From a5215b126b6c5fbac79993367864484eadd5b7b7 Mon Sep 17 00:00:00 2001
From: sBubshait <s.bobshit@gmail.com>
Date: Tue, 22 Jul 2025 09:44:20 +0300
Subject: [PATCH] feat: create /accept endpoint to accept invitations

---
 .../controller/InvitationController.java      | 21 ++++++++++++
 .../wesal/repository/AttendeeRepository.java  |  2 ++
 .../wesal/service/InvitationService.java      | 32 +++++++++++++++++++
 3 files changed, 55 insertions(+)

diff --git a/backend/src/main/java/online/wesal/wesal/controller/InvitationController.java b/backend/src/main/java/online/wesal/wesal/controller/InvitationController.java
index 75f5337..9aa7030 100644
--- a/backend/src/main/java/online/wesal/wesal/controller/InvitationController.java
+++ b/backend/src/main/java/online/wesal/wesal/controller/InvitationController.java
@@ -90,4 +90,25 @@ public class InvitationController {
             return ResponseEntity.status(500).body(ApiResponse.error("Something went wrong.. We're sorry but try again later"));
         }
     }
+    
+    @PostMapping("/accept")
+    @Operation(summary = "Accept invitation", description = "Accept an invitation by ID")
+    public ResponseEntity<ApiResponse<Void>> acceptInvitation(
+            @RequestParam Long id,
+            Authentication authentication) {
+        
+        if (id == null || id <= 0) {
+            return ResponseEntity.badRequest().body(ApiResponse.error("Valid invitation ID is required"));
+        }
+        
+        try {
+            String userEmail = authentication.getName();
+            invitationService.acceptInvitation(id, userEmail);
+            return ResponseEntity.ok(new ApiResponse<>(true));
+        } catch (RuntimeException e) {
+            return ResponseEntity.badRequest().body(ApiResponse.error(e.getMessage()));
+        } catch (Exception e) {
+            return ResponseEntity.status(500).body(ApiResponse.error("Something went wrong.. We're sorry but try again later"));
+        }
+    }
 }
\ No newline at end of file
diff --git a/backend/src/main/java/online/wesal/wesal/repository/AttendeeRepository.java b/backend/src/main/java/online/wesal/wesal/repository/AttendeeRepository.java
index 886beba..3131e3d 100644
--- a/backend/src/main/java/online/wesal/wesal/repository/AttendeeRepository.java
+++ b/backend/src/main/java/online/wesal/wesal/repository/AttendeeRepository.java
@@ -6,4 +6,6 @@ import org.springframework.stereotype.Repository;
 
 @Repository
 public interface AttendeeRepository extends JpaRepository<Attendee, Long> {
+    
+    boolean existsByInvitationIdAndUserId(Long invitationId, Long userId);
 }
\ No newline at end of file
diff --git a/backend/src/main/java/online/wesal/wesal/service/InvitationService.java b/backend/src/main/java/online/wesal/wesal/service/InvitationService.java
index 9ec3300..6cc6b93 100644
--- a/backend/src/main/java/online/wesal/wesal/service/InvitationService.java
+++ b/backend/src/main/java/online/wesal/wesal/service/InvitationService.java
@@ -2,9 +2,11 @@ package online.wesal.wesal.service;
 
 import online.wesal.wesal.dto.CreateInvitationRequest;
 import online.wesal.wesal.dto.InvitationResponse;
+import online.wesal.wesal.entity.Attendee;
 import online.wesal.wesal.entity.Invitation;
 import online.wesal.wesal.entity.Tag;
 import online.wesal.wesal.entity.User;
+import online.wesal.wesal.repository.AttendeeRepository;
 import online.wesal.wesal.repository.InvitationRepository;
 import online.wesal.wesal.repository.TagRepository;
 import online.wesal.wesal.repository.UserRepository;
@@ -28,6 +30,9 @@ public class InvitationService {
     @Autowired
     private UserRepository userRepository;
     
+    @Autowired
+    private AttendeeRepository attendeeRepository;
+    
     @Transactional
     public InvitationResponse createInvitation(CreateInvitationRequest request, String userEmail) {
         User creator = userRepository.findByEmail(userEmail)
@@ -63,6 +68,33 @@ public class InvitationService {
             .collect(Collectors.toList());
     }
     
+    @Transactional
+    public void acceptInvitation(Long invitationId, String userEmail) {
+        User user = userRepository.findByEmail(userEmail)
+            .orElseThrow(() -> new RuntimeException("Authentication error. Please log in again"));
+        
+        Invitation invitation = invitationRepository.findById(invitationId)
+            .orElseThrow(() -> new RuntimeException("This invitation does not exist"));
+        
+        if (invitation.getCreator().getId().equals(user.getId())) {
+            throw new RuntimeException("You cannot accept your own invitation");
+        }
+        
+        if (invitation.getCurrentAttendees() >= invitation.getMaxParticipants()) {
+            throw new RuntimeException("This invitation is already full");
+        }
+        
+        if (attendeeRepository.existsByInvitationIdAndUserId(invitationId, user.getId())) {
+            throw new RuntimeException("You have already accepted this invitation");
+        }
+        
+        Attendee attendee = new Attendee(invitation, user);
+        attendeeRepository.save(attendee);
+        
+        invitation.setCurrentAttendees(invitation.getCurrentAttendees() + 1);
+        invitationRepository.save(invitation);
+    }
+    
     private InvitationResponse mapToResponse(Invitation invitation) {
         InvitationResponse response = new InvitationResponse();
         response.setId(invitation.getId());