Use server response to consume dice as defined by the backend

Reviewed-on: #11

.gitignore

@@ -142,6 +142,7 @@ dist
 
 # production
 /build
+*/build/
 
 # misc
 .DS_Store

app/package-lock.json

@@ -14,6 +14,7 @@
         "@nestjs/platform-express": "^10.0.0",
         "@nestjs/platform-socket.io": "^10.4.7",
         "@nestjs/websockets": "^10.4.7",
+        "interface": "file:../interface",
         "reflect-metadata": "^0.2.0",
         "rxjs": "^7.8.1"
       },
@@ -32,6 +33,7 @@
         "eslint-plugin-prettier": "^5.0.0",
         "jest": "^29.5.0",
         "prettier": "^3.0.0",
+        "socket.io": "^4.8.1",
         "source-map-support": "^0.5.21",
         "supertest": "^7.0.0",
         "ts-jest": "^29.1.0",
@@ -41,6 +43,27 @@
         "typescript": "^5.1.3"
       }
     },
+    "../interface": {
+      "version": "1.0.0",
+      "license": "ISC",
+      "dependencies": {
+        "socket.io": "^4.8.1",
+        "socket.io-client": "^4.8.1",
+        "uuid": "^11.0.3"
+      },
+      "devDependencies": {
+        "@eslint/js": "^8.0.0",
+        "@types/node": "^22.9.0",
+        "@typescript-eslint/eslint-plugin": "^8.15.0",
+        "@typescript-eslint/parser": "^8.15.0",
+        "eslint": "^8.0.0",
+        "eslint-config-prettier": "^9.1.0",
+        "eslint-plugin-prettier": "^5.2.1",
+        "globals": "^15.12.0",
+        "typescript": "^5.6.3",
+        "typescript-eslint": "^8.15.0"
+      }
+    },
     "node_modules/@ampproject/remapping": {
       "version": "2.3.0",
       "resolved": "https://registry.npmjs.org/@ampproject/remapping/-/remapping-2.3.0.tgz",
@@ -1716,6 +1739,24 @@
         "rxjs": "^7.1.0"
       }
     },
+    "node_modules/@nestjs/platform-socket.io/node_modules/socket.io": {
+      "version": "4.8.0",
+      "resolved": "https://registry.npmjs.org/socket.io/-/socket.io-4.8.0.tgz",
+      "integrity": "sha512-8U6BEgGjQOfGz3HHTYaC/L1GaxDCJ/KM0XTkJly0EhZ5U/du9uNEZy4ZgYzEzIqlx2CMm25CrCqr1ck899eLNA==",
+      "license": "MIT",
+      "dependencies": {
+        "accepts": "~1.3.4",
+        "base64id": "~2.0.0",
+        "cors": "~2.8.5",
+        "debug": "~4.3.2",
+        "engine.io": "~6.6.0",
+        "socket.io-adapter": "~2.5.2",
+        "socket.io-parser": "~4.2.4"
+      },
+      "engines": {
+        "node": ">=10.2.0"
+      }
+    },
     "node_modules/@nestjs/schematics": {
       "version": "10.2.3",
       "resolved": "https://registry.npmjs.org/@nestjs/schematics/-/schematics-10.2.3.tgz",
@@ -5271,6 +5312,10 @@
         "node": ">=12.0.0"
       }
     },
+    "node_modules/interface": {
+      "resolved": "../interface",
+      "link": true
+    },
     "node_modules/ipaddr.js": {
       "version": "1.9.1",
       "resolved": "https://registry.npmjs.org/ipaddr.js/-/ipaddr.js-1.9.1.tgz",
@@ -7995,9 +8040,10 @@
       }
     },
     "node_modules/socket.io": {
-      "version": "4.8.0",
-      "resolved": "https://registry.npmjs.org/socket.io/-/socket.io-4.8.0.tgz",
-      "integrity": "sha512-8U6BEgGjQOfGz3HHTYaC/L1GaxDCJ/KM0XTkJly0EhZ5U/du9uNEZy4ZgYzEzIqlx2CMm25CrCqr1ck899eLNA==",
+      "version": "4.8.1",
+      "resolved": "https://registry.npmjs.org/socket.io/-/socket.io-4.8.1.tgz",
+      "integrity": "sha512-oZ7iUCxph8WYRHHcjBEc9unw3adt5CmSNlppj/5Q4k2RIrhl8Z5yY2Xr4j9zj0+wzVZ0bxmYoGSzKJnRl6A4yg==",
+      "dev": true,
       "license": "MIT",
       "dependencies": {
         "accepts": "~1.3.4",

app/package.json

@@ -6,12 +6,12 @@
   "private": true,
   "license": "UNLICENSED",
   "scripts": {
-    "build": "nest build",
+    "build": "npm run lint && nest build",
     "format": "prettier --write \"src/**/*.ts\" \"test/**/*.ts\"",
-    "start": "nest start --watch",
+    "start": "npm run build && nest start --watch",
     "start:debug": "nest start --debug --watch",
     "start:prod": "node dist/main",
-    "lint": "eslint \"{src,apps,libs,test}/**/*.ts\" --fix",
+    "lint": "eslint \"src/**/*.ts\" --fix",
     "test": "jest",
     "test:watch": "jest --watch",
     "test:cov": "jest --coverage",
@@ -24,6 +24,7 @@
     "@nestjs/platform-express": "^10.0.0",
     "@nestjs/platform-socket.io": "^10.4.7",
     "@nestjs/websockets": "^10.4.7",
+    "interface": "file:../interface",
     "reflect-metadata": "^0.2.0",
     "rxjs": "^7.8.1"
   },
@@ -42,6 +43,7 @@
     "eslint-plugin-prettier": "^5.0.0",
     "jest": "^29.5.0",
     "prettier": "^3.0.0",
+    "socket.io": "^4.8.1",
     "source-map-support": "^0.5.21",
     "supertest": "^7.0.0",
     "ts-jest": "^29.1.0",

app/src/app.module.ts

@@ -1,8 +1,9 @@
 import { Module } from '@nestjs/common';
 import { AppService } from './app.service';
+import { PlayerService } from './players/player.service';
 
 @Module({
   imports: [],
-  providers: [AppService],
+  providers: [AppService, PlayerService],
 })
 export class AppModule {}

app/src/app.service.ts

@@ -1,14 +1,41 @@
 import { Injectable, Logger } from '@nestjs/common';
-import { MessageBody, SubscribeMessage, WebSocketGateway } from '@nestjs/websockets';
+import {
+  ConnectedSocket,
+  OnGatewayConnection,
+  MessageBody,
+  SubscribeMessage,
+  WebSocketGateway,
+} from '@nestjs/websockets';
+import { PlayerService } from './players/player.service';
+import { Socket } from 'socket.io';
+import { ClientEvent, CreateLobbyEvent, JoinLobbyEvent } from 'interface';
 
 @WebSocketGateway({ cors: true })
 @Injectable()
-export class AppService {
+export class AppService implements OnGatewayConnection {
   private readonly logger = new Logger(AppService.name);
 
-  @SubscribeMessage('example-request')
-  handleCustomEvent(@MessageBody() data: string): unknown {
-    this.logger.debug(`Received request in backend with data: ${data}`);
-    return {event: "example-response", data: `Replying from backend, received data: ${data}`};
+  constructor(private readonly playerService: PlayerService) {}
+  handleConnection(client: Socket) {
+    this.playerService.createPlayer(client.id);
+    this.logger.log(client.id);
+  }
+
+  @SubscribeMessage(ClientEvent.CREATE_LOBBY)
+  handleCreateLobby(
+    @ConnectedSocket() client: Socket,
+    @MessageBody() event: CreateLobbyEvent,
+  ) {
+    this.playerService.addUserName(client.id, event.userName);
+    this.logger.log('Se ha creado un lobby');
+  }
+
+  @SubscribeMessage(ClientEvent.JOIN_LOBBY)
+  handleJoinLobby(
+    @ConnectedSocket() client: Socket,
+    @MessageBody() event: JoinLobbyEvent,
+  ) {
+    this.playerService.addUserName(client.id, event.userName);
+    this.logger.log('Te has unido a un lobby');
   }
 }

app/src/main.ts

@@ -3,6 +3,7 @@ import { AppModule } from './app.module';
 
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
-  await app.listen(process.env.PORT ?? 3010);
+  const port = process.env.PORT ?? 3010;
+  await app.listen(port);
 }
 bootstrap();

app/src/players/player.service.ts

@@ -0,0 +1,19 @@
+import { Injectable, Logger } from '@nestjs/common';
+import { Player } from './player';
+
+@Injectable()
+export class PlayerService {
+  private readonly logger = new Logger(PlayerService.name);
+  private readonly players: Map<string, Player> = new Map();
+
+  createPlayer(socketId: string) {
+    const player: Player = new Player(socketId);
+    this.players.set(socketId, player);
+    this.logger.log([...this.players.entries()]);
+  }
+
+  addUserName(socketId: string, userName: string) {
+    this.players.get(socketId).userName = userName;
+    this.logger.log([...this.players.entries()]);
+  }
+}

app/src/players/player.ts

@@ -0,0 +1,7 @@
+export class Player {
+  socketId: string;
+  userName?: string;
+  constructor(socketId: string) {
+    this.socketId = socketId;
+  }
+}

interface/.eslintrc.js

@@ -0,0 +1,19 @@
+module.exports = {
+  parser: "@typescript-eslint/parser",
+  parserOptions: {
+    project: "tsconfig.json",
+    tsconfigRootDir: __dirname,
+    sourceType: "module",
+  },
+  plugins: ["@typescript-eslint/eslint-plugin"],
+  extends: ["plugin:@typescript-eslint/strict", "plugin:prettier/recommended"],
+  root: true,
+  env: {
+    node: true,
+    jest: true,
+  },
+  ignorePatterns: [".eslintrc.js", "dist/"],
+  rules: {
+    "@typescript-eslint/no-non-null-assertion": "off",
+  },
+};

