users.py

import secrets
from db import db
from flask import session
from werkzeug.security import check_password_hash
import basket

def register_user(username, password_hash_value):

    sql = """INSERT INTO
            users (
                username,
                password
                )
                VALUES (
                    :username,
                    :password)
                    """

    db.session.execute(sql, {"username":username, "password":password_hash_value})
    db.session.commit()

def login(username, password):

    sql = """SELECT
            id,
            password
            FROM
            users
            WHERE
            username=:username
            """

    result = db.session.execute(sql, {"username":username})
    user = result.fetchone()

    if not user:
        return False

    hash_value = user.password
    if check_password_hash(hash_value, password):
        session["user_id"] = user.id
        session["username"] = username
        session["csrf_token"] = secrets.token_hex(16)
        return True

    return False
    
def get_user_id():

    return session.get("user_id", 0)


def logout():

    basket.empty_basket(session["user_id"])
    del session["user_id"]
    del session["username"]
    del session["csrf_token"]


def username_in_use(username):

    sql = """SELECT
            id
            FROM
            users
            WHERE
            username=:username
            """

    result = db.session.execute(sql, {"username":username}).fetchone()
    if result:
        return True
    return False