feat: add notification system

src/main/java/com/openisle/controller/AdminPostController.java

@@ -31,6 +31,11 @@ public class AdminPostController {
         return toDto(postService.approvePost(id));
     }
 
+    @PostMapping("/{id}/reject")
+    public PostDto reject(@PathVariable Long id) {
+        return toDto(postService.rejectPost(id));
+    }
+
     private PostDto toDto(Post post) {
         PostDto dto = new PostDto();
         dto.setId(post.getId());

src/main/java/com/openisle/controller/NotificationController.java

@@ -0,0 +1,62 @@
+package com.openisle.controller;
+
+import com.openisle.model.Notification;
+import com.openisle.model.NotificationType;
+import com.openisle.service.NotificationService;
+import lombok.Data;
+import lombok.RequiredArgsConstructor;
+import org.springframework.security.core.Authentication;
+import org.springframework.web.bind.annotation.*;
+
+import java.time.LocalDateTime;
+import java.util.List;
+import java.util.stream.Collectors;
+
+/** Endpoints for user notifications. */
+@RestController
+@RequestMapping("/api/notifications")
+@RequiredArgsConstructor
+public class NotificationController {
+    private final NotificationService notificationService;
+
+    @GetMapping
+    public List<NotificationDto> list(@RequestParam(value = "read", required = false) Boolean read,
+                                      Authentication auth) {
+        return notificationService.listNotifications(auth.getName(), read).stream()
+                .map(this::toDto)
+                .collect(Collectors.toList());
+    }
+
+    @PostMapping("/read")
+    public void markRead(@RequestBody MarkReadRequest req, Authentication auth) {
+        notificationService.markRead(auth.getName(), req.getIds());
+    }
+
+    private NotificationDto toDto(Notification n) {
+        NotificationDto dto = new NotificationDto();
+        dto.setId(n.getId());
+        dto.setType(n.getType());
+        dto.setPostId(n.getPost() != null ? n.getPost().getId() : null);
+        dto.setCommentId(n.getComment() != null ? n.getComment().getId() : null);
+        dto.setApproved(n.getApproved());
+        dto.setRead(n.isRead());
+        dto.setCreatedAt(n.getCreatedAt());
+        return dto;
+    }
+
+    @Data
+    private static class MarkReadRequest {
+        private List<Long> ids;
+    }
+
+    @Data
+    private static class NotificationDto {
+        private Long id;
+        private NotificationType type;
+        private Long postId;
+        private Long commentId;
+        private Boolean approved;
+        private boolean read;
+        private LocalDateTime createdAt;
+    }
+}

src/main/java/com/openisle/controller/PostController.java

@@ -44,8 +44,9 @@ public class PostController {
     }
 
     @GetMapping("/{id}")
-    public ResponseEntity<PostDto> getPost(@PathVariable Long id) {
-        Post post = postService.getPost(id);
+    public ResponseEntity<PostDto> getPost(@PathVariable Long id, Authentication auth) {
+        String viewer = auth != null ? auth.getName() : null;
+        Post post = postService.viewPost(id, viewer);
         return ResponseEntity.ok(toDto(post));
     }