from django.contrib.auth.password_validation import validate_password
from rest_framework import serializers
from rest_framework_simplejwt.serializers import TokenObtainPairSerializer

from .models import User


class CustomTokenObtainPairSerializer(TokenObtainPairSerializer):
    """Adds user identity/role to the JWT payload and to the login response."""

    @classmethod
    def get_token(cls, user):
        token = super().get_token(user)
        token['username'] = user.username
        token['role'] = user.role
        return token

    def validate(self, attrs):
        data = super().validate(attrs)
        data['user'] = {
            'id': self.user.id,
            'username': self.user.username,
            'email': self.user.email,
            'role': self.user.role,
        }
        return data


class UserSerializer(serializers.ModelSerializer):
    password = serializers.CharField(write_only=True, required=False, validators=[validate_password])

    class Meta:
        model = User
        fields = [
            'id', 'username', 'email', 'first_name', 'last_name',
            'role', 'is_active', 'password', 'date_joined',
        ]
        read_only_fields = ['id', 'date_joined']

    def create(self, validated_data):
        password = validated_data.pop('password', None)
        user = User(**validated_data)
        if password:
            user.set_password(password)
        else:
            user.set_unusable_password()
        user.save()
        return user

    def update(self, instance, validated_data):
        password = validated_data.pop('password', None)
        for attr, value in validated_data.items():
            setattr(instance, attr, value)
        if password:
            instance.set_password(password)
        instance.save()
        return instance