interface/BoardBuilder.ts

@@ -0,0 +1,115 @@
+import { CellType } from "./constants/CellType";
+import { Direction } from "./constants/Direction";
+import { ExitType } from "./constants/ExitType";
+import { Cell } from "./types/Cell";
+import { Exit } from "./types/Exit";
+
+const boardSize = 7;
+const universityLocations = [
+  [2, 0],
+  [4, 1],
+  [3, 3],
+];
+const factoryLocations = [
+  [0, 0],
+  [5, 2],
+  [4, 6],
+];
+const houseLocations = [
+  [0, 2],
+  [1, 5],
+  [2, 4],
+  [5, 4],
+];
+const mapPosition = (position: number[], type: CellType) => {
+  return {
+    row: position[0],
+    col: position[1],
+    type: type,
+  };
+};
+const specialUniversityCells = universityLocations.map((position) =>
+  mapPosition(position, CellType.UNIVERSITY),
+);
+const specialFactoryCells = factoryLocations.map((position) =>
+  mapPosition(position, CellType.FACTORY),
+);
+const specialHouseCells = houseLocations.map((position) =>
+  mapPosition(position, CellType.HOUSE),
+);
+const specialCells = specialUniversityCells
+  .concat(specialFactoryCells)
+  .concat(specialHouseCells);
+
+const specialExitIndexes1 = [1, 5];
+const specialExitIndexes2 = [3];
+
+function createBoard(): Cell[][] {
+  const indexes = Array.from(Array(boardSize).keys());
+  return indexes.map((rowIndex) =>
+    indexes.map((colIndex) => {
+      const specialCell = specialCells.find(
+        (specialCell) =>
+          specialCell.row === rowIndex && specialCell.col === colIndex,
+      );
+      return new Cell(specialCell ? specialCell.type : CellType.NORMAL);
+    }),
+  );
+}
+
+function connectAdjacentCells(board: Cell[][]) {
+  const indexes = Array.from(Array(boardSize).keys());
+  for (const rowIndex of indexes.slice(0, -1)) {
+    for (const colIndex of indexes) {
+      const cell = board[rowIndex][colIndex];
+      const bottomCell = board[rowIndex + 1][colIndex];
+      cell
+        .getNodeAt(Direction.SOUTH)
+        .linkToNode(bottomCell.getNodeAt(Direction.NORTH));
+    }
+  }
+
+  for (const rowIndex of indexes) {
+    for (const colIndex of indexes.slice(0, -1)) {
+      const cell = board[rowIndex][colIndex];
+      const rightCell = board[rowIndex][colIndex + 1];
+      cell
+        .getNodeAt(Direction.EAST)
+        .linkToNode(rightCell.getNodeAt(Direction.WEST));
+    }
+  }
+}
+
+function addExits(board: Cell[][]) {
+  // Add exits to top row
+  board[0].forEach((cell, colIndex) => {
+    let exitType = ExitType.AMBIVALENT;
+    if (specialExitIndexes1.includes(colIndex)) exitType = ExitType.ROAD;
+    if (specialExitIndexes2.includes(colIndex)) exitType = ExitType.RAIL;
+    cell.getNodeAt(Direction.NORTH).linkToNode(new Exit(exitType));
+  });
+
+  // Add exits to bottom row
+  board[boardSize - 1].forEach((cell, colIndex) => {
+    let exitType = ExitType.AMBIVALENT;
+    if (specialExitIndexes1.includes(colIndex)) exitType = ExitType.ROAD;
+    if (specialExitIndexes2.includes(colIndex)) exitType = ExitType.RAIL;
+    cell.getNodeAt(Direction.SOUTH).linkToNode(new Exit(exitType));
+  });
+
+  // Add exits to left and right columns
+  board.forEach((row, rowIndex) => {
+    let exitType = ExitType.AMBIVALENT;
+    if (specialExitIndexes1.includes(rowIndex)) exitType = ExitType.RAIL;
+    if (specialExitIndexes2.includes(rowIndex)) exitType = ExitType.ROAD;
+    row[0].getNodeAt(Direction.WEST).linkToNode(new Exit(exitType));
+    row[boardSize - 1].getNodeAt(Direction.EAST).linkToNode(new Exit(exitType));
+  });
+}
+
+export function buildBoard(): Cell[][] {
+  const board: Cell[][] = createBoard();
+  connectAdjacentCells(board);
+  addExits(board);
+  return board;
+}

interface/client-events/ClientEvent.ts

@@ -0,0 +1,5 @@
+export enum ClientEvent {
+  CREATE_LOBBY = "create-lobby",
+  JOIN_LOBBY = "join-lobby",
+  START_GAME = "start-game",
+}

interface/client-events/CreateLobbyEvent.ts

@@ -0,0 +1,13 @@
+import { Socket } from "socket.io-client";
+import { ClientEvent } from "./ClientEvent";
+
+export type CreateLobbyEvent = {
+  userName: string;
+};
+
+export function handleCreateLobby(
+  socket: Socket,
+  payload: CreateLobbyEvent,
+): void {
+  socket.emit(ClientEvent.CREATE_LOBBY, payload);
+}

interface/client-events/JoinLobbyEvent.ts

@@ -0,0 +1,11 @@
+import { Socket } from "socket.io-client";
+import { ClientEvent } from "./ClientEvent";
+
+export type JoinLobbyEvent = {
+  userName: string;
+  lobbyId: string;
+};
+
+export function handleJoinLobby(socket: Socket, payload: JoinLobbyEvent): void {
+  socket.emit(ClientEvent.JOIN_LOBBY, payload);
+}

interface/constants/CellType.ts

@@ -0,0 +1,6 @@
+export enum CellType {
+  NORMAL = "NORMAL",
+  HOUSE = "HOUSE",
+  FACTORY = "FACTORY",
+  UNIVERSITY = "UNIVERSITY",
+}

interface/constants/Direction.ts

@@ -0,0 +1,30 @@
+export enum Direction {
+  NORTH = "NORTH",
+  SOUTH = "SOUTH",
+  EAST = "EAST",
+  WEST = "WEST",
+}
+
+export const directions: Direction[] = [
+  Direction.NORTH,
+  Direction.SOUTH,
+  Direction.EAST,
+  Direction.WEST,
+];
+
+export function rotateDirection(
+  initialDirection: Direction,
+  rotationAngle: 0 | 90 | 180 | 270,
+): Direction {
+  const angleToDirectionMap: Record<Direction, 0 | 90 | 180 | 270> = {
+    [Direction.NORTH]: 0,
+    [Direction.EAST]: 90,
+    [Direction.SOUTH]: 180,
+    [Direction.WEST]: 270,
+  };
+  const finalAngle =
+    (360 + angleToDirectionMap[initialDirection] - rotationAngle) % 360;
+  return (Object.keys(angleToDirectionMap) as Direction[]).find(
+    (direction) => angleToDirectionMap[direction] === finalAngle,
+  )!;
+}

interface/constants/ExitType.ts

@@ -0,0 +1,5 @@
+export enum ExitType {
+  RAIL = "RAIL",
+  ROAD = "ROAD",
+  AMBIVALENT = "AMBIVALENT",
+}

interface/constants/InternalNodeType.ts

@@ -0,0 +1,4 @@
+export enum InternalNodeType {
+  NONE = "NONE",
+  STATION = "STATION",
+}

