index.js

require('dotenv').config();
const express = require('express');
const { fetchStats } = require('./src/fetcher');
const { renderCard } = require('./src/card');

const app = express();
const port = process.env.PORT || 3000;

// In-memory cache with a 1-hour expiration
const cache = new Map();
const CACHE_DURATION_MS = 60 * 60 * 1000; // 1 hour

app.get('/', async (req, res) => {
  const username = req.query.username || 'github';

  try {
    // Check if a valid, non-expired cache entry exists
    if (cache.has(username)) {
      const cachedData = cache.get(username);
      if (Date.now() - cachedData.timestamp < CACHE_DURATION_MS) {
        console.log(`Serving response for '${username}' from cache.`);
        const card = renderCard(cachedData.stats);
        res.setHeader('Content-Type', 'image/svg+xml');
        return res.send(card);
      }
    }

    // If no valid cache, fetch new data
    console.log(`Fetching new data for '${username}'.`);
    const stats = await fetchStats(username);

    // Store the new data and timestamp in the cache
    cache.set(username, { stats, timestamp: Date.now() });

    const card = renderCard(stats);
    res.setHeader('Content-Type', 'image/svg+xml');
    res.send(card);
  } catch (error) {
    res.status(500).send(error.message);
  }
});

app.listen(port, () => {
  console.log(`Server is running on port ${port}`);
});