Implement API Polling for Real-time Updates

/**
 * Starts polling an API endpoint at a specified interval.
 * @param {string} url - The API endpoint URL to poll.
 * @param {function(data: object): void} callback - Callback function to handle fetched data.
 * @param {number} interval - Polling interval in milliseconds.
 * @param {object} [options={}] - Fetch options for the API call.
 * @returns {{ stop: () => void, start: () => void }} An object with stop and start functions.
 */
function createApiPoller(url, callback, interval = 5000, options = {}) {
    let timerId = null;
    let isActive = false;

    const fetchData = async () => {
        try {
            const response = await fetch(url, options);
            if (!response.ok) {
                throw new Error(`HTTP error! status: ${response.status}`);
            }
            const data = await response.json();
            callback(data);
        } catch (error) {
            console.error('API polling error:', error);
            // Optionally, implement error handling or stop polling on persistent errors
            // stop();
        } finally {
            if (isActive) {
                timerId = setTimeout(fetchData, interval);
            }
        }
    };

    const start = () => {
        if (!isActive) {
            isActive = true;
            console.log(`Starting API polling for ${url} every ${interval}ms.`);
            // Fetch immediately on start, then start interval
            fetchData();
        }
    };

    const stop = () => {
        if (isActive) {
            isActive = false;
            clearTimeout(timerId);
            console.log(`Stopped API polling for ${url}.`);
        }
    };

    return { start, stop };
}

// Example usage:
// const statusPoller = createApiPoller(
//     'https://api.example.com/status',
//     (data) => {
//         console.log('Current status:', data);
//         document.getElementById('status-display').textContent = JSON.stringify(data, null, 2);
//     },
//     3000 // Poll every 3 seconds
// );

// // Start polling
// statusPoller.start();

// // Stop polling after some time (e.g., 30 seconds)
// // setTimeout(() => {
// //     statusPoller.stop();
// // }, 30000);