interface/constants/Pieces.ts

@@ -0,0 +1,410 @@
+import { Piece } from "../types/Piece";
+import { Direction } from "./Direction";
+import { InternalNodeType } from "./InternalNodeType";
+import { TrackType } from "./TrackType";
+
+const STRAIGHT_RAIL: Piece = new Piece({
+  useInternalTracks: false,
+  trackDefinitions: [
+    {
+      startPoint: Direction.NORTH,
+      endPoint: Direction.SOUTH,
+      type: TrackType.RAIL,
+    },
+  ],
+});
+const TURN_RAIL: Piece = new Piece({
+  useInternalTracks: false,
+  trackDefinitions: [
+    {
+      startPoint: Direction.SOUTH,
+      endPoint: Direction.EAST,
+      type: TrackType.RAIL,
+    },
+  ],
+});
+const FOUR_WAY_CROSS_RAIL: Piece = new Piece({
+  useInternalTracks: true,
+  internalNodeType: InternalNodeType.NONE,
+  trackDefinitions: [
+    {
+      startPoint: Direction.NORTH,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.EAST,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.SOUTH,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.WEST,
+      type: TrackType.RAIL,
+    },
+  ],
+});
+const T_JUNCTION_RAIL: Piece = new Piece({
+  useInternalTracks: true,
+  internalNodeType: InternalNodeType.NONE,
+  trackDefinitions: [
+    {
+      startPoint: Direction.WEST,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.SOUTH,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.EAST,
+      type: TrackType.RAIL,
+    },
+  ],
+});
+const DEAD_END_STATION_RAIL: Piece = new Piece({
+  useInternalTracks: true,
+  internalNodeType: InternalNodeType.STATION,
+  trackDefinitions: [
+    {
+      startPoint: Direction.SOUTH,
+      type: TrackType.RAIL,
+    },
+  ],
+});
+const TURN_RAIL_TO_ROAD: Piece = new Piece({
+  useInternalTracks: true,
+  internalNodeType: InternalNodeType.STATION,
+  trackDefinitions: [
+    {
+      startPoint: Direction.SOUTH,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.EAST,
+      type: TrackType.ROAD,
+    },
+  ],
+});
+const T_JUNCTION_WITH_ROAD_ON_SIDE: Piece = new Piece({
+  useInternalTracks: true,
+  internalNodeType: InternalNodeType.STATION,
+  trackDefinitions: [
+    {
+      startPoint: Direction.SOUTH,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.WEST,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.EAST,
+      type: TrackType.ROAD,
+    },
+  ],
+});
+const FOUR_WAY_WITH_ONE_ROAD: Piece = new Piece({
+  useInternalTracks: true,
+  internalNodeType: InternalNodeType.STATION,
+  trackDefinitions: [
+    {
+      startPoint: Direction.NORTH,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.EAST,
+      type: TrackType.ROAD,
+    },
+    {
+      startPoint: Direction.SOUTH,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.WEST,
+      type: TrackType.RAIL,
+    },
+  ],
+});
+const T_JUNCTION_WITH_ROAD_AT_CENTER: Piece = new Piece({
+  useInternalTracks: true,
+  internalNodeType: InternalNodeType.STATION,
+  trackDefinitions: [
+    {
+      startPoint: Direction.NORTH,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.EAST,
+      type: TrackType.ROAD,
+    },
+    {
+      startPoint: Direction.SOUTH,
+      type: TrackType.RAIL,
+    },
+  ],
+});
+const STRAIGHT_TRACK_CHANGE: Piece = new Piece({
+  useInternalTracks: true,
+  internalNodeType: InternalNodeType.STATION,
+  trackDefinitions: [
+    {
+      startPoint: Direction.EAST,
+      type: TrackType.ROAD,
+    },
+    {
+      startPoint: Direction.WEST,
+      type: TrackType.RAIL,
+    },
+  ],
+});
+const DEAD_END_STATION_ROAD: Piece = new Piece({
+  useInternalTracks: true,
+  internalNodeType: InternalNodeType.STATION,
+  trackDefinitions: [
+    {
+      startPoint: Direction.EAST,
+      type: TrackType.ROAD,
+    },
+  ],
+});
+const T_JUNCTION_WITH_RAIL_AT_CENTER: Piece = new Piece({
+  useInternalTracks: true,
+  internalNodeType: InternalNodeType.STATION,
+  trackDefinitions: [
+    {
+      startPoint: Direction.EAST,
+      type: TrackType.ROAD,
+    },
+    {
+      startPoint: Direction.SOUTH,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.WEST,
+      type: TrackType.ROAD,
+    },
+  ],
+});
+const FOUR_WAY_PERPENDICULAR_CROSSING: Piece = new Piece({
+  useInternalTracks: true,
+  internalNodeType: InternalNodeType.STATION,
+  trackDefinitions: [
+    {
+      startPoint: Direction.NORTH,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.SOUTH,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.WEST,
+      type: TrackType.ROAD,
+    },
+    {
+      startPoint: Direction.EAST,
+      type: TrackType.ROAD,
+    },
+  ],
+});
+const FOUR_WAY_WITH_ONE_RAIL: Piece = new Piece({
+  useInternalTracks: true,
+  internalNodeType: InternalNodeType.STATION,
+  trackDefinitions: [
+    {
+      startPoint: Direction.NORTH,
+      type: TrackType.ROAD,
+    },
+    {
+      startPoint: Direction.EAST,
+      type: TrackType.ROAD,
+    },
+    {
+      startPoint: Direction.SOUTH,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.WEST,
+      type: TrackType.ROAD,
+    },
+  ],
+});
+const FOUR_WAY_TURNING_CROSSING: Piece = new Piece({
+  useInternalTracks: true,
+  internalNodeType: InternalNodeType.STATION,
+  trackDefinitions: [
+    {
+      startPoint: Direction.NORTH,
+      type: TrackType.ROAD,
+    },
+    {
+      startPoint: Direction.EAST,
+      type: TrackType.ROAD,
+    },
+    {
+      startPoint: Direction.SOUTH,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.WEST,
+      type: TrackType.RAIL,
+    },
+  ],
+});
+const LEVEL_CROSSING: Piece = new Piece({
+  useInternalTracks: false,
+  trackDefinitions: [
+    {
+      startPoint: Direction.NORTH,
+      endPoint: Direction.SOUTH,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.EAST,
+      endPoint: Direction.WEST,
+      type: TrackType.ROAD,
+    },
+  ],
+});
+const STRAIGHT_ROAD: Piece = new Piece({
+  useInternalTracks: false,
+  trackDefinitions: [
+    {
+      startPoint: Direction.EAST,
+      endPoint: Direction.WEST,
+      type: TrackType.ROAD,
+    },
+  ],
+});
+const T_JUNCTION_ROAD: Piece = new Piece({
+  useInternalTracks: true,
+  internalNodeType: InternalNodeType.NONE,
+  trackDefinitions: [
+    {
+      startPoint: Direction.EAST,
+      type: TrackType.ROAD,
+    },
+    {
+      startPoint: Direction.SOUTH,
+      type: TrackType.ROAD,
+    },
+    {
+      startPoint: Direction.WEST,
+      type: TrackType.ROAD,
+    },
+  ],
+});
+const FOUR_WAY_CROSS_ROAD: Piece = new Piece({
+  useInternalTracks: true,
+  internalNodeType: InternalNodeType.NONE,
+  trackDefinitions: [
+    {
+      startPoint: Direction.NORTH,
+      type: TrackType.ROAD,
+    },
+    {
+      startPoint: Direction.EAST,
+      type: TrackType.ROAD,
+    },
+    {
+      startPoint: Direction.SOUTH,
+      type: TrackType.ROAD,
+    },
+    {
+      startPoint: Direction.WEST,
+      type: TrackType.ROAD,
+    },
+  ],
+});
+const DOUBLE_TURN_ROAD: Piece = new Piece({
+  useInternalTracks: false,
+  trackDefinitions: [
+    {
+      startPoint: Direction.NORTH,
+      endPoint: Direction.WEST,
+      type: TrackType.ROAD,
+    },
+    {
+      startPoint: Direction.EAST,
+      endPoint: Direction.SOUTH,
+      type: TrackType.ROAD,
+    },
+  ],
+});
+const TURN_ROAD: Piece = new Piece({
+  useInternalTracks: false,
+  trackDefinitions: [
+    {
+      startPoint: Direction.NORTH,
+      endPoint: Direction.WEST,
+      type: TrackType.ROAD,
+    },
+  ],
+});
+const DOUBLE_TURN_RAIL: Piece = new Piece({
+  useInternalTracks: false,
+  trackDefinitions: [
+    {
+      startPoint: Direction.NORTH,
+      endPoint: Direction.WEST,
+      type: TrackType.RAIL,
+    },
+    {
+      startPoint: Direction.EAST,
+      endPoint: Direction.SOUTH,
+      type: TrackType.RAIL,
+    },
+  ],
+});
+
+export enum PieceId {
+  P01 = "P01",
+  P02 = "P02",
+  P03 = "P03",
+  P04 = "P04",
+  P05 = "P05",
+  P06 = "P06",
+  P07 = "P07",
+  P08 = "P08",
+  P09 = "P09",
+  P10 = "P10",
+  P11 = "P11",
+  P12 = "P12",
+  P13 = "P13",
+  P14 = "P14",
+  P15 = "P15",
+  P16 = "P16",
+  P17 = "P17",
+  P18 = "P18",
+  P19 = "P19",
+  P20 = "P20",
+  P21 = "P21",
+  P22 = "P22",
+}
+
+export const pieceMap: Record<PieceId, Piece> = {
+  [PieceId.P01]: STRAIGHT_RAIL,
+  [PieceId.P02]: TURN_RAIL,
+  [PieceId.P03]: FOUR_WAY_CROSS_RAIL,
+  [PieceId.P04]: T_JUNCTION_RAIL,
+  [PieceId.P05]: DEAD_END_STATION_RAIL,
+  [PieceId.P06]: TURN_RAIL_TO_ROAD,
+  [PieceId.P07]: T_JUNCTION_WITH_ROAD_ON_SIDE,
+  [PieceId.P08]: FOUR_WAY_WITH_ONE_ROAD,
+  [PieceId.P09]: T_JUNCTION_WITH_ROAD_AT_CENTER,
+  [PieceId.P10]: STRAIGHT_TRACK_CHANGE,
+  [PieceId.P11]: DEAD_END_STATION_ROAD,
+  [PieceId.P12]: T_JUNCTION_WITH_RAIL_AT_CENTER,
+  [PieceId.P13]: FOUR_WAY_PERPENDICULAR_CROSSING,
+  [PieceId.P14]: FOUR_WAY_WITH_ONE_RAIL,
+  [PieceId.P15]: FOUR_WAY_TURNING_CROSSING,
+  [PieceId.P16]: LEVEL_CROSSING,
+  [PieceId.P17]: STRAIGHT_ROAD,
+  [PieceId.P18]: T_JUNCTION_ROAD,
+  [PieceId.P19]: FOUR_WAY_CROSS_ROAD,
+  [PieceId.P20]: DOUBLE_TURN_ROAD,
+  [PieceId.P21]: TURN_ROAD,
+  [PieceId.P22]: DOUBLE_TURN_RAIL,
+};

interface/constants/TrackType.ts

@@ -0,0 +1,4 @@
+export enum TrackType {
+  RAIL = "RAIL",
+  ROAD = "ROAD",
+}

interface/index.ts

@@ -0,0 +1,21 @@
+export * from "./constants/CellType";
+export * from "./constants/Direction";
+export * from "./constants/ExitType";
+export * from "./constants/InternalNodeType";
+export * from "./constants/Pieces";
+export * from "./constants/TrackType";
+export * from "./types/Border";
+export * from "./types/Cell";
+export * from "./types/Exit";
+export * from "./types/ExternalNode";
+export * from "./types/InternalNode";
+export * from "./types/Piece";
+export * from "./types/PlacedPiece";
+export * from "./BoardBuilder";
+export * from "./server-events/ServerError";
+export * from "./server-events/ServerEvent";
+export * from "./server-events/StartRoundEvent";
+export * from "./server-events/UpdateLobbyEvent";
+export * from "./client-events/ClientEvent";
+export * from "./client-events/CreateLobbyEvent";
+export * from "./client-events/JoinLobbyEvent";

interface/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "interface",
+  "version": "1.0.0",
+  "description": "A collection of common functions for the trains and roads project.",
+  "main": "dist/index.js",
+  "types": "dist/index.d.ts",
+  "scripts": {
+    "build": "npm run lint && tsc",
+    "lint": "eslint \"*.ts\" \"*/**/*.ts\" --fix"
+  },
+  "author": "",
+  "license": "ISC",
+  "devDependencies": {
+    "@eslint/js": "^8.0.0",
+    "@types/node": "^22.9.0",
+    "@typescript-eslint/eslint-plugin": "^8.15.0",
+    "@typescript-eslint/parser": "^8.15.0",
+    "eslint": "^8.0.0",
+    "eslint-config-prettier": "^9.1.0",
+    "eslint-plugin-prettier": "^5.2.1",
+    "globals": "^15.12.0",
+    "typescript": "^5.6.3",
+    "typescript-eslint": "^8.15.0"
+  },
+  "dependencies": {
+    "uuid": "^11.0.3",
+    "socket.io": "^4.8.1",
+    "socket.io-client": "^4.8.1"
+  }
+}

interface/server-events/ServerError.ts

@@ -0,0 +1,4 @@
+export enum ServerError {
+  CREATE_LOBBY_ERROR = "create-lobby-error",
+  JOIN_LOBBY_ERROR = "join-lobby-error",
+}

interface/server-events/ServerEvent.ts

@@ -0,0 +1,4 @@
+export enum ServerEvent {
+  LOBBY_UPDATE = "lobby-update",
+  START_ROUND = "start-round",
+}

