[FEAT] 앱 내 푸시알림 구현

.gitignore

@@ -44,3 +44,5 @@ src/main/generated/
 
 ## Apple Login Key File ##
 *.p8
+
+/src/main/resources/websoso-fcm.json

build.gradle

@@ -70,6 +70,9 @@ dependencies {
 
     //Apple Login
     implementation 'com.nimbusds:nimbus-jose-jwt:3.10'
+
+    // FCM
+    implementation 'com.google.firebase:firebase-admin:8.1.0'
 }
 
 tasks.named('test') {

src/main/java/org/websoso/WSSServer/controller/UserController.java

@@ -22,6 +22,7 @@
 import org.websoso.WSSServer.dto.feed.UserFeedsGetResponse;
 import org.websoso.WSSServer.dto.user.EditMyInfoRequest;
 import org.websoso.WSSServer.dto.user.EditProfileStatusRequest;
+import org.websoso.WSSServer.dto.user.FCMTokenRequest;
 import org.websoso.WSSServer.dto.user.LoginResponse;
 import org.websoso.WSSServer.dto.user.MyProfileResponse;
 import org.websoso.WSSServer.dto.user.NicknameValidation;
@@ -209,4 +210,14 @@ public ResponseEntity<UserIdAndNicknameResponse> getUserIdAndNicknameAndGender(P
                 .status(OK)
                 .body(userService.getUserIdAndNicknameAndGender(user));
     }
+
+    @PostMapping("/fcm-token")
+    public ResponseEntity<Void> registerFCMToken(Principal principal,
+                                                 @Valid @RequestBody FCMTokenRequest fcmTokenRequest) {
+        User user = userService.getUserOrException(Long.valueOf(principal.getName()));
+        userService.registerFCMToken(user, fcmTokenRequest.fcmToken());
+        return ResponseEntity
+                .status(OK)
+                .build();
+    }
 }

src/main/java/org/websoso/WSSServer/domain/User.java

@@ -49,6 +49,9 @@ public class User {
     @Column(nullable = false)
     private String socialId;
 
+    @Column
+    private String fcmToken;
+
     @Column(columnDefinition = "varchar(10)", nullable = false)
     private String nickname;
     //TODO 일부 특수문자 제외, 앞뒤 공백 불가능
@@ -136,4 +139,8 @@ public void editMyInfo(EditMyInfoRequest editMyInfoRequest) {
         this.gender = Gender.valueOf(editMyInfoRequest.gender());
         this.birth = Year.of(editMyInfoRequest.birth());
     }
+
+    public void updateFCMToken(String fcmToken) {
+        this.fcmToken = fcmToken;
+    }
 }

src/main/java/org/websoso/WSSServer/dto/user/FCMTokenRequest.java

@@ -0,0 +1,9 @@
+package org.websoso.WSSServer.dto.user;
+
+import jakarta.validation.constraints.NotBlank;
+
+public record FCMTokenRequest(
+        @NotBlank(message = "FCM Token 값은 null 이거나, 공백일 수 없습니다.")
+        String fcmToken
+) {
+}

src/main/java/org/websoso/WSSServer/notification/FCMConfig.java

@@ -0,0 +1,41 @@
+package org.websoso.WSSServer.notification;
+
+import com.google.auth.oauth2.GoogleCredentials;
+import com.google.firebase.FirebaseApp;
+import com.google.firebase.FirebaseOptions;
+import com.google.firebase.messaging.FirebaseMessaging;
+import java.io.IOException;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.io.ClassPathResource;
+
+@Slf4j
+@Configuration
+public class FCMConfig {
+
+    @Value("${fcm.key-path}")
+    private String firebaseConfigPath;
+
+    @Bean
+    public FirebaseMessaging firebaseMessaging() {
+        try {
+            GoogleCredentials googleCredentials = GoogleCredentials
+                    .fromStream(new ClassPathResource(firebaseConfigPath).getInputStream());
+
+            FirebaseOptions firebaseOptions = FirebaseOptions.builder()
+                    .setCredentials(googleCredentials)
+                    .build();
+
+            if (FirebaseApp.getApps().isEmpty()) {
+                FirebaseApp.initializeApp(firebaseOptions);
+            }
+
+            return FirebaseMessaging.getInstance();
+        } catch (IOException e) {
+            log.error("[FirebaseMessaging] Failed to initialize FirebaseMessaging", e);
+            throw new IllegalStateException("Failed to initialize FirebaseMessaging due to firebase key file", e);
+        }
+    }
+}

