replace flask_login with just python-cas - Update main_flask.py

will be sufficient

main_flask.py

@@ -1,18 +1,79 @@
-from flask import Flask, render_template
-from flask_login import LoginManager # TODO: user session management
+from flask import Flask, render_template, request, session, redirect, url_for
+#from flask_login import LoginManager # TODO: user session management
 from user import User # TODO:
+from cas import CASClient # use python-cas : https://djangocas.dev/blog/python-cas-flask-example/
+import os
+
+# TODO: add rate-limiting (Flask-Limiter ?)
 
 app = Flask(__name__)
-login_manager = LoginManager()
-login_manager.init_app(app)
-
+app.secret_key = os.getenv("FLASK_SECRET_KEY")
+#login_manager = LoginManager()
+#login_manager.init_app(app)
+
+cas_client = CASClient(
+    version=3, # 2 ?
+    service_url=os.getenv("CAS_SERVICE_URL") # i.e.: service_url='http://localhost:5000/login?next=%2Fprofile',
+    server_url=os.getenv("CAS_SERVER_URL") # i.e.: server_url='https://django-cas-ng-demo-server.herokuapp.com/cas/'
+)
+
 @app.route("/") 
 def home(): 
-    return render_template("home.html", user=user) 
-
+    return render_template("home.html")#, user=user)
+
+
+@app.route('/login')
+def login():
+    if "username" in session:
+        # Already logged in
+        if db.get(session["username"]) = None:
+            # Not linked to Discord yet
+            return redirect(url_for("discord_login"))
+        else:
+            return redirect(url_for("user"))
+
+    next = request.args.get("next")
+    ticket = request.args.get("ticket")
+    if not ticket:
+        # No ticket, the request come from end user, send to CAS login
+        cas_login_url = cas_client.get_login_url()
+        app.logger.debug('CAS login URL: %s', cas_login_url)
+        return redirect(cas_login_url)
+
+    # There is a ticket, the request come from CAS as callback.
+    # need call `verify_ticket()` to validate ticket and get user profile.
+    app.logger.debug('ticket: %s', ticket)
+    app.logger.debug('next: %s', next)
+
+    user, attributes, pgtiou = cas_client.verify_ticket(ticket)
+
+    app.logger.debug(
+        'CAS verify ticket response: user: %s, attributes: %s, pgtiou: %s', user, attributes, pgtiou)
+
+    if not user:
+        return 'Failed to verify ticket. Try to login again: <a href="/">Home</a>'
+        #return redirect(url_for(("home"))
+    else:  # Login successfully, redirect according `next` query parameter.
+        session['username'] = user
+        #session["attributes"] = attributes # TODO: check what attributes we get
+        return redirect(next)
+
+@app.route('/logout')
+def logout():
+    redirect_url = url_for('logout_callback', _external=True)
+    cas_logout_url = cas_client.get_logout_url(redirect_url)
+    app.logger.debug('CAS logout URL: %s', cas_logout_url)
+
+    return redirect(cas_logout_url)
+
+@app.route('/logout_callback')
+def logout_callback():
+    # redirect from CAS logout request after CAS logout successfully
+    session.pop('username', None)
+    #return 'Logged out from CAS. <a href="/login">Login</a>'
+    return redirect(url_for(("home")) # ?
 
-@app.route("/discord-login") 
-@login_required
+@app.route("/discord_login")
 def discord_login(): 
     if user.site_lang = "en":
         return render_template("discord-login_en.html"; user=user)
@@ -21,20 +82,29 @@ def discord_login():
 
 
 @app.route("/user")
-@login_required
-def user(): 
-    if user.site_lang = "en":
-        return render_template("user_en.html", user=user)
+def user(method=['GET']):
+    if 'username' in session:
+        user = session["username"]
+        #return 'Logged in as %s. <a href="/logout">Logout</a>' % session['username']
+        if user.site_lang = "en":
+            return render_template("user_en.html", user=user)
+        else:
+            return render_template("user_fr.html", user=user)
     else:
-        return render_template("user_fr.html", user=user)
+        return 'Login required. <a href="/">Back to Home</a>', 403
+        #return redirect(url_for("home"))
 
 @app.route("/test") 
 def test():
     test_user = User(
-        "Test",
-        "[email protected]"
+        ulbid="test",
+        email="[email protected]"
     )
     return render_template("test.html", user=test_user)
+
+@app.route("/ping")
+def ping():
+    return "pong"
 
 
 @app.route("/bot")