Added transaction event and mail sending for the transaction

Moonlight/App/Event/Args/TransactionCreatedEventArgs.cs

@@ -0,0 +1,10 @@
+using Moonlight.App.Database.Entities;
+using Moonlight.App.Database.Entities.Store;
+
+namespace Moonlight.App.Event.Args;
+
+public class TransactionCreatedEventArgs
+{
+    public Transaction Transaction { get; set; }
+    public User User { get; set; }
+}

Moonlight/App/Event/Events.cs

@@ -11,4 +11,5 @@ public class Events
     public static EventHandler<User> OnUserTotpSet;
     public static EventHandler<MailVerificationEventArgs> OnUserMailVerify;
     public static EventHandler<Service> OnServiceOrdered;
+    public static EventHandler<TransactionCreatedEventArgs> OnTransactionCreated;
 }

Moonlight/App/Services/Background/AutoMailSendService.cs

@@ -1,6 +1,7 @@
 using Moonlight.App.Database.Entities;
 using Moonlight.App.Database.Entities.Store;
 using Moonlight.App.Event;
+using Moonlight.App.Event.Args;
 
 namespace Moonlight.App.Services.Background;
 
@@ -14,6 +15,18 @@ public class AutoMailSendService // This service is responsible for sending mail
 
         Events.OnUserRegistered += OnUserRegistered;
         Events.OnServiceOrdered += OnServiceOrdered;
+        Events.OnTransactionCreated += OnTransactionCreated;
+    }
+
+    private async void OnTransactionCreated(object? sender, TransactionCreatedEventArgs eventArgs)
+    {
+        await MailService.Send(
+            eventArgs.User,
+            "New transaction",
+            "transactionCreated",
+            eventArgs.Transaction,
+            eventArgs.User
+        );
     }
 
     private async void OnServiceOrdered(object? _, Service service)

Moonlight/App/Services/Store/TransactionService.cs

@@ -1,5 +1,7 @@
 using Moonlight.App.Database.Entities;
 using Moonlight.App.Database.Entities.Store;
+using Moonlight.App.Event;
+using Moonlight.App.Extensions;
 using Moonlight.App.Helpers;
 using Moonlight.App.Repositories;
 
@@ -14,16 +16,17 @@ public class TransactionService
         UserRepository = userRepository;
     }
 
-    public Task Add(User u, double amount, string message)
+    public async Task Add(User u, double amount, string message)
     {
         var user = UserRepository.Get().First(x => x.Id == u.Id); // Load user with current repo
 
-        user.Transactions.Add(new Transaction()
+        var transaction = new Transaction()
         {
             Text = message,
             Price = amount
-        });
+        };
         
+        user.Transactions.Add(transaction);
         UserRepository.Update(user);
 
         // We divide the call to ensure the transaction can be written to the database 
@@ -33,6 +36,10 @@ public class TransactionService
         
         UserRepository.Update(user);
 
-        return Task.CompletedTask;
+        await Events.OnTransactionCreated.InvokeAsync(new()
+        {
+            Transaction = transaction,
+            User = user
+        });
     }
 }