.

app/routes.py

@@ -1,14 +1,22 @@
 from flask import render_template, flash, redirect, url_for
 from app import app
 from app.forms import LoginForm
+from flask_login import current_user, login_user
+from app.models import User
 
 
 @app.route("/login", methods=["GET", "POST"])
 def login():
+    if current_user.is_authenticated:
+        return redirect(url_for("index"))
     form = LoginForm()
     if form.validate_on_submit():
-        flash("Login requested for user {}, remember_me={}".format(form.username.data, form.remember_me.data))
-        return redirect("/index")
+        user = User.query.filter_by(username=form.username.data).first()
+        if user is None or not user.check_password(form.password.data):
+            flash("Invalid username or password")
+            return redirect(url_for("login"))
+        login_user(user)
+        return redirect(url_for("index"))
     return render_template("login.html", title="Sign In", form=form)