Dataset Marketplace

A web application marketplace for buying and selling datasets with integrated payment processing (Stripe, Klarna, Nano cryptocurrency).

Project Structure

datasets-exchange/
├── backend/                 # ASP.NET Core Web API
│   ├── src/
│   │   ├── DatasetMarketplace.API/          # API Layer
│   │   ├── DatasetMarketplace.Application/  # Application Layer (Services, DTOs)
│   │   ├── DatasetMarketplace.Domain/       # Domain Layer (Entities, Enums)
│   │   └── DatasetMarketplace.Infrastructure/ # Infrastructure Layer (Database, Repositories)
│   └── tests/
│       ├── DatasetMarketplace.UnitTests/
│       └── DatasetMarketplace.IntegrationTests/
├── frontend/                # Angular 17+ Application
│   └── src/
│       └── app/
│           ├── core/        # Core services, guards, interceptors
│           ├── shared/      # Shared components
│           └── features/    # Feature modules
└── PROJECT_PLAN.md          # Comprehensive project plan

Technology Stack

Backend

• Framework: ASP.NET Core 8.0
• Language: C# (.NET 8)
• Database: PostgreSQL 15+
• ORM: Entity Framework Core 8.0
• Authentication: JWT (JSON Web Tokens)
• API Documentation: Swagger/OpenAPI

Frontend

• Framework: Angular 17+
• Language: TypeScript 5+
• HTTP Client: Angular HttpClient with interceptors
• Forms: Reactive Forms
• Styling: SCSS

Phase 1 Implementation Status

✅ Completed Features:

Backend

• Clean Architecture project structure
• Domain entities (User, Dataset, Transaction, Category, Reviews, etc.)
• Entity Framework Core configuration
• PostgreSQL database configuration
• Repository pattern with Unit of Work
• JWT authentication service
• Auth controller (Register, Login, Password Reset)
• Swagger documentation setup
• CORS configuration for Angular

Frontend

• Angular 17 project with standalone components
• Core services (AuthService, ApiService)
• HTTP interceptors (Auth, Error)
• Route guards (AuthGuard)
• Login component
• Register component
• Marketplace component (placeholder)
• Lazy-loaded feature modules
• Environment configuration

Prerequisites

• .NET 8 SDK - Download
• Node.js 18+ and npm - Download
• PostgreSQL 15+ - Download
• Angular CLI - npm install -g @angular/cli

Setup Instructions

1. Database Setup

Create a PostgreSQL database:

CREATE DATABASE dataset_marketplace;

2. Backend Setup

Navigate to the backend API project:

cd backend/src/DatasetMarketplace.API

Update the connection string in appsettings.json:

{
  "ConnectionStrings": {
    "DefaultConnection": "Host=localhost;Port=5432;Database=dataset_marketplace;Username=your_username;Password=your_password"
  }
}

Run database migrations:

dotnet ef migrations add InitialCreate --project ../DatasetMarketplace.Infrastructure
dotnet ef database update

Run the API:

dotnet run

The API will be available at:

• HTTP: http://localhost:5000
• HTTPS: https://localhost:5001
• Swagger UI: http://localhost:5000/swagger

3. Frontend Setup

Navigate to the frontend directory:

cd frontend

Install dependencies:

npm install

Update the API URL in src/environments/environment.ts if needed:

export const environment = {
  production: false,
  apiUrl: 'http://localhost:5000'
};

Run the Angular development server:

ng serve

The app will be available at http://localhost:4200

API Endpoints

Authentication

Method	Endpoint	Description
POST	/api/auth/register	Register a new user
POST	/api/auth/login	Login with email/password
POST	/api/auth/refresh	Refresh access token
GET	/api/auth/verify-email	Verify email address
POST	/api/auth/forgot-password	Request password reset
POST	/api/auth/reset-password	Reset password

Example Register Request

{
  "email": "[email protected]",
  "password": "SecurePassword123",
  "firstName": "John",
  "lastName": "Doe",
  "userType": 1
}

UserType values:

• 1 = Buyer
• 2 = Seller
• 3 = Both

Testing the Application

Using Swagger UI

1. Navigate to http://localhost:5000/swagger
2. Try the /api/auth/register endpoint to create a user
3. Try the /api/auth/login endpoint to get a JWT token
4. Click "Authorize" and enter: Bearer <your-token>
5. Test protected endpoints

Using the Angular Frontend

1. Navigate to http://localhost:4200
2. Click "Login" or navigate to /auth/register
3. Create an account
4. Login with your credentials
5. You'll be redirected to the marketplace

Database Schema

Core Tables

• Users - User accounts (buyers/sellers)
• Datasets - Dataset listings
• Categories - Dataset categories
• Transactions - Purchase transactions
• DatasetReviews - User reviews and ratings
• DatasetPurchases - Purchase records
• DatasetFiles - Dataset file metadata
• DatasetMetadata - Dataset statistics and schema

Next Steps (Phase 2)

• Dataset upload functionality
• Dataset browsing and search
• Dataset preview generation
• File storage service (S3/Azure Blob)
• Seller dashboard
• Buyer dashboard

Next Steps (Phase 3)

• Stripe payment integration
• Klarna payment integration
• Nano cryptocurrency payment integration
• Transaction management
• Payout system

Development Notes

JWT Configuration

The JWT secret key is configured in appsettings.json. Change this in production!

{
  "JwtSettings": {
    "SecretKey": "YourSuperSecretKeyThatIsAtLeast32CharactersLongForHS256Algorithm",
    "Issuer": "DatasetMarketplace",
    "Audience": "DatasetMarketplaceUsers",
    "ExpiryMinutes": "60"
  }
}

CORS Configuration

The backend is configured to accept requests from http://localhost:4200. Update this in production:

// Program.cs
builder.Services.AddCors(options =>
{
    options.AddPolicy("AllowAngularApp", policy =>
    {
        policy.WithOrigins("https://your-production-domain.com")
              .AllowAnyHeader()
              .AllowAnyMethod()
              .AllowCredentials();
    });
});

Troubleshooting

Database Connection Issues

If you encounter database connection errors:

1. Ensure PostgreSQL is running
2. Verify the connection string in appsettings.json
3. Check that the database exists

CORS Errors

If you see CORS errors in the browser console:

1. Ensure the backend is running
2. Verify the CORS policy in Program.cs
3. Check that the Angular app is running on port 4200

JWT Token Errors

If authentication fails:

1. Check that the JWT secret key is configured
2. Verify the token is being sent in the Authorization header
3. Check token expiration

Contributing

Please refer to the PROJECT_PLAN.md for the complete development roadmap and implementation details.

License

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