from typing import List

from django.conf import settings
from django.contrib.auth import get_user_model
from django.contrib.auth.password_validation import get_password_validators, validate_password
from rest_framework import serializers
from rest_framework.exceptions import ValidationError
from rest_framework_simplejwt.serializers import TokenObtainPairSerializer

User = get_user_model()


AUTH_PASSWORD_VALIDATORS = getattr(settings, 'AUTH_PASSWORD_VALIDATORS')


class UserSerializer(serializers.ModelSerializer):
    permissions = serializers.SerializerMethodField()

    def get_permissions(self, obj: User) -> List[str]:
        group_permissions = obj.get_group_permissions()
        user_permissions = obj.get_user_permissions()

        return sorted(user_permissions.union(group_permissions))

    class Meta:
        model = User
        fields = (
            'username',
            'email',
            'first_name',
            'last_name',
            'is_staff',
            'is_superuser',
            'permissions',
        )
        read_only_fields = ('username', 'code', 'is_staff', 'is_superuser', 'permissions', )


class UpdatePasswordSerializer(serializers.ModelSerializer):
    old_password = serializers.CharField(write_only=True)
    new_password = serializers.CharField(write_only=True)
    new_password2 = serializers.CharField(write_only=True)

    def validate_old_password(self, password):
        user = self.context.get('request').user

        if not user.check_password(password):
            raise ValidationError('Wrong old password')

        return password

    def validate_new_password(self, password):
        old_password = self.context.get('request').data.get('old_password')

        if password == old_password:
            raise ValidationError('Password can\'t be the same as the old one')

        password2 = self.context.get('request').data.get('new_password2')
        if password != password2:
            raise ValidationError('Password mismatch')

        validate_password(password, password_validators=get_password_validators(AUTH_PASSWORD_VALIDATORS))

        return password

    def save(self, *args, **kwargs):
        new_password = self.validated_data.get('new_password')
        self.instance.set_password(new_password)
        self.instance.save()

    class Meta:
        model = User
        fields = ('old_password', 'new_password', 'new_password2', )