from rest_framework import serializers
from django.contrib.auth import get_user_model
from tenants.serializers import TenantSerializer
from rest_framework_simplejwt.serializers import TokenObtainPairSerializer

User = get_user_model()

class CustomTokenObtainPairSerializer(TokenObtainPairSerializer):
    @classmethod
    def get_token(cls, user):
        token = super().get_token(user)

        # Add custom claims
        token['role'] = getattr(user, 'role', 'student')
        token['tenant_id'] = user.tenant.id if getattr(user, 'tenant', None) else None

        return token

class UserSerializer(serializers.ModelSerializer):
    tenant = TenantSerializer(read_only=True)
    
    class Meta:
        model = User
        fields = ['id', 'username', 'email', 'first_name', 'last_name', 'role', 'tenant', 'is_active']
        read_only_fields = ['id']

class RegisterSerializer(serializers.ModelSerializer):
    password = serializers.CharField(write_only=True)
    
    class Meta:
        model = User
        fields = ['username', 'email', 'password', 'first_name', 'last_name', 'role']
        
    def create(self, validated_data):
        user = User.objects.create_user(
            username=validated_data['username'],
            email=validated_data.get('email', ''),
            password=validated_data['password'],
            first_name=validated_data.get('first_name', ''),
            last_name=validated_data.get('last_name', ''),
            role=validated_data.get('role', 'student'),
            tenant=self.context['request'].tenant if 'request' in self.context else None
        )
        return user