📱 Engdigo (English Learning Application) with NestJS Backend and React Native Frontend

This project is composed of:

• backend/: A NestJS-based REST API server and C# ASP.NET framework.
• mobile/: A mobile application built with React Native using Expo.

This guide walks you through setting up and running both components of the project.

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📦 Prerequisites

Make sure you have the following installed:

• Node.js (LTS version recommended)
• npm
• Docker & Docker Compose
• ngrok
• Expo CLI: Install via npm install -g expo-cli
• (Optional) Android Studio or a physical device with the Expo Go app

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🔧 Backend Setup (NestJS)

You can run the backend using Docker (recommended) or install and run it manually.

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🛠 Option 1: Run with Docker (Recommended)

1. Install Docker

   • macOS: https://docs.docker.com/docker-for-mac/install/
   • Windows: https://docs.docker.com/docker-for-windows/install/
   • Linux: Use your package manager (e.g., sudo apt install docker.io)

2. Create a .env file in the backend/ directory, here is example:

   DOCKER_HUB_USERNAME=your_dockerhub_username
   DATABASE_HOST=your_database_host
   DATABASE_NAME=your_database_name
   DATABASE_USERNAME=your_database_username
   DATABASE_PASSWORD=your_database_password
   DATABASE_PORT=5432
   AWS_BUCKET_NAME=your_aws_bucket_name
   AWS_REGION=your_aws_region
   AWS_ACCESS_KEY_ID=your_aws_access_key_id
   AWS_SECRET_ACCESS_KEY=your_aws_secret_access_key
   CLOUDFRONT_URL=https://your_cloudfront_url
   CLIENT_URL=http://localhost:8000
   COGNITO_USER_POOL_ID=your_cognito_user_pool_id
   COGNITO_CLIENT_ID=your_cognito_client_id
   COGNITO_CLIENT_SECRET=your_cognito_client_secret
   COGNITO_CLIENT=https://cognito-idp.your_region.amazonaws.com/your_user_pool_id
   COGNITO_DOMAIN=https://your_cognito_domain.auth.your_region.amazoncognito.com
   VNP_RETURN_URL=http://localhost:3000/api/course-buying/payment-return
   VNP_TMN_CODE=your_vnpay_tmn_code
   VNP_HASH_SECRET=your_vnpay_hash_secret
   VNPAY_URL=https://sandbox.vnpayment.vn/paymentv2/vpcpay.html
   
   

   Ensure your Dockerfile and docker-compose.yml are ready.

Build and start the containers:

cd backend
docker-compose up --build

Your backend should now be accessible at http://localhost:3000.

🛠 Option 2: Manual Setup without Docker

Create a .env file in backend/ directory (see example above).

Install dependencies:

cd backend
npm install

Run Nestjs server:

npm start

Go to DiscountService (where include DiscountService.csproj) and run ASP.NET server:

cd backend\src\services\DiscountService
dotnet run

Nest server will start at http://localhost:3000 ASP.NET server will start at http://localhost:5000

📱 Frontend Setup (React Native using Expo)

The mobile app communicates with the backend and can be run on a phone or emulator.

Expose Backend to the Internet using ngrok

Open a new terminal and run:

npx ngrok http 3000

Copy the Forwarding URL, e.g.: https://abcd1234.ngrok.app

In the mobile/ directory, create or update your .env file follow this:

API_URL=https://abcd1234.ngrok.app/api/
ACCESS_TOKEN=your_access_token

Install Mobile App Dependencies

cd mobile
npm install

Run the Mobile App

Option A: Run on Physical Device using Expo Go

Start the Expo server:

cd mobile
npx expo start -c

Press S to start the QR code mode.

Open the Expo Go app on your smartphone and scan the QR code.

Download Expo Go:

• iOS: https://expo.dev/go?sdkVersion=52

• Android: https://expo.dev/go?sdkVersion=52

Option B: Run on Android Emulator

Install Android Studio: Download here https://developer.android.com/studio

Launch Android Studio → AVD Manager → Create & Start Emulator

In your terminal:

cd mobile
npx expo start -c

Press A to launch the app in the Android emulator.

📌 Important Notes

• Ensure the API_URL in mobile/.env matches the ngrok URL.

• Restart ngrok and update the .env file whenever your ngrok URL changes.

🛠 Troubleshooting

Mobile app can't reach backend:

• Ensure ngrok is running and the API_URL is correctly set.

• Make sure CORS is enabled in the backend if needed.

Emulator issues:

• Ensure virtualization is enabled (BIOS).

• Restart Android Studio or your computer.

📬 Contact

For support, reach out to: [ngthachminhthanh@gmail.com]