Subway System Challenge

This project implements a RESTful API for a subway system, addressing two main challenges: route planning and fare management.

Prerequisites

• Node.js (v14+)
• Docker and Docker Compose

Quick Start

1. Clone the repository:

   git clone https://github.com/emad-siddiq/subway-system.git
   cd subway-system
   

2. Build and start the application using Docker:

   docker-compose up --build
   

   This will start both the backend service and the PostgreSQL database.

3. The server will be running on http://localhost:3000

Development Mode

To run the application in development mode:

NODE_ENV=development docker-compose up

This will start the application using ts-node-dev, which will watch for file changes and automatically restart the server.

Testing

Run tests:

npm test

Uninstall

To stop the application and remove the containers, volumes, and images:

docker-compose down -v --rmi all

Project Structure

.
├── src/
│   ├── controllers/
│   ├── db/
│   ├── models/
│   ├── routes/
│   ├── utils/
│   └── server.ts
├── docker-compose.yml
├── Dockerfile
├── package.json
├── tsconfig.json
└── README.md

Environment Variables

The application uses the following environment variables:

• NODE_ENV: Set to 'development' or 'production'
• DB_HOST: Database host (default: 'db')
• DB_USER: Database user (default: 'user')
• DB_PASSWORD: Database password (default: 'password')
• DB_NAME: Database name (default: 'subway_system')
• DB_NAME_TEST: Test database name (default: 'subway_system_test')
• DB_PORT: Database port (default: 5432)
• DB_PORT_TEST: Test database port (default: 5433)

These can be set in the docker-compose.yml file or as environment variables when running the application.

Endpoints

Subway System API

1. Create a Train Line

• POST /train-line
• Body:

  {
    "name": string,
    "stations": string[],
    "fare": number (optional)
  }

• Example:

  curl -X POST http://localhost:3000/train-line \
    -H "Content-Type: application/json" \
    -d '{"name": "1", "stations": ["Canal", "Houston", "Christopher", "14th"]}'

2. Get Optimal Route

• GET /route
• Query params: origin (string), destination (string)
• Example:

  curl "http://localhost:3000/route?origin=Houston&destination=23rd"

3. Create or Update Card

• POST /card
• Body:

  {
    "number": string,
    "amount": number
  }

• Example:

  curl -X POST http://localhost:3000/card \
    -H "Content-Type: application/json" \
    -d '{"number": "1234", "amount": 20.00}'

4. Enter Station

• POST /station/{station_name}/enter
• Body:

  {
    "card_number": string
  }

• Example:

  curl -X POST http://localhost:3000/station/Houston/enter \
    -H "Content-Type: application/json" \
    -d '{"card_number": "1234"}'

5. Exit Station

• POST /station/{station_name}/exit
• Body:

  {
    "card_number": string
  }

• Example:

  curl -X POST http://localhost:3000/station/14th/exit \
    -H "Content-Type: application/json" \
    -d '{"card_number": "1234"}'

Note: The server is assumed to be running on http://localhost:3000. Adjust the URL in the examples if your server is running on a different address or port.

Implementation Details

• Language: TypeScript
• Database: PostgreSQL
• Containerization: Docker

Creating Standalone Binaries

To create standalone executables for different platforms:

1. Install pkg globally:

   npm install -g pkg
   

2. Build the TypeScript project:

   npm run build
   

3. Generate the binaries:

   pkg . --out-path=./bin
   

This will create standalone executables for Linux, macOS, and Windows in the bin directory. Run the appropriate binary for your system.

Note: When running the standalone binary, you'll need to ensure that a PostgreSQL database is available and the correct environment variables are set for the database connection.