Move source code into "Source" folder

Source/LibationFileManager/PictureStorage.cs

@@ -0,0 +1,131 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Net.Http;
+using System.Threading.Tasks;
+
+namespace LibationFileManager
+{
+	public enum PictureSize { _80x80 = 80, _300x300 = 300, _500x500 = 500 }
+	public class PictureCachedEventArgs : EventArgs
+	{
+		public PictureDefinition Definition { get; internal set; }
+		public byte[] Picture { get; internal set; }
+	}
+	public struct PictureDefinition
+	{
+		public string PictureId { get; }
+		public PictureSize Size { get; }
+
+		public PictureDefinition(string pictureId, PictureSize pictureSize)
+		{
+			PictureId = pictureId;
+			Size = pictureSize;
+		}
+	}
+    public static class PictureStorage
+    {
+        // not customizable. don't move to config
+        private static string ImagesDirectory { get; }
+            = new DirectoryInfo(Configuration.Instance.LibationFiles).CreateSubdirectory("Images").FullName;
+
+		private static string getPath(PictureDefinition def)
+			=> Path.Combine(ImagesDirectory, $"{def.PictureId}{def.Size}.jpg");
+
+		static PictureStorage()
+		{
+			new Task(BackgroundDownloader, TaskCreationOptions.LongRunning)
+			.Start();
+		}
+
+		public static event EventHandler<PictureCachedEventArgs> PictureCached;
+
+		private static BlockingCollection<PictureDefinition> DownloadQueue { get; } = new BlockingCollection<PictureDefinition>();
+		private static object cacheLocker { get; } = new object();
+		private static Dictionary<PictureDefinition, byte[]> cache { get; } = new Dictionary<PictureDefinition, byte[]>();
+		private static Dictionary<PictureSize, byte[]> defaultImages { get; } = new Dictionary<PictureSize, byte[]>();
+		public static (bool isDefault, byte[] bytes) GetPicture(PictureDefinition def)
+		{
+			lock (cacheLocker)
+			{
+				if (cache.ContainsKey(def))
+					return (false, cache[def]);
+
+				var path = getPath(def);
+
+				if (File.Exists(path))
+				{
+					cache[def] = File.ReadAllBytes(path);
+					return (false, cache[def]);
+				}
+
+				DownloadQueue.Add(def);
+				return (true, getDefaultImage(def.Size));
+			}
+		}
+
+		public static byte[] GetPictureSynchronously(PictureDefinition def)
+		{
+			lock (cacheLocker)
+			{
+				if (!cache.ContainsKey(def) || cache[def] is null)
+				{
+					var path = getPath(def);
+					var bytes
+						= File.Exists(path)
+						? File.ReadAllBytes(path)
+						: downloadBytes(def);
+					cache[def] = bytes;
+				}
+				return cache[def];
+			}
+		}
+
+		public static void SetDefaultImage(PictureSize pictureSize, byte[] bytes)
+			=> defaultImages[pictureSize] = bytes;
+		private static byte[] getDefaultImage(PictureSize size)
+			=> defaultImages.ContainsKey(size)
+			? defaultImages[size]
+			: new byte[0];
+
+		static void BackgroundDownloader()
+		{
+			while (!DownloadQueue.IsCompleted)
+			{
+				if (!DownloadQueue.TryTake(out var def, System.Threading.Timeout.InfiniteTimeSpan))
+					continue;
+
+				var bytes = downloadBytes(def);
+				lock (cacheLocker)
+					cache[def] = bytes;
+
+				PictureCached?.Invoke(nameof(PictureStorage), new PictureCachedEventArgs { Definition = def, Picture = bytes });
+			}
+		}
+
+		private static HttpClient imageDownloadClient { get; } = new HttpClient();
+		private static byte[] downloadBytes(PictureDefinition def)
+		{
+			if (def.PictureId is null)
+				return getDefaultImage(def.Size);
+
+			try
+			{
+				var sz = (int)def.Size;
+				var bytes = imageDownloadClient.GetByteArrayAsync("ht" + $"tps://images-na.ssl-images-amazon.com/images/I/{def.PictureId}._SL{sz}_.jpg").Result;
+
+				// save image file. make sure to not save default image
+				var path = getPath(def);
+				File.WriteAllBytes(path, bytes);
+
+				return bytes;
+			}
+			catch
+			{
+				return getDefaultImage(def.Size);
+			}
+		}
+	}
+}