1 files changed, 63 insertions, 0 deletions
diff --git a/BackEnd/Timeline/Services/Exceptions/EntityAlreadyExistError.cs b/BackEnd/Timeline/Services/Exceptions/EntityAlreadyExistError.cs
new file mode 100644
index 00000000..7db2e860
--- /dev/null
+++ b/BackEnd/Timeline/Services/Exceptions/EntityAlreadyExistError.cs
@@ -0,0 +1,63 @@
+using System;
+using System.Globalization;
+using System.Text;
+
+namespace Timeline.Services.Exceptions
+{
+    /// <summary>
+    /// Thrown when an entity is already exists.
+    /// </summary>
+    /// <remarks>
+    /// For example, want to create a timeline but a timeline with the same name already exists.
+    /// </remarks>
+    [Serializable]
+    public class EntityAlreadyExistException : Exception
+    {
+        private readonly string? _entityName;
+
+        public EntityAlreadyExistException() : this(null, null, null, null) { }
+
+        public EntityAlreadyExistException(string? entityName) : this(entityName, null) { }
+
+        public EntityAlreadyExistException(string? entityName, Exception? inner) : this(entityName, null, null, null, inner) { }
+
+        public EntityAlreadyExistException(string? entityName, object? entity = null) : this(entityName, null, entity, null, null) { }
+        public EntityAlreadyExistException(Type? entityType, object? entity = null) : this(null, entityType, entity, null, null) { }
+        public EntityAlreadyExistException(string? entityName, Type? entityType, object? entity = null, string? message = null, Exception? inner = null) : base(MakeMessage(entityName, entityType, message), inner)
+        {
+            _entityName = entityName;
+            EntityType = entityType;
+            Entity = entity;
+        }
+
+        private static string MakeMessage(string? entityName, Type? entityType, string? message)
+        {
+            string? name = entityName ?? (entityType?.Name);
+
+            var result = new StringBuilder();
+
+            if (name == null)
+                result.Append(Resources.Services.Exceptions.EntityAlreadyExistErrorDefault);
+            else
+                result.AppendFormat(CultureInfo.InvariantCulture, Resources.Services.Exceptions.EntityAlreadyExistError, name);
+
+            if (message != null)
+            {
+                result.Append(' ');
+                result.Append(message);
+            }
+
+            return result.ToString();
+        }
+
+        protected EntityAlreadyExistException(
+          System.Runtime.Serialization.SerializationInfo info,
+          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }
+
+        public string? EntityName => _entityName ?? (EntityType?.Name);
+
+        public Type? EntityType { get; }
+
+        public object? Entity { get; }
+    }
+}