextUp(
                new NextUpQuery
                {
                    Limit = limit,
                    ParentId = parentId,
                    SeriesId = seriesId,
                    StartIndex = startIndex,
                    UserId = userId ?? Guid.Empty,
                    EnableTotalRecordCount = enableTotalRecordCount,
                    DisableFirstEpisode = disableFirstEpisode,
                    NextUpDateCutoff = nextUpDateCutoff ?? DateTime.MinValue,
                    Rewatching = rewatching
                },
                options);

            var user = userId is null || userId.Value.Equals(default)
                ? null
                : _userManager.GetUserById(userId.Value);

            var returnItems = _dtoService.GetBaseItemDtos(result.Items, options, user);

            return new QueryResult<BaseItemDto>(
                startIndex,
                result.TotalRecordCount,
                returnItems);
        }

        /// <summary>
        /// Gets a list of upcoming episodes.
        /// </summary>
        /// <param name="userId">The user id of the user to get the upcoming episodes for.</param>
        /// <param name="startIndex">Optional. The record index to start at. All items with a lower index will be dropped from the results.</param>
        /// <param name="limit">Optional. The maximum number of records to return.</param>
        /// <param name="fields">Optional. Specify additional fields of information to return in the output.</param>
        /// <param name="parentId">Optional. Specify this to localize the search to a specific item or folder. Omit to use the root.</param>
        /// <param name="enableImages">Optional. Include image information in output.</param>
        /// <param name="imageTypeLimit">Optional. The max number of images to return, per image type.</param>
        /// <param name="enableImageTypes">Optional. The image types to include in the output.</param>
        /// <param name="enableUserData">Optional. Include user data.</param>
        /// <returns>A <see cref="QueryResult{BaseItemDto}"/> with the next up episodes.</returns>
        [HttpGet("Upcoming")]
        [ProducesResponseType(StatusCodes.Status200OK)]
        public ActionResult<QueryResult<BaseItemDto>> GetUpcomingEpisodes(
            [FromQuery] Guid? userId,
            [FromQuery] int? startIndex,
            [FromQuery] int? limit,
            [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] ItemFields[] fields,
            [FromQuery] Guid? parentId,
            [FromQuery] bool? enableImages,
            [FromQuery] int? imageTypeLimit,
            [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] ImageType[] enableImageTypes,
            [FromQuery] bool? enableUserData)
        {
            var user = userId is null || userId.Value.Equals(default)
                ? null
                : _userManager.GetUserById(userId.Value);

            var minPremiereDate = DateTime.UtcNow.Date.AddDays(-1);

            var parentIdGuid = parentId ?? Guid.Empty;

            var options = new DtoOptions { Fields = fields }
                .AddClientFields(Request)
                .AddAdditionalDtoOptions(enableImages, enableUserData, imageTypeLimit, enableImageTypes);

            var itemsResult = _libraryManager.GetItemList(new InternalItemsQuery(user)
            {
                IncludeItemTypes = new[] { BaseItemKind.Episode },
                OrderBy = new[] { (ItemSortBy.PremiereDate, SortOrder.Ascending), (ItemSortBy.SortName, SortOrder.Ascending) },
                MinPremiereDate = minPremiereDate,
                StartIndex = startIndex,
                Limit = limit,
                ParentId = parentIdGuid,
                Recursive = true,
                DtoOptions = options
            });

            var returnItems = _dtoService.GetBaseItemDtos(itemsResult, options, user);

            return new QueryResult<BaseItemDto>(
                startIndex,
                itemsResult.Count,
                returnItems);
        }

