Resolve "Login screen setup (without backend)"

Closes #19 (closed)

backend/src/game/Game.ts

+// class for handling game logic
+
+import { User } from '../../types/User';
+import { IGame } from '../interfaces/IGame';
+import { ILobby } from '../interfaces/ILobby';
+import { IStats } from '../interfaces/IStats';
+import { Stats } from './Stats';
+
+export class Game implements IGame {
+  currentTurn: number;
+  lobby: ILobby;
+  gameStatus: boolean;
+  gameId: string;
+  users: [User, IStats][]; // left [0] and right [1] user
+
+  constructor(lobby: ILobby) {
+    this.lobby = lobby;
+    this.gameStatus = false; // game not finished
+    this.gameId = Math.random().toString(36);
+
+    // insert the lobby users into the game and create a new stats object for each user
+    this.users = lobby.getUsers().map((user) => [user, new Stats()]);
+
+    // set the stats for the left and right user
+    // todo add random tank type
+    this.users[0][1].setTankType('M107');
+    this.users[0][1].setTankDirection('left');
+    this.users[0][1].setIsMirrored(true); // this mirroring can also be done locally.
+
+    this.users[1][1].setTankType('M1A2');
+    this.users[1][1].setTankDirection('right');
+    this.users[1][1].setIsMirrored(false);
+
+    // make random number 0 or 1 to determine who starts
+    this.currentTurn = Math.round(Math.random());
+
+    this.notifyUsers(); // TODO: implement this method
+  }
+
+  setIsFinished(status: boolean): void {
+    this.gameStatus = status;
+  }
+
+  notifyUsers(): void {
+    throw new Error('Method not implemented.');
+  }
+
+  setGameStatus(status: boolean): void {
+    this.gameStatus = status;
+  }
+
+  getGameStatus(): boolean {
+    return this.gameStatus;
+  }
+
+  setScore(user: number, score: number): void {
+    if (!this.isValidUserNumber(user)) {
+      throw new Error('Unable to update score. Invalid userID.');
+    }
+    this.users[user][1].setScore(score);
+  }
+
+  getScore(user: number): number {
+    if (!this.isValidUserNumber(user)) {
+      throw new Error('Unable to get score. Invalid userID.');
+    }
+    return this.users[user][1].getScore();
+  }
+
+  getWinner(): User {
+    // return the the user with the highest score in stats
+    if (this.getGameStatus() == false) {
+      throw new Error('Game is not finished');
+    }
+    if (this.getScore(0) > this.getScore(1)) {
+      return this.users[0][0];
+    } else {
+      return this.users[1][0];
+    }
+  }
+  getLoser(): User {
+    // return the the user with the highest score in stats (duplicate code from getWinner)
+    if (this.getGameStatus() == false) {
+      throw new Error('Game is not finished');
+    }
+    if (this.getScore(0) < this.getScore(1)) {
+      return this.users[0][0];
+    } else {
+      return this.users[1][0];
+    }
+  }
+  calculateNextGameState(newGameStateJSON: string): void {
+    throw new Error('Method not implemented.');
+  }
+
+  getGameState(): IGame {
+    throw new Error('Method not implemented.');
+  }
+
+  isValidUserNumber(userNumber: number): boolean {
+    return userNumber === 0 || userNumber === 1;
+  }
+
+  getCurrentTurn(): number {
+    return this.currentTurn;
+  }
+
+  getCurrentTurnUser(): User {
+    return this.users[this.currentTurn][0];
+  }
+
+  // make json object of the game state (to send to clients)
+  getGameStateJSON(): string {
+    return JSON.stringify({
+      gameId: this.gameId,
+      gameStatus: this.gameStatus,
+      currentTurn: this.currentTurn,
+      users: this.users,
+    });
+  }
+}