from rest_framework import serializers
from django.contrib.auth import get_user_model
from .models import Contact, ContactGroup, ContactInteraction, ContactImport

User = get_user_model()


class ContactGroupSerializer(serializers.ModelSerializer):
    """Serializer for contact groups."""
    
    contact_count = serializers.SerializerMethodField()
    
    class Meta:
        model = ContactGroup
        fields = '__all__'
        read_only_fields = ('user', 'created_at', 'updated_at')
    
    def get_contact_count(self, obj):
        return obj.contacts.count()


class ContactSerializer(serializers.ModelSerializer):
    """Serializer for contacts."""
    
    full_name = serializers.CharField(source='get_full_name', read_only=True)
    address = serializers.CharField(source='get_address', read_only=True)
    group_name = serializers.CharField(source='group.name', read_only=True)
    interaction_count = serializers.SerializerMethodField()
    
    class Meta:
        model = Contact
        fields = '__all__'
        read_only_fields = ('user', 'created_at', 'updated_at')
    
    def get_interaction_count(self, obj):
        return obj.interactions.count()


class ContactCreateSerializer(serializers.ModelSerializer):
    """Serializer for creating contacts."""
    
    class Meta:
        model = Contact
        fields = (
            'group', 'first_name', 'last_name', 'email', 'phone', 'company',
            'job_title', 'notes', 'website', 'birthday', 'address_line1',
            'address_line2', 'city', 'state', 'postal_code', 'country',
            'linkedin', 'twitter', 'facebook', 'is_favorite', 'is_blocked'
        )
    
    def validate_email(self, value):
        user = self.context['request'].user
        if Contact.objects.filter(user=user, email=value).exists():
            raise serializers.ValidationError("A contact with this email already exists.")
        return value


class ContactInteractionSerializer(serializers.ModelSerializer):
    """Serializer for contact interactions."""
    
    contact_name = serializers.CharField(source='contact.get_full_name', read_only=True)
    created_by_name = serializers.CharField(source='created_by.get_full_name', read_only=True)
    
    class Meta:
        model = ContactInteraction
        fields = '__all__'
        read_only_fields = ('created_by', 'date')


class ContactImportSerializer(serializers.ModelSerializer):
    """Serializer for contact imports."""
    
    class Meta:
        model = ContactImport
        fields = '__all__'
        read_only_fields = ('user', 'status', 'total_contacts', 'imported_contacts', 'failed_contacts', 'error_log', 'created_at', 'completed_at')


class ContactBulkActionSerializer(serializers.Serializer):
    """Serializer for bulk contact actions."""
    
    ACTION_CHOICES = [
        ('add_to_group', 'Add to group'),
        ('remove_from_group', 'Remove from group'),
        ('mark_favorite', 'Mark as favorite'),
        ('mark_unfavorite', 'Mark as unfavorite'),
        ('block', 'Block'),
        ('unblock', 'Unblock'),
        ('delete', 'Delete'),
    ]
    
    contact_ids = serializers.ListField(
        child=serializers.IntegerField(),
        min_length=1
    )
    action = serializers.ChoiceField(choices=ACTION_CHOICES)
    group_id = serializers.IntegerField(required=False)
    
    def validate_contact_ids(self, value):
        user = self.context['request'].user
        # Verify all contacts belong to the user
        contact_count = Contact.objects.filter(id__in=value, user=user).count()
        if contact_count != len(value):
            raise serializers.ValidationError("Some contacts don't exist or don't belong to you.")
        return value
    
    def validate(self, attrs):
        action = attrs.get('action')
        group_id = attrs.get('group_id')
        
        if action in ['add_to_group', 'remove_from_group'] and not group_id:
            raise serializers.ValidationError("group_id is required for group actions.")
        
        return attrs


class ContactSearchSerializer(serializers.Serializer):
    """Serializer for contact search."""
    
    query = serializers.CharField(required=False)
    group = serializers.IntegerField(required=False)
    is_favorite = serializers.BooleanField(required=False)
    is_blocked = serializers.BooleanField(required=False)
    company = serializers.CharField(required=False)
    city = serializers.CharField(required=False)
    country = serializers.CharField(required=False)