refactor: use userservice and balance service inside blackjack service

backend/src/main/java/de/szut/casino/blackjack/BlackJackGameController.java

@@ -59,13 +59,7 @@ public class BlackJackGameController {
 
     @PostMapping("/blackjack/start")
     public ResponseEntity<Object> createBlackJackGame(@RequestBody @Valid BetDto betDto) {
-        UserEntity user = this.userService.getCurrentUser();
-
-        if (!this.balanceService.hasFunds(user, betDto)) {
-            throw new InsufficientFundsException();
-        }
-
-        return ResponseEntity.ok(blackJackService.createBlackJackGame(user, betDto.getBetAmount()));
+        return ResponseEntity.ok(blackJackService.createBlackJackGame(betDto));
     }
 
     private BlackJackGameEntity getBlackJackGame(Long gameId) {

backend/src/main/java/de/szut/casino/blackjack/BlackJackService.java

@@ -1,7 +1,11 @@
 package de.szut.casino.blackjack;
 
+import de.szut.casino.exceptionHandling.exceptions.InsufficientFundsException;
+import de.szut.casino.shared.dto.BetDto;
+import de.szut.casino.shared.service.BalanceService;
 import de.szut.casino.user.UserEntity;
 import de.szut.casino.user.UserRepository;
+import de.szut.casino.user.UserService;
 import jakarta.transaction.Transactional;
 import org.springframework.stereotype.Service;
 
@@ -13,11 +17,22 @@ import java.util.Random;
 public class BlackJackService {
     private final BlackJackGameRepository blackJackGameRepository;
     private final UserRepository userRepository;
-    private final Random random = new Random();
+    private final Random random;
+    private final BalanceService balanceService;
+    private final UserService userService;
 
-    public BlackJackService(BlackJackGameRepository blackJackGameRepository, UserRepository userRepository) {
+    public BlackJackService(
+            BlackJackGameRepository blackJackGameRepository,
+            UserRepository userRepository,
+            Random random,
+            BalanceService balanceService,
+            UserService userService
+    ) {
         this.blackJackGameRepository = blackJackGameRepository;
         this.userRepository = userRepository;
+        this.random = random;
+        this.balanceService = balanceService;
+        this.userService = userService;
     }
 
     public BlackJackGameEntity getBlackJackGame(Long id) {
@@ -25,16 +40,23 @@ public class BlackJackService {
     }
 
     @Transactional
-    public BlackJackGameEntity createBlackJackGame(UserEntity user, BigDecimal betAmount) {
+    public BlackJackGameEntity createBlackJackGame(BetDto betDto) {
+        UserEntity user = userService.getCurrentUser();
+
+        if (!this.balanceService.hasFunds(user, betDto)) {
+            throw new InsufficientFundsException();
+        }
+
+        this.balanceService.subtractFunds(user, betDto.getBetAmount());
+
         BlackJackGameEntity game = new BlackJackGameEntity();
         game.setUser(user);
-        game.setBet(betAmount);
+        game.setBet(betDto.getBetAmount());
 
         initializeDeck(game);
         dealInitialCards(game);
 
         game.setState(getState(game));
-        deductBetFromBalance(user, betAmount);
 
         return processGameBasedOnState(game);
     }
@@ -72,7 +94,8 @@ public class BlackJackService {
         UserEntity user = getUserWithFreshData(game.getUser());
         BigDecimal additionalBet = game.getBet();
 
-        deductBetFromBalance(user, additionalBet);
+        this.balanceService.subtractFunds(user, additionalBet);
+
         game.setBet(game.getBet().add(additionalBet));
 
         dealCardToPlayer(game);
@@ -150,11 +173,6 @@ public class BlackJackService {
         }
     }
 
-    private void deductBetFromBalance(UserEntity user, BigDecimal betAmount) {
-        user.setBalance(user.getBalance().subtract(betAmount));
-        userRepository.save(user);
-    }
-
     protected void updateUserBalance(BlackJackGameEntity game, boolean isWin) {
         UserEntity user = getUserWithFreshData(game.getUser());
         BigDecimal totalBet = game.getBet();