using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Jellyfin.Api.Constants;
using Jellyfin.Api.Helpers;
using MediaBrowser.Controller.Configuration;
using MediaBrowser.Controller.Drawing;
using MediaBrowser.Controller.Entities;
using MediaBrowser.Controller.Library;
using MediaBrowser.Controller.Net;
using MediaBrowser.Controller.Providers;
using MediaBrowser.Model.Dto;
using MediaBrowser.Model.Entities;
using MediaBrowser.Model.IO;
using MediaBrowser.Model.Net;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;

namespace Jellyfin.Api.Controllers
{
    /// <summary>
    /// Image controller.
    /// </summary>
    public class ImageController : BaseJellyfinApiController
    {
        private readonly IUserManager _userManager;
        private readonly ILibraryManager _libraryManager;
        private readonly IProviderManager _providerManager;
        private readonly IImageProcessor _imageProcessor;
        private readonly IFileSystem _fileSystem;
        private readonly IAuthorizationContext _authContext;
        private readonly ILogger<ImageController> _logger;
        private readonly IServerConfigurationManager _serverConfigurationManager;

        /// <summary>
        /// Initializes a new instance of the <see cref="ImageController"/> 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="providerManager">Instance of the <see cref="IProviderManager"/> interface.</param>
        /// <param name="imageProcessor">Instance of the <see cref="IImageProcessor"/> interface.</param>
        /// <param name="fileSystem">Instance of the <see cref="IFileSystem"/> interface.</param>
        /// <param name="authContext">Instance of the <see cref="IAuthorizationContext"/> interface.</param>
        /// <param name="logger">Instance of the <see cref="ILogger{ImageController}"/> interface.</param>
        /// <param name="serverConfigurationManager">Instance of the <see cref="IServerConfigurationManager"/> interface.</param>
        public ImageController(
            IUserManager userManager,
            ILibraryManager libraryManager,
            IProviderManager providerManager,
            IImageProcessor imageProcessor,
            IFileSystem fileSystem,
            IAuthorizationContext authContext,
            ILogger<ImageController> logger,
            IServerConfigurationManager serverConfigurationManager)
        {
            _userManager = userManager;
            _libraryManager = libraryManager;
            _providerManager = providerManager;
            _imageProcessor = imageProcessor;
            _fileSystem = fileSystem;
            _authContext = authContext;
            _logger = logger;
            _serverConfigurationManager = serverConfigurationManager;
        }

        /// <summary>
        /// Sets the user image.
        /// </summary>
        /// <param name="userId">User Id.</param>
        /// <param name="imageType">(Unused) Image type.</param>
        /// <param name="index">(Unused) Image index.</param>
        /// <response code="204">Image updated.</response>
        /// <returns>A <see cref="NoContentResult"/>.</returns>
        [HttpPost("/Users/{userId}/Images/{imageType}")]
        [HttpPost("/Users/{userId}/Images/{imageType}/{index?}")]
        [SuppressMessage("Microsoft.Performance", "CA1801:ReviewUnusedParameters", MessageId = "imageType", Justification = "Imported from ServiceStack")]
        [SuppressMessage("Microsoft.Performance", "CA1801:ReviewUnusedParameters", MessageId = "index", Justification = "Imported from ServiceStack")]
        public async Task<ActionResult> PostUserImage(
            [FromRoute] Guid userId,
            [FromRoute] ImageType imageType,
            [FromRoute] int? index = null)
        {
            if (!RequestHelpers.AssertCanUpdateUser(_authContext, HttpContext.Request, userId, true))
            {
                return Forbid("User is not allowed to update the image.");
            }

            var user = _userManager.GetUserById(userId);
            await using var memoryStream = await GetMemoryStream(Request.Body).ConfigureAwait(false);

