Payment System 👛💻

Welcome to the Payment System! This project demonstrates a payment system that focuses on multi-payment providers. It utilizes the Factory Pattern and Adapter Pattern to create a flexible environment where new payment providers can be easily added and used for the payment process. The project also includes a simple frontend built with Angular, showcasing a simple shoe store that works with the backend to allow customers to add products to their cart, proceed to checkout, and complete the payment process. Additionally, it provides a payment history feature.

Project Structure 📁

The Payment test project consists of the following components:

Payment.Domain 🏦

The Payment.Domain project contains the domain models that represent the core entities and concepts of the payment system.

Payment.Application 📝

The Payment.Application project is the application layer that contains classes and interfaces related to the application logic. It includes view models, services and repository interfaces, factory and adapter pattern interfaces, and AutoMapper profile classes.

Payment.Infrastructure 🏢

The Payment.Infrastructure project is the infrastructure layer responsible for interacting with external services (such Adyen or PayPal) and managing persistence. It includes services that interact with payment providers and implementations of repositories.

Payment.Api 🌐

The Payment.Api project is the API project that exposes endpoints for interacting with the payment system. It handles request processing, dependency injection registration, and integrates the different layers of the system.

Payment.Tests ✅

The Payment.Tests project contains all the unit tests for the various components of the Payment project. It ensures the correctness and reliability of the implemented functionality.

payment-client 💻

The payment-client folder contains the Angular client application that provides the user interface for the shoe store and payment process. It communicates with the backend API to perform payment-related operations and display the payment history.

Running the Project ▶️

To run the Payment project, follow these steps:

Backend 🖥️🔙

1. Ensure that you have a relational database (such as MySQL or SqlServer) set up and running.

2. Open the appsettings.json file and define a ConnectionString value based on your selected database. (I have previously defined two examples, one for MySql and the other for SqlServer).

3. Open the Program.cs file and, in the register section where the DbContext is being registered using AddDbContext, perform the configuration based on your selected database. Note that you need to first install the appropriate Provider for that database as a NuGet Package. (By default, I have installed the Providers for MySql and SqlServer).

4. Open a command prompt or terminal and navigate to the Payment directory (the root directory of all projects).

5. Run the following command to generate migration files for selected database.

   dotnet ef migrations add Init -s Payment.Api -p Payment.Infrastructure
   

6. After that, Run the following command to apply the database migrations and create the necessary database and tables:

   dotnet ef database update -s Payment.Api -p Payment.Infrastructure
   

   This will create the database based on the existing database configuration in the backend project.

7. Open the launchSettings.json file located in the Properties folder of the Payment.Api project and set the desired address and port in the "applicationUrl" property to specify where the backend API should listen for requests (the default ports are 5000 for http and 5001 for https).

8. Build and run the Payment.Api project.

Frontend 💻

1. Open a command prompt or terminal and navigate to the payment-client directory.

2. Run the following command to install the necessary dependencies:

   npm install
   

3. Open the src/environments/environment.ts file in the payment-client project. Set the baseUrl property to the address and port where the backend API is running. This will allow the frontend to communicate with the backend (the default port is 5000 for http).

4. After the dependencies are installed, run the following command to start the Angular development server:

   ng serve
   

5. Open your web browser and navigate to the http://localhost:4200 to access the Payment frontend project.

Adding a New Payment Provider ➕🏦

To add a new payment provider to the backend, follow these steps:

1. Create a class that implements the IPaymentProvider interface. This class will encapsulate the logic for interacting with the specific payment provider's API.

   Make sure to assign a name of new provider to Name property of IPaymentProvider. Assign it in the constructor of new class.

   The name should be same as the Provider entry value, under the PaymentSettings entry of appsettings.json file.

2. Create a class that implements the IPaymentResponse interface. This class will be responsible for converting the response received from the new payment provider's API into a common response format defined by the domain.

3. Register the new payment provider in the PaymentProviderFactoryExtension class. Open the Web -> Payment.Api -> Extensions -> PaymentProviderFactoryExtension.cs file and add the registration for the new provider in the AddPaymentProviderFactory method.

4. Update the appsettings.json file with the necessary settings for the new payment provider. Add the required configuration under the PaymentSettings section.

Example configuration for a new payment provider in the appsettings.json file:

{
  "PaymentSettings": {
    "Provider": "new-payment-provider-name",
    "NewPaymentProviderSettings": {
      "ApiKey": "your-api-key",
      "OtherSettings": "other-values"
    }
  }
}

Make sure to replace "your-api-key" and "OtherSettings" with the actual values and settings required for the new payment provider.

Thank You! 🙏