Update app.py

app.py

@@ -0,0 +1,57 @@
+# ✅ app.py for Google OAuth Login in Colab
+
+from flask import Flask, redirect, url_for, session
+from authlib.integrations.flask_client import OAuth
+from flask_ngrok import run_with_ngrok
+import os
+
+# 🔐 Secure secrets from Colab
+from google.colab import userdata
+CLIENT_ID = userdata.get("GOOGLE_CLIENT_ID")
+CLIENT_SECRET = userdata.get("GOOGLE_CLIENT_SECRET")
+
+# 🔧 Flask App Setup
+app = Flask(__name__)
+app.secret_key = os.urandom(24)
+run_with_ngrok(app)  # Auto-start ngrok in Colab
+
+# 🌐 OAuth2 Config
+oauth = OAuth(app)
+google = oauth.register(
+    name='google',
+    client_id=CLIENT_ID,
+    client_secret=CLIENT_SECRET,
+    access_token_url='https://oauth2.googleapis.com/token',
+    authorize_url='https://accounts.google.com/o/oauth2/auth',
+    api_base_url='https://www.googleapis.com/oauth2/v1/',
+    userinfo_endpoint='https://openidconnect.googleapis.com/v1/userinfo',
+    client_kwargs={'scope': 'openid email profile'},
+)
+
+# 📍 Routes
+@app.route('/')
+def home():
+    email = session.get('email', None)
+    if email:
+        return f"<h2>✅ Logged in as: {email}</h2><br><a href='/logout'>Logout</a>"
+    return "<a href='/login'>🔐 Login with Google</a>"
+
+@app.route('/login')
+def login():
+    redirect_uri = url_for('auth_callback', _external=True)
+    return google.authorize_redirect(redirect_uri)
+
+@app.route('/auth_callback')
+def auth_callback():
+    token = google.authorize_access_token()
+    user_info = google.get('userinfo').json()
+    session['email'] = user_info['email']
+    return redirect('/')
+
+@app.route('/logout')
+def logout():
+    session.clear()
+    return redirect('/')
+
+# 🚀 Run App
+app.run()