[CastIt.Domain] Added a new ffmpeg exception

CastIt.Domain/Enums/AppMessageType.cs

@@ -23,5 +23,6 @@ public enum AppMessageType
         ConnectionToDeviceIsStillInProgress = 302,
         FFmpegError = 303,
         ServerIsClosing = 304,
+        FFmpegExecutableNotFound = 305,
     }
 }

CastIt.Domain/Exceptions/FFMpegInvalidExecutable.cs

@@ -0,0 +1,18 @@
+using CastIt.Domain.Enums;
+
+namespace CastIt.Domain.Exceptions
+{
+    public class FFmpegInvalidExecutable : BaseAppException
+    {
+        public FFmpegInvalidExecutable(string ffmpegPath, string ffprobePath) : this(
+            $"Either the ffmpeg exe = {ffmpegPath} or ffprobe exe = {ffprobePath} are not valid or were not found",
+            AppMessageType.FFmpegExecutableNotFound)
+        {
+        }
+
+        private FFmpegInvalidExecutable(string message, AppMessageType errorMessageId)
+            : base(message, errorMessageId)
+        {
+        }
+    }
+}

CastIt.Domain/Extensions/AppMessageTypeExtensions.cs

@@ -27,6 +27,7 @@ public static string GetErrorMsg(this AppMessageType type)
                 AppMessageType.FileNotFound => "File was not found",
                 AppMessageType.FFmpegError => "Unknown error on FFmpeg",
                 AppMessageType.ServerIsClosing => "Server is closing",
+                AppMessageType.FFmpegExecutableNotFound => "Ffmpeg executable is not valid or was not found",
                 _ => throw new ArgumentOutOfRangeException(nameof(type), type, $"The provided type = {type} is not valid")
             };
         }