This is a RESTful API that allows users to record donations to projects and retrieve their total donations converted to a specified currency.

• Token-based authentication using api_token.
• Users can record donations with an amount, currency, and project identifier.
• Users can retrieve their total donations, converted into a specified currency.
• Uses PostgreSQL as the database.
• Runs inside Docker for easy setup and testing.

Then:

cd donation_api

Create a .env file with:

EXCHANGE_RATE_API_KEY=<YOUR_API_KEY>

To get an exchange rate API key, you can follow this link.

Ensure you have Docker installed, then run:

docker-compose up --build

This will:

• Set up PostgreSQL databases (development & test).
• Run the Rails server at http://localhost:3000.

Note: The --build flag is needed only the first time or when dependencies change.

Once the Docker containers are running, run:

docker-compose exec api rails db:create db:migrate db:seed

Run the test suite inside the test container:

docker-compose run --rm test

• Every User has an api_token stored in the database.
• Requests must include an Authorization header with the token.
• Users can only access their own donation data.
• To create a new user with an API token, run:

  docker-compose exec api rake user:create

  This will generate and display a new user ID and API token.

To create donations, a project identifier is necessary. A rake task can be used to create projects in the database:

docker-compose exec api rake project:create[<YOUR_PROJECT_NAME>]

Records a user's donation to a project.

{
  "Authorization": "<API_TOKEN>"
}

{
  "amount": 100,
  "currency": "USD",
  "project_id": 1
}

{
  "donation": {
    "id": 1,
    "amount": 100,
    "currency": "USD",
    "project_id": 1
  }
}

Returns the total donation amount converted to the specified currency.

{
  "Authorization": "<API_TOKEN>"
}

{
  "total_amount": 150,
  "currency": "EUR"
}

{
  "error": "Currency must be ISO 4217."
}

The API supports 161 commonly used world currencies based on the ISO 4217 standard. Some examples:

For the full list of supported currencies, check ISO 4217.

I followed RESTful principles, ensuring a clean separation of concerns:

• Controllers handle API requests.
• Models manage data.
• Services (e.g., CurrencyConverter) handle business logic.

• Implemented token-based authentication (api_token) for user-specific access.
• Users can record donations with an amount, currency, and project ID.

• The CurrencyConverter service fetches real-time exchange rates and converts donations efficiently.
• Optimized the process by only passing necessary data.

• Modular design for easy extension.
• Error handling ensures graceful failures.
• Dockerized for seamless setup and testing.

MIT License