uncloud/uncloud/uncloud_pay/serializers.py

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

from functools import reduce
from uncloud_vm.serializers import VMProductSerializer
from uncloud_vm.models import VMProduct

class BillSerializer(serializers.ModelSerializer):
    class Meta:
        model = Bill
        fields = ['owner', 'amount', 'due_date', 'creation_date',
                'starting_date', 'ending_date', 'paid']

class PaymentSerializer(serializers.ModelSerializer):
    class Meta:
        model = Payment
        fields = ['owner', 'amount', 'source', 'timestamp']

class PaymentMethodSerializer(serializers.ModelSerializer):
    class Meta:
        model = PaymentMethod
        fields = ['owner', 'primary', 'source', 'description']

class ProductSerializer(serializers.Serializer):
    vms = VMProductSerializer(many=True, required=False)

    def create(self, validated_data):
        owner = validated_data.pop('owner')
        order = validated_data.pop('order')

        vms = validated_data.pop('vms')
        for vm in vms:
            VMProduct.objects.create(owner=owner, order=order, **vm)

        return True # FIXME: shoudl return created objects


class OrderSerializer(serializers.ModelSerializer):
    products = ProductSerializer()
    class Meta:
        model = Order
        fields = '__all__'

    def create(self, validated_data):
        products_data = validated_data.pop('products')
        validated_data['owner'] = self.context["request"].user

        # FIXME: find something to do with this:
        validated_data['recurring_price'] = 0
        validated_data['one_time_price'] = 0

        order = Order.objects.create(**validated_data)

        # Forward product creation to ProductSerializer.
        products = ProductSerializer(data=products_data)
        products.is_valid(raise_exception=True)
        products.save(order=order,owner=order.owner)

        return order

class UserSerializer(serializers.ModelSerializer):
    class Meta:
        model = get_user_model()
        fields = ['username', 'email', 'balance']

    # Display current 'balance'
    balance = serializers.SerializerMethodField('get_balance')
    def __sum_balance(self, entries):
        return reduce(lambda acc, entry: acc + entry.amount, entries, 0)

    def get_balance(self, user):
        bills = self.__sum_balance(Bill.objects.filter(owner=user))
        payments = self.__sum_balance(Payment.objects.filter(owner=user))
        balance = payments - bills

        return balance