improve user view images

MediaBrowser.Server.Implementations/Photos/BaseDynamicImageProvider.cs

@@ -0,0 +1,189 @@
+using MediaBrowser.Common.Extensions;
+using MediaBrowser.Common.IO;
+using MediaBrowser.Controller.Entities;
+using MediaBrowser.Controller.Library;
+using MediaBrowser.Controller.Providers;
+using MediaBrowser.Model.Entities;
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.Drawing.Imaging;
+using System.Globalization;
+using System.IO;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MediaBrowser.Server.Implementations.Photos
+{
+    public abstract class BaseDynamicImageProvider<T> : IHasChangeMonitor
+        where T : IHasImages
+    {
+        protected IFileSystem FileSystem { get; private set; }
+        protected IProviderManager ProviderManager { get; private set; }
+
+        protected BaseDynamicImageProvider(IFileSystem fileSystem, IProviderManager providerManager)
+        {
+            ProviderManager = providerManager;
+            FileSystem = fileSystem;
+        }
+
+        public async Task<ItemUpdateType> FetchAsync(T item, MetadataRefreshOptions options, CancellationToken cancellationToken)
+        {
+            if (!Supports(item))
+            {
+                return ItemUpdateType.None;
+            }
+
+            var primaryResult = await FetchAsync(item, ImageType.Primary, options, cancellationToken).ConfigureAwait(false);
+            var thumbResult = await FetchAsync(item, ImageType.Thumb, options, cancellationToken).ConfigureAwait(false);
+
+            return primaryResult | thumbResult;
+        }
+
+        protected virtual bool Supports(IHasImages item)
+        {
+            return true;
+        }
+
+        protected abstract Task<List<BaseItem>> GetItemsWithImages(IHasImages item);
+
+        private const string Version = "3";
+        protected  string GetConfigurationCacheKey(List<BaseItem> items)
+        {
+            return (Version + "_" + string.Join(",", items.Select(i => i.Id.ToString("N")).ToArray())).GetMD5().ToString("N");
+        }
+
+        protected async Task<ItemUpdateType> FetchAsync(IHasImages item, ImageType imageType, MetadataRefreshOptions options, CancellationToken cancellationToken)
+        {
+            var items = await GetItemsWithImages(item).ConfigureAwait(false);
+            var cacheKey = GetConfigurationCacheKey(items);
+
+            if (!HasChanged(item, imageType, cacheKey))
+            {
+                return ItemUpdateType.None;
+            }
+
+            return await FetchAsyncInternal(item, items, imageType, cacheKey, options, cancellationToken).ConfigureAwait(false);
+        }
+
+        protected async Task<ItemUpdateType> FetchAsyncInternal(IHasImages item, 
+            List<BaseItem> itemsWithImages,
+            ImageType imageType, 
+            string cacheKey, 
+            MetadataRefreshOptions options, 
+            CancellationToken cancellationToken)
+        {
+            var img = await CreateImageAsync(item, itemsWithImages, imageType, 0).ConfigureAwait(false);
+
+            if (img == null)
+            {
+                return ItemUpdateType.None;
+            }
+
+            using (var ms = new MemoryStream())
+            {
+                img.Save(ms, ImageFormat.Png);
+
+                ms.Position = 0;
+
+                await ProviderManager.SaveImage(item, ms, "image/png", imageType, null, cacheKey, cancellationToken).ConfigureAwait(false);
+            }
+
+            return ItemUpdateType.ImageUpdate;
+        }
+
+        protected Task<Image> GetThumbCollage(List<BaseItem> items)
+        {
+            return DynamicImageHelpers.GetThumbCollage(items.Select(i => i.GetImagePath(ImageType.Primary)).ToList(),
+                FileSystem,
+                1600,
+                900);
+        }
+
+        protected Task<Image> GetSquareCollage(List<BaseItem> items)
+        {
+            return DynamicImageHelpers.GetSquareCollage(items.Select(i => i.GetImagePath(ImageType.Primary)).ToList(),
+                FileSystem,
+                800);
+        }
+
+        public string Name
+        {
+            get { return "Dynamic Image Provider"; }
+        }
+
+        public async Task<Image> CreateImageAsync(IHasImages item, 
+            List<BaseItem> itemsWithImages,
+            ImageType imageType, 
+            int imageIndex)
+        {
+            if (itemsWithImages.Count == 0)
+            {
+                return null;
+            }
+
+            return imageType == ImageType.Thumb ?
+                await GetThumbCollage(itemsWithImages).ConfigureAwait(false) :
+                await GetSquareCollage(itemsWithImages).ConfigureAwait(false);
+        }
+
+        public bool HasChanged(IHasMetadata item, IDirectoryService directoryService, DateTime date)
+        {
+            if (!Supports(item))
+            {
+                return false;
+            }
+
+            var items = GetItemsWithImages(item).Result;
+            var cacheKey = GetConfigurationCacheKey(items);
+
+            return HasChanged(item, ImageType.Primary, cacheKey) || HasChanged(item, ImageType.Thumb, cacheKey);
+        }
+
+        protected bool HasChanged(IHasImages item, ImageType type, string cacheKey)
+        {
+            var image = item.GetImageInfo(type, 0);
+
+            if (image != null)
+            {
+                if (!FileSystem.ContainsSubPath(item.GetInternalMetadataPath(), image.Path))
+                {
+                    return false;
+                }
+
+                var currentPathCacheKey = (Path.GetFileNameWithoutExtension(image.Path) ?? string.Empty).Split('_').LastOrDefault();
+
+                if (string.Equals(cacheKey, currentPathCacheKey, StringComparison.OrdinalIgnoreCase))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        protected List<BaseItem> GetFinalItems(List<BaseItem> items)
+        {
+            // Rotate the images no more than once per week
+            var random = new Random(GetWeekOfYear()).Next();
+
+            return items
+                .OrderBy(i => random - items.IndexOf(i))
+                .Take(4)
+                .OrderBy(i => i.Name)
+                .ToList();
+        }
+
+        private int GetWeekOfYear()
+        {
+            var usCulture = new CultureInfo("en-US");
+            var weekNo = usCulture.Calendar.GetWeekOfYear(
+                            DateTime.Now,
+                            usCulture.DateTimeFormat.CalendarWeekRule,
+                            usCulture.DateTimeFormat.FirstDayOfWeek);
+
+            return weekNo;
+        }
+    }
+}