checkout.py

from main import app
from flask import Flask, session, g, redirect, url_for, render_template, abort, flash, make_response, request
import sqlite3
from functools import wraps

# ALWAYS check user session valid
@app.before_request
def user_logged_in():
    user_id = session.get('access_mode')
    if user_id is None:
        # Session not found
        g.user = None
    else:
        g.user= user_id

@app.route('/shopping_cart', methods = ['GET','POST'])
def shopping_cart():
        if request.method == 'POST':
            if request.form['Submit'] == 'GO BACK':
                return redirect(url_for('homepage'))
            # 'cancel' the shopping cart
            elif request.form['Submit'] == 'CLEAR CART':
                # Keep access_mode or user will be logged out, cart session cleared
                remember_user = session['access_mode']
                session.clear()
                session['access_mode'] = remember_user
                return redirect(url_for('homepage'))
            elif request.form['Submit'] == 'CHECKOUT':
                return redirect(url_for('checkout'))
        else:
            return render_template('cart.html', page=url_for('shopping_cart'))

# not in homepage.py with add_book because seperate page alltogether
# help from 5001CEM https://coventry.aula.education/?#/dashboard/d0f2228a-9eff-445e-953d-ebf4082fa218/journey/materials/2d09838b-a7da-45dd-9ff0-667c0f1e5a95
@app.route('/shopping_cart/remove', methods = ['POST'])
def remove():
    _isbn = request.form['isbn']
    session['book'][_isbn]['quantity'] -= 1
    session['book'][_isbn]['total_individual_price'] -= session['book'][_isbn]['price']
    session['total_quantity'] -= 1
    session['total_price'] -= session['book'][_isbn]['price']
    # if ALL instances of session['book'][_isbn] no longer exist:
    if session['book'][_isbn]['quantity'] == 0:
        #create row
        book_val = (_isbn,session['book'][_isbn])
        #in the code below, we create a new session['book'] and put there all elements, except the one that has 0 quantity in our basket
        # we do it by iterating over our session['book'] and put all of the elements that is not the one that we have just removed the last copy of, in a new list
        session['book'] = dict([i for i in list(session['book'].items()) if i != book_val])
    # if book qunatity is 0 there are no books
    if session['total_quantity'] == 0:
        session.pop('book',None)
        # template will cause error if no books in cart as 'book' would be empty, so must redirect
        return redirect(url_for('homepage'))
    return redirect(url_for('shopping_cart'))
# end of borrowed code
        
@app.route('/checkout', methods = ['GET','POST'])
def checkout():
        # help from 5001CEM https://coventry.aula.education/?#/dashboard/d0f2228a-9eff-445e-953d-ebf4082fa218/journey/materials/2d09838b-a7da-45dd-9ff0-667c0f1e5a95
        if request.method == 'POST':
            if request.form['button_chooser'] == 'sold_out':
                return redirect(url_for('homepage'))
            elif request.form['button_chooser'] == 'proceed':
                return redirect(url_for('payment'))
        else:
            # For every book selected:
            for key, value in session['book'].items():
                    # if session quantity > qty_left (pulled from db col 8)
                    if session['book'][key]['qty_left'] < session['book'][key]['quantity']:
                        books_over = session['book'][key]['quantity'] - session['book'][key]['qty_left']
                        # Ammend checkout and update prices
                        session['total_quantity'] -= books_over 
                        session['total_price'] -= session['book'][key]['price'] * books_over
                        session['book'][key]['total_individual_price'] -= session['book'][key]['price'] * books_over
                        session['book'][key]['quantity'] = session['book'][key]['qty_left']
                        # Sold out books
                        if 'sold_out' in session:
                            session['sold_out'].append([session['book'][key]['title']])
                        else:
                            session['sold_out'] = [session['book'][key]['title']]
                        if session['book'][key]['quantity'] == 0:
                            book_val = (key,value)
                            # Sold out book removed
                            session['book'] = dict([i for i in list(session['book'].items()) if i != book_val])
            if 'sold_out' in session:
                # Pretty much storing all the missing books for user message
                session['sold_out'] = ', '.join(str(z) for z in session['sold_out'])
            # If first book is 3 and all are + 1 then postal cost always = number of books + 2
            _post_cost = session['total_quantity'] + 2
            session['total_cost'] = session['total_price'] + _post_cost
            session['total_cost'] = "{:.1f}".format(float(session['total_cost']))
            session['total_cost'] = float(session['total_cost'])
            return render_template('checkout.html',page=url_for('checkout'), post_cost = _post_cost)
                
@app.route('/checkout/payment')
def payment():
        # Dummy template with no validation or verification - in alignment with req
        return render_template('payment.html')

# Payment complete screen 
@app.route('/checkout/payment/complete', methods=["GET", "POST"])
def dummy_payment():
    if request.method == "POST":
        con = sqlite3.connect('bookshop_database.db') 
        con.row_factory = lambda cursor, row: row[0]
        cur = con.cursor()
        # For EVERY book thats in cart update the quantity
        # Note this only happens after payment has COMPLETED to stop books dissapearing
        for key, value in session['book'].items():
            # Select the row with the same isbn value
            cur.execute('SELECT quantity FROM books WHERE isbn13 = ? ', (key, ))
            before_qty = cur.fetchone()
            # Take cart quantity value from the current qnty
            upd_quantity = int(before_qty) - session['book'][key]['quantity']
            # Update row to new quantity
            cur.execute('UPDATE BOOKS set quantity=? WHERE isbn13=?',(upd_quantity, key))
        con.commit()
        con.close()
        # Clearing session in order to clear basket 
        remember_user = session['access_mode']
        session.clear()
        session['access_mode'] = remember_user
        flash('Thank you for your purchase')
        # Basic template
        return render_template('payment_done.html')