interface/server-events/StartRoundEvent.ts

@@ -0,0 +1,22 @@
+import { Socket as ServerSocket } from "socket.io";
+import { Socket as ClientSocket } from "socket.io-client";
+import { ServerEvent } from "./ServerEvent";
+import { PieceId } from "../constants/Pieces";
+
+export type StartRoundEvent = {
+  pieceIds: PieceId[];
+};
+
+export const emitStartRoundEvent = (
+  socket: ServerSocket,
+  payload: StartRoundEvent,
+) => {
+  socket.emit(ServerEvent.START_ROUND, payload);
+};
+
+export function attachHandlerToStartRoundEvent(
+  socket: ClientSocket,
+  handler: (event: StartRoundEvent) => void,
+): void {
+  socket.once(ServerEvent.START_ROUND, handler);
+}

interface/server-events/UpdateLobbyEvent.ts

@@ -0,0 +1,22 @@
+import { Socket as ServerSocket } from "socket.io";
+import { Socket as ClientSocket } from "socket.io-client";
+import { ServerEvent } from "./ServerEvent";
+
+export type UpdateLobbyEvent = {
+  playerNames: Array<string>;
+  gameCode: string;
+};
+
+export const emitUpdateLobbyEvent = (
+  socket: ServerSocket,
+  payload: UpdateLobbyEvent,
+) => {
+  socket.emit(ServerEvent.LOBBY_UPDATE, payload);
+};
+
+export function attachHandlerToUpdateLobbyEvent(
+  socket: ClientSocket,
+  handler: (event: UpdateLobbyEvent) => void,
+): void {
+  socket.once(ServerEvent.LOBBY_UPDATE, handler);
+}

interface/tsconfig.json

@@ -0,0 +1,110 @@
+{
+  "compilerOptions": {
+    /* Visit https://aka.ms/tsconfig to read more about this file */
+
+    /* Projects */
+    // "incremental": true,                              /* Save .tsbuildinfo files to allow for incremental compilation of projects. */
+    // "composite": true,                                /* Enable constraints that allow a TypeScript project to be used with project references. */
+    // "tsBuildInfoFile": "./.tsbuildinfo",              /* Specify the path to .tsbuildinfo incremental compilation file. */
+    // "disableSourceOfProjectReferenceRedirect": true,  /* Disable preferring source files instead of declaration files when referencing composite projects. */
+    // "disableSolutionSearching": true,                 /* Opt a project out of multi-project reference checking when editing. */
+    // "disableReferencedProjectLoad": true,             /* Reduce the number of projects loaded automatically by TypeScript. */
+
+    /* Language and Environment */
+    "target": "es2016",                                  /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
+    // "lib": [],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
+    // "jsx": "preserve",                                /* Specify what JSX code is generated. */
+    "experimentalDecorators": true,                   /* Enable experimental support for legacy experimental decorators. */
+    "emitDecoratorMetadata": true,                    /* Emit design-type metadata for decorated declarations in source files. */
+    // "jsxFactory": "",                                 /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h'. */
+    // "jsxFragmentFactory": "",                         /* Specify the JSX Fragment reference used for fragments when targeting React JSX emit e.g. 'React.Fragment' or 'Fragment'. */
+    // "jsxImportSource": "",                            /* Specify module specifier used to import the JSX factory functions when using 'jsx: react-jsx*'. */
+    // "reactNamespace": "",                             /* Specify the object invoked for 'createElement'. This only applies when targeting 'react' JSX emit. */
+    // "noLib": true,                                    /* Disable including any library files, including the default lib.d.ts. */
+    // "useDefineForClassFields": true,                  /* Emit ECMAScript-standard-compliant class fields. */
+    // "moduleDetection": "auto",                        /* Control what method is used to detect module-format JS files. */
+
+    /* Modules */
+    "module": "commonjs",                                /* Specify what module code is generated. */
+    "rootDir": "./",                                  /* Specify the root folder within your source files. */
+    // "moduleResolution": "node10",                     /* Specify how TypeScript looks up a file from a given module specifier. */
+    // "baseUrl": "./",                                  /* Specify the base directory to resolve non-relative module names. */
+    // "paths": {},                                      /* Specify a set of entries that re-map imports to additional lookup locations. */
+    // "rootDirs": [],                                   /* Allow multiple folders to be treated as one when resolving modules. */
+    // "typeRoots": [],                                  /* Specify multiple folders that act like './node_modules/@types'. */
+    // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
+    // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
+    // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
+    // "allowImportingTsExtensions": true,               /* Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set. */
+    // "resolvePackageJsonExports": true,                /* Use the package.json 'exports' field when resolving package imports. */
+    // "resolvePackageJsonImports": true,                /* Use the package.json 'imports' field when resolving imports. */
+    // "customConditions": [],                           /* Conditions to set in addition to the resolver-specific defaults when resolving imports. */
+    // "noUncheckedSideEffectImports": true,             /* Check side effect imports. */
+    // "resolveJsonModule": true,                        /* Enable importing .json files. */
+    // "allowArbitraryExtensions": true,                 /* Enable importing files with any extension, provided a declaration file is present. */
+    // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */
+
+    /* JavaScript Support */
+    // "allowJs": true,                                  /* Allow JavaScript files to be a part of your program. Use the 'checkJS' option to get errors from these files. */
+    // "checkJs": true,                                  /* Enable error reporting in type-checked JavaScript files. */
+    // "maxNodeModuleJsDepth": 1,                        /* Specify the maximum folder depth used for checking JavaScript files from 'node_modules'. Only applicable with 'allowJs'. */
+
+    /* Emit */
+    "declaration": true,                              /* Generate .d.ts files from TypeScript and JavaScript files in your project. */
+    "declarationMap": true,                           /* Create sourcemaps for d.ts files. */
+    // "emitDeclarationOnly": true,                      /* Only output d.ts files and not JavaScript files. */
+    "sourceMap": true,                                /* Create source map files for emitted JavaScript files. */
+    // "inlineSourceMap": true,                          /* Include sourcemap files inside the emitted JavaScript. */
+    // "noEmit": true,                                   /* Disable emitting files from a compilation. */
+    // "outFile": "./",                                  /* Specify a file that bundles all outputs into one JavaScript file. If 'declaration' is true, also designates a file that bundles all .d.ts output. */
+    "outDir": "./dist",                                   /* Specify an output folder for all emitted files. */
+    // "removeComments": true,                           /* Disable emitting comments. */
+    // "importHelpers": true,                            /* Allow importing helper functions from tslib once per project, instead of including them per-file. */
+    // "downlevelIteration": true,                       /* Emit more compliant, but verbose and less performant JavaScript for iteration. */
+    // "sourceRoot": "",                                 /* Specify the root path for debuggers to find the reference source code. */
+    // "mapRoot": "",                                    /* Specify the location where debugger should locate map files instead of generated locations. */
+    // "inlineSources": true,                            /* Include source code in the sourcemaps inside the emitted JavaScript. */
+    // "emitBOM": true,                                  /* Emit a UTF-8 Byte Order Mark (BOM) in the beginning of output files. */
+    // "newLine": "crlf",                                /* Set the newline character for emitting files. */
+    // "stripInternal": true,                            /* Disable emitting declarations that have '@internal' in their JSDoc comments. */
+    // "noEmitHelpers": true,                            /* Disable generating custom helper functions like '__extends' in compiled output. */
+    // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
+    // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
+    // "declarationDir": "./",                           /* Specify the output directory for generated declaration files. */
+
+    /* Interop Constraints */
+    // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */
+    // "verbatimModuleSyntax": true,                     /* Do not transform or elide any imports or exports not marked as type-only, ensuring they are written in the output file's format based on the 'module' setting. */
+    // "isolatedDeclarations": true,                     /* Require sufficient annotation on exports so other tools can trivially generate declaration files. */
+    // "allowSyntheticDefaultImports": true,             /* Allow 'import x from y' when a module doesn't have a default export. */
+    "esModuleInterop": true,                             /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables 'allowSyntheticDefaultImports' for type compatibility. */
+    // "preserveSymlinks": true,                         /* Disable resolving symlinks to their realpath. This correlates to the same flag in node. */
+    "forceConsistentCasingInFileNames": true,            /* Ensure that casing is correct in imports. */
+
+    /* Type Checking */
+    "strict": true,                                      /* Enable all strict type-checking options. */
+    // "noImplicitAny": true,                            /* Enable error reporting for expressions and declarations with an implied 'any' type. */
+    // "strictNullChecks": true,                         /* When type checking, take into account 'null' and 'undefined'. */
+    // "strictFunctionTypes": true,                      /* When assigning functions, check to ensure parameters and the return values are subtype-compatible. */
+    // "strictBindCallApply": true,                      /* Check that the arguments for 'bind', 'call', and 'apply' methods match the original function. */
+    // "strictPropertyInitialization": true,             /* Check for class properties that are declared but not set in the constructor. */
+    // "strictBuiltinIteratorReturn": true,              /* Built-in iterators are instantiated with a 'TReturn' type of 'undefined' instead of 'any'. */
+    // "noImplicitThis": true,                           /* Enable error reporting when 'this' is given the type 'any'. */
+    // "useUnknownInCatchVariables": true,               /* Default catch clause variables as 'unknown' instead of 'any'. */
+    // "alwaysStrict": true,                             /* Ensure 'use strict' is always emitted. */
+    // "noUnusedLocals": true,                           /* Enable error reporting when local variables aren't read. */
+    // "noUnusedParameters": true,                       /* Raise an error when a function parameter isn't read. */
+    // "exactOptionalPropertyTypes": true,               /* Interpret optional property types as written, rather than adding 'undefined'. */
+    // "noImplicitReturns": true,                        /* Enable error reporting for codepaths that do not explicitly return in a function. */
+    // "noFallthroughCasesInSwitch": true,               /* Enable error reporting for fallthrough cases in switch statements. */
+    // "noUncheckedIndexedAccess": true,                 /* Add 'undefined' to a type when accessed using an index. */
+    // "noImplicitOverride": true,                       /* Ensure overriding members in derived classes are marked with an override modifier. */
+    // "noPropertyAccessFromIndexSignature": true,       /* Enforces using indexed accessors for keys declared using an indexed type. */
+    // "allowUnusedLabels": true,                        /* Disable error reporting for unused labels. */
+    // "allowUnreachableCode": true,                     /* Disable error reporting for unreachable code. */
+
+    /* Completeness */
+    // "skipDefaultLibCheck": true,                      /* Skip type checking .d.ts files that are included with TypeScript. */
+    "skipLibCheck": true                                 /* Skip type checking all .d.ts files. */
+  }
+}

