from django.contrib.auth import get_user_model
from rest_framework import serializers

from .models import User

UserModel = get_user_model()


class RegisterSerializer(serializers.ModelSerializer[User]):
    password = serializers.CharField(write_only=True, min_length=8)
    password_confirm = serializers.CharField(write_only=True, min_length=8)

    class Meta:
        model = User
        fields = ["email", "username", "display_name", "password", "password_confirm"]

    def validate(self, attrs):
        if attrs["password"] != attrs.pop("password_confirm"):
            raise serializers.ValidationError({"password_confirm": "Passwords do not match."})
        return attrs

    def create(self, validated_data):
        password = validated_data.pop("password")
        user = UserModel(**validated_data)
        user.set_password(password)
        user.save()
        return user


class UserSerializer(serializers.ModelSerializer[User]):
    avatar_url = serializers.SerializerMethodField()

    class Meta:
        model = User
        fields = [
            "id", "email", "username", "display_name", "avatar_url",
            "date_joined", "is_verified", "reading_preferences",
        ]
        read_only_fields = ["id", "email", "date_joined", "is_verified"]

    def get_avatar_url(self, obj: User) -> str | None:
        return obj.avatar_url


class ChangePasswordSerializer(serializers.Serializer):
    old_password = serializers.CharField(required=True)
    new_password = serializers.CharField(required=True, min_length=8)

    def validate_old_password(self, value: str) -> str:
        user = self.context["request"].user
        if not user.check_password(value):
            raise serializers.ValidationError("Current password is incorrect.")
        return value