import math

class Checkout():

    def __init__(self, pricing_rules):
        self.pricing_rules = pricing_rules
        self.basket = {}

    def scan(self, item):
        self.basket[item] = self.basket[item] + 1 if item in self.basket else 1

    def total(self):
        basket_total = 0
        for item_type, quantity in self.basket.items():
            basket_total = basket_total + self.pricing_rules[item_type](quantity)
        return basket_total


def bogof(quantity):
    return math.ceil(quantity / 2.0)

def bulkbuy(threshold_quantity, original_price, new_price, actual_quantity):
    return original_price if actual_quantity < threshold_quantity else new_price

#### test.py###
import math
from do_something import Checkout, bogof, bulkbuy

def cf1_rule(quantity):
    return 1123 * quantity

def fr1_rule(quantity):
    return 311 * bogof(quantity)

def sr1_rule(quantity):
    return quantity * bulkbuy(3, 500, 450, quantity)

def test_fr1():
    checkout = Checkout({'FR1': fr1_rule})
    checkout.scan('FR1')
    assert checkout.total() == 311

def test_dataset_1():
    """
    Second test from provided data
    """
    checkout = Checkout({
        'FR1': fr1_rule,
        'SR1': sr1_rule,
        'CF1': cf1_rule
    })
    checkout.scan('FR1')
    checkout.scan('SR1')
    checkout.scan('FR1')
    checkout.scan('FR1')
    checkout.scan('CF1')
    assert checkout.total() == 2245

def test_dataset_2():
    """
    Second test from provided data
    """
    checkout = Checkout({'FR1': fr1_rule})
    checkout.scan('FR1')
    checkout.scan('FR1')
    assert checkout.total() == 311

def test_dataset_3():
    """
    third test from provided data
    """
    checkout = Checkout({
        'FR1': fr1_rule,
        'SR1': sr1_rule
    })
    checkout.scan('SR1')
    checkout.scan('SR1')
    checkout.scan('FR1')
    checkout.scan('SR1')
    assert checkout.total() == 1661

def test_scan_single():
    checkout = Checkout({})
    checkout.scan('FR1')
    assert checkout.basket == {'FR1': 1}

def test_scan_same_item():
    checkout = Checkout({})
    checkout.scan('FR1')
    checkout.scan('FR1')
    assert checkout.basket == {'FR1': 2}

def test_scan_same_item():
    checkout = Checkout({})
    checkout.scan('FR1')
    checkout.scan('CF1')
    assert checkout.basket == {'FR1': 1, 'CF1': 1}


def test_bogof():
    assert bogof(2) == 1

def test_bogof_2():
    assert bogof(3) == 2

def test_bogof_1():
    assert bogof(1) == 1

def test_not_bulkbuy():
    assert bulkbuy(3, 500, 450, 2) == 500

def test_bulkbuy():
    assert bulkbuy(3, 500, 450, 3) == 450