interface/types/Border.ts

@@ -0,0 +1,22 @@
+import { Exit } from "./Exit";
+import { ExternalNode } from "./ExternalNode";
+
+export class Border {
+  private readonly firstNode: ExternalNode;
+  private readonly secondNode: ExternalNode | Exit;
+
+  constructor(firstNode: ExternalNode, secondNode: ExternalNode | Exit) {
+    this.firstNode = firstNode;
+    this.secondNode = secondNode;
+  }
+
+  public traverseFrom(node: ExternalNode): ExternalNode | Exit {
+    if (node === this.firstNode) {
+      return this.secondNode;
+    }
+    if (node === this.secondNode) {
+      return this.firstNode;
+    }
+    throw Error("Unable to traverse border");
+  }
+}

interface/types/Cell.ts

@@ -0,0 +1,112 @@
+import { CellType } from "../constants/CellType";
+import { Direction } from "../constants/Direction";
+import { ExitType } from "../constants/ExitType";
+import { PieceId, pieceMap } from "../constants/Pieces";
+import { Exit } from "./Exit";
+import { ExternalNode } from "./ExternalNode";
+import { InternalNode } from "./InternalNode";
+import { Piece } from "./Piece";
+import { PlacedPiece } from "./PlacedPiece";
+
+export class Cell {
+  public readonly externalNodes: Map<Direction, ExternalNode>;
+  public readonly cellType: CellType;
+  public placedPiece?: {
+    piece: PlacedPiece;
+    id: PieceId;
+  };
+
+  constructor(cellType: CellType) {
+    this.externalNodes = new Map([
+      [Direction.NORTH, new ExternalNode(this, Direction.NORTH)],
+      [Direction.SOUTH, new ExternalNode(this, Direction.SOUTH)],
+      [Direction.EAST, new ExternalNode(this, Direction.EAST)],
+      [Direction.WEST, new ExternalNode(this, Direction.WEST)],
+    ]);
+    this.cellType = cellType;
+  }
+
+  public getNodeAt(direction: Direction): ExternalNode {
+    const node = this.externalNodes.get(direction);
+    if (!node) throw Error(`Could not find node at ${direction}`);
+    return node!;
+  }
+
+  /**
+   * @param rotation in degrees counter-clockwise
+   */
+  public placePiece(pieceId: PieceId, rotation: 0 | 90 | 180 | 270) {
+    if (this.placedPiece !== undefined) return;
+    const piece: Piece = pieceMap[pieceId].rotate(rotation);
+
+    this.validatePiecePlacement(piece);
+
+    this.placedPiece = {
+      piece: piece.toPlacedPiece(this),
+      id: pieceId,
+    };
+  }
+
+  private validatePiecePlacement(piece: Piece) {
+    const hasAnyConnection = Array.from(piece.tracks)
+      .map((track) => {
+        const trackExternalNodes = [
+          this.getNodeAt(track.joinedPoints.firstPoint),
+        ];
+        if (!(track.joinedPoints.secondPoint instanceof InternalNode)) {
+          trackExternalNodes.push(
+            this.getNodeAt(track.joinedPoints.secondPoint),
+          );
+        }
+        return {
+          trackExternalNodes: trackExternalNodes,
+          trackType: track.type,
+        };
+      })
+      .reduce((isConnected, { trackExternalNodes, trackType }) => {
+        let isTrackConnected: boolean = false;
+        trackExternalNodes
+          .filter((node) => node.traverseBorder() instanceof Exit)
+          .forEach((node) => {
+            const exitType = (node.traverseBorder() as Exit).type;
+            isTrackConnected = true;
+            if (
+              exitType !== ExitType.AMBIVALENT &&
+              exitType.toString() !== trackType.toString()
+            ) {
+              throw Error(
+                `Unable to place piece, invalid exit type at direction ${node.direction}`,
+              );
+            }
+          });
+
+        trackExternalNodes
+          .filter((node) => node.traverseBorder() instanceof ExternalNode)
+          .forEach((node) => {
+            const adjacentExternalNode = node.traverseBorder() as ExternalNode;
+            const adjacentTrack =
+              adjacentExternalNode.cell.placedPiece?.piece.findTrackForDirection(
+                adjacentExternalNode.direction,
+              );
+            if (adjacentTrack !== undefined) {
+              isTrackConnected = true;
+              if (adjacentTrack.type !== trackType) {
+                throw Error(
+                  `Unable to place piece next to another due to conflicting track types at ${node.direction}`,
+                );
+              }
+            }
+          });
+
+        return isConnected || isTrackConnected;
+      }, false);
+
+    if (!hasAnyConnection) {
+      throw Error("No adjacent exit or piece available to connect to");
+    }
+  }
+
+  public removePiece() {
+    this.placedPiece = undefined;
+  }
+}

interface/types/Exit.ts

@@ -0,0 +1,9 @@
+import { ExitType } from "../constants/ExitType";
+
+export class Exit {
+  public readonly type: ExitType;
+
+  constructor(type: ExitType) {
+    this.type = type;
+  }
+}

interface/types/ExternalNode.ts

@@ -0,0 +1,29 @@
+import { Direction } from "../constants/Direction";
+import { Border } from "./Border";
+import { Cell } from "./Cell";
+import { Exit } from "./Exit";
+
+export class ExternalNode {
+  public readonly direction: Direction;
+  private border?: Border;
+  public readonly cell: Cell;
+
+  constructor(cell: Cell, direction: Direction) {
+    this.cell = cell;
+    this.direction = direction;
+  }
+
+  public linkToNode(other: ExternalNode | Exit) {
+    this.border = new Border(this, other);
+    if (other instanceof ExternalNode) {
+      other.border = this.border;
+    }
+  }
+
+  public traverseBorder(): ExternalNode | Exit {
+    if (!this.border) {
+      throw Error(`Missing border for node`);
+    }
+    return this.border.traverseFrom(this);
+  }
+}

interface/types/InternalNode.ts

@@ -0,0 +1,12 @@
+import { v4 as uuidv4 } from "uuid";
+import { InternalNodeType } from "../constants/InternalNodeType";
+
+export class InternalNode {
+  id: string;
+  type: InternalNodeType;
+
+  constructor(type: InternalNodeType) {
+    this.id = uuidv4();
+    this.type = type;
+  }
+}

interface/types/Piece.ts

@@ -0,0 +1,115 @@
+import { Direction, rotateDirection } from "../constants/Direction";
+import { TrackType } from "../constants/TrackType";
+import { Cell } from "./Cell";
+import { InternalNode } from "./InternalNode";
+import { PlacedPiece } from "./PlacedPiece";
+import { InternalNodeType } from "../constants/InternalNodeType";
+
+export interface PieceProps {
+  readonly useInternalTracks: boolean;
+  readonly internalNodeType?: InternalNodeType;
+  readonly trackDefinitions: {
+    readonly startPoint: Direction;
+    readonly endPoint?: Direction;
+    readonly type: TrackType;
+  }[];
+}
+
+type Track = {
+  readonly joinedPoints: {
+    readonly firstPoint: Direction;
+    readonly secondPoint: Direction | InternalNode;
+  };
+  readonly type: TrackType;
+};
+
+export class Piece {
+  readonly tracks: Set<Track>;
+  readonly internalNode?: InternalNode;
+
+  constructor(pieceProps: PieceProps) {
+    if (pieceProps.useInternalTracks) {
+      if (!pieceProps.internalNodeType) {
+        throw Error(
+          "Expected to find internal node type when useInternalTracks is set",
+        );
+      }
+      this.internalNode = new InternalNode(pieceProps.internalNodeType);
+      this.tracks = new Set(
+        pieceProps.trackDefinitions.map((trackDefinition) => {
+          return {
+            joinedPoints: {
+              firstPoint: trackDefinition.startPoint,
+              secondPoint: this.internalNode!,
+            },
+            type: trackDefinition.type,
+          };
+        }),
+      );
+    } else {
+      this.internalNode = undefined;
+      this.tracks = new Set(
+        pieceProps.trackDefinitions.map((trackDefinition) => {
+          if (!trackDefinition.endPoint) {
+            throw Error("Missing end point for non-internal track");
+          }
+          return {
+            joinedPoints: {
+              firstPoint: trackDefinition.startPoint,
+              secondPoint: trackDefinition.endPoint,
+            },
+            type: trackDefinition.type,
+          };
+        }),
+      );
+    }
+  }
+
+  rotate(rotation: 0 | 90 | 180 | 270): Piece {
+    return new Piece({
+      useInternalTracks: this.internalNode !== undefined,
+      internalNodeType: this.internalNode?.type,
+      trackDefinitions: Array.from(this.tracks).map((track) => {
+        if (track.joinedPoints.secondPoint instanceof InternalNode) {
+          return {
+            type: track.type,
+            startPoint: rotateDirection(
+              track.joinedPoints.firstPoint,
+              rotation,
+            ),
+          };
+        } else {
+          return {
+            type: track.type,
+            startPoint: rotateDirection(
+              track.joinedPoints.firstPoint,
+              rotation,
+            ),
+            endPoint: rotateDirection(track.joinedPoints.secondPoint, rotation),
+          };
+        }
+      }),
+    });
+  }
+
+  toPlacedPiece(cell: Cell) {
+    return new PlacedPiece(
+      new Set(
+        Array.from(this.tracks).map((track) => {
+          return {
+            nodes: {
+              firstNode: cell.getNodeAt(track.joinedPoints.firstPoint),
+              secondNode:
+                track.joinedPoints.secondPoint instanceof InternalNode
+                  ? (track.joinedPoints.secondPoint as InternalNode)
+                  : cell.getNodeAt(track.joinedPoints.secondPoint as Direction),
+            },
+            type: track.type,
+          };
+        }),
+      ),
+      this.internalNode,
+      cell,
+    );
+  }
+}

