from rest_framework import serializers

from collection import models
from collection.models import Guide
from collection.serializers.common import CollectionBaseSerializer
from establishment.models import Establishment
from location.models import Country
from location.serializers import CountrySimpleSerializer
from product.models import Product
from utils.exceptions import (
    BindingObjectNotFound, ObjectAlreadyAdded,
    RemovedBindingObjectNotFound,
)


class CollectionBackOfficeSerializer(CollectionBaseSerializer):
    """Collection back serializer."""
    country_id = serializers.PrimaryKeyRelatedField(
        source='country', write_only=True,
        queryset=Country.objects.all())
    collection_type_display = serializers.CharField(
        source='get_collection_type_display', read_only=True)
    country = CountrySimpleSerializer(read_only=True)
    count_related_objects = serializers.IntegerField(read_only=True)
    related_object_names = serializers.ListField(read_only=True)

    class Meta:
        model = models.Collection
        fields = CollectionBaseSerializer.Meta.fields + [
            'id',
            'name',
            'collection_type',
            'collection_type_display',
            'is_publish',
            'on_top',
            'country',
            'country_id',
            # 'block_size',
            'description',
            'slug',
            # 'start',
            # 'end',
            'count_related_objects',
            'related_object_names',
            'rank',
        ]
        extra_kwargs = {
            'slug': {'read_only': True},
        }


class CollectionBindObjectSerializer(serializers.Serializer):
    """Serializer for binding collection and objects"""

    ESTABLISHMENT = 'establishment'
    PRODUCT = 'product'

    TYPE_CHOICES = (
        (ESTABLISHMENT, 'Establishment'),
        (PRODUCT, 'Product'),
    )

    type = serializers.ChoiceField(TYPE_CHOICES)
    object_id = serializers.IntegerField()

    def validate(self, attrs):
        view = self.context.get('view')
        request = self.context.get('request')

        obj_type = attrs.get('type')
        obj_id = attrs.get('object_id')

        collection = view.get_object()
        attrs['collection'] = collection

        if obj_type == self.ESTABLISHMENT:
            establishment = Establishment.objects.filter(pk=obj_id). \
                first()
            if not establishment:
                raise BindingObjectNotFound()
            if request.method == 'POST' and collection.establishments. \
                    filter(pk=establishment.pk).exists():
                raise ObjectAlreadyAdded()
            if request.method == 'DELETE' and not collection. \
                    establishments.filter(pk=establishment.pk). \
                    exists():
                raise RemovedBindingObjectNotFound()
            attrs['related_object'] = establishment
        elif obj_type == self.PRODUCT:
            product = Product.objects.filter(pk=obj_id).first()
            if not product:
                raise BindingObjectNotFound()
            if request.method == 'POST' and collection.products. \
                    filter(pk=product.pk).exists():
                raise ObjectAlreadyAdded()
            if request.method == 'DELETE' and not collection.products. \
                    filter(pk=product.pk).exists():
                raise RemovedBindingObjectNotFound()
            attrs['related_object'] = product
        return attrs


class GuideBindObjectSerializer(serializers.Serializer):
    """Serializer for binding guide and objects"""

    GUIDE = 'guide'
    PRODUCT = 'product'

    TYPE_CHOICES = (
        (GUIDE, 'Guide'),
        (PRODUCT, 'Product'),
    )

    type = serializers.ChoiceField(TYPE_CHOICES)
    object_id = serializers.IntegerField()

    def validate(self, attrs):
        view = self.context.get('view')
        request = self.context.get('request')

        obj_type = attrs.get('type')
        obj_id = attrs.get('object_id')

        guide = view.get_object()
        attrs['guide'] = guide

        if obj_type == self.GUIDE:
            guide = Guide.objects.filter(pk=obj_id).first()
            if not guide:
                raise BindingObjectNotFound()
            if request.method == 'POST' and guide.establishments.filter(pk=guide.pk).exists():
                raise ObjectAlreadyAdded()
            if request.method == 'DELETE' and not guide. \
                    establishments.filter(pk=guide.pk). \
                    exists():
                raise RemovedBindingObjectNotFound()
            attrs['related_object'] = guide

        elif obj_type == self.PRODUCT:
            product = Product.objects.filter(pk=obj_id).first()
            if not product:
                raise BindingObjectNotFound()
            if request.method == 'POST' and guide.products. \
                    filter(pk=product.pk).exists():
                raise ObjectAlreadyAdded()
            if request.method == 'DELETE' and not guide.products. \
                    filter(pk=product.pk).exists():
                raise RemovedBindingObjectNotFound()
            attrs['related_object'] = product

        return attrs