bookmanager.py

import os
from flask import Flask
from flask import render_template
from flask import request
from flask import redirect
import pickle
import sqlite3
from flask_sqlalchemy import SQLAlchemy
from flask import flash, session, url_for

app = Flask(__name__)
app.secret_key = "secret key"

@app.route('/')
def main():                                                                         #main function with our default url
    return render_template("login.html")                                            #display the login page
database={'admin':'p455w0rd','customer1':'p455w0rd','customer2':'p455w0rd'}         #database with usernames and passwords

@app.route('/form_login',methods=['POST','GET'])
def login():                                                                        #function that checks login information
    name1=request.form['username']                                                  #extracting the username and putting in a variable
    pwd=request.form['password']                                                    #extracting the password and putting in a variable
    if name1 not in database:
	    return render_template('login.html',info='Invalid User')                    #if username wrong return the login page and say wrong username
    else:
        if database[name1]!=pwd:
            return render_template('login.html',info='Invalid Password')            #if password wrong return the login page and say wrong password
        elif name1 == 'admin':
            return render_template('admin.html', name=name1)                        #check if it's admin and return the admin page
        else:
	         return render_template('profile.html',name=name1)                      #check if it's customer and return the customer page
		
@app.route('/add', methods=['POST'])
def add_product_to_cart():                                                          
    cursor = None
    try:
        _quantity = int(request.form['quantity'])
        _code = request.form['code']
        
        if _quantity and _code and request.method == 'POST':
            con = sqlite3.connect('books0.db')
            cur = con.cursor();
            cur.execute("SELECT * FROM books0 WHERE code=?;", [_code])
            row = cur.fetchone()
            itemArray = { row[2] : {'name' : row[1], 'code' : row[2], 'quantity' : _quantity, 'price' : row[4], 'image' : row[3], 'total_price': _quantity * row[4]}}
            print('itemArray is', itemArray)
            
            all_total_price = 0
            all_total_quantity = 0
            
            session.modified = True
            
            if 'cart_item' in session:
                print('in session')
                if row[2] in session['cart_item']:
                    for key, value in session['cart_item'].items():
                        if row[2] == key:
                            old_quantity = session['cart_item'][key]['quantity']
                            total_quantity = old_quantity + _quantity
                            session['cart_item'][key]['quantity'] = total_quantity
                            session['cart_item'][key]['total_price'] = total_quantity * row[4]
                else:
                    session['cart_item'] = array_merge(session['cart_item'], itemArray)
                    
                for key, value in session['cart_item'].items():
                    individual_quantity = int(session['cart_item'][key]['quantity'])
                    individual_price = float(session['cart_item'][key]['total_price'])
                    all_total_quantity = all_total_quantity + individual_quantity
                    all_total_price = all_total_price + individual_price
            else:
                session['cart_item'] = itemArray
                all_total_quantity = all_total_quantity + _quantity
                all_total_price = all_total_price + _quantity * row[4]
                
            session['all_total_quantity'] = all_total_quantity
            session['all_total_price'] = all_total_price
            
            return redirect(url_for('.products'))
        else:
            return 'Error while adding item to cart'
    except Exception as e:
        print(e)
    finally:
        cur.close()
        con.close()
		
@app.route('/products')
def products():                                                                               
    try:
        con = sqlite3.connect('books0.db')
        cur = con.cursor();
        cur.execute("SELECT * FROM books0")
        rows = cur.fetchall()
        return render_template('products.html', products=rows)
    except Exception as e:
        print(e)
    finally:
        cur.close()
        con.close()
        
@app.route('/cart')                                                                            
def cart():
    return render_template("cart.html")	

@app.route('/empty')                                                                         
def empty_cart():
	try:
		session.clear()
		return redirect(url_for('.cart'))
	except Exception as e:
		print(e)

@app.route('/delete/<string:code>')                                                            #mapping url with associated fucntion
def delete_product(code):
	try:
		all_total_price = 0                                                                    #sum of product prices
		all_total_quantity = 0                                                                 #sum of product quantites in the cart
		session.modified = True                                                                #using sessions to keep track of the user activity
		
		for item in session['cart_item'].items():
			if item[0] == code:				
				session['cart_item'].pop(item[0], None)                                        #pop() removes items from list hence deleting it
				if 'cart_item' in session:
					for key, value in session['cart_item'].items():
						individual_quantity = int(session['cart_item'][key]['quantity'])       #defining the variable for quantity of one item
						individual_price = float(session['cart_item'][key]['total_price'])     #defining the variable for the price of one product
						all_total_quantity = all_total_quantity + individual_quantity          #calculating quantity of the cart
						all_total_price = all_total_price + individual_price                   #calculating the total price of all products in the cart
				break
		
		if all_total_quantity == 0:                                                            #if there is nothing in the cart do nothing
			session.clear()
		else:
			session['all_total_quantity'] = all_total_quantity                                 #otherwise put the total quantity in session
			session['all_total_price'] = all_total_price                                       #otherwise put the total price in session
		return redirect(url_for('.cart'))                                                      #redirect to cart and show the products and their price there
	except Exception as e:
		print(e)
		
def array_merge( first_array , second_array ):
	if isinstance( first_array , list ) and isinstance( second_array , list ):
		return first_array + second_array
	elif isinstance( first_array , dict ) and isinstance( second_array , dict ):
		return dict( list( first_array.items() ) + list( second_array.items() ) )
	elif isinstance( first_array , set ) and isinstance( second_array , set ):
		return first_array.union( second_array )
	return False	

@app.route('/stock')
def stock():
    try:
        con = sqlite3.connect('books0.db')
        cur = con.cursor();
        cur.execute("SELECT * FROM books0")
        rows = cur.fetchall()
        return render_template('stock.html', products=rows)
    except Exception as e:
        print(e)
    finally:
        cur.close()
        con.close()
        
@app.route('/add_stock')
def add_stock():
    return render_template("add_stock.html")


"""
        
@app.route('/admin')
def back_admin():
    return render_template("admin.html")	

@app.route('/customer')
def back_customer():
    return render_template("profile.html")"""

if __name__ == "__main__":
    app.run(host='0.0.0.0', debug=True)