            // Handle image/png; charset=utf-8
            var mimeType = Request.ContentType.Split(';').FirstOrDefault();
            var userDataPath = Path.Combine(_serverConfigurationManager.ApplicationPaths.UserConfigurationDirectoryPath, user.Username);
            user.ProfileImage = new Data.Entities.ImageInfo(Path.Combine(userDataPath, "profile" + MimeTypes.ToExtension(mimeType)));

            await _providerManager
                .SaveImage(user, memoryStream, mimeType, user.ProfileImage.Path)
                .ConfigureAwait(false);
            await _userManager.UpdateUserAsync(user).ConfigureAwait(false);

            return NoContent();
        }

        /// <summary>
        /// Delete the user's image.
        /// </summary>
        /// <param name="userId">User Id.</param>
        /// <param name="imageType">(Unused) Image type.</param>
        /// <param name="index">(Unused) Image index.</param>
        /// <response code="204">Image deleted.</response>
        /// <returns>A <see cref="NoContentResult"/>.</returns>
        [HttpDelete("/Users/{userId}/Images/{itemType}")]
        [HttpDelete("/Users/{userId}/Images/{itemType}/{index?}")]
        [SuppressMessage("Microsoft.Performance", "CA1801:ReviewUnusedParameters", MessageId = "imageType", Justification = "Imported from ServiceStack")]
        [SuppressMessage("Microsoft.Performance", "CA1801:ReviewUnusedParameters", MessageId = "index", Justification = "Imported from ServiceStack")]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        public ActionResult DeleteUserImage(
            [FromRoute] Guid userId,
            [FromRoute] ImageType imageType,
            [FromRoute] int? index = null)
        {
            if (!RequestHelpers.AssertCanUpdateUser(_authContext, HttpContext.Request, userId, true))
            {
                return Forbid("User is not allowed to delete the image.");
            }

            var user = _userManager.GetUserById(userId);
            try
            {
                System.IO.File.Delete(user.ProfileImage.Path);
            }
            catch (IOException e)
            {
                _logger.LogError(e, "Error deleting user profile image:");
            }

            _userManager.ClearProfileImage(user);
            return NoContent();
        }

        /// <summary>
        /// Delete an item's image.
        /// </summary>
        /// <param name="itemId">Item id.</param>
        /// <param name="imageType">Image type.</param>
        /// <param name="imageIndex">The image index.</param>
        /// <response code="204">Image deleted.</response>
        /// <response code="404">Item not found.</response>
        /// <returns>A <see cref="NoContentResult"/> on success, or a <see cref="NotFoundResult"/> if item not found.</returns>
        [HttpDelete("/Items/{itemId}/Images/{imageType}")]
        [HttpDelete("/Items/{itemId}/Images/{imageType}/{imageIndex?}")]
        [Authorize(Policy = Policies.RequiresElevation)]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public ActionResult DeleteItemImage(
            [FromRoute] Guid itemId,
            [FromRoute] ImageType imageType,
            [FromRoute] int? imageIndex = null)
        {
            var item = _libraryManager.GetItemById(itemId);
            if (item == null)
            {
                return NotFound();
            }

            item.DeleteImage(imageType, imageIndex ?? 0);
            return NoContent();
        }

        /// <summary>
        /// Set item image.
        /// </summary>
        /// <param name="itemId">Item id.</param>
        /// <param name="imageType">Image type.</param>
        /// <param name="imageIndex">(Unused) Image index.</param>
        /// <response code="204">Image saved.</response>
        /// <response code="400">Item not found.</response>
        /// <returns>A <see cref="NoContentResult"/> on success, or a <see cref="NotFoundResult"/> if item not found.</returns>
        [HttpPost("/Items/{itemId}/Images/{imageType}")]
        [HttpPost("/Items/{itemId}/Images/{imageType}/{imageIndex?}")]
        [Authorize(Policy = Policies.RequiresElevation)]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        [SuppressMessage("Microsoft.Performance", "CA1801:ReviewUnusedParameters", MessageId = "index", Justification = "Imported from ServiceStack")]
        public async Task<ActionResult> SetItemImage(
            [FromRoute] Guid itemId,
            [FromRoute] ImageType imageType,
            [FromRoute] int? imageIndex = null)
        {
            var item = _libraryManager.GetItemById(itemId);
            if (item == null)
            {
                return NotFound();
            }

