"""Serializer for app timetable"""
from rest_framework import serializers
from timetable.models import Timetable
from establishment.models import Establishment
from django.utils.translation import gettext_lazy as _


class ScheduleRUDSerializer(serializers.ModelSerializer):
    """Serializer for Establishment model."""
    weekday_display = serializers.CharField(source='get_weekday_display',
                                            read_only=True)
    lunch_start = serializers.TimeField(required=False, allow_null=True)
    lunch_end = serializers.TimeField(required=False, allow_null=True)
    dinner_start = serializers.TimeField(required=False, allow_null=True)
    dinner_end = serializers.TimeField(required=False, allow_null=True)
    opening_at = serializers.TimeField(required=False, allow_null=True)
    closed_at = serializers.TimeField(required=False, allow_null=True)

    class Meta:
        """Meta class."""
        model = Timetable
        fields = [
            'id',
            'weekday_display',
            'lunch_start',
            'lunch_end',
            'dinner_start',
            'dinner_end',
            'opening_at',
            'closed_at',
            'continuous_opening',
        ]


class ScheduleCreateSerializer(ScheduleRUDSerializer):
    """Serializer for Establishment model."""
    weekday = serializers.IntegerField(write_only=True)

    class Meta:
        """Meta class."""
        model = Timetable
        fields = ScheduleRUDSerializer.Meta.fields + [
            'weekday',
        ]

    def validate(self, attrs):
        """Override validate method"""
        # Validate by continuous_opening
        if attrs.get('continuous_opening'):
            for attr in attrs:
                if attr.startswith('lunch') or attr.startswith('dinner'):
                    raise serializers.ValidationError(
                        {'detail': _('Lunch or Dinner times should not be '
                                     'in request data with continuous opening.')})
            if not ('opening_at' in attrs) and ('closed_at' in attrs):
                raise serializers.ValidationError(
                    {'detail': _('Opening or Closed times not in request data.')})
        else:
            if not (('lunch_start' in attrs) and ('lunch_end' in attrs) and
                    ('dinner_start' in attrs) and ('dinner_end' in attrs)):
                raise serializers.ValidationError(
                    {'detail': _('Lunch or dinner times not in request data.')})

        establishment_pk = self.context.get('request')\
                                       .parser_context.get('view')\
                                       .kwargs.get('pk')

        # Check if exists establishment.
        establishment_qs = Establishment.objects.filter(pk=establishment_pk)
        if not establishment_qs.exists():
            raise serializers.ValidationError({'detail': _('Establishment not found.')})
        attrs['establishment'] = establishment_qs.first()
        return attrs

    def create(self, validated_data):
        """Override create method"""
        establishment = validated_data.pop('establishment')
        weekday = validated_data.get('weekday')
        instance = super().create(validated_data)
        schedule_qs = establishment.schedule.filter(weekday=weekday)
        if schedule_qs.exists():
            schedule_qs.delete()
        establishment.schedule.add(instance)
        return instance