Feat: Add complete auth system (Login, Register, OTP/2FA via Telegram, Session management)

lib/otp.ts

@@ -8,32 +8,57 @@ interface OTPData {
   expiresAt: number;
 }
 
-export function generateOTP(): string {
-  return Math.floor(100000 + Math.random() * 900000).toString();
-}
+// Map username -> OTP Data
+type OTPStore = Record<string, OTPData>;
 
-export function saveOTP(code: string) {
-  const data: OTPData = {
-    code,
-    expiresAt: Date.now() + 5 * 60 * 1000 // 5 minutes
-  };
+function getStore(): OTPStore {
+  if (!fs.existsSync(OTP_FILE)) return {};
   try {
-    fs.writeFileSync(OTP_FILE, JSON.stringify(data));
-  } catch (err) {
-    console.error("Error saving OTP:", err);
+    return JSON.parse(fs.readFileSync(OTP_FILE, 'utf8'));
+  } catch {
+    return {};
   }
 }
 
-export function verifyOTP(code: string): boolean {
-  if (!fs.existsSync(OTP_FILE)) return false;
-  
+function saveStore(store: OTPStore) {
   try {
-    const data: OTPData = JSON.parse(fs.readFileSync(OTP_FILE, 'utf8'));
-    if (Date.now() > data.expiresAt) return false;
-    // Simple check
-    return String(data.code).trim() === String(code).trim();
-  } catch (e) {
-    console.error("Error verifying OTP:", e);
+    fs.writeFileSync(OTP_FILE, JSON.stringify(store));
+  } catch (err) {
+    console.error("Error saving OTP store:", err);
+  }
+}
+
+export function generateOTP(username: string): string {
+  const code = Math.floor(100000 + Math.random() * 900000).toString(); // 6 digits
+  const store = getStore();
+  
+  store[username] = {
+    code,
+    expiresAt: Date.now() + 5 * 60 * 1000, // 5 minutes
+  };
+  
+  saveStore(store);
+  return code;
+}
+
+export function verifyOTP(username: string, code: string): boolean {
+  const store = getStore();
+  const entry = store[username];
+  
+  if (!entry) return false;
+  
+  if (Date.now() > entry.expiresAt) {
+    delete store[username];
+    saveStore(store);
     return false;
   }
+  
+  // Compare strings safely
+  if (String(entry.code).trim() === String(code).trim()) {
+    delete store[username]; // Consume OTP so it can't be reused
+    saveStore(store);
+    return true;
+  }
+  
+  return false;
 }