create and base config payments service project

.gitignore

@@ -16,6 +16,7 @@ poetry.lock
 
 venv
 
+.env*
 .env.dev
 .env.prod
 

backend/payments/.pre-commit-config.yaml

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+repos:
+- repo: https://github.com/pycqa/flake8.git
+  rev: 6.0.0
+  hooks:
+  - id: flake8
+    args: [
+      "--ignore=E501"
+    ]
+    additional_dependencies: [
+      "flake8-bugbear",
+      "flake8-builtins",
+      "pep8-naming",
+      "flake8-commas",
+      "flake8-quotes",
+      "flake8-todo",
+      "flake8-django",
+      "flake8-cognitive-complexity",
+      "flake8-isort",
+   ]

backend/payments/README.md

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+# GSpot Payments
+
+REST API сервис для работы с финансами интернет магазина видеоигр GSpot
+
+
+## Как запустить local-версию
+
+TODO
+
+## Переменные окружения
+
+Образ Django считывает настройки из переменных окружения:
+- `SECRET_KEY` - соль для генерации хэшей. Значение может быть произвольной строкой
+- `DEBUG`- настройка Django для ключения отладочного режима.
+- `ALLOWED_HOSTS` - список разрешенных хостов.
+- `DATABASE_URL` - адрес для подключения к БД PostgreSQL. [Формат записи](https://github.com/jacobian/dj-database-url#url-schema)
+- `account_id` - id вашего магазина yookassa.
+- `shop_secret_key` - api ключ вашего магазина yookassa.
+
+## Установка и настройка flake8
+На проекте используется линтер flake8 с плагинами. Flake8 не дает возможности перечислить используемые плагины,
+поэтому если у вас есть другие проекты с flake8, то их плагины начнут мешать друг другу. Чтобы избежать этого
+необходимо создать отдельное виртуальное окружение под линтер.
+
+Устанавливаем flake8 и плагины для него:
+```shell
+virtualenv venv
+source ../venv/bin/activate
+pip install -r flake8-requirements.txt
+```
+
+Настройте IDE для использования flake8 из виртуального окружения (не из глобального):
+- Pycharm - [статья 1](https://melevir.medium.com/pycharm-loves-flake-671c7fac4f52), [статья 2](https://habr.com/en/company/dataart/blog/318776/);
+- [Vscode](https://stackoverflow.com/questions/54160207/using-flake8-in-vscode/54160321#54160321).
+
+### Насторойка flake8 для запуска проверки в pre-commit hooks
+
+Установить pre-commit:
+```shell
+pre-commit install
+```
+
+В последующем все проиндексированные файлы будут проверяться с помощью flake8 перед коммитом.
+
+Для проверки с помощью flake8 файлов проиндексированных для коммита выполнить:
+```shell
+pre-commit run  
+```
+В случае необходимости пропустить использование pre-commit hook коммит нужно выполнить с флагом `-n` или `--no-verify`:
+```shell
+git commit --no-verify
+```
+Для автоматического обновления версии hooks, используемых в pre-commit выполнить:
+```shell
+pre-commit autoupdate
+```

backend/payments/apps/payment_accounts/admin.py

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+from django.contrib import admin
+
+# Register your models here.

backend/payments/apps/payment_accounts/apps.py

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+from django.apps import AppConfig
+
+
+class PaymentAccountsConfig(AppConfig):
+    default_auto_field = 'django.db.models.BigAutoField'
+    name = 'apps.payment_accounts'
+    verbose_name = 'Счета пользователя'

backend/payments/apps/payment_accounts/models.py

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+from __future__ import annotations
+
+from decimal import Decimal
+
+from django.conf import settings
+from django.core.validators import MinValueValidator
+from django.db import models, transaction
+from django.shortcuts import get_object_or_404
+
+
+# Create your models here.
+def is_amount_positive(method):
+    def wrapper(cls, *args, **kwargs):
+        amount = kwargs['amount']
+        if amount < 0:
+            raise ValueError('Should be positive value')
+        return method(cls, *args, **kwargs)
+    return wrapper
+
+
+class Account(models.Model):
+
+    user_uid = models.UUIDField(unique=True, editable=False, db_index=True)
+    balance = models.DecimalField(
+        decimal_places=2,
+        max_digits=settings.MAX_BALANCE_DIGITS,
+        validators=[MinValueValidator(0, message='Insufficient Funds')],
+        default=0,
+    )
+
+    @classmethod
+    @is_amount_positive
+    def deposit(cls, *, pk: int, amount: Decimal) -> Account:
+        """
+        Use a classmethod instead of an instance method,
+        to acquire the lock we need to tell the database
+        to lock it, preventing data update collisions.
+        When operating on self the object is already fetched.
+        And we don't have  any guaranty that it was locked.
+        """
+        with transaction.atomic():
+            account = get_object_or_404(
+                cls.objects.select_for_update(),
+                pk=pk,
+            )
+            account.balance += amount
+            account.save()
+        return account
+
+    @classmethod
+    @is_amount_positive
+    def withdraw(cls, *, pk: int, amount: Decimal) -> Account:
+        with transaction.atomic():
+            account = get_object_or_404(
+                cls.objects.select_for_update(),
+                pk=pk,
+            )
+            account.balance -= amount
+            account.save()
+        return account
+
+    def __str__(self) -> str:
+        return f'User id: {self.user_uid}'
+
+
+class BalanceChange(models.Model):
+    class TransactionType(models.TextChoices):
+        WITHDRAW = ('WD', 'WITHDRAW')
+        DEPOSIT = ('DT', 'DEPOSIT')
+
+    account_id = models.ForeignKey(
+        Account, on_delete=models.PROTECT,
+        related_name='balance_changes',
+    )
+    amount = models.DecimalField(
+        max_digits=settings.MAX_BALANCE_DIGITS,
+        validators=[MinValueValidator(0, message='Should be positive value')],
+        decimal_places=2,
+        editable=False,
+    )
+    date_time_creation = models.DateTimeField(
+        auto_now_add=True,
+        editable=False,
+        db_index=True,
+    )
+    is_accepted = models.BooleanField(default=False)
+    operation_type = models.CharField(max_length=20, choices=TransactionType.choices)
+
+    def __str__(self) -> str:
+        return f'Account id:  {self.account_id} ' \
+               f'Date time of creation: {self.date_time_creation}' \
+               f'Amount: {self.amount}'
+
+    class Meta:
+        ordering = ['-date_time_creation']

