from typing import Optional
from rest_framework import serializers
from django.db.models.functions import Lower

from labs.models import (
    CertificateIssuance,
    CertificateRecipient,
    CertificateType,
)


class CertURLEncryptSerializer(serializers.Serializer):
    user_login = serializers.CharField(required=True)
    course_id = serializers.CharField(required=True)


class LearnerInfoSerializer(serializers.Serializer):
    user_gid = serializers.CharField(required=False)
    email = serializers.EmailField(required=False)
    first_name = serializers.CharField(required=False)
    last_name = serializers.CharField(required=False)


class LearnerCertPublicURLSerializer(serializers.Serializer):
    email = serializers.EmailField(required=True)
    first_name = serializers.CharField(required=True)
    last_name = serializers.CharField(required=True)
    cert_abbr_code = serializers.CharField(required=True)


class VerifyCertificateSerializer(serializers.Serializer):
    cert_id = serializers.CharField(required=True)


class TLMSCallbackSerializer(serializers.Serializer):
    user = serializers.CharField(required=True)
    course = serializers.CharField(required=True)


class CertificateRecipientDetailSerializer(serializers.ModelSerializer):
    class Meta:
        model = CertificateRecipient
        fields = [
            "first_name",
            "last_name",
        ]


class CertificateTypeDetailSerializer(serializers.ModelSerializer):
    class Meta:
        model = CertificateType
        fields = [
            "name",
            "short_name",
            "description",
            "issuer_name",
            "issuer_website",
        ]


class CertificateIssuanceDetailSerializer(serializers.ModelSerializer):
    recipient = CertificateRecipientDetailSerializer()
    cert_type = CertificateTypeDetailSerializer()
    issued_at = serializers.DateTimeField(format="%d/%m/%Y")
    file_public_url = serializers.SerializerMethodField()

    def get_file_public_url(self, obj: CertificateIssuance) -> str:
        return obj.get_file_public_url()

    class Meta:
        model = CertificateIssuance
        fields = [
            "recipient",
            "cert_type",
            "cert_number",
            "issued_at",
            "file_public_url",
        ]


class CertificateNumberSearchSerializer(serializers.Serializer):
    email = serializers.EmailField(required=True)
    first_name = serializers.CharField(required=True)
    last_name = serializers.CharField(required=True)
    cert_short_name = serializers.CharField(required=True)

    def get_certificate_issuance(self) -> Optional[CertificateIssuance]:
        email = self.validated_data.get("email")
        first_name = self.validated_data.get("first_name")
        last_name = self.validated_data.get("last_name")
        cert_short_name = self.validated_data.get("cert_short_name")
        return (
            CertificateIssuance.objects.annotate(
                email_lower=Lower("recipient__email"),
                first_name_lower=Lower("recipient__first_name"),
                last_name_lower=Lower("recipient__last_name"),
            )
            .filter(
                email_lower=email.lower(),
                first_name_lower=first_name.lower(),
                last_name_lower=last_name.lower(),
                cert_type__short_name=cert_short_name,
            )
            .order_by("-issued_at")
            .first()
        )


class TLMSToCertificateNumberSerializer(serializers.Serializer):
    user_gid = serializers.CharField(required=True)
    course_id = serializers.CharField(required=True)

    def get_certificate_issuance(self) -> Optional[CertificateIssuance]:
        user_gid = self.validated_data.get("user_gid")
        course_id = self.validated_data.get("course_id")
        return (
            CertificateIssuance.objects.filter(
                recipient__deprecated_gid=user_gid,
                tlms_course_id=course_id,
            )
            .order_by("-issued_at")
            .first()
        )