using MediaBrowser.Common.Extensions;
using MediaBrowser.Controller.Configuration;
using MediaBrowser.Controller.IO;
using MediaBrowser.Controller.Library;
using MediaBrowser.Controller.Localization;
using MediaBrowser.Controller.Persistence;
using MediaBrowser.Controller.Providers;
using MediaBrowser.Controller.Resolvers;
using MediaBrowser.Model.Entities;
using MediaBrowser.Model.Logging;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.Serialization;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace MediaBrowser.Controller.Entities
{
    /// <summary>
    /// Class BaseItem
    /// </summary>
    public abstract class BaseItem : IHasProviderIds
    {
        protected BaseItem()
        {
            Genres = new List<string>();
            TrailerUrls = new List<string>();
            Studios = new List<string>();
            People = new List<PersonInfo>();
            CriticReviews = new List<ItemReview>();
            Taglines = new List<string>();
            ScreenshotImagePaths = new List<string>();
            BackdropImagePaths = new List<string>();
            ProductionLocations = new List<string>();
            Images = new Dictionary<ImageType, string>();
            ProviderIds = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
            Tags = new List<string>();
            ThemeSongIds = new List<Guid>();
            ThemeVideoIds = new List<Guid>();
            LocalTrailerIds = new List<Guid>();
        }

        /// <summary>
        /// The trailer folder name
        /// </summary>
        public const string TrailerFolderName = "trailers";
        public const string ThemeSongsFolderName = "theme-music";
        public const string ThemeVideosFolderName = "backdrops";

        private string _name;
        /// <summary>
        /// Gets or sets the name.
        /// </summary>
        /// <value>The name.</value>
        public virtual string Name
        {
            get
            {
                return _name;
            }
            set
            {
                _name = value;

                // lazy load this again
                _sortName = null;
            }
        }

        /// <summary>
        /// Gets or sets the id.
        /// </summary>
        /// <value>The id.</value>
        public virtual Guid Id { get; set; }

        /// <summary>
        /// Gets or sets the path.
        /// </summary>
        /// <value>The path.</value>
        public virtual string Path { get; set; }

        /// <summary>
        /// Gets or sets the type of the location.
        /// </summary>
        /// <value>The type of the location.</value>
        public virtual LocationType LocationType
        {
            get
            {
                if (string.IsNullOrEmpty(Path))
                {
                    return LocationType.Virtual;
                }

                return System.IO.Path.IsPathRooted(Path) ? LocationType.FileSystem : LocationType.Remote;
            }
        }

        /// <summary>
        /// This is just a helper for convenience
        /// </summary>
        /// <value>The primary image path.</value>
        [IgnoreDataMember]
        public string PrimaryImagePath
        {
            get { return GetImage(ImageType.Primary); }
            set { SetImage(ImageType.Primary, value); }
        }

        /// <summary>
        /// Gets or sets the images.
        /// </summary>
        /// <value>The images.</value>
        public virtual Dictionary<ImageType, string> Images { get; set; }

        /// <summary>
        /// Gets or sets the date created.
        /// </summary>
        /// <value>The date created.</value>
        public DateTime DateCreated { get; set; }

        /// <summary>
        /// Gets or sets the date modified.
        /// </summary>
        /// <value>The date modified.</value>
        public DateTime DateModified { get; set; }

        /// <summary>
        /// The logger
        /// </summary>
        public static ILogger Logger { get; set; }
        public static ILibraryManager LibraryManager { get; set; }
        public static IServerConfigurationManager ConfigurationManager { get; set; }
        public static IProviderManager ProviderManager { get; set; }

        /// <summary>
        /// Returns a <see cref="System.String" /> that represents this instance.
        /// </summary>
        /// <returns>A <see cref="System.String" /> that represents this instance.</returns>
        public override string ToString()
        {
            return Name;
        }

        /// <summary>
        /// Returns true if this item should not attempt to fetch metadata
        /// </summary>
        /// <value><c>true</c> if [dont fetch meta]; otherwise, <c>false</c>.</value>
        [IgnoreDataMember]
        public virtual bool DontFetchMeta
        {
            get
            {
                if (Path != null)
                {
                    return Path.IndexOf("[dontfetchmeta]", StringComparison.OrdinalIgnoreCase) != -1;
                }

                return false;
            }
        }

        /// <summary>
        /// Determines whether the item has a saved local image of the specified name (jpg or png).
        /// </summary>
        /// <param name="name">The name.</param>
        /// <returns><c>true</c> if [has local image] [the specified item]; otherwise, <c>false</c>.</returns>
        /// <exception cref="System.ArgumentNullException">name</exception>
        public bool HasLocalImage(string name)
        {
            if (string.IsNullOrEmpty(name))
            {
                throw new ArgumentNullException("name");
            }

            return ResolveArgs.ContainsMetaFileByName(name + ".jpg") ||
                ResolveArgs.ContainsMetaFileByName(name + ".png");
        }

        /// <summary>
        /// Should be overridden to return the proper folder where metadata lives
        /// </summary>
        /// <value>The meta location.</value>
        [IgnoreDataMember]
        public virtual string MetaLocation
        {
            get
            {
                return Path ?? "";
            }
        }

