from django.db import IntegrityError
from django.db.transaction import atomic
from rest_framework import serializers
from rest_framework.exceptions import APIException

from apps.users.serializers import PublicUserSerializer
from .models import Transaction


class TransactionSerializer(serializers.ModelSerializer):
    payer = PublicUserSerializer(required=False)
    payee = PublicUserSerializer(required=False, read_only=True)

    # application_client_id = serializers.IntegerField(required=False, read_only=True)

    class Meta:
        model = Transaction
        fields = ('uuid',
                  'payer',
                  'payee',
                  "create",
                  "state",
                  'amount',
                  'delay',
                  'last_update',
                  # 'detail_id',
                  # 'application_client_id'
                  )

        read_only_fields = ['uuid', 'last_update', 'state', 'create']  # , 'detail_id']  #, 'application_client_id']

    def create(self, validated_data):

        payer = validated_data.get('payer')
        request = self.context.get('request')
        user = request.user if request else payer

        if user == payer:
            with atomic():
                transaction = Transaction.objects.create_transaction(**validated_data)
                transaction.pay()

        else:
            transaction = Transaction.objects.create_transaction(**validated_data)

        return transaction


class ServiceTransactionSerializer(serializers.ModelSerializer):
    # payer = PublicUserSerializer(required=True)
    # payee = PublicUserSerializer(required=True)
    user = PublicUserSerializer(required=False, write_only=True)
    uuid = serializers.UUIDField(required=True)

    # application_client_id = serializers.IntegerField(required=False, read_only=True)

    class Meta:
        model = Transaction
        fields = (
            'user',
            'uuid',
            'payer',
            'payee',
            "create",
            "state",
            'amount',
            'delay',
            'last_update',
            # 'detail_id',
            # 'application_client_id'
        )

        read_only_fields = ['last_update', 'state', 'create', 'user']  # , 'detail_id']  #, 'application_client_id']

    def create(self, validated_data):
        payer = validated_data.get('payer')
        payee = validated_data.get('payee')
        user = validated_data.pop('user')

        if user not in [payee, payer]:
            raise APIException('user must be in payer or payee')

        with atomic():
            try:
                transaction = Transaction.objects.create_transaction(**validated_data)
                transaction.submit()
            except IntegrityError as e:
                raise APIException('duplicate uuid')

        return transaction