src/main/java/org/websoso/WSSServer/notification/FCMService.java

@@ -0,0 +1,83 @@
+package org.websoso.WSSServer.notification;
+
+import com.google.firebase.messaging.ApnsConfig;
+import com.google.firebase.messaging.Aps;
+import com.google.firebase.messaging.ApsAlert;
+import com.google.firebase.messaging.FirebaseMessaging;
+import com.google.firebase.messaging.FirebaseMessagingException;
+import com.google.firebase.messaging.Message;
+import com.google.firebase.messaging.MulticastMessage;
+import java.util.List;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+import org.websoso.WSSServer.notification.dto.FCMMessageRequest;
+
+@Slf4j
+@Service
+@RequiredArgsConstructor
+public class FCMService {
+
+    private final FirebaseMessaging firebaseMessaging;
+
+    public void sendPushMessage(String targetFCMToken, FCMMessageRequest fcmMessageRequest) {
+        Message message = createMessage(targetFCMToken, fcmMessageRequest);
+
+        try {
+            firebaseMessaging.send(message);
+        } catch (FirebaseMessagingException e) {
+            log.error("[FirebaseMessagingException] exception ", e);
+            // TODO: discord로 알림 추가 혹은 후속 작업 논의 후 추가
+        }
+    }
+
+    private Message createMessage(String targetFCMToken, FCMMessageRequest fcmMessageRequest) {
+        ApnsConfig apnsConfig = ApnsConfig.builder()
+                .setAps(Aps.builder()
+                        .setAlert(ApsAlert.builder()
+                                .setTitle(fcmMessageRequest.title())
+                                .setBody(fcmMessageRequest.body())
+                                .build())
+                        .build())
+                .build();
+
+        return Message.builder()
+                .setToken(targetFCMToken)
+                .putData("title", fcmMessageRequest.title())
+                .putData("body", fcmMessageRequest.body())
+                .putData("feedId", fcmMessageRequest.feedId())
+                .putData("view", fcmMessageRequest.view())
+                .setApnsConfig(apnsConfig)
+                .build();
+    }
+
+    public void sendMulticastPushMessage(List<String> targetFCMTokens, FCMMessageRequest fcmMessageRequest) {
+        MulticastMessage multicastMessage = createMulticastMessage(targetFCMTokens, fcmMessageRequest);
+        try {
+            firebaseMessaging.sendMulticast(multicastMessage);
+        } catch (Exception e) {
+            log.error("[FirebaseMessagingException] exception ", e);
+            // TODO: discord로 알림 추가 혹은 후속 작업 논의 후 추가
+        }
+    }
+
+    private MulticastMessage createMulticastMessage(List<String> targetFCMTokens, FCMMessageRequest fcmMessageRequest) {
+        ApnsConfig apnsConfig = ApnsConfig.builder()
+                .setAps(Aps.builder()
+                        .setAlert(ApsAlert.builder()
+                                .setTitle(fcmMessageRequest.title())
+                                .setBody(fcmMessageRequest.body())
+                                .build())
+                        .build())
+                .build();
+
+        return MulticastMessage.builder()
+                .addAllTokens(targetFCMTokens)
+                .putData("title", fcmMessageRequest.title())
+                .putData("body", fcmMessageRequest.body())
+                .putData("feedId", fcmMessageRequest.feedId())
+                .putData("view", fcmMessageRequest.view())
+                .setApnsConfig(apnsConfig)
+                .build();
+    }
+}

src/main/java/org/websoso/WSSServer/notification/dto/FCMMessageRequest.java

@@ -0,0 +1,13 @@
+package org.websoso.WSSServer.notification.dto;
+
+public record FCMMessageRequest(
+        String title,
+        String body,
+        String feedId,
+        String view
+) {
+
+    public static FCMMessageRequest of(String title, String body, String feedId, String view) {
+        return new FCMMessageRequest(title, body, feedId, view);
+    }
+}

src/main/java/org/websoso/WSSServer/service/CommentService.java

@@ -15,13 +15,16 @@
 import org.springframework.transaction.annotation.Transactional;
 import org.websoso.WSSServer.domain.Comment;
 import org.websoso.WSSServer.domain.Feed;
+import org.websoso.WSSServer.domain.Novel;
 import org.websoso.WSSServer.domain.User;
 import org.websoso.WSSServer.domain.common.DiscordWebhookMessage;
 import org.websoso.WSSServer.domain.common.ReportedType;
 import org.websoso.WSSServer.dto.comment.CommentGetResponse;
 import org.websoso.WSSServer.dto.comment.CommentsGetResponse;
 import org.websoso.WSSServer.dto.user.UserBasicInfo;
 import org.websoso.WSSServer.exception.exception.CustomCommentException;
+import org.websoso.WSSServer.notification.FCMService;
+import org.websoso.WSSServer.notification.dto.FCMMessageRequest;
 import org.websoso.WSSServer.repository.CommentRepository;
 
 @Service
@@ -35,9 +38,63 @@ public class CommentService {
     private final BlockService blockService;
     private final ReportedCommentService reportedCommentService;
     private final MessageService messageService;
+    private final FCMService fcmService;
+    private final NovelService novelService;
 