        /// <summary>
        /// The _provider data
        /// </summary>
        private Dictionary<Guid, BaseProviderInfo> _providerData;
        /// <summary>
        /// Holds persistent data for providers like last refresh date.
        /// Providers can use this to determine if they need to refresh.
        /// The BaseProviderInfo class can be extended to hold anything a provider may need.
        /// Keyed by a unique provider ID.
        /// </summary>
        /// <value>The provider data.</value>
        public Dictionary<Guid, BaseProviderInfo> ProviderData
        {
            get
            {
                return _providerData ?? (_providerData = new Dictionary<Guid, BaseProviderInfo>());
            }
            set
            {
                _providerData = value;
            }
        }

        /// <summary>
        /// The _file system stamp
        /// </summary>
        private Guid? _fileSystemStamp;
        /// <summary>
        /// Gets a directory stamp, in the form of a string, that can be used for
        /// comparison purposes to determine if the file system entries for this item have changed.
        /// </summary>
        /// <value>The file system stamp.</value>
        [IgnoreDataMember]
        public Guid FileSystemStamp
        {
            get
            {
                if (!_fileSystemStamp.HasValue)
                {
                    _fileSystemStamp = GetFileSystemStamp();
                }

                return _fileSystemStamp.Value;
            }
        }

        /// <summary>
        /// Gets the type of the media.
        /// </summary>
        /// <value>The type of the media.</value>
        [IgnoreDataMember]
        public virtual string MediaType
        {
            get
            {
                return null;
            }
        }

        /// <summary>
        /// Gets a directory stamp, in the form of a string, that can be used for
        /// comparison purposes to determine if the file system entries for this item have changed.
        /// </summary>
        /// <returns>Guid.</returns>
        private Guid GetFileSystemStamp()
        {
            // If there's no path or the item is a file, there's nothing to do
            if (LocationType != LocationType.FileSystem || !ResolveArgs.IsDirectory)
            {
                return Guid.Empty;
            }

            var sb = new StringBuilder();

            // Record the name of each file 
            // Need to sort these because accoring to msdn docs, our i/o methods are not guaranteed in any order
            foreach (var file in ResolveArgs.FileSystemChildren
                .Where(i => !i.Attributes.HasFlag(FileAttributes.System))
                .OrderBy(f => f.Name))
            {
                sb.Append(file.Name);
            }
            foreach (var file in ResolveArgs.MetadataFiles.OrderBy(f => f.Name))
            {
                sb.Append(file.Name);
            }

            return sb.ToString().GetMD5();
        }

        /// <summary>
        /// The _resolve args
        /// </summary>
        private ItemResolveArgs _resolveArgs;
        /// <summary>
        /// The _resolve args initialized
        /// </summary>
        private bool _resolveArgsInitialized;
        /// <summary>
        /// The _resolve args sync lock
        /// </summary>
        private object _resolveArgsSyncLock = new object();
        /// <summary>
        /// We attach these to the item so that we only ever have to hit the file system once
        /// (this includes the children of the containing folder)
        /// Use ResolveArgs.FileSystemDictionary to check for the existence of files instead of File.Exists
        /// </summary>
        /// <value>The resolve args.</value>
        [IgnoreDataMember]
        public ItemResolveArgs ResolveArgs
        {
            get
            {
                try
                {
                    LazyInitializer.EnsureInitialized(ref _resolveArgs, ref _resolveArgsInitialized, ref _resolveArgsSyncLock, () => CreateResolveArgs());

                }
                catch (IOException ex)
                {
                    Logger.ErrorException("Error creating resolve args for ", ex, Path);

                    throw;
                }

                return _resolveArgs;
            }
            set
            {
                _resolveArgs = value;
                _resolveArgsInitialized = value != null;

                // Null this out so that it can be lazy loaded again
                _fileSystemStamp = null;
            }
        }

        /// <summary>
        /// Resets the resolve args.
        /// </summary>
        /// <param name="pathInfo">The path info.</param>
        public void ResetResolveArgs(FileSystemInfo pathInfo)
        {
            ResolveArgs = CreateResolveArgs(pathInfo);
        }

        /// <summary>
        /// Creates ResolveArgs on demand
        /// </summary>
        /// <param name="pathInfo">The path info.</param>
        /// <returns>ItemResolveArgs.</returns>
        /// <exception cref="System.IO.IOException">Unable to retrieve file system info for  + path</exception>
        protected internal virtual ItemResolveArgs CreateResolveArgs(FileSystemInfo pathInfo = null)
        {
            var path = Path;

            // non file-system entries will not have a path
            if (LocationType != LocationType.FileSystem || string.IsNullOrEmpty(path))
            {
                return new ItemResolveArgs(ConfigurationManager.ApplicationPaths);
            }

            if (UseParentPathToCreateResolveArgs)
            {
                path = System.IO.Path.GetDirectoryName(path);
            }

            pathInfo = pathInfo ?? FileSystem.GetFileSystemInfo(path);

            if (pathInfo == null || !pathInfo.Exists)
            {
                throw new IOException("Unable to retrieve file system info for " + path);
            }

            var args = new ItemResolveArgs(ConfigurationManager.ApplicationPaths)
            {
                FileInfo = pathInfo,
                Path = path,
                Parent = Parent
            };

            // Gather child folder and files

            if (args.IsDirectory)
            {
                var isPhysicalRoot = args.IsPhysicalRoot;

                // When resolving the root, we need it's grandchildren (children of user views)
                var flattenFolderDepth = isPhysicalRoot ? 2 : 0;

                args.FileSystemDictionary = FileData.GetFilteredFileSystemEntries(args.Path, Logger, flattenFolderDepth: flattenFolderDepth, args: args, resolveShortcuts: isPhysicalRoot || args.IsVf);
            }