        /// <summary>
        /// Gets episodes for a tv season.
        /// </summary>
        /// <param name="seriesId">The series id.</param>
        /// <param name="userId">The user id.</param>
        /// <param name="fields">Optional. Specify additional fields of information to return in the output. This allows multiple, comma delimited. Options: Budget, Chapters, DateCreated, Genres, HomePageUrl, IndexOptions, MediaStreams, Overview, ParentId, Path, People, ProviderIds, PrimaryImageAspectRatio, Revenue, SortName, Studios, Taglines, TrailerUrls.</param>
        /// <param name="season">Optional filter by season number.</param>
        /// <param name="seasonId">Optional. Filter by season id.</param>
        /// <param name="isMissing">Optional. Filter by items that are missing episodes or not.</param>
        /// <param name="adjacentTo">Optional. Return items that are siblings of a supplied item.</param>
        /// <param name="startItemId">Optional. Skip through the list until a given item is found.</param>
        /// <param name="startIndex">Optional. The record index to start at. All items with a lower index will be dropped from the results.</param>
        /// <param name="limit">Optional. The maximum number of records to return.</param>
        /// <param name="enableImages">Optional, include image information in output.</param>
        /// <param name="imageTypeLimit">Optional, the max number of images to return, per image type.</param>
        /// <param name="enableImageTypes">Optional. The image types to include in the output.</param>
        /// <param name="enableUserData">Optional. Include user data.</param>
        /// <param name="sortBy">Optional. Specify one or more sort orders, comma delimited. Options: Album, AlbumArtist, Artist, Budget, CommunityRating, CriticRating, DateCreated, DatePlayed, PlayCount, PremiereDate, ProductionYear, SortName, Random, Revenue, Runtime.</param>
        /// <returns>A <see cref="QueryResult{BaseItemDto}"/> with the episodes on success or a <see cref="NotFoundResult"/> if the series was not found.</returns>
        [HttpGet("{seriesId}/Episodes")]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public ActionResult<QueryResult<BaseItemDto>> GetEpisodes(
            [FromRoute, Required] Guid seriesId,
            [FromQuery] Guid? userId,
            [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] ItemFields[] fields,
            [FromQuery] int? season,
            [FromQuery] Guid? seasonId,
            [FromQuery] bool? isMissing,
            [FromQuery] string? adjacentTo,
            [FromQuery] Guid? startItemId,
            [FromQuery] int? startIndex,
            [FromQuery] int? limit,
            [FromQuery] bool? enableImages,
            [FromQuery] int? imageTypeLimit,
            [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] ImageType[] enableImageTypes,
            [FromQuery] bool? enableUserData,
            [FromQuery] string? sortBy)
        {
            var user = userId is null || userId.Value.Equals(default)
                ? null
                : _userManager.GetUserById(userId.Value);

            List<BaseItem> episodes;

            var dtoOptions = new DtoOptions { Fields = fields }
                .AddClientFields(Request)
                .AddAdditionalDtoOptions(enableImages, enableUserData, imageTypeLimit, enableImageTypes);

            if (seasonId.HasValue) // Season id was supplied. Get episodes by season id.
            {
                var item = _libraryManager.GetItemById(seasonId.Value);
                if (item is not Season seasonItem)
                {
                    return NotFound("No season exists with Id " + seasonId);
                }

                episodes = seasonItem.GetEpisodes(user, dtoOptions);
            }
            else if (season.HasValue) // Season number was supplied. Get episodes by season number
            {
                if (_libraryManager.GetItemById(seriesId) is not Series series)
                {
                    return NotFound("Series not found");
                }

                var seasonItem = series
                    .GetSeasons(user, dtoOptions)
                    .FirstOrDefault(i => i.IndexNumber == season.Value);

                episodes = seasonItem == null ?
                    new List<BaseItem>()
                    : ((Season)seasonItem).GetEpisodes(user, dtoOptions);
            }
            else // No season number or season id was supplied. Returning all episodes.
            {
                if (_libraryManager.GetItemById(seriesId) is not Series series)
                {
                    return NotFound("Series not found");
                }

                episodes = series.GetEpisodes(user, dtoOptions).ToList();
            }

            // Filter after the fact in case the ui doesn't want them
            if (isMissing.HasValue)
            {
                var val = isMissing.Value;
                episodes = episodes
                    .Where(i => ((Episode)i).IsMissingEpisode == val)
                    .ToList();
            }

            if (startItemId.HasValue)
            {
                episodes = episodes
                    .SkipWhile(i => !startItemId.Value.Equals(i.Id))
                    .ToList();
            }

