import logging
from datetime import datetime

from dateutil.tz import UTC

from lib_b2b.change import ChangeRecord
from lib_b2b.errors import VersionConflictError
from lib_b2b.order import Order
from lib_b2b.order_change import OrderChangeRequest, SimpleOrderPredicate, OrderStatusChangeDataProvider
from lib_b2b.order_status import OrderStatus
from lib_b2b.policy import Policy

logger = logging.getLogger(__name__)


class OrderCloseAsShippedChangeRequest(OrderChangeRequest):
    # TODO: - Move these policies to be data driven
    _policy = Policy(
        name='closeasshipped_change_policy',
        subject=Policy.SUBJECT_ALL,
        predicates=[
            SimpleOrderPredicate(
                lambda o: o.status not in (OrderStatus.SHIPPED, OrderStatus.CANCELLED, OrderStatus.REJECTED),
                'Close as shipped is only allowed prior to full shipment.')
        ]
    )

    def __init__(self, on_behalf_of: str, change_data_provider: OrderStatusChangeDataProvider):
        super().__init__(on_behalf_of, OrderCloseAsShippedChangeRequest._policy)
        self.change_data_provider = change_data_provider

    def will_change(self, order: Order) -> bool:
        return self.change_data_provider.new_status is not order.status \
               and self.change_data_provider.new_status is OrderStatus.SHIPPED

    def apply(self, order: Order):
        try:
            self.changeable_object = order
            if super().permitted(order):
                if self.will_change(order):
                    before_status = order.status
                    order.set_status(self.change_data_provider.new_status,
                                     version=self.change_data_provider.version())
                    order.record(
                        ChangeRecord(before=before_status.value, after=self.change_data_provider.new_status.value,
                                     description="Order was closed as shipped", when=datetime.now().astimezone(UTC),
                                     who=self.on_behalf_of)
                    )
        except ValueError as ve:
            raise VersionConflictError(str(ve))