            //update our dates
            EntityResolutionHelper.EnsureDates(this, args);

            return args;
        }

        /// <summary>
        /// Some subclasses will stop resolving at a directory and point their Path to a file within. This will help ensure the on-demand resolve args are identical to the
        /// original ones.
        /// </summary>
        /// <value><c>true</c> if [use parent path to create resolve args]; otherwise, <c>false</c>.</value>
        [IgnoreDataMember]
        protected virtual bool UseParentPathToCreateResolveArgs
        {
            get
            {
                return false;
            }
        }

        /// <summary>
        /// Gets or sets the name of the forced sort.
        /// </summary>
        /// <value>The name of the forced sort.</value>
        public string ForcedSortName { get; set; }

        private string _sortName;
        /// <summary>
        /// Gets or sets the name of the sort.
        /// </summary>
        /// <value>The name of the sort.</value>
        [IgnoreDataMember]
        public string SortName
        {
            get
            {
                return ForcedSortName ?? _sortName ?? (_sortName = CreateSortName());
            }
        }

        /// <summary>
        /// Creates the name of the sort.
        /// </summary>
        /// <returns>System.String.</returns>
        protected virtual string CreateSortName()
        {
            if (Name == null) return null; //some items may not have name filled in properly

            var sortable = Name.Trim().ToLower();
            sortable = ConfigurationManager.Configuration.SortRemoveCharacters.Aggregate(sortable, (current, search) => current.Replace(search.ToLower(), string.Empty));

            sortable = ConfigurationManager.Configuration.SortReplaceCharacters.Aggregate(sortable, (current, search) => current.Replace(search.ToLower(), " "));

            foreach (var search in ConfigurationManager.Configuration.SortRemoveWords)
            {
                var searchLower = search.ToLower();
                // Remove from beginning if a space follows
                if (sortable.StartsWith(searchLower + " "))
                {
                    sortable = sortable.Remove(0, searchLower.Length + 1);
                }
                // Remove from middle if surrounded by spaces
                sortable = sortable.Replace(" " + searchLower + " ", " ");

                // Remove from end if followed by a space
                if (sortable.EndsWith(" " + searchLower))
                {
                    sortable = sortable.Remove(sortable.Length - (searchLower.Length + 1));
                }
            }
            return sortable;
        }

        /// <summary>
        /// Gets or sets the parent.
        /// </summary>
        /// <value>The parent.</value>
        [IgnoreDataMember]
        public Folder Parent { get; set; }

        /// <summary>
        /// Gets the collection folder parent.
        /// </summary>
        /// <value>The collection folder parent.</value>
        [IgnoreDataMember]
        public Folder CollectionFolder
        {
            get
            {
                if (this is AggregateFolder)
                {
                    return null;
                }

                if (IsFolder)
                {
                    var iCollectionFolder = this as ICollectionFolder;

                    if (iCollectionFolder != null)
                    {
                        return (Folder)this;
                    }
                }

                var parent = Parent;

                while (parent != null)
                {
                    var iCollectionFolder = parent as ICollectionFolder;

                    if (iCollectionFolder != null)
                    {
                        return parent;
                    }

                    parent = parent.Parent;
                }

                return null;
            }
        }

        /// <summary>
        /// When the item first debuted. For movies this could be premiere date, episodes would be first aired
        /// </summary>
        /// <value>The premiere date.</value>
        public DateTime? PremiereDate { get; set; }

        /// <summary>
        /// Gets or sets the end date.
        /// </summary>
        /// <value>The end date.</value>
        public DateTime? EndDate { get; set; }

        /// <summary>
        /// Gets or sets the display type of the media.
        /// </summary>
        /// <value>The display type of the media.</value>
        public virtual string DisplayMediaType { get; set; }

        /// <summary>
        /// Gets or sets the backdrop image paths.
        /// </summary>
        /// <value>The backdrop image paths.</value>
        public List<string> BackdropImagePaths { get; set; }

        /// <summary>
        /// Gets or sets the screenshot image paths.
        /// </summary>
        /// <value>The screenshot image paths.</value>
        public List<string> ScreenshotImagePaths { get; set; }

        /// <summary>
        /// Gets or sets the official rating.
        /// </summary>
        /// <value>The official rating.</value>
        public virtual string OfficialRating { get; set; }

        /// <summary>
        /// Gets or sets the custom rating.
        /// </summary>
        /// <value>The custom rating.</value>
        public virtual string CustomRating { get; set; }

        /// <summary>
        /// Gets or sets the language.
        /// </summary>
        /// <value>The language.</value>
        public string Language { get; set; }
        /// <summary>
        /// Gets or sets the overview.
        /// </summary>
        /// <value>The overview.</value>
        public string Overview { get; set; }
        /// <summary>
        /// Gets or sets the taglines.
        /// </summary>
        /// <value>The taglines.</value>
        public List<string> Taglines { get; set; }

        /// <summary>
        /// Gets or sets the people.
        /// </summary>
        /// <value>The people.</value>
        public List<PersonInfo> People { get; set; }

        /// <summary>
        /// Gets or sets the tags.
        /// </summary>
        /// <value>The tags.</value>
        public List<string> Tags { get; set; }

        /// <summary>
        /// Override this if you need to combine/collapse person information
        /// </summary>
        /// <value>All people.</value>
        [IgnoreDataMember]
        public virtual IEnumerable<PersonInfo> AllPeople
        {
            get { return People; }
        }

