1 files changed, 54 insertions, 0 deletions
diff --git a/Timeline/Services/ImageException.cs b/Timeline/Services/ImageException.cs
new file mode 100644
index 00000000..c6126aa3
--- /dev/null
+++ b/Timeline/Services/ImageException.cs
@@ -0,0 +1,54 @@
+using System;
+using System.Globalization;
+
+namespace Timeline.Services
+{
+    [Serializable]
+    public class ImageException : Exception
+    {
+        public enum ErrorReason
+        {
+            /// <summary>
+            /// Decoding image failed.
+            /// </summary>
+            CantDecode,
+            /// <summary>
+            /// Decoding succeeded but the real type is not the specified type.
+            /// </summary>
+            UnmatchedFormat,
+            /// <summary>
+            /// Image is not a square.
+            /// </summary>
+            NotSquare
+        }
+
+        public ImageException() : base(MakeMessage(null)) { }
+        public ImageException(string message) : base(message) { }
+        public ImageException(string message, Exception inner) : base(message, inner) { }
+
+        public ImageException(ErrorReason error, byte[]? data = null, string? requestType = null, string? realType = null) : base(MakeMessage(error)) { Error = error; ImageData = data; RequestType = requestType; RealType = realType; }
+        public ImageException(Exception inner, ErrorReason error, byte[]? data = null, string? requestType = null, string? realType = null) : base(MakeMessage(error), inner) { Error = error; ImageData = data; RequestType = requestType; RealType = realType; }
+
+        protected ImageException(
+          System.Runtime.Serialization.SerializationInfo info,
+          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }
+
+        private static string MakeMessage(ErrorReason? reason) =>
+            string.Format(CultureInfo.InvariantCulture, Resources.Services.Exception.ImageException, reason switch
+            {
+                ErrorReason.CantDecode => Resources.Services.Exception.ImageExceptionCantDecode,
+                ErrorReason.UnmatchedFormat => Resources.Services.Exception.ImageExceptionUnmatchedFormat,
+                ErrorReason.NotSquare => Resources.Services.Exception.ImageExceptionBadSize,
+                _ => Resources.Services.Exception.ImageExceptionUnknownError
+            });
+
+        public ErrorReason? Error { get; }
+#pragma warning disable CA1819 // Properties should not return arrays
+        public byte[]? ImageData { get; }
+#pragma warning restore CA1819 // Properties should not return arrays
+        public string? RequestType { get; }
+
+        // This field will be null if decoding failed.
+        public string? RealType { get; }
+    }
+}