feat: tíng năng trò chuyện giữa các thành viên và tin nhắn trực tiếp cho bạn bè

backend/prisma/schema.prisma

@@ -75,7 +75,11 @@ model User {
   uploadedPhotos          Photo[]
   paidExpenses            Expense[]          @relation("ExpensePaidBy")
   comments                Comment[]
-
+  sentConnections         UserConnection[]   @relation("ConnectionRequester")
+  receivedConnections     UserConnection[]   @relation("ConnectionReceiver")
+  sentMessages            DirectMessage[]    @relation("MessageSender")
+  receivedMessages        DirectMessage[]    @relation("MessageReceiver")
+  tourMessages            TourMessage[]
 }
 
 model Tour {
@@ -100,6 +104,7 @@ model Tour {
   legs         Leg[]
   photos       Photo[]
   invitations  TourInvitation[]
+  tourMessages TourMessage[]
 }
 
 model JoinRequest {
@@ -227,3 +232,67 @@ model TourInvitation {
 
   @@unique([tourId, email])
 }
+
+enum ConnectionStatus {
+  PENDING
+  ACCEPTED
+  REJECTED
+}
+
+enum ConnectionType {
+  FRIEND
+  FAMILY
+}
+
+model UserConnection {
+  id           String           @id @default(uuid())
+  requesterId  String
+  receiverId   String
+  status       ConnectionStatus @default(PENDING)
+  type         ConnectionType   @default(FRIEND)
+  createdAt    DateTime         @default(now())
+  updatedAt    DateTime         @updatedAt
+
+  requester    User             @relation("ConnectionRequester", fields: [requesterId], references: [id], onDelete: Cascade)
+  receiver     User             @relation("ConnectionReceiver", fields: [receiverId], references: [id], onDelete: Cascade)
+
+  @@unique([requesterId, receiverId])
+  @@index([requesterId])
+  @@index([receiverId])
+}
+
+model DirectMessage {
+  id            String   @id @default(uuid())
+  senderId      String
+  receiverId    String
+  content       String   @db.Text
+  attachmentUrl String?
+  latitude      Float?
+  longitude     Float?
+  createdAt     DateTime @default(now())
+  updatedAt     DateTime @updatedAt
+
+  sender        User     @relation("MessageSender", fields: [senderId], references: [id], onDelete: Cascade)
+  receiver      User     @relation("MessageReceiver", fields: [receiverId], references: [id], onDelete: Cascade)
+
+  @@index([senderId])
+  @@index([receiverId])
+}
+
+model TourMessage {
+  id            String   @id @default(uuid())
+  tourId        String
+  senderId      String
+  content       String   @db.Text
+  attachmentUrl String?
+  latitude      Float?
+  longitude     Float?
+  createdAt     DateTime @default(now())
+  updatedAt     DateTime @updatedAt
+
+  tour          Tour     @relation(fields: [tourId], references: [id], onDelete: Cascade)
+  sender        User     @relation(fields: [senderId], references: [id], onDelete: Cascade)
+
+  @@index([tourId])
+  @@index([senderId])
+}