BelvoApp/transactions/serializers.py

"""
Transactions app serializer
"""
from rest_framework import serializers
from django.utils.translation import ugettext_lazy as _
from django.contrib.auth import get_user_model
from .models import Transaction

User = get_user_model()


class CreateTransactionSerializer(serializers.ModelSerializer):
    """
    Create transaction serializer
    """
    user_id = serializers.PrimaryKeyRelatedField(
        queryset=User.objects.all(), source='user', write_only=True, help_text='User Id')

    def __init__(self, *args, **kwargs):
        many = kwargs.pop('many', True)
        super().__init__(many=many, *args, **kwargs)

    def validate(self, data):
        """
        Check the type is outflow or inflow
        Check the inflow is positive and outflow is negative
        """
        if data['type'] not in ('outflow', 'inflow'):
            raise serializers.ValidationError(
                {"type": _("Must be `outflow` or `inflow` ")})
        if data['amount'] > 0 and data['type'] == 'outflow':
            raise serializers.ValidationError(
                {"amount": _("Outflow type only allow negatives amount")})
        if data['amount'] < 0 and data['type'] == 'inflow':
            raise serializers.ValidationError(
                {"amount": _("Inflow type only allow positives amount")})
        return data

    class Meta:
        """
        Meta class definitions
        """
        model = Transaction
        fields = ('user_id', 'reference',
                  'account', 'type', 'amount',
                  'category', 'date')


class BalanceByAccountSerializer(serializers.ModelSerializer):
    """
    Balanced by account serializer
    """
    balance = serializers.FloatField(label='balance', read_only=True)
    total_inflow = serializers.FloatField(label='balance', read_only=True)
    total_outflow = serializers.FloatField(label='balance', read_only=True)

    class Meta:
        """
        Meta class definitions
        """
        model = Transaction
        fields = ['account', 'balance', 'total_inflow', 'total_outflow']