        /// <summary>
        /// Gets or sets the studios.
        /// </summary>
        /// <value>The studios.</value>
        public virtual List<string> Studios { get; set; }

        /// <summary>
        /// Gets or sets the genres.
        /// </summary>
        /// <value>The genres.</value>
        public virtual List<string> Genres { get; set; }

        /// <summary>
        /// Gets or sets the home page URL.
        /// </summary>
        /// <value>The home page URL.</value>
        public string HomePageUrl { get; set; }

        /// <summary>
        /// Gets or sets the budget.
        /// </summary>
        /// <value>The budget.</value>
        public double? Budget { get; set; }

        /// <summary>
        /// Gets or sets the revenue.
        /// </summary>
        /// <value>The revenue.</value>
        public double? Revenue { get; set; }

        /// <summary>
        /// Gets or sets the production locations.
        /// </summary>
        /// <value>The production locations.</value>
        public List<string> ProductionLocations { get; set; }

        /// <summary>
        /// Gets or sets the critic rating.
        /// </summary>
        /// <value>The critic rating.</value>
        public float? CriticRating { get; set; }

        /// <summary>
        /// Gets or sets the critic rating summary.
        /// </summary>
        /// <value>The critic rating summary.</value>
        public string CriticRatingSummary { get; set; }

        /// <summary>
        /// Gets or sets the community rating.
        /// </summary>
        /// <value>The community rating.</value>
        public float? CommunityRating { get; set; }
        /// <summary>
        /// Gets or sets the run time ticks.
        /// </summary>
        /// <value>The run time ticks.</value>
        public long? RunTimeTicks { get; set; }

        /// <summary>
        /// Gets or sets the aspect ratio.
        /// </summary>
        /// <value>The aspect ratio.</value>
        public string AspectRatio { get; set; }
        /// <summary>
        /// Gets or sets the production year.
        /// </summary>
        /// <value>The production year.</value>
        public virtual int? ProductionYear { get; set; }

        /// <summary>
        /// If the item is part of a series, this is it's number in the series.
        /// This could be episode number, album track number, etc.
        /// </summary>
        /// <value>The index number.</value>
        public int? IndexNumber { get; set; }

        /// <summary>
        /// For an episode this could be the season number, or for a song this could be the disc number.
        /// </summary>
        /// <value>The parent index number.</value>
        public int? ParentIndexNumber { get; set; }

        /// <summary>
        /// Gets or sets the critic reviews.
        /// </summary>
        /// <value>The critic reviews.</value>
        public List<ItemReview> CriticReviews { get; set; }

        public List<Guid> ThemeSongIds { get; set; }
        public List<Guid> ThemeVideoIds { get; set; }
        public List<Guid> LocalTrailerIds { get; set; }

        /// <summary>
        /// Loads local trailers from the file system
        /// </summary>
        /// <returns>List{Video}.</returns>
        private IEnumerable<Trailer> LoadLocalTrailers()
        {
            if (LocationType != LocationType.FileSystem)
            {
                return new List<Trailer>();
            }

            ItemResolveArgs resolveArgs;

            try
            {
                resolveArgs = ResolveArgs;
            }
            catch (IOException ex)
            {
                Logger.ErrorException("Error getting ResolveArgs for {0}", ex, Path);
                return new List<Trailer>();
            }

            if (!resolveArgs.IsDirectory)
            {
                return new List<Trailer>();
            }

            var folder = resolveArgs.GetFileSystemEntryByName(TrailerFolderName);

            // Path doesn't exist. No biggie
            if (folder == null)
            {
                return new List<Trailer>();
            }

            IEnumerable<FileSystemInfo> files;

            try
            {
                files = new DirectoryInfo(folder.FullName).EnumerateFiles();
            }
            catch (IOException ex)
            {
                Logger.ErrorException("Error loading trailers for {0}", ex, Name);
                return new List<Trailer>();
            }

            return LibraryManager.ResolvePaths<Trailer>(files, null).Select(video =>
            {
                // Try to retrieve it from the db. If we don't find it, use the resolved version
                var dbItem = LibraryManager.RetrieveItem(video.Id) as Trailer;

                if (dbItem != null)
                {
                    dbItem.ResolveArgs = video.ResolveArgs;
                    video = dbItem;
                }

                return video;
            }).ToList();
        }

        /// <summary>
        /// Loads the theme songs.
        /// </summary>
        /// <returns>List{Audio.Audio}.</returns>
        private IEnumerable<Audio.Audio> LoadThemeSongs()
        {
            if (LocationType != LocationType.FileSystem)
            {
                return new List<Audio.Audio>();
            }

            ItemResolveArgs resolveArgs;

            try
            {
                resolveArgs = ResolveArgs;
            }
            catch (IOException ex)
            {
                Logger.ErrorException("Error getting ResolveArgs for {0}", ex, Path);
                return new List<Audio.Audio>();
            }

            if (!resolveArgs.IsDirectory)
            {
                return new List<Audio.Audio>();
            }

            var folder = resolveArgs.GetFileSystemEntryByName(ThemeSongsFolderName);

            // Path doesn't exist. No biggie
            if (folder == null)
            {
                return new List<Audio.Audio>();
            }

