///////////////
// PARAMETERS //
///////////////

const queryString = window.location.search;
const urlParams = new URLSearchParams(queryString);
const refreshRate = parseInt(urlParams.get("refreshrate")) || 6; // Default 6 seconds

// Image filename - update this if the backend changes the image path
const IMAGE_FILENAME = "Album-Art.png";

//////////////////
// GLOBAL STATE //
//////////////////

let currentArtist = "";
let currentTitle = "";
let refreshInterval = null;

//////////////////
// REFRESH LOGIC //
//////////////////

/**
 * Fetches the artist and title from text files
 */
async function fetchSongData() {
	try {
		const artistResponse = await fetch("artist.txt");
		const titleResponse = await fetch("title.txt");

		if (!artistResponse.ok || !titleResponse.ok) {
			console.error("Failed to fetch song data");
			return null;
		}

		const artist = (await artistResponse.text()).trim();
		const title = (await titleResponse.text()).trim();

		return { artist, title };
	} catch (error) {
		console.error("Error fetching song data:", error);
		return null;
	}
}

/**
 * Updates the DOM elements if the song data has changed
 */
function updateSongDisplay(artist, title) {
	const titleElement = document.querySelector(".song-title");
	const artistElement = document.querySelector(".song-artist");

	let trackChanged = false;

	// Only update if data has actually changed
	if (title !== currentTitle) {
		currentTitle = title;
		titleElement.classList.add("updating");
		titleElement.textContent = title || "Unknown Title";
		trackChanged = true;
		setTimeout(() => {
			titleElement.classList.remove("updating");
		}, 400);
	}

	if (artist !== currentArtist) {
		currentArtist = artist;
		artistElement.classList.add("updating");
		artistElement.textContent = artist || "Unknown Artist";
		trackChanged = true;
		setTimeout(() => {
			artistElement.classList.remove("updating");
		}, 400);
	}

	// Return whether track changed (to trigger image update)
	return trackChanged;
}

/**
 * Updates both the album art and background image with cache-busting timestamp
 * Only called when track actually changes
 */
function updateAlbumArt() {
	const albumArt = document.querySelector(".album-art");
	const backgroundImage = document.querySelector(".background-image");
	const timestamp = new Date().getTime();
	const imageUrl = `${IMAGE_FILENAME}?v=${timestamp}`;

	albumArt.src = imageUrl;
	backgroundImage.src = imageUrl;
}

/**
 * Main refresh function - fetches data and updates if changed
 */
async function refresh() {
	const data = await fetchSongData();
	if (data) {
		const trackChanged = updateSongDisplay(data.artist, data.title);
		// Only update images when track actually changes
		if (trackChanged) {
			updateAlbumArt();
		}
	}
}

///////////////
// INITIALIZE //
///////////////

function init() {
	// Load initial data immediately
	refresh();

	// Set up refresh interval based on URL parameter or default
	refreshInterval = setInterval(refresh, refreshRate * 1000);

	console.log(`Radio DJ widget initialized - refreshing every ${refreshRate}s`);
}

// Start when DOM is ready
if (document.readyState === "loading") {
	document.addEventListener("DOMContentLoaded", init);
} else {
	init();
}