feat: Save balance after successful payment

backend/src/main/java/de/szut/casino/deposit/WebhookController.java

@@ -0,0 +1,64 @@
+package de.szut.casino.deposit;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+
+import com.stripe.Stripe;
+import com.stripe.exception.SignatureVerificationException;
+import com.stripe.exception.StripeException;
+import com.stripe.model.*;
+import com.stripe.model.checkout.Session;
+import com.stripe.net.Webhook;
+import com.stripe.param.checkout.SessionRetrieveParams;
+import de.szut.casino.user.UserEntity;
+import de.szut.casino.user.UserRepository;
+import jakarta.annotation.PostConstruct;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import java.math.BigDecimal;
+import java.util.Objects;
+import java.util.Optional;
+
+@RestController
+public class WebhookController {
+    private static final Logger logger = LoggerFactory.getLogger(WebhookController.class);
+    @Value("${stripe.secret.key}")
+    private String stripeSecretKey;
+
+    @Value("${stripe.webhook.secret}")
+    private String webhookSecret;
+
+    private final TransactionService transactionService;
+
+    public WebhookController(TransactionService transactionService) {
+        this.transactionService = transactionService;
+    }
+
+    @PostConstruct
+    public void init() {
+        Stripe.apiKey = stripeSecretKey;
+    }
+
+    @PostMapping("/webhook")
+    public ResponseEntity<String> webhook(@RequestBody String payload, @RequestHeader("Stripe-Signature") String sigHeader) throws StripeException {
+        Event event = Webhook.constructEvent(payload, sigHeader, webhookSecret);
+
+        System.out.println(event.getType());
+
+        switch (event.getType()) {
+            case "checkout.session.completed":
+            case "checkout.session.async_payment_succeeded":
+                Session session = (Session) event.getData().getObject();
+
+                this.transactionService.fulfillCheckout(session.getId());
+                break;
+            default:
+
+        }
+
+        return ResponseEntity.ok().body(null);
+    }
+}