            IEnumerable<FileSystemInfo> files;

            try
            {
                files = new DirectoryInfo(folder.FullName).EnumerateFiles();
            }
            catch (IOException ex)
            {
                Logger.ErrorException("Error loading theme songs for {0}", ex, Name);
                return new List<Audio.Audio>();
            }

            return LibraryManager.ResolvePaths<Audio.Audio>(files, null).Select(audio =>
            {
                // Try to retrieve it from the db. If we don't find it, use the resolved version
                var dbItem = LibraryManager.RetrieveItem(audio.Id) as Audio.Audio;

                if (dbItem != null)
                {
                    dbItem.ResolveArgs = audio.ResolveArgs;
                    audio = dbItem;
                }

                return audio;
            }).ToList();
        }

        /// <summary>
        /// Loads the video backdrops.
        /// </summary>
        /// <returns>List{Video}.</returns>
        private IEnumerable<Video> LoadThemeVideos()
        {
            if (LocationType != LocationType.FileSystem)
            {
                return new List<Video>();
            }

            ItemResolveArgs resolveArgs;

            try
            {
                resolveArgs = ResolveArgs;
            }
            catch (IOException ex)
            {
                Logger.ErrorException("Error getting ResolveArgs for {0}", ex, Path);
                return new List<Video>();
            }

            if (!resolveArgs.IsDirectory)
            {
                return new List<Video>();
            }

            var folder = resolveArgs.GetFileSystemEntryByName(ThemeVideosFolderName);

            // Path doesn't exist. No biggie
            if (folder == null)
            {
                return new List<Video>();
            }

            IEnumerable<FileSystemInfo> files;

            try
            {
                files = new DirectoryInfo(folder.FullName).EnumerateFiles();
            }
            catch (IOException ex)
            {
                Logger.ErrorException("Error loading video backdrops for {0}", ex, Name);
                return new List<Video>();
            }

            return LibraryManager.ResolvePaths<Video>(files, null).Select(item =>
            {
                // Try to retrieve it from the db. If we don't find it, use the resolved version
                var dbItem = LibraryManager.RetrieveItem(item.Id) as Video;

                if (dbItem != null)
                {
                    dbItem.ResolveArgs = item.ResolveArgs;
                    item = dbItem;
                }

                return item;
            }).ToList();
        }

        /// <summary>
        /// Overrides the base implementation to refresh metadata for local trailers
        /// </summary>
        /// <param name="cancellationToken">The cancellation token.</param>
        /// <param name="forceSave">if set to <c>true</c> [is new item].</param>
        /// <param name="forceRefresh">if set to <c>true</c> [force].</param>
        /// <param name="allowSlowProviders">if set to <c>true</c> [allow slow providers].</param>
        /// <param name="resetResolveArgs">if set to <c>true</c> [reset resolve args].</param>
        /// <returns>true if a provider reports we changed</returns>
        public virtual async Task<bool> RefreshMetadata(CancellationToken cancellationToken, bool forceSave = false, bool forceRefresh = false, bool allowSlowProviders = true, bool resetResolveArgs = true)
        {
            if (resetResolveArgs)
            {
                ResolveArgs = null;
            }

            // Refresh for the item
            var itemRefreshTask = ProviderManager.ExecuteMetadataProviders(this, cancellationToken, forceRefresh, allowSlowProviders);

            cancellationToken.ThrowIfCancellationRequested();

            var themeSongsChanged = await RefreshThemeSongs(cancellationToken, forceSave, forceRefresh, allowSlowProviders).ConfigureAwait(false);

            var themeVideosChanged = await RefreshThemeVideos(cancellationToken, forceSave, forceRefresh, allowSlowProviders).ConfigureAwait(false);

            var localTrailersChanged = await RefreshLocalTrailers(cancellationToken, forceSave, forceRefresh, allowSlowProviders).ConfigureAwait(false);

            cancellationToken.ThrowIfCancellationRequested();

            cancellationToken.ThrowIfCancellationRequested();

            // Get the result from the item task
            var changed = await itemRefreshTask.ConfigureAwait(false);

            if (changed || forceSave || themeSongsChanged || themeVideosChanged || localTrailersChanged)
            {
                cancellationToken.ThrowIfCancellationRequested();

                await LibraryManager.UpdateItem(this, cancellationToken).ConfigureAwait(false);
            }

            return changed;
        }

        private async Task<bool> RefreshLocalTrailers(CancellationToken cancellationToken, bool forceSave = false, bool forceRefresh = false, bool allowSlowProviders = true)
        {
            var newItems = LoadLocalTrailers().ToList();
            var newItemIds = newItems.Select(i => i.Id).ToList();

            var itemsChanged = !LocalTrailerIds.SequenceEqual(newItemIds);

            var tasks = newItems.Select(i => i.RefreshMetadata(cancellationToken, forceSave, forceRefresh, allowSlowProviders));

            var results = await Task.WhenAll(tasks).ConfigureAwait(false);

            LocalTrailerIds = newItemIds;

            return itemsChanged || results.Contains(true);
        }
        
        private async Task<bool> RefreshThemeVideos(CancellationToken cancellationToken, bool forceSave = false, bool forceRefresh = false, bool allowSlowProviders = true)
        {
            var newThemeVideos = LoadThemeVideos().ToList();
            var newThemeVideoIds = newThemeVideos.Select(i => i.Id).ToList();

            var themeVideosChanged = !ThemeVideoIds.SequenceEqual(newThemeVideoIds);

            var tasks = newThemeVideos.Select(i => i.RefreshMetadata(cancellationToken, forceSave, forceRefresh, allowSlowProviders));

            var results = await Task.WhenAll(tasks).ConfigureAwait(false);

