1 files changed, 58 insertions, 0 deletions
diff --git a/BackEnd/Timeline/Services/Imaging/ImageException.cs b/BackEnd/Timeline/Services/Imaging/ImageException.cs
new file mode 100644
index 00000000..926ecc0a
--- /dev/null
+++ b/BackEnd/Timeline/Services/Imaging/ImageException.cs
@@ -0,0 +1,58 @@
+using System;
+using System.Globalization;
+
+namespace Timeline.Services.Imaging
+{
+    [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 of required size.
+            /// </summary>
+            NotSquare,
+            /// <summary>
+            /// Other unknown errer.
+            /// </summary>
+            Unknown
+        }
+
+        public ImageException() : this(null) { }
+        public ImageException(string? message) : this(message, null) { }
+        public ImageException(string? message, Exception? inner) : this(ErrorReason.Unknown, null, null, null, message, inner) { }
+
+        public ImageException(ErrorReason error, byte[]? data, string? requestType, string? realType, Exception? inner) : this(error, data, requestType, realType, null, inner) { }
+        public ImageException(ErrorReason error, byte[]? data, string? requestType = null, string? realType = null, string? message = null, Exception? inner = null) : base(message ?? 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, Resource.ExceptionImage, reason switch
+            {
+                ErrorReason.CantDecode => Resource.ExceptionImageReasonCantDecode,
+                ErrorReason.UnmatchedFormat => Resource.ExceptionImageReasonUnmatchedFormat,
+                ErrorReason.NotSquare => Resource.ExceptionImageReasonBadSize,
+                _ => Resource.ExceptionImageReasonUnknownError
+            });
+
+        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; }
+    }
+}