from rest_framework import serializers

from finance.models import Bill, Invoice


class BillSerializer(serializers.ModelSerializer):
    opener = serializers.SerializerMethodField()
    user = serializers.SerializerMethodField()
    course = serializers.SerializerMethodField()
    invoices = serializers.SerializerMethodField()

    class Meta:
        model = Bill
        fields = '__all__'

    @staticmethod
    def get_user(self):
        return self.user.email

    @staticmethod
    def get_course(self):
        return self.course.title

    @staticmethod
    def get_invoices(self):
        return [InvoiceSerializer(i).data for i in self.invoice_set.all()]

    @staticmethod
    def get_opener(self):
        return self.opener.email


class InvoiceSerializer(serializers.ModelSerializer):

    class Meta:
        model = Invoice
        exclude = ('bill', )