import re

from rest_framework import serializers
from .models import Factory, COOPERATION_MODE_CHOICES


USCC_PATTERN = re.compile(r'^[0-9A-Z]{18}$')


class FactorySerializer(serializers.ModelSerializer):
    """
    工厂序列化器
    """
    material_count = serializers.SerializerMethodField()
    usernames = serializers.SerializerMethodField()
    cooperation_mode_display = serializers.CharField(source='get_cooperation_mode_display', read_only=True)
    unified_social_credit_code = serializers.CharField(
        required=True, allow_null=False, allow_blank=False, max_length=18
    )
    cooperation_mode = serializers.ChoiceField(
        choices=COOPERATION_MODE_CHOICES, required=True, allow_null=False, allow_blank=False
    )

    class Meta:
        model = Factory
        fields = ['id', 'dealer_name', 'product_category', 'factory_name',
                  'short_name', 'unified_social_credit_code',
                  'cooperation_mode', 'cooperation_mode_display',
                  'interaction_capability',
                  'province', 'city', 'district',
                  'address', 'website', 'created_at', 'updated_at',
                  'material_count', 'usernames']
        read_only_fields = ['id', 'created_at', 'updated_at', 'material_count',
                            'usernames', 'cooperation_mode_display']

    def get_material_count(self, obj):
        return obj.materials.count()

    def get_usernames(self, obj):
        return list(obj.users.values_list('username', flat=True))

    def validate_unified_social_credit_code(self, value):
        if not USCC_PATTERN.match(value or ''):
            raise serializers.ValidationError('统一社会信用代码必须为 18 位数字或大写字母')
        return value


class FactoryListSerializer(serializers.ModelSerializer):
    """
    工厂列表序列化器（简化版）
    """
    usernames = serializers.SerializerMethodField()
    cooperation_mode_display = serializers.CharField(source='get_cooperation_mode_display', read_only=True)

    class Meta:
        model = Factory
        fields = ['id', 'factory_name', 'short_name', 'province', 'city',
                  'dealer_name', 'usernames',
                  'cooperation_mode', 'cooperation_mode_display']

    def get_usernames(self, obj):
        return list(obj.users.values_list('username', flat=True))