feat: chat — group chat creation (create-group view, backend endpoint, group room display)

backend/migrations/076_chat_group_rooms.sql

@@ -0,0 +1,4 @@
+-- Allow 'group' room type (drop old check constraint, add new one)
+ALTER TABLE chat_rooms DROP CONSTRAINT IF EXISTS chat_rooms_type_check;
+ALTER TABLE chat_rooms ADD CONSTRAINT chat_rooms_type_check
+  CHECK (type IN ('general', 'direct', 'notifications', 'group'));

backend/src/routes/chat.ts

@@ -97,12 +97,17 @@ const chatRoutes: FastifyPluginAsync = async (fastify) => {
                 (SELECT u.name FROM chat_room_members crm JOIN users u ON u.id = crm.user_id WHERE crm.room_id = r.id AND crm.user_id != $2 LIMIT 1) AS other_user_name,
                 (SELECT u.role FROM chat_room_members crm JOIN users u ON u.id = crm.user_id WHERE crm.room_id = r.id AND crm.user_id != $2 LIMIT 1) AS other_user_role,
                 (SELECT crm.user_id FROM chat_room_members crm WHERE crm.room_id = r.id AND crm.user_id != $2 LIMIT 1) AS other_user_id,
+                (SELECT COUNT(*) FROM chat_room_members crm WHERE crm.room_id = r.id) AS member_count,
+                (SELECT json_agg(u.name ORDER BY u.name) FROM chat_room_members crm JOIN users u ON u.id = crm.user_id WHERE crm.room_id = r.id AND crm.user_id != $2 LIMIT 4) AS member_names,
                 (SELECT rs.last_read FROM chat_read_status rs WHERE rs.room_id = r.id AND rs.user_id != $2 LIMIT 1) AS other_user_last_read
            FROM chat_rooms r
           WHERE r.hotel_id = $1
             AND (r.type IN ('general', 'notifications') OR EXISTS (
               SELECT 1 FROM chat_room_members crm WHERE crm.room_id = r.id AND crm.user_id = $2
             ))
+            AND (r.type != 'group' OR EXISTS (
+              SELECT 1 FROM chat_room_members crm WHERE crm.room_id = r.id AND crm.user_id = $2
+            ))
           ORDER BY last_message_at DESC NULLS LAST, r.type = 'general' DESC`,
         [hotelId, userId],
       )
@@ -324,6 +329,68 @@ const chatRoutes: FastifyPluginAsync = async (fastify) => {
     },
   )
 
+  // ── POST group room ───────────────────────────────────────────────────────
+
+  fastify.post<SlugParam & { Body: { name: string; memberIds: string[] } }>(
+    '/api/hotels/:slug/chat/group',
+    { onRequest: [fastify.authenticate] },
+    async (request, reply) => {
+      const { slug } = request.params
+      if (!canAccess(request.user.hotelSlug, request.user.role, slug))
+        return reply.code(403).send({ error: 'Forbidden' })
+      const hotelId = await getHotelId(slug)
+      if (!hotelId) return reply.code(404).send({ error: 'Hotel not found' })
+
+      const { name, memberIds } = request.body
+      if (!name?.trim()) return reply.code(400).send({ error: 'Name required' })
+
+      const userId = request.user.sub
+      const allMembers = [...new Set([userId, ...memberIds])]
+
+      const { rows: [room] } = await db.query(
+        `INSERT INTO chat_rooms (hotel_id, type, name) VALUES ($1, 'group', $2) RETURNING id`,
+        [hotelId, name.trim()],
+      )
+      const memberValues = allMembers.map((_, i) => `($1, $${i + 2})`).join(', ')
+      await db.query(
+        `INSERT INTO chat_room_members (room_id, user_id) VALUES ${memberValues}`,
+        [room.id, ...allMembers],
+      )
+      return reply.code(201).send({ roomId: room.id })
+    },
+  )
+
+  // ── PATCH group room (rename / add/remove members) ────────────────────────
+
+  fastify.patch<RoomParam & { Body: { name?: string; addMemberIds?: string[]; removeMemberIds?: string[] } }>(
+    '/api/hotels/:slug/chat/rooms/:roomId/group',
+    { onRequest: [fastify.authenticate] },
+    async (request, reply) => {
+      const { slug, roomId } = request.params
+      if (!canAccess(request.user.hotelSlug, request.user.role, slug))
+        return reply.code(403).send({ error: 'Forbidden' })
+
+      const { name, addMemberIds = [], removeMemberIds = [] } = request.body
+      if (name) {
+        await db.query('UPDATE chat_rooms SET name = $1 WHERE id = $2', [name.trim(), roomId])
+      }
+      if (addMemberIds.length > 0) {
+        const vals = addMemberIds.map((_, i) => `($1, $${i + 2})`).join(', ')
+        await db.query(
+          `INSERT INTO chat_room_members (room_id, user_id) VALUES ${vals} ON CONFLICT DO NOTHING`,
+          [roomId, ...addMemberIds],
+        )
+      }
+      if (removeMemberIds.length > 0) {
+        await db.query(
+          `DELETE FROM chat_room_members WHERE room_id = $1 AND user_id = ANY($2::uuid[])`,
+          [roomId, removeMemberIds],
+        )
+      }
+      return { ok: true }
+    },
+  )
+
   // ── PATCH mark read ───────────────────────────────────────────────────────
 
   fastify.patch<RoomParam>(