update newMessage

 type Mutation {
-  newMessage(receiverId: Int, message: String!, roomId: Int): Message!
+  newMessage(receiverEmail: String, message: String!, roomId: Int): Message!
 }

 import { isAuthenticated, prisma } from "../../../utils";
 import { ONE_TO_ONE_MESSAGE } from "../../../topics";
 
+// newMessage 에서는 1:1, 1:n 메시지 방만 가정하고 있음
+// 나머지 랜덤채팅은 아직 구상중 (5/4) 기준
 export default {
   Mutation: {
     newMessage: async (_, args, { request, pubsub }) => {
       isAuthenticated(request);
       const { user } = request;
-      const { receiverId, message, roomId } = args;
-      let room = await prisma.room.findOne({
+      const { receiverEmail, message, roomId } = args;
+      const receiver = await prisma.user.findOne({
         where: {
-          id: roomId,
+          email: receiverEmail,
         },
       });
-      room = await prisma.room.update({
+
+      let room = await prisma.room.findOne({
         where: {
           id: roomId,
         },
-        data: {
-          participants: {
-            connect: [{ id: user.id }, { id: receiverId }],
-          },
-        },
       });
+
       // 방이 없는 경우
       if (room === undefined || room === null) {
         // 보내는 사람과 받는 사람이 다른 경우
-        if (user.id !== receiverId) {
+        if (user.id !== receiver.id) {
           room = await prisma.room.create({
             data: {
               participants: {
-                connect: [{ id: receiverId }, { id: user.id }],
+                connect: [{ id: receiver.id }, { id: user.id }],
               },
             },
           });
@@ -43,23 +42,32 @@ export default {
             },
           });
         }
+      } else {
+        // 방이 원래 있던 경우 업데이트
+        room = await prisma.room.update({
+          where: {
+            id: roomId,
+          },
+          data: {
+            participants: {
+              connect: [{ id: user.id }, { id: receiver.id }],
+            },
+          },
+        });
       }
+
       if (!room) {
         throw new Error("There is no room");
       }
-      const toUser = await prisma.user.findOne({
-        where: {
-          id: receiverId,
-        },
-      });
+
       const subMessage = await prisma.message.create({
         data: {
           text: message,
           to: {
-            connect: [{ id: toUser.id }],
+            connect: { id: receiver.id },
           },
           from: {
-            connect: [{ id: user.id }],
+            connect: { id: user.id },
           },
           room: {
             connect: {