            // Handle image/png; charset=utf-8
            var mimeType = Request.ContentType.Split(';').FirstOrDefault();
            await _providerManager.SaveImage(item, Request.Body, mimeType, imageType, null, CancellationToken.None).ConfigureAwait(false);
            item.UpdateToRepository(ItemUpdateType.ImageUpdate, CancellationToken.None);

            return NoContent();
        }

        /// <summary>
        /// Updates the index for an item image.
        /// </summary>
        /// <param name="itemId">Item id.</param>
        /// <param name="imageType">Image type.</param>
        /// <param name="imageIndex">Old image index.</param>
        /// <param name="newIndex">New image index.</param>
        /// <response code="204">Image index updated.</response>
        /// <response code="404">Item not found.</response>
        /// <returns>A <see cref="NoContentResult"/> on success, or a <see cref="NotFoundResult"/> if item not found.</returns>
        [HttpPost("/Items/{itemId}/Images/{imageType}/{imageIndex}/Index")]
        [Authorize(Policy = Policies.RequiresElevation)]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public ActionResult UpdateItemImageIndex(
            [FromRoute] Guid itemId,
            [FromRoute] ImageType imageType,
            [FromRoute] int imageIndex,
            [FromQuery] int newIndex)
        {
            var item = _libraryManager.GetItemById(itemId);
            if (item == null)
            {
                return NotFound();
            }

            item.SwapImages(imageType, imageIndex, newIndex);
            return NoContent();
        }

        /// <summary>
        /// Get item image infos.
        /// </summary>
        /// <param name="itemId">Item id.</param>
        /// <response code="200">Item images returned.</response>
        /// <response code="404">Item not found.</response>
        /// <returns>The list of image infos on success, or <see cref="NotFoundResult"/> if item not found.</returns>
        [HttpGet("/Items/{itemId}/Images")]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public ActionResult<IEnumerable<ImageInfo>> GetItemImageInfos([FromRoute] Guid itemId)
        {
            var item = _libraryManager.GetItemById(itemId);
            if (item == null)
            {
                return NotFound();
            }

            var list = new List<ImageInfo>();
            var itemImages = item.ImageInfos;

            if (itemImages.Length == 0)
            {
                // short-circuit
                return list;
            }

            _libraryManager.UpdateImages(item); // this makes sure dimensions and hashes are correct

            foreach (var image in itemImages)
            {
                if (!item.AllowsMultipleImages(image.Type))
                {
                    var info = GetImageInfo(item, image, null);

                    if (info != null)
                    {
                        list.Add(info);
                    }
                }
            }

            foreach (var imageType in itemImages.Select(i => i.Type).Distinct().Where(item.AllowsMultipleImages))
            {
                var index = 0;

                // Prevent implicitly captured closure
                var currentImageType = imageType;

                foreach (var image in itemImages.Where(i => i.Type == currentImageType))
                {
                    var info = GetImageInfo(item, image, index);

                    if (info != null)
                    {
                        list.Add(info);
                    }

                    index++;
                }
            }

            return list;
        }

        private static async Task<MemoryStream> GetMemoryStream(Stream inputStream)
        {
            using var reader = new StreamReader(inputStream);
            var text = await reader.ReadToEndAsync().ConfigureAwait(false);

            var bytes = Convert.FromBase64String(text);
            return new MemoryStream(bytes)
            {
                Position = 0
            };
        }

        private ImageInfo? GetImageInfo(BaseItem item, ItemImageInfo info, int? imageIndex)
        {
            int? width = null;
            int? height = null;
            string? blurhash = null;
            long length = 0;

            try
            {
                if (info.IsLocalFile)
                {
                    var fileInfo = _fileSystem.GetFileInfo(info.Path);
                    length = fileInfo.Length;

                    blurhash = info.BlurHash;
                    width = info.Width;
                    height = info.Height;

                    if (width <= 0 || height <= 0)
                    {
                        width = null;
                        height = null;
                    }
                }
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error getting image information for {Item}", item.Name);
            }

            try
            {
                return new ImageInfo
                {
                    Path = info.Path,
                    ImageIndex = imageIndex,
                    ImageType = info.Type,
                    ImageTag = _imageProcessor.GetImageCacheTag(item, info),
                    Size = length,
                    BlurHash = blurhash,
                    Width = width,
                    Height = height
                };
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error getting image information for {Path}", info.Path);

                return null;
            }
        }
    }
}