게임 시작, 종료 구현

@@ -47,6 +47,9 @@ export class ServerInboundMessageRecordMap {
     ready: Boolean,
   });
 
+  // 방장이 게임을 시작합니다.
+  startGame = Record({});
+
   // drawer가 단어를 선택합니다.
   chooseWord = Record({
     word: String,

@@ -177,7 +177,7 @@ export class WorldGuessingGame implements Game {
   private finishGame(): void {
     this.room.broadcast("finishGame", {});
 
-    // TODO
+    this.room.finishGame();
   }
 
   private forceFinishGame() {

@@ -9,6 +9,8 @@ import {
 } from "../../common";
 import { RoomDescription, RoomInfo, UserData } from "../../common/dataType";
 import { RoomManager } from "./RoomManager";
+import { Game } from "../game/Game";
+import { WorldGuessingGame } from "../game/WordGuessingGame";
 
 export class Room {
   public readonly uuid: string;
@@ -22,6 +24,8 @@ export class Room {
   public usersReady: User[] = [];
   public admin?: User;
 
+  public game?: Game;
+
   public closed: boolean = false;
 
   public handler: MessageHandler;
@@ -60,6 +64,17 @@ export class Room {
         this.setReady(user, message.ready);
         return { ok: true };
       },
+      startGame: (user, message) => {
+        if (user !== this.admin) {
+          return { ok: false };
+        }
+        const result = this.canStart();
+        if (!result.ok) {
+          return result;
+        }
+        this.startGame();
+        return { ok: true };
+      },
     });
 
     if (this.admin) {
@@ -149,16 +164,31 @@ export class Room {
     return this.usersReady.includes(user);
   }
 
-  public canStart(): boolean {
+  public canStart(): { ok: boolean; reason?: string } {
+    if (this.isPlayingGame()) {
+      return { ok: false, reason: "이미 게임이 진행 중입니다." };
+    }
     if (this.users.length < 2) {
-      return false;
+      return { ok: false, reason: "최소 2명의 플레이어가 필요합니다." };
     }
     for (let i = 0; i < this.users.length; i++) {
       if (!this.isAdmin(this.users[i]) && !this.isReady(this.users[i])) {
-        return false;
+        return { ok: false, reason: "모든 플레이어가 준비해야 합니다." };
       }
     }
-    return true;
+    return { ok: true };
+  }
+
+  private startGame(): void {
+    this.game = new WorldGuessingGame(this);
+  }
+
+  public finishGame(): void {
+    this.game = undefined;
+  }
+
+  public isPlayingGame(): boolean {
+    return this.game !== undefined;
   }
 
   public sendChat(user: User, message: string): void {