            ThemeVideoIds = newThemeVideoIds;

            return themeVideosChanged || results.Contains(true);
        }
        
        /// <summary>
        /// Refreshes the theme songs.
        /// </summary>
        private async Task<bool> RefreshThemeSongs(CancellationToken cancellationToken, bool forceSave = false, bool forceRefresh = false, bool allowSlowProviders = true)
        {
            var newThemeSongs = LoadThemeSongs().ToList();
            var newThemeSongIds = newThemeSongs.Select(i => i.Id).ToList();

            var themeSongsChanged = !ThemeSongIds.SequenceEqual(newThemeSongIds);

            var tasks = newThemeSongs.Select(i => i.RefreshMetadata(cancellationToken, forceSave, forceRefresh, allowSlowProviders));

            var results = await Task.WhenAll(tasks).ConfigureAwait(false);

            ThemeSongIds = newThemeSongIds;

            return themeSongsChanged || results.Contains(true);
        }

        /// <summary>
        /// Clear out all metadata properties. Extend for sub-classes.
        /// </summary>
        public virtual void ClearMetaValues()
        {
            Images.Clear();
            ForcedSortName = null;
            PremiereDate = null;
            BackdropImagePaths.Clear();
            OfficialRating = null;
            CustomRating = null;
            Overview = null;
            Taglines.Clear();
            Language = null;
            Studios.Clear();
            Genres.Clear();
            CommunityRating = null;
            RunTimeTicks = null;
            AspectRatio = null;
            ProductionYear = null;
            ProviderIds.Clear();
            DisplayMediaType = GetType().Name;
            ResolveArgs = null;
        }

        /// <summary>
        /// Gets or sets the trailer URL.
        /// </summary>
        /// <value>The trailer URL.</value>
        public List<string> TrailerUrls { get; set; }

        /// <summary>
        /// Gets or sets the provider ids.
        /// </summary>
        /// <value>The provider ids.</value>
        public Dictionary<string, string> ProviderIds { get; set; }

        /// <summary>
        /// Override this to false if class should be ignored for indexing purposes
        /// </summary>
        /// <value><c>true</c> if [include in index]; otherwise, <c>false</c>.</value>
        [IgnoreDataMember]
        public virtual bool IncludeInIndex
        {
            get { return true; }
        }

        /// <summary>
        /// Override this to true if class should be grouped under a container in indicies
        /// The container class should be defined via IndexContainer
        /// </summary>
        /// <value><c>true</c> if [group in index]; otherwise, <c>false</c>.</value>
        [IgnoreDataMember]
        public virtual bool GroupInIndex
        {
            get { return false; }
        }

        /// <summary>
        /// Override this to return the folder that should be used to construct a container
        /// for this item in an index.  GroupInIndex should be true as well.
        /// </summary>
        /// <value>The index container.</value>
        [IgnoreDataMember]
        public virtual Folder IndexContainer
        {
            get { return null; }
        }

        /// <summary>
        /// Gets the user data key.
        /// </summary>
        /// <returns>System.String.</returns>
        public virtual string GetUserDataKey()
        {
            return Id.ToString();
        }

        /// <summary>
        /// Determines if a given user has access to this item
        /// </summary>
        /// <param name="user">The user.</param>
        /// <returns><c>true</c> if [is parental allowed] [the specified user]; otherwise, <c>false</c>.</returns>
        /// <exception cref="System.ArgumentNullException"></exception>
        public bool IsParentalAllowed(User user)
        {
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }

            if (user.Configuration.MaxParentalRating == null)
            {
                return true;
            }

            return Ratings.Level(CustomRating ?? OfficialRating) <= user.Configuration.MaxParentalRating.Value;
        }

        /// <summary>
        /// Determines if this folder should be visible to a given user.
        /// Default is just parental allowed. Can be overridden for more functionality.
        /// </summary>
        /// <param name="user">The user.</param>
        /// <returns><c>true</c> if the specified user is visible; otherwise, <c>false</c>.</returns>
        /// <exception cref="System.ArgumentNullException">user</exception>
        public virtual bool IsVisible(User user)
        {
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }

            return IsParentalAllowed(user);
        }

        /// <summary>
        /// Finds the particular item by searching through our parents and, if not found there, loading from repo
        /// </summary>
        /// <param name="id">The id.</param>
        /// <returns>BaseItem.</returns>
        /// <exception cref="System.ArgumentException"></exception>
        protected BaseItem FindParentItem(Guid id)
        {
            if (id == Guid.Empty)
            {
                throw new ArgumentException();
            }

            var parent = Parent;
            while (parent != null && !parent.IsRoot)
            {
                if (parent.Id == id) return parent;
                parent = parent.Parent;
            }

            //not found - load from repo
            return LibraryManager.RetrieveItem(id);
        }

        /// <summary>
        /// Gets a value indicating whether this instance is folder.
        /// </summary>
        /// <value><c>true</c> if this instance is folder; otherwise, <c>false</c>.</value>
        [IgnoreDataMember]
        public virtual bool IsFolder
        {
            get
            {
                return false;
            }
        }

