from rest_framework import serializers

from .models import JobApplication, JobUpdate


class SanitizedCharField(serializers.CharField):
    """CharField that strips control characters on deserialization."""

    def to_internal_value(self, data: object) -> object:
        value = super().to_internal_value(data)
        if isinstance(value, str):
            value = value.strip()
            if "\x00" in value:
                raise serializers.ValidationError("Input contains invalid characters.")
            import re
            value = re.sub(r"[\x00-\x08\x0b\x0c\x0e-\x1f]", "", value)
        return value


class JobUpdateSerializer(serializers.ModelSerializer):
    company_name = serializers.CharField(source="job_application.company_name", read_only=True)
    position_title = serializers.CharField(source="job_application.position_title", read_only=True)
    job_id = serializers.IntegerField(source="job_application.id", read_only=True)

    class Meta:
        model = JobUpdate
        fields = [
            "id",
            "job_id",
            "company_name",
            "position_title",
            "from_status",
            "to_status",
            "notes",
            "created_at",
            "metrics",
        ]


class JobApplicationSerializer(serializers.ModelSerializer):
    user_id = serializers.IntegerField(read_only=True)
    notes = SanitizedCharField(required=False, allow_blank=True, default="")
    company_name = SanitizedCharField(max_length=255)
    position_title = SanitizedCharField(max_length=255)

    class Meta:
        model = JobApplication
        fields = [
            "id",
            "user_id",
            "company_name",
            "position_title",
            "status",
            "notes",
            "created_at",
            "updated_at",
        ]
        read_only_fields = ["user_id"]

    def create(self, validated_data):
        validated_data["user"] = self.context["request"].user
        return super().create(validated_data)


class DashboardMetricsSerializer(serializers.Serializer):
    total_applications = serializers.IntegerField()
    status_breakdown = serializers.DictField(child=serializers.IntegerField())
    interviews_count = serializers.IntegerField()
    offers_count = serializers.IntegerField()
    rejection_rate = serializers.FloatField()