applyze_payment

Applyze Payment Service

Table of Contents

• Summary
• Constants
• Authorization
• Authentication
• Filters
• Controllers
• Exception Handler
• IPaymentService
• Repositories
• How To Contribute ?

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Summary

Directories	Description
Contexts	Database contexts are here. Currently MongoDB Context is here.
Controllers	Default folder of MVC for Controllers. Controller Versions are seperated by folders like V1, V2 etc.
Dtos	Includes Data Transfer Objects inside. They're grouped by Request and Response.
Extensions	Includes Classes with Extension Methods.
Helpers	Includes helper class to make things easier.
Middleware	Includes stuffs which handles and works for all requests. Like Auth., Exceptions etc.
Models	Default folder of MVC for Models. Includes database models and service models.
Repositories	Includes queries of database. It's an access layer to database.
Services	Includes connections of services. It's an access layer to other services. Like Payment, Tenant etc.

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Constants

Constants.cs is ignored by default. This may have sensitive datas. You should use your own Constants class locally. Create a Constants.cs to your local and add following constants:

    public class Constants
    {
#if DEBUG

        public const string TENANT_BASE_URL = "";
        public const string ECOMMERCE_BASE_URL = "";
        public const string SECRET_KEY = "";        
        public const string CALLBACK_BASE_BASE_URL = "";
        //DEBUG PARAMETERS HERE
        
#else   //------------------------------------

        public const string TENANT_BASE_URL =  "";
        public const string ECOMMERCE_BASE_URL = "";
        public const string SECRET_KEY = "";
        public const string CALLBACK_BASE_BASE_URL = "";
        //RELEASE PARAMETERS HERE

#endif
    }

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Midlewares

Authorization

All requests to this API must have api-Key and app-key in header. These are handled in Middleware.Authenticator.

And it's configured on startup with app.UseAuthenticator(); in Configure() method.

Authentication

Authentication is provided by Applyze Tenant Microservice. Communication between services are providing by HTTP.

Services.Abstraction.ITenantService is called to connect Tenenat Service and this interface implemented to Services.Concrate.TenantService.

All proccess are handled in Middleware.Authenticator. After authentication, App data added to HttpContext.Items, it can be used from anywhere until request finishes.

Filters

Filters allows to define some requirements to Controllers or actions.

• SecretKeyRequiredAttribute is to validate user to modify sensitive datas.

[SecretKeyRequired] //  < --- This endpoint requires secret key in header.
public IActionResult Get()
{
        //do something...
}

• ConfigurationRequiredAttribute is to get app's payment configurations from eCommerce Service for payment endpoints. Endpoints without this attribute, won't try to get configuration from eCommerce Service.

[ConfigurationRequired] //  < --- This endpoint requires payment configurations.
public IActionResult Get()
{
    //do something...
}

Exception Handler & Logging

All Exceptions are handling and logging in Middleware.ExceptionHandler . It's configured on startup with app.ConfigureExceptionHandler() Also logger can be sent to ExceptionHandler to logging exceptions.

Project use GrayLog. Its configured at Program.cs with ConfigureLogging(). And it's parameters are can be changed from appsettings.json.

When an exception handled, 500 Internal Server Error returns.

To return 400 Bad Request response, you can throw CustomException with message.

 //Exception handler returns 400 Bad Request
 throw new CustomException("name parameter is invalid!");  

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Controllers

Controllers are seperated by Api Versions. Naming is like Controllers.V (Controllers.V1).

• To manage all controllers from one point, There is BaseController under Controllers folder. This provides to reach Authenticated App data from Controller via calling App property in any controller inherits BaseController.

        
            //---- in a controller which inherits from BaseController.---
            //...
            if (!ModelState.IsValid)
                return GetBadRequest(ModelState);       

                            //Example: App from here comes from BaseController.
            await paymentRepository.AddAsync(App.id, payment); // < ----
            //...      

• Also BaseController has some ready response message methods to standardize all responses. All Endpoints response with ApiResult model:

ApiResult {
    Result  : boolean
    Message : string
    Data    : object
}

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IPaymentService

IPaymentService Interface is located in Services.Abstraction. This interface includes all payment functionalities and controllers are using this. To import more than one payment classes into system; just implement this interface to new class and configure on Startup.cs like:

            // **Payment Injection to IPaymentService**
            services.AddPayment<IyzicoService>();       // < --- One of Payment Service
            services.AddPayment<PayUService>();         // < --- One of Payment Service
            //services.AddPayment<YourNewService>();    // < --- Add new Payment Services
            //...
            services.BuildPayment<IPaymentService>();   // < --- Interface to Inject

AddPayment method configured in Helpers.PaymentProviderFactory.

Then, to call a payment provider;

        private readonly Func<string, IPaymentService> paymentAccessor;

        public PaymentsController(Func<string, IPaymentService> paymentAccessor) //Constructor
        {
            this.paymentAccessor = paymentAccessor;
        }

And, to use:

            //to get one service's interface
            IPaymentService paymentService = paymentAccessor("iyzico");
            IPaymentService paymentService = paymentAccessor("payu");
            //...

            //or directly pass parameters:
            var response = await paymentAccessor(provider).PayAsync(dto);

Payment ErrorCodes

Payment error codes are standardized by Enum. You can find codes from State and StateCode in any Payment Request response data. You can see enum and codes following block:

StateCode	State	Description
0	None	Successful
800	NOT_SUFFICIENT_FUNDS	Balance is not enough
801	DO_NOT_HONOUR	Process did not approved
900	INVALID_PAYMENT_INFO	Card Info is not correct
901	LOST_OR_STOLEN_CARD	Lost or stolen card. Keep the card.
902	EXPIRED_CARD	Date is expired of card
903	INVALID_CVC2	Invalid Cvc
904	DEBIT_CARDS_REQUIRES_3DS	This process requires 3D Secure
905	DEBIT_CARDS_INSTALLMENT_NOT_ALLOWED	Installment can't be applied with Debit card
906	TOO_MANY_INVALID_ATTEMPTS	Too many invalid attempts
907	NOT_ENOUGH_LIMIT	Limit is not enough for this amount
1000	Other	Any other errors
1100	INVALID_ENUM	invalid an enum like Currency, Locale or RefundReason
1101	ALREADY_DONE_BEFORE	The proccess done before

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To be continued...