implement basics

index.ts

@@ -0,0 +1,170 @@
+import express, { Request, Response } from "express";
+import { Database } from "sqlite3";
+import bcrypt from "bcrypt";
+import session from "express-session";
+
+const db = new Database("db.sqlite");
+
+declare module "express-session" {
+  // noinspection JSUnusedGlobalSymbols
+  interface SessionData {
+    user?: number;
+  }
+}
+
+(async () => {
+  await dbRun("CREATE TABLE IF NOT EXISTS version ( version INT );");
+  const dbVersion: { version: number } | undefined
+      = await dbGet("SELECT version FROM version;");
+
+  if (dbVersion && dbVersion.version === 1) {
+    console.log("skip db setup")
+    return;
+  }
+
+  await dbRun(`CREATE TABLE IF NOT EXISTS users (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      name TEXT NOT NULL,
+      pass TEXT NOT NULL
+    )`);
+  await dbRun("CREATE UNIQUE INDEX IF NOT EXISTS idx_users_name ON users (name);");
+
+  await dbRun(`CREATE TABLE IF NOT EXISTS highScores (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      user INTEGER,
+      score BIGINT NOT NULL,
+      FOREIGN KEY (user) REFERENCES users(id)
+    )`);
+  await dbRun("INSERT INTO version VALUES (1)");
+})();
+
+const app = express();
+app.use(express.json());
+app.use(session({
+  secret: "your mom",
+  resave: true,
+}));
+
+app.get("/", (_req: Request, res: Response) => {
+  res.send("Hello World!");
+});
+
+app.get("/leaderboard", async (req: Request, res: Response) => {
+  const { limit = 100, offset = 0 } = req.query;
+
+  const leaders = await dbAll(`
+select h.score, u.name
+from highScores h
+    join main.users u on u.id = h.user
+order by score desc
+limit ? offset ?`, limit, offset);
+
+  res.json(leaders);
+});
+app.put("/leaderboard", async (req: Request, res: Response) => {
+  const { score } = req.body;
+
+  if (!req.session.user) {
+    res.status(403).json({ success: false, message: "unauthorised" });
+    return;
+  }
+
+  if (!score) {
+    res.status(400).json({ success: false, message: "provide score" });
+    return;
+  }
+
+  await dbRun("insert into highScores (user, score) VALUES (?, ?)", req.session.user, score);
+
+  res.status(200).json({ success: true });
+});
+
+app.post("/login", async (req: Request, res: Response) => {
+  await sleep(Math.random() * 50 + 50);
+
+  const { username, password } = req.body;
+
+  const user: {
+    name: string,
+    pass: string,
+    id: number,
+  } = await dbGet("SELECT * FROM users WHERE name = ?", username);
+
+  if (!user) {
+    res.status(403).json({ success: false, message: "invalid credentials" });
+    return;
+  }
+
+  if (!await bcrypt.compare(password, user.pass)) {
+    res.status(403).json({ success: false, message: "invalid credentials" });
+    return;
+  }
+
+  await new Promise(res => req.session.regenerate(res));
+
+  req.session.user = user.id;
+
+  res.status(200).json({ success: true });
+});
+
+app.post("/register", async (req: Request, res: Response) => {
+  await sleep(Math.random() * 50 + 50);
+
+  const { username, password } = req.body;
+
+  if (!username || !password) {
+    res.status(400).json({ success: false, message: "invalid credentials" });
+    return;
+  }
+
+  const pass = await bcrypt.hash(password, 12);
+
+  const success = await dbRun("INSERT INTO users (name, pass) VALUES (?, ?)", [ username, pass ])
+      .then(() => true, () => false);
+
+  if (!success) {
+    res.status(400).json({ success: false, message: "invalid credentials" });
+  } else {
+    res.status(200).json({ success: true });
+  }
+});
+
+app.post("/logout", async (req: Request, res: Response) => {
+  await new Promise(res => req.session.destroy(res));
+  res.send(200).json({ success: true });
+});
+
+app.listen(3000, () => {
+  console.log("Server running on port 3000");
+});
+
+function dbGet<T>(query: string, ...args: any[]): Promise<T> {
+  return new Promise((res, rej) => {
+    db.get(query, ...args, (err: unknown, result: T) => {
+      if (err) rej(err);
+      else res(result);
+    });
+  });
+}
+
+function dbAll<T>(query: string, ...args: any[]): Promise<T[]> {
+  return new Promise((res, rej) => {
+    db.all(query, ...args, (err: unknown, result: T[]) => {
+      if (err) rej(err);
+      else res(result);
+    });
+  });
+}
+
+function dbRun(query: string, ...args: any[]): Promise<void> {
+  return new Promise((res, rej) => {
+    db.run(query, ...args, (err: unknown) => {
+      if (err) rej(err);
+      else res();
+    });
+  })
+}
+
+function sleep(ms: number) {
+  return new Promise(resolve => setTimeout(resolve, ms));
+}

package.json

@@ -1,4 +1,21 @@
 {
   "name": "backend",
-  "packageManager": "yarn@4.5.1"
+  "packageManager": "yarn@4.5.1",
+  "devDependencies": {
+    "@types/bcrypt": "^5",
+    "@types/express": "^4",
+    "@types/express-session": "^1",
+    "ts-node": "^10.9.2",
+    "ts-node-dev": "^2.0.0",
+    "typescript": "^5.6.3"
+  },
+  "scripts": {
+    "start": "ts-node-dev ./index.ts"
+  },
+  "dependencies": {
+    "bcrypt": "^5.1.1",
+    "express": "^4.21.1",
+    "express-session": "^1.18.1",
+    "sqlite3": "^5.1.7"
+  }
 }

tsconfig.json

@@ -0,0 +1,10 @@
+{
+  "compilerOptions": {
+    "target": "es2016",
+    "module": "commonjs",
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "strict": true,
+    "skipLibCheck": true
+  }
+}