interface/types/PlacedPiece.ts

@@ -0,0 +1,41 @@
+import { Direction } from "../constants/Direction";
+import { TrackType } from "../constants/TrackType";
+import { Cell } from "./Cell";
+import { ExternalNode } from "./ExternalNode";
+import { InternalNode } from "./InternalNode";
+
+export class PlacedPiece {
+  tracks: Set<{
+    nodes: {
+      firstNode: ExternalNode;
+      secondNode: ExternalNode | InternalNode;
+    };
+    type: TrackType;
+  }>;
+  internalNode?: InternalNode;
+  cell: Cell;
+  constructor(
+    tracks: Set<{
+      nodes: {
+        firstNode: ExternalNode;
+        secondNode: ExternalNode | InternalNode;
+      };
+      type: TrackType;
+    }>,
+    internalNodes: InternalNode | undefined,
+    cell: Cell,
+  ) {
+    this.tracks = tracks;
+    this.internalNode = internalNodes;
+    this.cell = cell;
+  }
+
+  public findTrackForDirection(direction: Direction) {
+    return Array.from(this.tracks).find(
+      (track) =>
+        track.nodes.firstNode.direction === direction ||
+        (track.nodes.secondNode instanceof ExternalNode &&
+          track.nodes.secondNode.direction === direction),
+    );
+  }
+}

web/.eslintrc.js

@@ -0,0 +1,24 @@
+module.exports = {
+  parser: "@typescript-eslint/parser",
+  parserOptions: {
+    project: "tsconfig.json",
+    tsconfigRootDir: __dirname,
+    sourceType: "module",
+  },
+  plugins: ["@typescript-eslint/eslint-plugin"],
+  extends: ["plugin:@typescript-eslint/strict", "plugin:prettier/recommended"],
+  root: true,
+  env: {
+    node: true,
+    jest: true,
+  },
+  ignorePatterns: [".eslintrc.js", "dist/", "node_modules/", "build/"],
+  rules: {
+    "prettier/prettier": [
+      "error",
+      {
+        endOfLine: "auto",
+      },
+    ],
+  },
+};

web/package.json

@@ -3,13 +3,15 @@
   "version": "0.1.0",
   "private": true,
   "dependencies": {
+    "@picocss/pico": "^2.0.6",
     "@testing-library/jest-dom": "^5.17.0",
     "@testing-library/react": "^13.4.0",
     "@testing-library/user-event": "^13.5.0",
     "@types/jest": "^27.5.2",
-    "@types/node": "^16.18.119",
+    "@types/node": "^17.0.29",
     "@types/react": "^18.3.12",
     "@types/react-dom": "^18.3.1",
+    "interface": "file:../interface",
     "react": "^18.3.1",
     "react-dom": "^18.3.1",
     "react-scripts": "5.0.1",
@@ -20,9 +22,10 @@
   },
   "scripts": {
     "start": "react-scripts start",
-    "build": "react-scripts build",
+    "build": "npm run lint && react-scripts build",
     "test": "react-scripts test",
-    "eject": "react-scripts eject"
+    "eject": "react-scripts eject",
+    "lint": "eslint \"*/**/*.tsx\" \"*/**/*.ts\" --fix"
   },
   "eslintConfig": {
     "extends": [
@@ -41,5 +44,13 @@
       "last 1 firefox version",
       "last 1 safari version"
     ]
+  },
+  "devDependencies": {
+    "@eslint/js": "^8.0.0",
+    "@typescript-eslint/parser": "^8.15.0",
+    "eslint": "^8.0.0",
+    "eslint-config-prettier": "^9.1.0",
+    "eslint-plugin-prettier": "^5.2.1",
+    "typescript-eslint": "^8.15.0"
   }
 }

web/src/App.scss

@@ -1,12 +1,3 @@
-body {
-    font-size: 20px;
-
-    header > button {
-        background-color: aliceblue;
-        padding: 10px;
-        margin-bottom: 10px;
-        border: 1px solid black;
-        border-radius: 10%;
-        display: block;
-    }
-}
+@use "node_modules/@picocss/pico/scss/pico" with (
+    $theme-color: "pumpkin"
+);

web/src/App.test.tsx

@@ -1,8 +0,0 @@
-import React from 'react';
-import { render, screen } from '@testing-library/react';
-import App from './App';
-
-test('Renders hello world', () => {
-  render(<App />);
-  expect(screen.getByText("Hello World! Front")).toBeInTheDocument();
-});

web/src/App.tsx

@@ -1,21 +1,57 @@
-import React from 'react';
-import { io } from "socket.io-client";
+import React, { useCallback, useState } from "react";
+import { Socket } from "socket.io-client";
+import LandingPage from "./pages/landing/LandingPage";
+import GamePage from "./pages/game/GamePage";
+import LobbyPage from "./pages/lobby/LobbyPage";
+import {
+  attachHandlerToStartRoundEvent,
+  attachHandlerToUpdateLobbyEvent,
+  PieceId,
+} from "interface";
 
-function App() {
-  const socket = io("http://localhost:3010");
-  const emitData = () => console.log(socket.emit("example-request", "custom-request"));
-  socket.on("example-response", (data) => console.log(`Received response in front end with data: ${data}`));
-
-  return (
-    <div className="App">
-      <header className="App-header">
-        <button onClick={emitData}>
-          Emit Data
-        </button>
-        Hello World! Front
-      </header>
-    </div>
-  );
+export interface AppProps {
+  socket: Socket;
 }
 
+const App = (props: AppProps) => {
+  const { socket } = props;
+  const [renderedPage, setRenderedPage] = useState("LANDING");
+
+  const [initialPlayerNames, setInitialPlayerNames] = useState([] as string[]);
+  const [gameCode, setGameCode] = useState("");
+  const [initialPieceIds, setInitialPieceIds] = useState([] as PieceId[]);
+
+  const setupNextPageTransition = useCallback(() => {
+    if (renderedPage === "LANDING") {
+      attachHandlerToUpdateLobbyEvent(socket, (event) => {
+        setInitialPlayerNames(event.playerNames);
+        setGameCode(event.gameCode);
+        setRenderedPage("LOBBY");
+      });
+    } else if (renderedPage === "LOBBY") {
+      attachHandlerToStartRoundEvent(socket, (event) => {
+        setInitialPieceIds(event.pieceIds);
+        setRenderedPage("GAME");
+      });
+    }
+  }, [renderedPage]);
+
+  setupNextPageTransition();
+  return (
+    <div className="app">
+      {renderedPage === "LANDING" && <LandingPage {...props} />}
+      {renderedPage === "LOBBY" && (
+        <LobbyPage
+          {...props}
+          initialPlayerNames={initialPlayerNames}
+          gameCode={gameCode}
+        />
+      )}
+      {renderedPage === "GAME" && (
+        <GamePage initialPieceIds={initialPieceIds} />
+      )}
+    </div>
+  );
+};
+
 export default App;

web/src/index.tsx

@@ -1,13 +1,15 @@
-import React from 'react';
-import ReactDOM from 'react-dom/client';
-import App from './App';
-import './App.scss'
+import React from "react";
+import ReactDOM from "react-dom/client";
+import App from "./App";
+import "./App.scss";
+import { io } from "socket.io-client";
 
 const root = ReactDOM.createRoot(
-  document.getElementById('root') as HTMLElement
+  document.getElementById("root") as HTMLElement,
 );
+const socket = io("http://localhost:3010");
 root.render(
   <React.StrictMode>
-    <App />
-  </React.StrictMode>
+    <App socket={socket} />
+  </React.StrictMode>,
 );

web/src/pages/game/GamePage.scss

@@ -0,0 +1,17 @@
+h1 {
+    text-align: center;
+    padding: 10px;
+    margin: 0;
+}
+
+.game-panel {
+    user-select: none; /* Standard syntax */
+    display: flex;
+    flex-direction: row;
+
+    .right-panel {
+        display: flex;
+        flex-direction: column;
+        padding: 50px;
+    }
+}

web/src/pages/game/GamePage.tsx

@@ -0,0 +1,134 @@
+import React, { useState } from "react";
+import GameBoard from "./components/GameBoard";
+import DiceSet from "./components/DiceSet";
+import "./GamePage.scss";
+import { buildBoard, PieceId } from "interface";
+import { DieViewProps } from "./types/DieViewProps";
+import { PlacePieceActionStack } from "./types/PlacePieceActionStack";
+
+export interface GamePageProps {
+  initialPieceIds: PieceId[];
+}
+
+const GamePage = (props: GamePageProps) => {
+  const { initialPieceIds } = props;
+
+  const [pieceIds] = useState(initialPieceIds);
+
+  const getDiceSet: () => DieViewProps[] = () =>
+    pieceIds.map((pieceId) => {
+      return {
+        pieceId: pieceId,
+        isSelected: false,
+        isDisabled: false,
+        isSpecial: false,
+        rotation: 0,
+      };
+    });
+
+  const [dice, setDice] = useState(getDiceSet());
+  const [specialDice, setSpecialDice] = useState(
+    [
+      PieceId.P03,
+      PieceId.P08,
+      PieceId.P13,
+      PieceId.P14,
+      PieceId.P15,
+      PieceId.P19,
+    ].map((pieceId) => {
+      return {
+        pieceId: pieceId,
+        isSelected: false,
+        isDisabled: false,
+        isSpecial: true,
+        rotation: 0,
+      };
+    }),
+  );
+  const [specialDieUsedInRound, setSpecialDieUsedInRound] = useState(false);
+
+  const modifyDieState = (
+    matcher: (die: DieViewProps) => boolean,
+    newStateComputer: (die: DieViewProps) => Partial<DieViewProps>,
+  ) => {
+    setDice(
+      dice.map((die) => {
+        if (!matcher(die)) return die;
+        return {
+          ...die,
+          ...newStateComputer(die),
+        };
+      }),
+    );
+    setSpecialDice(
+      specialDice.map((die) => {
+        if (!matcher(die)) return die;
+        return {
+          ...die,
+          ...newStateComputer(die),
+        };
+      }),
+    );
+  };
+
+  const fetchDie = (matcher: (die: DieViewProps) => boolean) => {
+    return dice.concat(specialDice).find((die) => matcher(die));
+  };
+
+  const [board, setBoard] = useState(buildBoard());
+  const [id, setId] = useState(1);
+  const refreshBoardRender = () => {
+    setBoard(board);
+    setId(id + 1);
+  };
+
+  const [placePieceActionStack, setPlacePieceActionStack] = useState(
+    new PlacePieceActionStack(),
+  );
+  const resetBoard = () => {
+    placePieceActionStack.resetActions(board);
+    setBoard(board);
+    modifyDieState(
+      () => true,
+      () => {
+        return { isSelected: false, isDisabled: false };
+      },
+    );
+    setId(id + 1);
+  };
+  const commitBoard = () => {
+    if (dice.some((die) => !die.isDisabled)) return;
+    placePieceActionStack.commitActions();
+    setDice(getDiceSet());
+    setSpecialDieUsedInRound(false);
+  };
+
+  return (
+    <React.Fragment>
+      <h1>Game Page Title</h1>
+      <div className="game-panel" id={id.toString()}>
+        <GameBoard
+          modifyDieState={modifyDieState}
+          fetchDie={fetchDie}
+          setSpecialDieUsedInRound={setSpecialDieUsedInRound}
+          refreshBoardRender={refreshBoardRender}
+          board={board}
+          placePieceActionStack={placePieceActionStack}
+          setPlacePieceActionStack={setPlacePieceActionStack}
+        />
+        <div className="right-panel">
+          <DiceSet
+            dice={dice}
+            specialDice={specialDice}
+            modifyDieState={modifyDieState}
+            specialDieUsedInRound={specialDieUsedInRound}
+            resetBoard={resetBoard}
+            commitBoard={commitBoard}
+          />
+        </div>
+      </div>
+    </React.Fragment>
+  );
+};
+
+export default GamePage;