        /// <summary>
        /// Determine if we have changed vs the passed in copy
        /// </summary>
        /// <param name="copy">The copy.</param>
        /// <returns><c>true</c> if the specified copy has changed; otherwise, <c>false</c>.</returns>
        /// <exception cref="System.ArgumentNullException"></exception>
        public virtual bool HasChanged(BaseItem copy)
        {
            if (copy == null)
            {
                throw new ArgumentNullException();
            }

            var changed = copy.DateModified != DateModified;
            if (changed)
            {
                Logger.Debug(Name + " changed - original creation: " + DateCreated + " new creation: " + copy.DateCreated + " original modified: " + DateModified + " new modified: " + copy.DateModified);
            }
            return changed;
        }

        /// <summary>
        /// Determines if the item is considered new based on user settings
        /// </summary>
        /// <returns><c>true</c> if [is recently added] [the specified user]; otherwise, <c>false</c>.</returns>
        /// <exception cref="System.ArgumentNullException"></exception>
        public bool IsRecentlyAdded()
        {
            return (DateTime.UtcNow - DateCreated).TotalDays < ConfigurationManager.Configuration.RecentItemDays;
        }

        /// <summary>
        /// Adds a person to the item
        /// </summary>
        /// <param name="person">The person.</param>
        /// <exception cref="System.ArgumentNullException"></exception>
        public void AddPerson(PersonInfo person)
        {
            if (person == null)
            {
                throw new ArgumentNullException("person");
            }

            if (string.IsNullOrWhiteSpace(person.Name))
            {
                throw new ArgumentNullException();
            }

            // If the type is GuestStar and there's already an Actor entry, then update it to avoid dupes
            if (string.Equals(person.Type, PersonType.GuestStar, StringComparison.OrdinalIgnoreCase))
            {
                var existing = People.FirstOrDefault(p => p.Name.Equals(person.Name, StringComparison.OrdinalIgnoreCase) && p.Type.Equals(PersonType.Actor, StringComparison.OrdinalIgnoreCase));

                if (existing != null)
                {
                    existing.Type = PersonType.GuestStar;
                    return;
                }
            }

            if (string.Equals(person.Type, PersonType.Actor, StringComparison.OrdinalIgnoreCase))
            {
                // If the actor already exists without a role and we have one, fill it in
                var existing = People.FirstOrDefault(p => p.Name.Equals(person.Name, StringComparison.OrdinalIgnoreCase) && (p.Type.Equals(PersonType.Actor, StringComparison.OrdinalIgnoreCase) || p.Type.Equals(PersonType.GuestStar, StringComparison.OrdinalIgnoreCase)));
                if (existing == null)
                {
                    // Wasn't there - add it
                    People.Add(person);
                }
                else
                {
                    // Was there, if no role and we have one - fill it in
                    if (string.IsNullOrWhiteSpace(existing.Role) && !string.IsNullOrWhiteSpace(person.Role)) existing.Role = person.Role;
                }
            }
            else
            {
                // Check for dupes based on the combination of Name and Type
                if (!People.Any(p => p.Name.Equals(person.Name, StringComparison.OrdinalIgnoreCase) && p.Type.Equals(person.Type, StringComparison.OrdinalIgnoreCase)))
                {
                    People.Add(person);
                }
            }
        }

        /// <summary>
        /// Adds a studio to the item
        /// </summary>
        /// <param name="name">The name.</param>
        /// <exception cref="System.ArgumentNullException"></exception>
        public void AddStudio(string name)
        {
            if (string.IsNullOrWhiteSpace(name))
            {
                throw new ArgumentNullException("name");
            }

            if (!Studios.Contains(name, StringComparer.OrdinalIgnoreCase))
            {
                Studios.Add(name);
            }
        }

        /// <summary>
        /// Adds a tagline to the item
        /// </summary>
        /// <param name="name">The name.</param>
        /// <exception cref="System.ArgumentNullException"></exception>
        public void AddTagline(string name)
        {
            if (string.IsNullOrWhiteSpace(name))
            {
                throw new ArgumentNullException("name");
            }

            if (!Taglines.Contains(name, StringComparer.OrdinalIgnoreCase))
            {
                Taglines.Add(name);
            }
        }

        /// <summary>
        /// Adds a TrailerUrl to the item
        /// </summary>
        /// <param name="url">The URL.</param>
        /// <exception cref="System.ArgumentNullException"></exception>
        public void AddTrailerUrl(string url)
        {
            if (string.IsNullOrWhiteSpace(url))
            {
                throw new ArgumentNullException("url");
            }

            if (TrailerUrls == null)
            {
                TrailerUrls = new List<string>();
            }

            if (!TrailerUrls.Contains(url, StringComparer.OrdinalIgnoreCase))
            {
                TrailerUrls.Add(url);
            }
        }

        /// <summary>
        /// Adds a genre to the item
        /// </summary>
        /// <param name="name">The name.</param>
        /// <exception cref="System.ArgumentNullException"></exception>
        public void AddGenre(string name)
        {
            if (string.IsNullOrWhiteSpace(name))
            {
                throw new ArgumentNullException("name");
            }

            if (!Genres.Contains(name, StringComparer.OrdinalIgnoreCase))
            {
                Genres.Add(name);
            }
        }

        /// <summary>
        /// Adds the production location.
        /// </summary>
        /// <param name="location">The location.</param>
        /// <exception cref="System.ArgumentNullException">location</exception>
        public void AddProductionLocation(string location)
        {
            if (string.IsNullOrWhiteSpace(location))
            {
                throw new ArgumentNullException("location");
            }

            if (ProductionLocations == null)
            {
                ProductionLocations = new List<string>();
            }

            if (!ProductionLocations.Contains(location, StringComparer.OrdinalIgnoreCase))
            {
                ProductionLocations.Add(location);
            }
        }