backend/payments/apps/payment_accounts/serializers.py

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+from django.conf import settings
+from django.core.validators import MinValueValidator
+from rest_framework import serializers
+
+
+class CreatePaymentSerializer(serializers.Serializer):
+    uuid = serializers.UUIDField()
+    value = serializers.DecimalField(
+        decimal_places=2,
+        max_digits=settings.MAX_BALANCE_DIGITS,
+        validators=[MinValueValidator(0, message='Insufficient Funds')],
+    )
+    commission = serializers.DecimalField(
+        decimal_places=1,
+        max_digits=settings.MAX_BALANCE_DIGITS,
+        validators=[MinValueValidator(0, message='Insufficient Funds')],
+    )
+    payment_type = serializers.CharField(max_length=20)
+    return_url = serializers.URLField()

backend/payments/apps/payment_accounts/services/create_payment.py

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+from environs import Env
+from yookassa import Configuration, Payment
+
+from ..models import Account, BalanceChange
+
+env = Env()
+env.read_env()
+Configuration.account_id = env.int('account_id')
+Configuration.secret_key = env.str('shop_secret_key')
+
+
+def create_payment(uuid, value, commission, payment_type, return_url):
+    value_with_commission = value * (1 / (1 - commission / 100))
+    user_account, created = Account.objects.get_or_create(
+        user_uid=uuid,
+    )
+
+    change = BalanceChange.objects.create(
+        account_id=user_account,
+        amount=value,
+        is_accepted=False,
+        operation_type='DEPOSIT',
+    )
+    change.save()
+
+    payment = Payment.create({
+        'amount': {
+            'value': value_with_commission,
+            'currency': 'RUB',
+        },
+        'payment_method_data': {
+            'type': payment_type,
+        },
+        'confirmation': {
+            'type': 'redirect',
+            'return_url': return_url,
+        },
+        'metadata': {
+            'table_id': change.id,
+            'user_id': user_account.id,
+        },
+        'capture': True,
+        'refundable': False,
+        'description': 'Пополнение на ' + str(value),
+    })
+
+    return payment.confirmation.confirmation_url

backend/payments/apps/payment_accounts/tests.py

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+from django.test import TestCase
+
+# Create your tests here.

backend/payments/apps/payment_accounts/urls.py

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+from django.urls import path
+
+from . import views
+
+urlpatterns = [
+    path('create_payment/', views.CreatePaymentView.as_view()),
+    path('payment_acceptance/', views.CreatePaymentAcceptanceView.as_view()),
+]

backend/payments/apps/payment_accounts/views.py

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+import json
+from decimal import Decimal
+
+import rollbar
+from django.core.exceptions import ObjectDoesNotExist
+from rest_framework.generics import CreateAPIView
+from rest_framework.response import Response
+
+from .models import Account, BalanceChange
+from .serializers import CreatePaymentSerializer
+from .services.create_payment import create_payment
+
+
+class CreatePaymentView(CreateAPIView):
+    serializer_class = CreatePaymentSerializer
+
+    def post(self, request, *args, **kwargs):
+        serializer = CreatePaymentSerializer(data=request.POST)
+
+        if serializer.is_valid():
+            serialized_data = serializer.validated_data
+        else:
+            return Response(400)
+
+        confirmation_url = create_payment(
+            uuid=serialized_data.get('uuid'),
+            value=serialized_data.get('value'),
+            commission=serialized_data.get('commission'),
+            payment_type=serialized_data.get('payment_type'),
+            return_url=serialized_data.get('return_url'),
+        )
+
+        return Response({'confirmation_url': confirmation_url}, 200)
+
+
+class CreatePaymentAcceptanceView(CreateAPIView):
+
+    def post(self, request, *args, **kwargs):
+        response = json.loads(request.body)
+
+        try:
+            table = BalanceChange.objects.get(
+                id=response['object']['metadata']['table_id'],
+            )
+        except ObjectDoesNotExist:
+            rollbar.report_message(
+                "Can't get table for payment id {0}".format(
+                    response['object']['id'],
+                ),
+                'warning',
+            )
+            return Response(404)
+
+        if response['event'] == 'payment.succeeded':
+            table.is_accepted = True
+            table.save()
+            Account.deposit(
+                pk=response['object']['metadata']['user_id'],
+                amount=Decimal(response['object']['income_amount']['value']),
+            )
+        elif response['event'] == 'payment.canceled':
+            table.delete()
+
+        return Response(200)

backend/payments/apps/transactions/admin.py

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+from django.contrib import admin
+
+# Register your models here.

backend/payments/apps/transactions/apps.py

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+from django.apps import AppConfig
+
+
+class TransactionsConfig(AppConfig):
+    default_auto_field = 'django.db.models.BigAutoField'
+    name = 'apps.transactions'
+    vebose_name = 'Транзакции'

backend/payments/apps/transactions/exceptions.py

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+class DuplicateError(Exception):
+    pass