web/src/pages/game/components/BoardCell.scss

@@ -0,0 +1,108 @@
+.cell {
+    width: 100px;
+    height: 100px;
+    border: 2px solid black;
+    border-radius: 10%;
+    position: relative;
+
+    .piece {
+        border-radius: 10%;
+        position: absolute;
+        top: 0;
+
+        &.rotate-90 {
+            transform: rotate(-90deg);
+        }
+
+        &.rotate-180 {
+            transform: rotate(180deg);
+        }
+
+        &.rotate-270 {
+            transform: rotate(90deg);
+        }
+    }
+
+    .cell-type-icon {
+        width: 25px;
+        height: 25px;
+        padding: 2px;
+        margin: 2px;
+        position: absolute;
+        top: 0;
+        left: 0;
+    }
+}
+
+.cell .exit {
+    position: absolute;
+    width: 20px;
+    height: 20px;
+
+    &:has(.exit-road) {
+        border: solid black;
+        border-width: 0 1px;
+
+        .exit-road {
+            margin: auto;
+            width: 0;
+            height: 100%;
+            border: dashed black;
+            border-width: 0 1px;
+            transform: translate(calc(50% - 1px));
+        }
+    }
+
+    &:has(.exit-rail) {
+        border-width: 0 1px;
+
+        .exit-rail {
+            margin: auto;
+            width: 0;
+            height: 100%;
+            border: solid black;
+            border-width: 0 1px;
+            transform: translate(calc(50% - 1px));
+        }
+    }
+
+    &:has(.exit-ambivalent) {
+        border-width: 0 1px;
+        border-style: dotted;
+
+        .exit-ambivalent {
+            margin: auto;
+            width: 0;
+            height: 100%;
+            border: dotted black;
+            border-width: 0 1px 0 0;
+            transform: translate(calc(50%));
+        }
+    }
+    &:has(.exit-north), &:has(.exit-south) {
+        left: 50%;
+    }
+
+    &:has(.exit-north) {
+        transform: translate(calc(-50% - 1px), -100%);
+    }
+
+    &:has(.exit-south) {
+        top: 100%;
+        transform: translate(calc(-50% - 1px), 0%);
+    }
+
+    &:has(.exit-east), &:has(.exit-west) {
+        top: 50%;
+    }
+
+    &:has(.exit-east) {
+        left: 100%;
+        transform: rotate(90deg) translate(-50%, 0);
+    }
+
+    &:has(.exit-west) {
+        left: 0%;
+        transform: rotate(90deg) translate(-50%, 100%);
+    }
+}

web/src/pages/game/components/BoardCell.tsx

@@ -0,0 +1,85 @@
+import { Cell, CellType, directions, Exit, PieceId } from "interface";
+import "./BoardCell.scss";
+import { useState } from "react";
+import { DieViewProps } from "../types/DieViewProps";
+
+export interface BoardCellProps {
+  cell: Cell;
+  refreshBoardRender: () => void;
+  modifyDieState: (
+    matcher: (die: DieViewProps) => boolean,
+    newStateComputer: (die: DieViewProps) => Partial<DieViewProps>,
+  ) => void;
+  fetchDie: (
+    matcher: (die: DieViewProps) => boolean,
+  ) => DieViewProps | undefined;
+  setSpecialDieUsedInRound: React.Dispatch<React.SetStateAction<boolean>>;
+  placePieceActionHandler: (pieceId: PieceId, rotation: number) => void;
+}
+
+const BoardCell = (props: BoardCellProps) => {
+  const {
+    cell,
+    refreshBoardRender,
+    modifyDieState,
+    fetchDie,
+    setSpecialDieUsedInRound,
+    placePieceActionHandler,
+  } = props;
+  const [pieceRotationAngle, setPieceRotationAngle] = useState(0);
+  const handleBoardCellClick = () => {
+    const selectedDie = fetchDie((die) => die.isSelected);
+    if (!selectedDie) return;
+    try {
+      placePieceActionHandler(selectedDie.pieceId, selectedDie.rotation);
+    } catch (error) {
+      console.log(error);
+      return;
+    }
+    modifyDieState(
+      (die) => die === selectedDie,
+      () => {
+        return {
+          isSelected: false,
+          isDisabled: true,
+        };
+      },
+    );
+    if (selectedDie.isSpecial) setSpecialDieUsedInRound(true);
+    // Set rotation to the piece in the board, not the die
+    setPieceRotationAngle(selectedDie.rotation);
+    refreshBoardRender();
+  };
+
+  return (
+    <div className={"cell"} onClick={handleBoardCellClick}>
+      {directions.map((direction) => {
+        const traversedNode = cell.getNodeAt(direction).traverseBorder();
+        const isExit = traversedNode instanceof Exit;
+        if (!isExit) return;
+        const className =
+          `exit-${direction.toLowerCase()}` +
+          ` exit-${(traversedNode as Exit).type.toLowerCase()}`;
+        return (
+          <div className="exit">
+            <div className={className} />
+          </div>
+        );
+      })}
+      {cell.placedPiece && (
+        <img
+          className={`piece rotate-${pieceRotationAngle}`}
+          src={`pieces/${cell.placedPiece.id}.jpeg`}
+        ></img>
+      )}
+      {cell.cellType !== CellType.NORMAL && (
+        <img
+          className="cell-type-icon"
+          src={`./${cell.cellType.toLowerCase()}-icon.png`}
+        ></img>
+      )}
+    </div>
+  );
+};
+
+export default BoardCell;

web/src/pages/game/components/DiceSet.scss

@@ -0,0 +1,40 @@
+.dice-set-actions {
+    display: flex;
+    flex-direction: row;
+    width: max-content;
+    margin: auto auto 50px auto;
+
+    img {
+        border: 3px solid green;
+        box-shadow: 0 0 10px green;
+        border-radius: 20%;
+        padding: 5px;
+        width: 70px;
+        height: 70px;
+        margin-right: 10px;
+
+        &.icon-inverted {
+            transform: scaleX(-1);
+        }
+
+        &:last-child {
+            margin-right: 0;
+        }
+    }
+}
+
+.dice-set {
+    display: grid;
+    grid-template-columns: repeat(2, auto);
+    gap: 20px;
+    margin: 0 0 50px 0;
+}
+
+.special-dice-set {
+    display: grid;
+    grid-template-columns: repeat(3, auto);
+    margin: 0 0 50px 0;
+    column-gap: 12%;
+    row-gap: 20px;
+    width: 100%;
+}

web/src/pages/game/components/DiceSet.tsx

@@ -0,0 +1,80 @@
+import "./DiceSet.scss";
+import Die from "./Die";
+import React from "react";
+import { DieViewProps } from "../types/DieViewProps";
+
+export interface DiceSetProps {
+  dice: DieViewProps[];
+  specialDice: DieViewProps[];
+  modifyDieState: (
+    matcher: (die: DieViewProps) => boolean,
+    newStateComputer: (die: DieViewProps) => Partial<DieViewProps>,
+  ) => void;
+  specialDieUsedInRound: boolean;
+  resetBoard: () => void;
+  commitBoard: () => void;
+}
+const DiceSet = (props: DiceSetProps) => {
+  const {
+    dice,
+    specialDice,
+    modifyDieState,
+    specialDieUsedInRound,
+    resetBoard,
+    commitBoard,
+  } = props;
+  const handleDieClick = (clickedDie: DieViewProps) => {
+    if (clickedDie.isDisabled) return;
+    const isSpecialDie = clickedDie.isSpecial;
+    if (isSpecialDie && specialDieUsedInRound) return;
+    modifyDieState(
+      () => true,
+      (die) => {
+        return {
+          isSelected: die === clickedDie,
+        };
+      },
+    );
+  };
+
+  const handleRotateButton = (rotation: number) => {
+    modifyDieState(
+      (die) => die.isSelected,
+      (die) => {
+        return {
+          rotation: (die.rotation + rotation + 360) % 360,
+        };
+      },
+    );
+  };
+
+  return (
+    <React.Fragment>
+      <div className="dice-set-actions">
+        <img
+          src="./rotate-icon.png"
+          onClick={() => handleRotateButton(-90)}
+        ></img>
+        <img
+          src="./rotate-icon.png"
+          className="icon-inverted"
+          onClick={() => handleRotateButton(90)}
+        ></img>
+        <img src="./clean-icon.png" onClick={resetBoard}></img>
+        <img src="./commit-icon.png" onClick={commitBoard}></img>
+      </div>
+      <div className="dice-set">
+        {dice.map((die) => (
+          <Die die={die} handleDieClick={handleDieClick} />
+        ))}
+      </div>
+      <div className="special-dice-set">
+        {specialDice.map((die) => (
+          <Die die={die} handleDieClick={handleDieClick} />
+        ))}
+      </div>
+    </React.Fragment>
+  );
+};
+
+export default DiceSet;

web/src/pages/game/components/Die.scss

@@ -0,0 +1,37 @@
+.dice {
+    height: 150px;
+    width: 150px;
+    border: 2px solid black;
+    border-radius: 10%;
+
+    img{
+        border-radius: 10%;
+    }
+
+    &.selected {
+        box-shadow: 0 0 20px green;
+    }
+
+    &.disabled {
+        box-shadow: 0 0 20px grey;
+    }
+
+    &.rotate-90 {
+        transform: rotate(-90deg);
+    }
+
+    &.rotate-180 {
+        transform: rotate(180deg);
+    }
+
+    &.rotate-270 {
+        transform: rotate(90deg);
+    }
+
+    transition: transform 0.5s cubic-bezier(.47,1.64,.41,.8);
+}
+
+.special-dice-set .dice {
+    height: 80px;
+    width: 80px;
+}

