from datetime import date, timedelta

import pytest

from domain.model import allocate, OrderLine, Batch, OutOfStock

today = date.today()

tomorrow = today + timedelta(days=1)

later = tomorrow + timedelta(days=10)

def test_prefers_current_stock_batches_to_shipments():

in_stock_batch = Batch("in-stock-batch", "RETRO-CLOCK", 100, eta=None)

shipment_batch = Batch("shipment-batch", "RETRO-CLOCK", 100, eta=tomorrow)

line = OrderLine("oref", "RETRO-CLOCK", 10)

updated_batch = allocate(line, [in_stock_batch, shipment_batch])

assert updated_batch.ref == in_stock_batch.ref

assert updated_batch.available_quantity == 90

def test_prefers_earlier_batches():

earliest = Batch("speedy-batch", "MINIMALIST-SPOON", 100, eta=today)

medium = Batch("normal-batch", "MINIMALIST-SPOON", 100, eta=tomorrow)

latest = Batch("slow-batch", "MINIMALIST-SPOON", 100, eta=later)

line = OrderLine("order1", "MINIMALIST-SPOON", 10)

updated_batch = allocate(line, [medium, earliest, latest])

assert updated_batch.ref == earliest.ref

assert updated_batch.available_quantity == 90

def test_raises_out_of_stock_exception_if_cannot_allocate():

batch = Batch("batch1", "SMALL-FORK", 10, eta=today)

updated_batch = allocate(OrderLine("order1", "SMALL-FORK", 10), [batch])

assert updated_batch

with pytest.raises(OutOfStock, match="SMALL-FORK"):

result = allocate(OrderLine("order2", "SMALL-FORK", 1), [updated_batch])

assert result is None