NBP Currency App

Web application to view and analyze currency exchange rates using the NBP (National Bank of Poland) public API.
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About NBP Currency App

✨ Features

• ✅ Display the current exchange rates fetched from the NBP API
• ✅ View currency details and historical exchange rates
• ✅ Interactive charts showing currency rate changes over the last 30 days
• ✅ Date range picker for custom time period analysis
• ✅ Currency converter between PLN and other currencies
• ✅ Server and client-side conversion with live data

🔧 Improvements / Future Enhancements

This section outlines potential improvements that could be implemented in the project to enhance its functionality, performance, and maintainability:

• Improve API Error Handling: Enhance error handling in terms of UX/UI to give users a clearer understanding when issues occur.
• Skeleton Loading State: Add skeletons or loading indicators when fetching data to improve the user experience.
• Leverage Streaming More: Increase the use of streaming for data fetching, as currently some parts of the content are blocked while waiting for data.
• Separate Fetchers into Files: Move data fetching logic into separate files to adhere to better code organization and separation of concerns.
• Testing: Introduce at least unit tests to ensure code quality and reliability.
• API Rate Limiting: Implement mechanisms to prevent users from spamming the API with too many requests.
• Husky for Pre-Commit Hooks: Use Husky to run linting and Prettier checks on each commit to maintain code style and quality automatically.
• Reusable Components: Add more reusable components (e.g., buttons) to improve maintainability and consistency across the app.

🛠️ Built with

• Next.js (App Router)
• React (with TypeScript)
• Tailwind CSS for styling
• Recharts for interactive charts
• Zod for form validation
• ESLint and Prettier for code formatting

🚀 Getting Started

Prerequisites

• Node.js and Bun

npm install -g bun

Installation

1. Clone the repository

git clone https://github.com/rawic/nbp-currency-app.git

2. Navigate to the project directory

cd nbp-currency-app

3. Install dependencies

bun install

4. Create a .env.local file in the root directory and add the following environment variables:

NEXT_PUBLIC_NBP_API_URL=https://api.nbp.pl/api/
NEXT_PUBLIC_NBP_CURRENCY_MIN_DATE=2002-01-02
NEXT_PUBLIC_NBP_CURRENCY_MAX_DATE_RANGE_DIFFERENCE=93

Usage

To start the development server:

bun run dev

To build the app for production:

bun run build

Features Breakdown

• List of Currencies: View all available currencies and their current average exchange rates.
• Currency Details: Click on a currency to view detailed historical exchange rates and an interactive chart.
• Date Range Selector: Select a custom date range to see how a currency's exchange rate has fluctuated.
• Currency Converter: Convert amounts between PLN and selected currencies using live exchange rates. The conversion can be done on both the client-side and server-side.

License

Distributed under the MIT License. See LICENSE for more information.

Contact

Rafał Wichowski - @rafalwichowski - [email protected]

Project Link: https://github.com/rawic/nbp-currency-app