web/src/pages/game/components/Die.tsx

@@ -0,0 +1,25 @@
+import "./Die.scss";
+import { DieViewProps } from "../types/DieViewProps";
+
+interface DieProps {
+  die: DieViewProps;
+  handleDieClick: (die: DieViewProps) => void;
+}
+
+const Die = (props: DieProps) => {
+  const { die, handleDieClick } = props;
+  const { pieceId, isSelected, isDisabled, rotation } = die;
+  const className =
+    "dice" +
+    (isSelected ? " selected" : "") +
+    (isDisabled ? " disabled" : "") +
+    ` rotate-${rotation}`;
+
+  return (
+    <div className={className} onClick={() => handleDieClick(die)}>
+      <img src={`pieces/${pieceId}.jpeg`}></img>
+    </div>
+  );
+};
+
+export default Die;

web/src/pages/game/components/GameBoard.scss

@@ -0,0 +1,10 @@
+.game-board {
+    height: 850px;
+    width: 850px;
+    min-height: 850px;
+    min-width: 850px;
+    display: grid;
+    grid-template-columns: repeat(7, auto);
+    gap: auto;
+    padding: 50px;
+}

web/src/pages/game/components/GameBoard.tsx

@@ -0,0 +1,49 @@
+import { Cell } from "interface";
+import "./GameBoard.scss";
+import BoardCell from "./BoardCell";
+import { DieViewProps } from "../types/DieViewProps";
+import { PlacePieceActionStack } from "../types/PlacePieceActionStack";
+import { PlacePieceAction } from "../types/PlacePieceAction";
+
+export interface GameBoardProps {
+  modifyDieState: (
+    matcher: (die: DieViewProps) => boolean,
+    newStateComputer: (die: DieViewProps) => Partial<DieViewProps>,
+  ) => void;
+  fetchDie: (
+    matcher: (die: DieViewProps) => boolean,
+  ) => DieViewProps | undefined;
+  setSpecialDieUsedInRound: React.Dispatch<React.SetStateAction<boolean>>;
+  refreshBoardRender: () => void;
+  board: Cell[][];
+  placePieceActionStack: PlacePieceActionStack;
+  setPlacePieceActionStack: React.Dispatch<
+    React.SetStateAction<PlacePieceActionStack>
+  >;
+}
+
+const GameBoard = (props: GameBoardProps) => {
+  const { board, placePieceActionStack, setPlacePieceActionStack } = props;
+
+  return (
+    <div className="game-board">
+      {board.flatMap((row, rowIndex) =>
+        row.map((cell, colIndex) => (
+          <BoardCell
+            {...props}
+            cell={cell}
+            placePieceActionHandler={(pieceId, rotation) => {
+              placePieceActionStack.executeAction(
+                new PlacePieceAction(pieceId, rotation, rowIndex, colIndex),
+                board,
+              );
+              setPlacePieceActionStack(placePieceActionStack);
+            }}
+          />
+        )),
+      )}
+    </div>
+  );
+};
+
+export default GameBoard;

web/src/pages/game/types/DieViewProps.ts

@@ -0,0 +1,9 @@
+import { PieceId } from "interface";
+
+export interface DieViewProps {
+  pieceId: PieceId;
+  isSelected: boolean;
+  isDisabled: boolean;
+  readonly isSpecial: boolean;
+  rotation: number;
+}

web/src/pages/game/types/PlacePieceAction.ts

@@ -0,0 +1,32 @@
+import { Cell, PieceId } from "interface";
+
+export class PlacePieceAction {
+  pieceId: PieceId;
+  rotation: number;
+  cell: {
+    row: number;
+    col: number;
+  };
+
+  constructor(pieceId: PieceId, rotation: number, row: number, col: number) {
+    this.pieceId = pieceId;
+    this.rotation = rotation;
+    this.cell = {
+      row: row,
+      col: col,
+    };
+  }
+
+  do(board: Cell[][]) {
+    const cell = board[this.cell.row][this.cell.col];
+    cell.placePiece(this.pieceId, this.rotation as 0 | 90 | 180 | 270);
+  }
+
+  undo(board: Cell[][]) {
+    const cell = board[this.cell.row][this.cell.col];
+    if (!cell.placedPiece || cell.placedPiece.id !== this.pieceId) {
+      throw Error("Un-doing action error");
+    }
+    cell.removePiece();
+  }
+}

web/src/pages/game/types/PlacePieceActionStack.ts

@@ -0,0 +1,40 @@
+import { Cell } from "interface";
+import { PlacePieceAction } from "./PlacePieceAction";
+
+export class PlacePieceActionStack {
+  readonly committedActions: PlacePieceAction[] = [];
+  inProgressActions: PlacePieceAction[] = [];
+
+  executeAction(action: PlacePieceAction, board: Cell[][]) {
+    action.do(board);
+    this.inProgressActions.push(action);
+  }
+
+  undoLastAction(board: Cell[][]) {
+    const lastAction = this.inProgressActions.pop();
+    if (!lastAction) {
+      throw Error("No in progress action to undo");
+    }
+    lastAction.undo(board);
+  }
+
+  resetActions(board: Cell[][]) {
+    try {
+      while (true) {
+        this.undoLastAction(board);
+      }
+    } catch (error) {
+      if (
+        !(error instanceof Error) ||
+        error.message !== "No in progress action to undo"
+      ) {
+        throw error;
+      }
+    }
+  }
+
+  commitActions() {
+    this.committedActions.push(...this.inProgressActions);
+    this.inProgressActions = [];
+  }
+}

web/src/pages/landing/LandingPage.tsx

@@ -0,0 +1,55 @@
+import {
+  CreateLobbyEvent,
+  handleCreateLobby,
+  handleJoinLobby,
+  JoinLobbyEvent,
+} from "interface";
+import React, { ChangeEvent } from "react";
+import { Socket } from "socket.io-client";
+
+export interface LandingPageProps {
+  socket: Socket;
+}
+
+const LandingPage = (props: LandingPageProps) => {
+  const { socket } = props;
+
+  const createLobbyPayload: CreateLobbyEvent = { userName: "" };
+  const joinLobbyPayload: JoinLobbyEvent = { userName: "", lobbyId: "" };
+  const registerUsername = (event: ChangeEvent<HTMLInputElement>) => {
+    createLobbyPayload.userName = event.target.value;
+    joinLobbyPayload.userName = event.target.value;
+  };
+  const registerLobbyId = (event: ChangeEvent<HTMLInputElement>) =>
+    (joinLobbyPayload.lobbyId = event.target.value);
+
+  return (
+    <React.Fragment>
+      <div className="landing-page-title">
+        <h1>Trains And Roads</h1>
+      </div>
+      <div className="user-name-input">
+        <input placeholder="Enter username" onChange={registerUsername}></input>
+      </div>
+      <div className="create-lobby-button">
+        <button onClick={() => handleCreateLobby(socket, createLobbyPayload)}>
+          Create Lobby
+        </button>
+      </div>
+      <div className="join-lobby">
+        <input
+          className="lobby-id-input"
+          placeholder="Enter Lobby Id"
+          onChange={registerLobbyId}
+        ></input>
+        <button
+          className="join-lobby-button secondary"
+          onClick={() => handleJoinLobby(socket, joinLobbyPayload)}
+        >
+          Join Lobby
+        </button>
+      </div>
+    </React.Fragment>
+  );
+};
+export default LandingPage;

web/src/pages/lobby/LobbyPage.scss

@@ -0,0 +1,50 @@
+.lobby-page {
+    height: 100%;
+    width: 100%;
+    padding: 2%;
+    margin: 0 auto;
+    text-align: center;
+
+    background: linear-gradient(-45deg, #03444a, #00a8a8, #f1bc52, #ff8f4b);
+    background-size: 400% 400%;
+    animation: gradient 15s ease infinite;
+    height: 100vh;
+
+    @keyframes gradient {
+        0% {
+            background-position: 0% 50%;
+        }
+        50% {
+            background-position: 100% 50%;
+        }
+        100% {
+            background-position: 0% 50%;
+        }
+    }
+
+    .lobby-page-body {
+        margin: auto;
+        width: 20%;
+        min-width: 300px;
+
+        .lobby-user-name {
+            margin: 0 auto 10px;
+            padding: 10px;
+            width: 60%;
+            border: 2px solid cyan;
+            border-radius: 10px;
+        }
+
+        .game-code {
+            margin: 0 auto 10px;
+            padding: 10px;
+            width: 60%;
+            border: 2px solid blue;
+            border-radius: 10px;
+        }
+
+        .start-game-button {
+            margin: 30px 0;
+        }
+    }
+}

web/src/pages/lobby/LobbyPage.tsx

@@ -0,0 +1,39 @@
+import { useState } from "react";
+import "./LobbyPage.scss";
+import { Socket } from "socket.io-client";
+import { attachHandlerToUpdateLobbyEvent, ClientEvent } from "interface";
+
+export interface LobbyPageProps {
+  initialPlayerNames: string[];
+  gameCode: string;
+  socket: Socket;
+}
+
+const LobbyPage = (props: LobbyPageProps) => {
+  const { initialPlayerNames, gameCode, socket } = props;
+  const [playerNames, setPlayerNames] = useState(initialPlayerNames);
+
+  attachHandlerToUpdateLobbyEvent(socket, (event) => {
+    setPlayerNames(event.playerNames);
+  });
+  const startGame = () => socket.emit(ClientEvent.START_GAME);
+
+  return (
+    <div className="lobby-page">
+      <div className="landing-page-title">
+        <h1>Trains And Roads</h1>
+      </div>
+      <div className="lobby-page-body">
+        {playerNames.map((name) => (
+          <article className="lobby-user-name">{name}</article>
+        ))}
+        <div className="start-game-button">
+          <button onClick={startGame}>Start Game</button>
+        </div>
+        <article className="game-code">Game code: {gameCode}</article>
+      </div>
+    </div>
+  );
+};
+
+export default LobbyPage;

web/src/setupTests.ts

@@ -2,4 +2,4 @@
 // allows you to do things like:
 // expect(element).toHaveTextContent(/react/i)
 // learn more: https://github.com/testing-library/jest-dom
-import '@testing-library/jest-dom';
+import "@testing-library/jest-dom";