import unittest

from module_business.domain.enums import (
    DocumentStatus,
    PalletEventType,
    PalletFlowState,
    ReturnStatus,
)
from module_business.domain.pallet_state_machine import (
    InvalidPalletTransition,
    PalletStateMachine,
)


class PalletStateMachineTest(unittest.TestCase):
    def test_dispatch_cannot_skip_receiving_confirmation(self) -> None:
        with self.assertRaises(InvalidPalletTransition):
            PalletStateMachine.ensure_transition(
                PalletFlowState.FILLED_IN_WAREHOUSE,
                PalletFlowState.AT_SITE_UNUSED,
            )

    ALLOWED_TRANSITIONS = (
        (PalletFlowState.UNSTOCKED, PalletFlowState.EMPTY_IN_WAREHOUSE),
        (PalletFlowState.EMPTY_IN_WAREHOUSE, PalletFlowState.FILLED_IN_WAREHOUSE),
        (PalletFlowState.FILLED_IN_WAREHOUSE, PalletFlowState.IN_TRANSIT),
        (PalletFlowState.IN_TRANSIT, PalletFlowState.AT_SITE_UNUSED),
        (PalletFlowState.AT_SITE_UNUSED, PalletFlowState.AT_SITE_PARTIAL),
        (PalletFlowState.AT_SITE_UNUSED, PalletFlowState.AT_SITE_EMPTY),
        (PalletFlowState.AT_SITE_UNUSED, PalletFlowState.RETURNING),
        (PalletFlowState.AT_SITE_PARTIAL, PalletFlowState.AT_SITE_PARTIAL),
        (PalletFlowState.AT_SITE_PARTIAL, PalletFlowState.AT_SITE_EMPTY),
        (PalletFlowState.AT_SITE_PARTIAL, PalletFlowState.RETURNING),
        (PalletFlowState.AT_SITE_EMPTY, PalletFlowState.RETURNING),
        (PalletFlowState.RETURNING, PalletFlowState.FILLED_IN_WAREHOUSE),
        (PalletFlowState.RETURNING, PalletFlowState.EMPTY_IN_WAREHOUSE),
    )

    def test_confirmed_flow_is_allowed(self) -> None:
        for current, target in self.ALLOWED_TRANSITIONS:
            PalletStateMachine.ensure_transition(current, target)

    def test_refill_at_customer_site_is_rejected(self) -> None:
        with self.assertRaises(InvalidPalletTransition):
            PalletStateMachine.ensure_transition(
                PalletFlowState.AT_SITE_EMPTY,
                PalletFlowState.FILLED_IN_WAREHOUSE,
            )

    def test_raw_string_states_are_rejected(self) -> None:
        with self.assertRaisesRegex(TypeError, 'PalletFlowState'):
            PalletStateMachine.ensure_transition(
                'UNSTOCKED',
                'EMPTY_IN_WAREHOUSE',
            )

    def test_mixed_state_types_are_rejected(self) -> None:
        mixed_states = (
            ('UNSTOCKED', PalletFlowState.EMPTY_IN_WAREHOUSE),
            (PalletFlowState.UNSTOCKED, 'EMPTY_IN_WAREHOUSE'),
        )
        for current, target in mixed_states:
            with self.subTest(current=current, target=target), self.assertRaisesRegex(TypeError, 'PalletFlowState'):
                PalletStateMachine.ensure_transition(current, target)

    def test_confirmed_flow_is_the_only_allowed_transition_set(self) -> None:
        actual_allowed = set()
        for current in PalletFlowState:
            for target in PalletFlowState:
                try:
                    PalletStateMachine.ensure_transition(current, target)
                except InvalidPalletTransition:
                    continue
                actual_allowed.add((current, target))

        self.assertEqual(set(self.ALLOWED_TRANSITIONS), actual_allowed)


class PalletEnumTest(unittest.TestCase):
    def test_supporting_enum_values_match_domain_contract(self) -> None:
        self.assertEqual(
            [
                'UNSTOCKED',
                'EMPTY_IN_WAREHOUSE',
                'FILLED_IN_WAREHOUSE',
                'IN_TRANSIT',
                'AT_SITE_UNUSED',
                'AT_SITE_PARTIAL',
                'AT_SITE_EMPTY',
                'RETURNING',
            ],
            [item.value for item in PalletFlowState],
        )
        self.assertEqual(['DRAFT', 'CONFIRMED'], [item.value for item in DocumentStatus])
        self.assertEqual(
            ['REQUESTED', 'CONFIRMED'],
            [item.value for item in ReturnStatus],
        )
        self.assertEqual(
            [
                'INBOUND_CONFIRMED',
                'FILLING_CONFIRMED',
                'SHIPMENT_CONFIRMED',
                'SHIPMENT_RECEIVED',
                'TUNNEL_ENTERED',
                'USAGE_RECORDED',
                'RETURN_REQUESTED',
                'RETURN_CONFIRMED',
            ],
            [item.value for item in PalletEventType],
        )


if __name__ == '__main__':
    unittest.main()