app.py

from flask import Flask, redirect, render_template,url_for, request,g, session

from database import connect_to_database, getDatabase
from werkzeug.security import generate_password_hash, check_password_hash
import os

app = Flask(__name__)
app.config['SECRET_KEY'] = os.urandom(24)

@app.teardown_appcontext
def close_database(error):
    if hasattr(g, 'quizapp_db'):
        g.quizapp_db.close()

def get_current_user():
    user_result = None
    if 'user' in session:
        user = session['user']
        db = getDatabase()
        user_cursor = db.execute("select * from users where name = ?", [user])
        user_result = user_cursor.fetchone()
    return user_result



@app.route('/')
def index():
    user = get_current_user()
    return render_template('home.html', user = user)

@app.route('/login', methods = ["POST", "GET"])
def login():
    user = get_current_user()
    error = None
    if request.method == "POST":
        name = request.form["name"]
        password = request.form["password"]
        db = getDatabase()
        fetchperson_cursor = db.execute("SELECT * FROM users WHERE name = ?", [name])
        personfromdatabase = fetchperson_cursor.fetchone()
        if personfromdatabase:
            if check_password_hash(personfromdatabase["password"], password):
                session['user'] = personfromdatabase['name']
                return redirect(url_for('index'))
            else:
                error = "Username or password does not match. Try again"
                return render_template("login.html", error = error)
        else:
            error  = "Username or password does not match, Try again"
            return redirect(url_for('login'))



    return render_template('login.html')

@app.route('/register', methods = ["POST", "GET"])
def register():
    user = get_current_user()
    error = None
    if request.method == "POST":
        db = getDatabase()
        name = request.form ["name"]
        password = request.form["password"]
        user_fetching_cursor  = db.execute("select * from users where name = ?", [name])
        existing_user = user_fetching_cursor.fetchone()
        if existing_user:
            error = "Username already exist, please use a different username"
            return render_template("register.html", error = error   )

        hashed_password = generate_password_hash(password, method = 'pbkdf2:sha256')
        db.execute (" INSERT INTO users (name, password,teacher,admin) values(?,?,?,?)",[name,hashed_password,'0','0'])
        db.commit()
        session['user'] = name
        return redirect(url_for('index') )
    return render_template('register.html',user = user)


@app.route('/askquestions')
def askquestions():
    user = get_current_user()
    return render_template('askquestions.html', user = user)

@app.route('/answerquestions')
def askquestions():
    user = get_current_user()
    return render_template('answerquestions.html', user = user)


@app.route('/allusers', methods = ['POST', 'GET'])
def allusers():
    user = get_current_user()
    db = getDatabase()
    user_cursor = db.execute('SELECT * FROM users')
    allusers = user_cursor.fetchall()
    return render_template("allusers.html", user = user, allusers = allusers)


@app.route('/promote/<int:id>', methods = ['POST', 'GET'])
def promote(id):
    user = get_current_user()
    if request.method == 'GET':
        db = getDatabase()
        db.execute('update users set teacher = 1 where id = ?', [id])
        db.commit()
        return redirect(url_for('allusers'))
    return render_template('allusers.html', user = user)

@app.route('/logout')
def logout():
    session.pop('user', None)
    return redirect(url_for('index'))

if __name__ == "__main__":
    app.run(debug= True)