Feat: 이벤트 종료일 및 당첨자 발표일 알림 전송 로직 구현

src/main/java/com/cmc/suppin/fcm/service/PushNotificationService.java

@@ -0,0 +1,67 @@
+package com.cmc.suppin.fcm.service;
+
+import com.cmc.suppin.event.events.domain.Event;
+import com.cmc.suppin.fcm.domain.DeviceToken;
+import com.cmc.suppin.fcm.domain.respository.DeviceTokenRepository;
+import com.google.firebase.messaging.*;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+@Service
+@RequiredArgsConstructor
+public class PushNotificationService {
+
+    private final DeviceTokenRepository deviceTokenRepository;
+
+    public void sendEventEndNotification(Event event) {
+        // 이벤트 종료 알림 전송 로직 구현
+        String message = "[ " + event.getTitle() + " ] 의 응답을 확인하시고 당첨자를 선정해 주세요.";
+        sendPushNotification(event, message);
+    }
+
+    public void sendAnnouncementNotification(Event event) {
+        // 당첨자 발표일 알림 전송 로직 구현
+        String message = "[ " + event.getTitle() + " ] 의 당첨자 발표일입니다.";
+        sendPushNotification(event, message);
+    }
+
+    public void sendPushNotification(Event event, String message) {
+        List<DeviceToken> deviceTokens = deviceTokenRepository.findAllByMember(event.getMember());
+
+        List<String> tokenStrings = deviceTokens.stream()
+                .map(DeviceToken::getDeviceToken)
+                .collect(Collectors.toList());
+
+        if (!tokenStrings.isEmpty()) {
+            Notification notification = Notification.builder()
+                    .setTitle(event.getTitle())
+                    .setBody(message)
+                    .build();
+
+            MulticastMessage notificationMessage = MulticastMessage.builder()
+                    .setNotification(notification)
+                    .putData("message", message)
+                    .addAllTokens(tokenStrings)
+                    .build();
+
+            try {
+                BatchResponse response = FirebaseMessaging.getInstance().sendMulticast(notificationMessage);
+                System.out.println("Successfully sent message: " + response.getSuccessCount() + " messages sent successfully");
+            } catch (FirebaseMessagingException e) {
+                e.printStackTrace();
+                System.err.println("Error sending message: " + e.getMessage());
+            }
+        }
+    }
+
+    private List<String> getDeviceTokensForEvent(Event event) {
+        // 이벤트에 참여한 사용자들의 디바이스 토큰을 가져오는 로직
+        return new ArrayList<>(); // 예시로 빈 리스트 반환
+    }
+}
+
+