        /// <summary>
        /// Marks the item as either played or unplayed
        /// </summary>
        /// <param name="user">The user.</param>
        /// <param name="wasPlayed">if set to <c>true</c> [was played].</param>
        /// <param name="userManager">The user manager.</param>
        /// <returns>Task.</returns>
        /// <exception cref="System.ArgumentNullException"></exception>
        public virtual async Task SetPlayedStatus(User user, bool wasPlayed, IUserDataRepository userManager)
        {
            if (user == null)
            {
                throw new ArgumentNullException();
            }

            var key = GetUserDataKey();

            var data = await userManager.GetUserData(user.Id, key).ConfigureAwait(false);

            if (wasPlayed)
            {
                data.PlayCount = Math.Max(data.PlayCount, 1);

                if (!data.LastPlayedDate.HasValue)
                {
                    data.LastPlayedDate = DateTime.UtcNow;
                }
            }
            else
            {
                //I think it is okay to do this here.
                // if this is only called when a user is manually forcing something to un-played
                // then it probably is what we want to do...
                data.PlayCount = 0;
                data.PlaybackPositionTicks = 0;
                data.LastPlayedDate = null;
            }

            data.Played = wasPlayed;

            await userManager.SaveUserData(user.Id, key, data, CancellationToken.None).ConfigureAwait(false);
        }

        /// <summary>
        /// Do whatever refreshing is necessary when the filesystem pertaining to this item has changed.
        /// </summary>
        /// <returns>Task.</returns>
        public virtual Task ChangedExternally()
        {
            return RefreshMetadata(CancellationToken.None);
        }

        /// <summary>
        /// Finds a parent of a given type
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <returns>``0.</returns>
        public T FindParent<T>()
            where T : Folder
        {
            var parent = Parent;

            while (parent != null)
            {
                var result = parent as T;
                if (result != null)
                {
                    return result;
                }

                parent = parent.Parent;
            }

            return null;
        }

        /// <summary>
        /// Gets an image
        /// </summary>
        /// <param name="type">The type.</param>
        /// <returns>System.String.</returns>
        /// <exception cref="System.ArgumentException">Backdrops should be accessed using Item.Backdrops</exception>
        public string GetImage(ImageType type)
        {
            if (type == ImageType.Backdrop)
            {
                throw new ArgumentException("Backdrops should be accessed using Item.Backdrops");
            }
            if (type == ImageType.Screenshot)
            {
                throw new ArgumentException("Screenshots should be accessed using Item.Screenshots");
            }

            if (Images == null)
            {
                return null;
            }

            string val;
            Images.TryGetValue(type, out val);
            return val;
        }

        /// <summary>
        /// Gets an image
        /// </summary>
        /// <param name="type">The type.</param>
        /// <returns><c>true</c> if the specified type has image; otherwise, <c>false</c>.</returns>
        /// <exception cref="System.ArgumentException">Backdrops should be accessed using Item.Backdrops</exception>
        public bool HasImage(ImageType type)
        {
            if (type == ImageType.Backdrop)
            {
                throw new ArgumentException("Backdrops should be accessed using Item.Backdrops");
            }
            if (type == ImageType.Screenshot)
            {
                throw new ArgumentException("Screenshots should be accessed using Item.Screenshots");
            }

            return !string.IsNullOrEmpty(GetImage(type));
        }

        /// <summary>
        /// Sets an image
        /// </summary>
        /// <param name="type">The type.</param>
        /// <param name="path">The path.</param>
        /// <exception cref="System.ArgumentException">Backdrops should be accessed using Item.Backdrops</exception>
        public void SetImage(ImageType type, string path)
        {
            if (type == ImageType.Backdrop)
            {
                throw new ArgumentException("Backdrops should be accessed using Item.Backdrops");
            }
            if (type == ImageType.Screenshot)
            {
                throw new ArgumentException("Screenshots should be accessed using Item.Screenshots");
            }

            var typeKey = type;

            // If it's null remove the key from the dictionary
            if (string.IsNullOrEmpty(path))
            {
                if (Images != null)
                {
                    if (Images.ContainsKey(typeKey))
                    {
                        Images.Remove(typeKey);
                    }
                }
            }
            else
            {
                Images[typeKey] = path;
            }
        }

        /// <summary>
        /// Deletes the image.
        /// </summary>
        /// <param name="type">The type.</param>
        /// <param name="index">The index.</param>
        /// <returns>Task.</returns>
        public Task DeleteImage(ImageType type, int? index)
        {
            if (type == ImageType.Backdrop)
            {
                if (!index.HasValue)
                {
                    throw new ArgumentException("Please specify a backdrop image index to delete.");
                }

                var file = BackdropImagePaths[index.Value];

                BackdropImagePaths.Remove(file);

                // Delete the source file
                File.Delete(file);
            }
            else if (type == ImageType.Screenshot)
            {
                if (!index.HasValue)
                {
                    throw new ArgumentException("Please specify a screenshot image index to delete.");
                }

                var file = ScreenshotImagePaths[index.Value];

                ScreenshotImagePaths.Remove(file);

                // Delete the source file
                File.Delete(file);
            }
            else
            {
                // Delete the source file
                File.Delete(GetImage(type));

                // Remove it from the item
                SetImage(type, null);
            }

            // Refresh metadata
            return RefreshMetadata(CancellationToken.None);
        }
    }
}