from rest_framework import serializers, status

from apps.product.exceptions import QuotaExpiredTimeException
from apps.product.models import OrganizationQuotaStats
from apps.warehouse import models as warehouse_models
from apps.warehouse.exceptions import WareHouseException


class InventoryEntrySerializer(serializers.ModelSerializer):
    class Meta:
        model = warehouse_models.InventoryEntry
        fields = [
            "id",
            "create_date",
            "modify_date",
            "organization",
            "quota",
            'org_quota_stat',
            "weight",
            "balance",
            "lading_number",
            "delivery_address",
            "is_confirmed",
            "notes",
        ]

    def validate(self, attrs):
        """
        check if inventory entries weight is not more than
        distribution weight & check quota expired time
        """
        quota = attrs['quota']
        org = attrs['organization']

        # check for quota expired time
        if not quota.is_in_valid_time():
            raise QuotaExpiredTimeException()

        # total inventory entries weight
        # total_entered = distribution.inventory_entry.filter(is_confirmed=True).aggregate(
        #     total=models.Sum('weight')
        # )['total'] or 0

        org_quota_stat = OrganizationQuotaStats.objects.get(
            organization=org,
            quota=quota
        )

        total_entered_weight = org_quota_stat.inventory_received
        remaining_weight_to_enter = org_quota_stat.remaining_amount

        # if instance exists, for update check weight with distribution weight
        if self.instance:
            if self.instance.weight == 0:
                if total_entered_weight + attrs['weight'] > remaining_weight_to_enter:
                    raise WareHouseException(
                        "وزن وارد شده برای ورود به انبار نباید از باقیمانده سهمیه بیشتر باشد",  # noqa
                        status.HTTP_403_FORBIDDEN
                    )
            elif self.instance.weight != 0:
                if total_entered_weight - self.instance.weight + attrs['weight'] > remaining_weight_to_enter:
                    raise WareHouseException(
                        "وزن وارد شده برای ورود به انبار نباید از باقیمانده سهمیه بیشتر باشد",  # noqa
                        status.HTTP_403_FORBIDDEN
                    )

        # if instance is not exists for create, check entry weight with distribution
        else:
            if total_entered_weight + attrs['weight'] > remaining_weight_to_enter:
                # total_entered + attrs['weight'] > distribution.remaining_weight:
                raise WareHouseException(
                    "وزن وارد شده برای ورود به انبار نباید از باقیمانده سهمیه بیشتر باشد",  # noqa
                    status.HTTP_403_FORBIDDEN
                )

        return attrs

    def to_representation(self, instance):
        """ custom output of inventory entry serializer """

        representation = super().to_representation(instance)
        if instance.document:
            representation['document'] = instance.document
        if instance.distribution:
            # distribution data
            representation['distribution'] = {
                'distribution': instance.distribution.distribution_id,
                'sale_unit': instance.distribution.quota.sale_unit.unit,
                'id': instance.distribution.id
            }
            representation['quota'] = instance.distribution.quota.id
            representation['product'] = {
                'name': instance.distribution.quota.product.name
            }

        return representation


class InventoryQuotaSaleTransactionSerializer(serializers.ModelSerializer):
    class Meta:
        model = warehouse_models.InventoryQuotaSaleTransaction
        fields = '__all__'
        depth = 0

    def validate(self, attrs):
        """
        validate total inventory sale should be fewer than
        inventory entry from distribution
        """
        inventory_entry = attrs['inventory_entry']
        distribution = attrs['quota_distribution']

        return attrs

    def to_representation(self, instance):
        """ custom output of inventory sale transaction serializer """

        representation = super().to_representation(instance)
        representation['items'] = InventoryQuotaSaleItemSerializer(
            instance.items.all(),
            many=True
        ).data

        if instance.rancher:
            representation['rancher'] = {
                'id': instance.rancher.id,
                'national_code': instance.rancher.national_code
            }

        if instance.seller_organization:
            representation['seller_organization'] = {
                'id': instance.seller_organization.id,
                'name': instance.seller_organization.name
            }

        return representation


class InventoryQuotaSaleItemSerializer(serializers.ModelSerializer):
    class Meta:
        model = warehouse_models.InventoryQuotaSaleItem
        fields = '__all__'