            // This must be the last filter
            if (!string.IsNullOrEmpty(adjacentTo))
            {
                episodes = UserViewBuilder.FilterForAdjacency(episodes, adjacentTo).ToList();
            }

            if (string.Equals(sortBy, ItemSortBy.Random, StringComparison.OrdinalIgnoreCase))
            {
                episodes.Shuffle();
            }

            var returnItems = episodes;

            if (startIndex.HasValue || limit.HasValue)
            {
                returnItems = ApplyPaging(episodes, startIndex, limit).ToList();
            }

            var dtos = _dtoService.GetBaseItemDtos(returnItems, dtoOptions, user);

            return new QueryResult<BaseItemDto>(
                startIndex,
                episodes.Count,
                dtos);
        }

        /// <summary>
        /// Gets seasons for a tv series.
        /// </summary>
        /// <param name="seriesId">The series id.</param>
        /// <param name="userId">The user id.</param>
        /// <param name="fields">Optional. Specify additional fields of information to return in the output. This allows multiple, comma delimited. Options: Budget, Chapters, DateCreated, Genres, HomePageUrl, IndexOptions, MediaStreams, Overview, ParentId, Path, People, ProviderIds, PrimaryImageAspectRatio, Revenue, SortName, Studios, Taglines, TrailerUrls.</param>
        /// <param name="isSpecialSeason">Optional. Filter by special season.</param>
        /// <param name="isMissing">Optional. Filter by items that are missing episodes or not.</param>
        /// <param name="adjacentTo">Optional. Return items that are siblings of a supplied item.</param>
        /// <param name="enableImages">Optional. Include image information in output.</param>
        /// <param name="imageTypeLimit">Optional. The max number of images to return, per image type.</param>
        /// <param name="enableImageTypes">Optional. The image types to include in the output.</param>
        /// <param name="enableUserData">Optional. Include user data.</param>
        /// <returns>A <see cref="QueryResult{BaseItemDto}"/> on success or a <see cref="NotFoundResult"/> if the series was not found.</returns>
        [HttpGet("{seriesId}/Seasons")]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public ActionResult<QueryResult<BaseItemDto>> GetSeasons(
            [FromRoute, Required] Guid seriesId,
            [FromQuery] Guid? userId,
            [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] ItemFields[] fields,
            [FromQuery] bool? isSpecialSeason,
            [FromQuery] bool? isMissing,
            [FromQuery] string? adjacentTo,
            [FromQuery] bool? enableImages,
            [FromQuery] int? imageTypeLimit,
            [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] ImageType[] enableImageTypes,
            [FromQuery] bool? enableUserData)
        {
            var user = userId is null || userId.Value.Equals(default)
                ? null
                : _userManager.GetUserById(userId.Value);

            if (_libraryManager.GetItemById(seriesId) is not Series series)
            {
                return NotFound("Series not found");
            }

            var seasons = series.GetItemList(new InternalItemsQuery(user)
            {
                IsMissing = isMissing,
                IsSpecialSeason = isSpecialSeason,
                AdjacentTo = adjacentTo
            });

            var dtoOptions = new DtoOptions { Fields = fields }
                .AddClientFields(Request)
                .AddAdditionalDtoOptions(enableImages, enableUserData, imageTypeLimit, enableImageTypes);

            var returnItems = _dtoService.GetBaseItemDtos(seasons, dtoOptions, user);

            return new QueryResult<BaseItemDto>(returnItems);
        }

        /// <summary>
        /// Applies the paging.
        /// </summary>
        /// <param name="items">The items.</param>
        /// <param name="startIndex">The start index.</param>
        /// <param name="limit">The limit.</param>
        /// <returns>IEnumerable{BaseItem}.</returns>
        private IEnumerable<BaseItem> ApplyPaging(IEnumerable<BaseItem> items, int? startIndex, int? limit)
        {
            // Start at
            if (startIndex.HasValue)
            {
                items = items.Skip(startIndex.Value);
            }

            // Return limit
            if (limit.HasValue)
            {
                items = items.Take(limit.Value);
            }

            return items;
        }
    }
}