-    public void createComment(Long userId, Feed feed, String commentContent) {
-        commentRepository.save(Comment.create(userId, feed, commentContent));
+    public void createComment(User user, Feed feed, String commentContent) {
+        commentRepository.save(Comment.create(user.getUserId(), feed, commentContent));
+        sendCommentPushMessageToFeedOwner(user, feed);
+        sendCommentPushMessageToCommenters(user, feed);
+    }
+
+    private void sendCommentPushMessageToFeedOwner(User user, Feed feed) {
+        if (isUserCommentOwner(user, feed.getUser())) {
+            return;
+        }
+
+        FCMMessageRequest fcmMessageRequest = FCMMessageRequest.of(
+                createNotificationTitle(feed),
+                String.format("%s님이 내 수다글에 댓글을 남겼어요", user.getNickname()),
+                String.valueOf(feed.getFeedId()),
+                "feedDetail"
+        );
+        fcmService.sendPushMessage(
+                feed.getUser().getFcmToken(),
+                fcmMessageRequest
+        );
+    }
+
+    private String createNotificationTitle(Feed feed) {
+        if (feed.getNovelId() == null) {
+            String feedContent = feed.getFeedContent();
+            return feedContent.length() <= 12
+                    ? feedContent
+                    : "'" + feedContent.substring(0, 12) + "...'";
+        }
+        Novel novel = novelService.getNovelOrException(feed.getNovelId());
+        return novel.getTitle();
+    }
+
+    private void sendCommentPushMessageToCommenters(User user, Feed feed) {
+        List<String> commentersUserId = feed.getComments()
+                .stream()
+                .map(Comment::getUserId)
+                .filter(userId -> !userId.equals(user.getUserId()))
+                .distinct()
+                .map(userService::getUserOrException)
+                .map(User::getFcmToken)
+                .toList();
+
+        FCMMessageRequest fcmMessageRequest = FCMMessageRequest.of(
+                createNotificationTitle(feed),
+                "내가 댓글 단 수다글에 또 다른 댓글이 달렸어요.",
+                String.valueOf(feed.getFeedId()),
+                "feedDetail"
+        );
+        fcmService.sendMulticastPushMessage(
+                commentersUserId,
+                fcmMessageRequest
+        );
     }
 
     public void updateComment(Long userId, Feed feed, Long commentId, String commentContent) {

src/main/java/org/websoso/WSSServer/service/FeedService.java

@@ -44,6 +44,8 @@
 import org.websoso.WSSServer.dto.user.UserBasicInfo;
 import org.websoso.WSSServer.exception.exception.CustomFeedException;
 import org.websoso.WSSServer.exception.exception.CustomUserException;
+import org.websoso.WSSServer.notification.FCMService;
+import org.websoso.WSSServer.notification.dto.FCMMessageRequest;
 import org.websoso.WSSServer.repository.AvatarRepository;
 import org.websoso.WSSServer.repository.FeedRepository;
 import org.websoso.WSSServer.repository.NovelRepository;
@@ -70,6 +72,7 @@ public class FeedService {
     private final MessageService messageService;
     private final UserService userService;
     private final NovelRepository novelRepository;
+    private final FCMService fcmService;
 
     public void createFeed(User user, FeedCreateRequest request) {
         if (request.novelId() != null) {
@@ -115,6 +118,36 @@ public void likeFeed(User user, Long feedId) {
         if (isPopularFeed) {
             popularFeedService.createPopularFeed(feed);
         }
+
+        sendLikePushMessage(user, feed);
+    }
+
+    private void sendLikePushMessage(User liker, Feed feed) {
+        if (liker.equals(feed.getUser())) {
+            return;
+        }
+
+        FCMMessageRequest fcmMessageRequest = FCMMessageRequest.of(
+                createNotificationTitle(feed),
+                String.format("%s님이 내 수다글을 좋아해요.", liker.getNickname()),
+                String.valueOf(feed.getFeedId()),
+                "feedDetail"
+        );
+        fcmService.sendPushMessage(
+                feed.getUser().getFcmToken(),
+                fcmMessageRequest
+        );
+    }
+
+    private String createNotificationTitle(Feed feed) {
+        if (feed.getNovelId() == null) {
+            String feedContent = feed.getFeedContent();
+            return feedContent.length() <= 12
+                    ? feedContent
+                    : "'" + feedContent.substring(0, 12) + "...'";
+        }
+        Novel novel = novelService.getNovelOrException(feed.getNovelId());
+        return novel.getTitle();
     }
 
     public void unLikeFeed(User user, Long feedId) {
@@ -154,7 +187,7 @@ public FeedsGetResponse getFeeds(User user, String category, Long lastFeedId, in
     public void createComment(User user, Long feedId, CommentCreateRequest request) {
         Feed feed = getFeedOrException(feedId);
         validateFeedAccess(feed, user);
-        commentService.createComment(user.getUserId(), feed, request.commentContent());
+        commentService.createComment(user, feed, request.commentContent());
     }
 
     public void updateComment(User user, Long feedId, Long commentId, CommentUpdateRequest request) {