using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Threading.Tasks;
using Jellyfin.Api.Constants;
using Jellyfin.Api.Extensions;
using Jellyfin.Api.Helpers;
using Jellyfin.Api.ModelBinders;
using Jellyfin.Api.Models.PlaylistDtos;
using MediaBrowser.Controller.Dto;
using MediaBrowser.Controller.Library;
using MediaBrowser.Controller.Playlists;
using MediaBrowser.Model.Dto;
using MediaBrowser.Model.Entities;
using MediaBrowser.Model.Playlists;
using MediaBrowser.Model.Querying;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.ModelBinding;

namespace Jellyfin.Api.Controllers
{
    /// <summary>
    /// Playlists controller.
    /// </summary>
    [Authorize(Policy = Policies.DefaultAuthorization)]
    public class PlaylistsController : BaseJellyfinApiController
    {
        private readonly IPlaylistManager _playlistManager;
        private readonly IDtoService _dtoService;
        private readonly IUserManager _userManager;
        private readonly ILibraryManager _libraryManager;

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

        /// <summary>
        /// Creates a new playlist.
        /// </summary>
        /// <remarks>
        /// For backwards compatibility parameters can be sent via Query or Body, with Query having higher precedence.
        /// </remarks>
        /// <param name="name">The playlist name.</param>
        /// <param name="ids">The item ids.</param>
        /// <param name="userId">The user id.</param>
        /// <param name="mediaType">The media type.</param>
        /// <param name="createPlaylistRequest">The create playlist payload.</param>
        /// <returns>
        /// A <see cref="Task" /> that represents the asynchronous operation to create a playlist.
        /// The task result contains an <see cref="OkResult"/> indicating success.
        /// </returns>
        [HttpPost]
        [ProducesResponseType(StatusCodes.Status200OK)]
        public async Task<ActionResult<PlaylistCreationResult>> CreatePlaylist(
            [FromQuery] string? name,
            [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] IReadOnlyList<Guid> ids,
            [FromQuery] Guid? userId,
            [FromQuery] string? mediaType,
            [FromBody(EmptyBodyBehavior = EmptyBodyBehavior.Allow)] CreatePlaylistDto? createPlaylistRequest)
        {
            if (ids.Count == 0)
            {
                ids = createPlaylistRequest?.Ids ?? Array.Empty<Guid>();
            }

            var result = await _playlistManager.CreatePlaylist(new PlaylistCreationRequest
            {
                Name = name ?? createPlaylistRequest?.Name,
                ItemIdList = ids,
                UserId = userId ?? createPlaylistRequest?.UserId ?? default,
                MediaType = mediaType ?? createPlaylistRequest?.MediaType
            }).ConfigureAwait(false);

            return result;
        }

        /// <summary>
        /// Adds items to a playlist.
        /// </summary>
        /// <param name="playlistId">The playlist id.</param>
        /// <param name="ids">Item id, comma delimited.</param>
        /// <param name="userId">The userId.</param>
        /// <response code="204">Items added to playlist.</response>
        /// <returns>An <see cref="NoContentResult"/> on success.</returns>
        [HttpPost("{playlistId}/Items")]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        public async Task<ActionResult> AddToPlaylist(
            [FromRoute, Required] Guid playlistId,
            [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] Guid[] ids,
            [FromQuery] Guid? userId)
        {
            await _playlistManager.AddToPlaylistAsync(playlistId, ids, userId ?? Guid.Empty).ConfigureAwait(false);
            return NoContent();
        }

        /// <summary>
        /// Moves a playlist item.
        /// </summary>
        /// <param name="playlistId">The playlist id.</param>
        /// <param name="itemId">The item id.</param>
        /// <param name="newIndex">The new index.</param>
        /// <response code="204">Item moved to new index.</response>
        /// <returns>An <see cref="NoContentResult"/> on success.</returns>
        [HttpPost("{playlistId}/Items/{itemId}/Move/{newIndex}")]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        public async Task<ActionResult> MoveItem(
            [FromRoute, Required] string playlistId,
            [FromRoute, Required] string itemId,
            [FromRoute, Required] int newIndex)
        {
            await _playlistManager.MoveItemAsync(playlistId, itemId, newIndex).ConfigureAwait(false);
            return NoContent();
        }

        /// <summary>
        /// Removes items from a playlist.
        /// </summary>
        /// <param name="playlistId">The playlist id.</param>
        /// <param name="entryIds">The item ids, comma delimited.</param>
        /// <response code="204">Items removed.</response>
        /// <returns>An <see cref="NoContentResult"/> on success.</returns>
        [HttpDelete("{playlistId}/Items")]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        public async Task<ActionResult> RemoveFromPlaylist(
            [FromRoute, Required] string playlistId,
            [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] string[] entryIds)
        {
            await _playlistManager.RemoveFromPlaylistAsync(playlistId, entryIds).ConfigureAwait(false);
            return NoContent();
        }

        /// <summary>
        /// Gets the original items of a playlist.
        /// </summary>
        /// <param name="playlistId">The playlist id.</param>
        /// <param name="userId">User id.</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="enableImages">Optional. Include image information in output.</param>
        /// <param name="enableUserData">Optional. Include user data.</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>
        /// <response code="200">Original playlist returned.</response>
        /// <response code="404">Playlist not found.</response>
        /// <returns>The original playlist items.</returns>
        [HttpGet("{playlistId}/Items")]
        public ActionResult<QueryResult<BaseItemDto>> GetPlaylistItems(
            [FromRoute, Required] Guid playlistId,
            [FromQuery, Required] Guid userId,
            [FromQuery] int? startIndex,
            [FromQuery] int? limit,
            [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] ItemFields[] fields,
            [FromQuery] bool? enableImages,
            [FromQuery] bool? enableUserData,
            [FromQuery] int? imageTypeLimit,
            [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] ImageType[] enableImageTypes)
        {
            var playlist = (Playlist)_libraryManager.GetItemById(playlistId);
            if (playlist == null)
            {
                return NotFound();
            }

            var user = !userId.Equals(Guid.Empty) ? _userManager.GetUserById(userId) : null;

            var items = playlist.GetManageableItems().ToArray();

            var count = items.Length;

            if (startIndex.HasValue)
            {
                items = items.Skip(startIndex.Value).ToArray();
            }

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

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

            var dtos = _dtoService.GetBaseItemDtos(items.Select(i => i.Item2).ToList(), dtoOptions, user);

            for (int index = 0; index < dtos.Count; index++)
            {
                dtos[index].PlaylistItemId = items[index].Item1.Id;
            }

            var result = new QueryResult<BaseItemDto>
            {
                Items = dtos,
                TotalRecordCount = count
            };

            return result;
        }
    }
}