From caa210a80ecc269582eac764737789edf980225d Mon Sep 17 00:00:00 2001
From: Phan Huy Tran <p.tran@neusta.de>
Date: Thu, 27 Mar 2025 12:08:57 +0100
Subject: [PATCH 1/2] refactor: add blackjack state enum

---
 .../java/de/szut/casino/blackjack/BlackJackGameEntity.java  | 3 ++-
 .../java/de/szut/casino/blackjack/BlackJackService.java     | 6 +++++-
 .../main/java/de/szut/casino/blackjack/BlackJackState.java  | 6 ++++++
 3 files changed, 13 insertions(+), 2 deletions(-)
 create mode 100644 backend/src/main/java/de/szut/casino/blackjack/BlackJackState.java

diff --git a/backend/src/main/java/de/szut/casino/blackjack/BlackJackGameEntity.java b/backend/src/main/java/de/szut/casino/blackjack/BlackJackGameEntity.java
index 112e9f0..0193991 100644
--- a/backend/src/main/java/de/szut/casino/blackjack/BlackJackGameEntity.java
+++ b/backend/src/main/java/de/szut/casino/blackjack/BlackJackGameEntity.java
@@ -33,7 +33,8 @@ public class BlackJackGameEntity {
         return user != null ? user.getId() : null;
     }
 
-    private String state;
+    @Enumerated(EnumType.STRING)
+    private BlackJackState state;
     private BigDecimal bet;
 
     @OneToMany(mappedBy = "game", cascade = CascadeType.ALL, orphanRemoval = true)
diff --git a/backend/src/main/java/de/szut/casino/blackjack/BlackJackService.java b/backend/src/main/java/de/szut/casino/blackjack/BlackJackService.java
index 44e5858..f28bc5e 100644
--- a/backend/src/main/java/de/szut/casino/blackjack/BlackJackService.java
+++ b/backend/src/main/java/de/szut/casino/blackjack/BlackJackService.java
@@ -23,7 +23,7 @@ public class BlackJackService {
         BlackJackGameEntity game = new BlackJackGameEntity();
         game.setUser(user);
         game.setBet(betAmount);
-        game.setState("IN_PROGRESS");
+        game.setState(getState(game));
         initializeDeck(game);
 
         for (int i = 0; i < 2; i++) {
@@ -63,4 +63,8 @@ public class BlackJackService {
 
         return game.getDeck().removeFirst();
     }
+
+    private BlackJackState getState(BlackJackGameEntity game) {
+        return BlackJackState.IN_PROGRESS;
+    }
 }
diff --git a/backend/src/main/java/de/szut/casino/blackjack/BlackJackState.java b/backend/src/main/java/de/szut/casino/blackjack/BlackJackState.java
new file mode 100644
index 0000000..3c8efa0
--- /dev/null
+++ b/backend/src/main/java/de/szut/casino/blackjack/BlackJackState.java
@@ -0,0 +1,6 @@
+package de.szut.casino.blackjack;
+
+public enum BlackJackState {
+    PLAYER_WON,
+    IN_PROGRESS
+}
-- 
2.47.2


From 90abd13a2c245569fdfbc118552e84c4272302fe Mon Sep 17 00:00:00 2001
From: Phan Huy Tran <p.tran@neusta.de>
Date: Thu, 27 Mar 2025 12:45:52 +0100
Subject: [PATCH 2/2] feat: handle player drawing blackjack at the start of the
 game

---
 .../casino/blackjack/BlackJackService.java    | 27 ++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/backend/src/main/java/de/szut/casino/blackjack/BlackJackService.java b/backend/src/main/java/de/szut/casino/blackjack/BlackJackService.java
index f28bc5e..86a159c 100644
--- a/backend/src/main/java/de/szut/casino/blackjack/BlackJackService.java
+++ b/backend/src/main/java/de/szut/casino/blackjack/BlackJackService.java
@@ -5,6 +5,7 @@ import de.szut.casino.user.UserRepository;
 import org.springframework.stereotype.Service;
 
 import java.math.BigDecimal;
+import java.util.List;
 import java.util.Random;
 
 @Service
@@ -23,7 +24,6 @@ public class BlackJackService {
         BlackJackGameEntity game = new BlackJackGameEntity();
         game.setUser(user);
         game.setBet(betAmount);
-        game.setState(getState(game));
         initializeDeck(game);
 
         for (int i = 0; i < 2; i++) {
@@ -34,6 +34,7 @@ public class BlackJackService {
         CardEntity dealerCard = drawCardFromDeck(game);
         game.getDealerCards().add(dealerCard);
 
+        game.setState(getState(game));
         user.setBalance(user.getBalance().subtract(betAmount));
 
         userRepository.save(user);
@@ -65,6 +66,30 @@ public class BlackJackService {
     }
 
     private BlackJackState getState(BlackJackGameEntity game) {
+        int playerHandValue = calculateHandValue(game.getPlayerCards());
+
+        if (playerHandValue == 21) {
+            return BlackJackState.PLAYER_WON;
+        }
+
         return BlackJackState.IN_PROGRESS;
     }
+
+    public int calculateHandValue(List<CardEntity> hand) {
+        int sum = 0;
+        int aceCount = 0;
+        for (CardEntity card : hand) {
+            sum += card.getRank().getValue();
+            if (card.getRank() == Rank.ACE) {
+                aceCount++;
+            }
+        }
+
+        while (sum > 21 && aceCount > 0) {
+            sum -= 10;
+            aceCount--;
+        }
+
+        return sum;
+    }
 }
-- 
2.47.2