def get_cart_items_by_user_id(user_id):
"""The function find all the items in the user's cart and return the info
required by the front-end
Keyword arguments:
user_id -- the user id
"""
# Clean the input data
user_id = str(user_id).strip()
# Check for the existence of user
if find_user(param=user_id, method='id') is None:
raise ValidationError('Invalid user id.')
# Establish db connection
dao = DAO()
cursor = dao.cursor()
# Query database
sql = """SELECT cart_item.cart_item_id,
cart_item.product_id,
product.product_name,
product.price,
cart_item.amount
FROM cart_item, product WHERE
cart_item.product_id = product.product_id AND
user_id = %(user_id)s ORDER BY created_at DESC"""
cursor.execute(sql, {'user_id': user_id})
result = cursor.fetchall()
return result
def redeem(user_id, redeem_code):
# Clean the input data
user_id = str(user_id).strip()
redeem_code = str(redeem_code).strip()
# Find redeem card
redeem_card = find_redeem_card(redeem_code)
if redeem_card is None:
raise ValidationError('Invalid redeen code.')
# Find user
user = find_user(method='id', param=user_id)
if user is None:
raise ValidationError('user not found.')
# Establish db connection
dao = DAO()
cursor = dao.cursor()
sql = """UPDATE user SET balance = %(new_balance)s WHERE user_id = %(user_id)s"""
new_balance = user['balance'] + redeem_card['value']
cursor.execute(sql, {'new_balance': new_balance, 'user_id': user_id})
sql = """DELETE FROM redeem_card WHERE redeem_code = %(redeem_code)s"""
cursor.execute(sql, {'redeem_code': redeem_code})
dao.commit()
def create_cart_item(user_id, product_id, amount=1):
"""The function creates a cart item if the cart item does not exist.
Otherwise, the cart item will be updated in an "append" manner
"""
# Clean the input data
user_id = str(user_id).strip()
product_id = str(product_id).strip()
amount = str(amount).strip()
# Check is the input valid
if not user_id or not product_id:
raise ValidationError('Invalid identifier(s).')
if not amount.isdecimal():
raise ValidationError('Invalid amount.')
# Check for the existence of user and product
if find_user(method='id', param=user_id) is None:
raise ValidationError('Invalid user id.')
if find_product(method='product_id', param=product_id) is None:
raise ValidationError('Invalid product id.')
# Check the user's cart. If the item already exists, perform update instead of insertion
item = find_cart_item_id(user_id, product_id)
if item is not None:
return update_cart_item_amount(item['cart_item_id'],
int(item['amount']) + int(amount))
# Establish db connection
dao = DAO()
cursor = dao.cursor()
sql = """INSERT INTO cart_item (
user_id,
product_id,
amount
) VALUES (
%(user_id)s,
%(product_id)s,
%(amount)s
)"""
cursor.execute(sql, {
'user_id': user_id,
'product_id': product_id,
'amount': amount
})
dao.commit()
def get_user_transaction_history(user_id):
# Clean the input data
user_id = str(user_id).strip()
# Check for the existence of user
if find_user(method='id', param=user_id) is None:
raise ValidationError('Invalid user id.')
# Establish db connection
dao = DAO()
cursor = dao.cursor()
# Query database
sql = """SELECT * FROM `order` WHERE user_id = %(user_id)s ORDER BY created_at DESC"""
cursor.execute(sql, {'user_id': user_id})
result = cursor.fetchall()
return result
def place_redeem(user_id, amount):
# Clean the input data
user_id = str(user_id).strip()
amount = str(amount).strip()
# Verify the amount
if not is_money(amount):
raise ValidationError('Invalid amount.')
# Verify the user_id
if find_user(method='id', param=user_id) is None:
raise ValidationError('Invalid user id.')
# Insert into order
# Establish db connection
dao = DAO()
cursor = dao.cursor()
sql = """INSERT INTO `order` (
user_id,
total,
actual_paid,
status
) VALUES (
%(user_id)s,
%(total)s,
%(actual_paid)s,
%(status)s
)"""
# A status code of 100 means it is a desposite
cursor.execute(sql, {
'user_id': user_id,
'total': -amount,
'actual_paid': 0,
'status': 100
})
dao.commit()
def place_order(user_id, payment, coupon_code=''):
"""The function places an order of all the items in the user's cart
Parameters:
user_id -- the user's id
payment -- the method the user chose to pay
coupon_code -- the coupon code (if any)
"""
# Check the validity of the payment method
if payment not in ['balance', 'credit_card', 'paypal']:
raise ValidationError('Invalid payment method.')
# Clean the input data
user_id = str(user_id).strip()
if coupon_code is None:
coupon_code = ''
coupon_code = str(coupon_code).strip()
# If the user did input a coupon but the coupon is invalid
coupon = None
if len(coupon_code) > 0:
coupon = find_coupon_and_check_validity(coupon_code)
if coupon is None:
raise ValidationError('Invalid coupon code.')
# Check for the existence of user
if find_user(method='id', param=user_id) is None:
raise ValidationError('Invalid user id.')
# Check the user's cart. If the item already exists, perform update instead of amount
items = get_cart_items_by_user_id(user_id)
if len(items) == 0:
raise ValidationError('No item is found in cart.')
# Calculate the total in the user's cart
total = 0
for item in items:
total += item['price'] * item['amount']
actual_paid = total
# Calculate according to the given coupon
if coupon is not None:
if total >= coupon['threshold']:
actual_paid -= coupon['value']
# Establish db connection
dao = DAO()
cursor = dao.cursor()
# Proceed to the payment
if payment == 'balance':
user_pay(user_id, actual_paid, cursor)
else:
raise ValidationError(
'The payment method is not supported by the current merchant.')
# Create new order
sql = """INSERT INTO `order` (
actual_paid
) VALUES (
%(actual_paid)s
)"""
cursor.execute(sql, {'actual_paid': actual_paid})
# Retrive the newly inserted row
cursor.execute('SELECT LAST_INSERT_ID()')
order_id = cursor.fetchone()['LAST_INSERT_ID()']
# Insert into user_order
sql = """INSERT INTO user_order (
user_id,
order_id
) VALUES (
%(user_id)s,
%(order_id)s
)"""
cursor.execute(sql, {'user_id': user_id, 'order_id': order_id})
for item in items:
create_purchased_item(product_name=item['product_name'],
product_price=item['price'],
amount=item['amount'],
order_id=order_id,
cursor=cursor)
delete_cart_item(cart_item_id=item['cart_item_id'],
relay_cursor=cursor)
# When all the procedures are successful and no exception was raised
dao.commit()