Thêm tính năng pending khi một thành viên thêm một người khác vào

prisma/schema.prisma

@@ -19,6 +19,12 @@ enum ParticipantRole {
   VIEWER_ONLY
 }
 
+enum JoinRequestStatus {
+  PENDING
+  ACCEPTED
+  REJECTED
+}
+
 enum ExpenseCategory {
   ACCOMMODATION
   FOOD
@@ -59,10 +65,12 @@ model User {
   isAdmin       Boolean       @default(false)
   isBlocked     Boolean       @default(false)
   
-  createdTours  Tour[]            @relation("TourCreator")
-  tourParticipations TourParticipant[]
-  uploadedPhotos Photo[]
-  paidExpenses  Expense[]         @relation("ExpensePaidBy")
+  createdTours            Tour[]              @relation("TourCreator")
+  tourParticipations      TourParticipant[]
+  requestedJoinRequests   JoinRequest[]      @relation("JoinRequestUser")
+  receivedJoinRequests    JoinRequest[]      @relation("JoinRequester")
+  uploadedPhotos          Photo[]
+  paidExpenses            Expense[]          @relation("ExpensePaidBy")
 }
 
 model Tour {
@@ -77,10 +85,27 @@ model Tour {
   creator     User         @relation("TourCreator", fields: [createdById], references: [id])
   
   participants TourParticipant[]
+  joinRequests JoinRequest[]
   legs         Leg[]
   photos       Photo[]
 }
 
+model JoinRequest {
+  id            String           @id @default(uuid())
+  tourId        String
+  userId        String
+  requestedById String
+  status        JoinRequestStatus @default(PENDING)
+  createdAt     DateTime         @default(now())
+
+  tour          Tour         @relation(fields: [tourId], references: [id], onDelete: Cascade)
+  user          User         @relation("JoinRequestUser", fields: [userId], references: [id], onDelete: Cascade)
+  requestedBy   User         @relation("JoinRequester", fields: [requestedById], references: [id], onDelete: Cascade)
+
+  @@index([tourId, status])
+  @@index([userId])
+}
+
 model TourParticipant {
   tourId      String
   userId      String