from datetime import date

from allocation.domain.model import Batch, OrderLine

def test_allocating_to_a_batch_reduces_the_available_quantity():

batch = Batch("batch-001", "SMALL-TABLE", qty=20, eta=date.today())

line = OrderLine('order-ref', "SMALL-TABLE", 2)

batch.allocate(line)

assert batch.available_quantity == 18

def make_batch_and_line(sku, batch_qty, line_qty):

return (

Batch("batch-001", sku, batch_qty, eta=date.today()),

OrderLine("order-123", sku, line_qty)

)

def test_can_allocate_if_available_greater_than_required():

large_batch, small_line = make_batch_and_line("ELEGANT-LAMP", 20, 2)

assert large_batch.can_allocate(small_line)

def test_cannot_allocate_if_available_smaller_than_required():

small_batch, large_line = make_batch_and_line("ELEGANT-LAMP", 2, 20)

assert small_batch.can_allocate(large_line) is False

def test_can_allocate_if_available_equal_to_required():

batch, line = make_batch_and_line("ELEGANT-LAMP", 2, 2)

assert batch.can_allocate(line)

def test_cannot_allocate_if_skus_do_not_match():

batch = Batch("batch-001", "UNCOMFORTABLE-CHAIR", 100, eta=None)

different_sku_line = OrderLine("order-123", "EXPENSIVE-TOASTER", 10)

assert batch.can_allocate(different_sku_line) is False

def test_allocation_is_idempotent():

batch, line = make_batch_and_line("ANGULAR-DESK", 20, 2)

batch.allocate(line)

batch.allocate(line)

assert batch.available_quantity == 18