let pauseStartTime = null;
let endpoint = null;
let artworkEndpoint = null;
let token = null;
let intervalId = null;
let lastSentArtworkKey = null;

const defaultArtwork = "https://placehold.co/150/1E1F22/FFF?text=Nothing%20playing";
const pausedTimeout = 300000; // 5 minutes
const metadataFetchInterval = 1000; // 1 second

// Cache for artwork base64 by URL
const artworkBase64Cache = {
	lastArtworkUrl: null,
	lastArtworkBase64: null
};

async function imageUrlToBase64(url) {
	try {
		const response = await fetch(url);
		const blob = await response.blob();
		return await new Promise((resolve, reject) => {
			const reader = new FileReader();
			reader.onloadend = () => resolve(reader.result);
			reader.onerror = reject;
			reader.readAsDataURL(blob);
		});
	} catch (e) {
		console.error("Failed to fetch and convert image:", e);
		return null;
	}
}

async function getNowPlayingData() {
	const audio = document.querySelector('audio#apple-music-player');

	// From PreMiD Apple Music Presence
	const video = document.querySelector('apple-music-video-player')?.shadowRoot
		?.querySelector('amp-window-takeover > .container > amp-video-player-internal')?.shadowRoot
		?.querySelector('amp-video-player')?.shadowRoot
		?.querySelector('div#video-container > video#apple-music-video-player');

	const media = video || audio;
	const timestampInput = document.querySelector('amp-lcd.lcd.lcd__music')?.shadowRoot
		?.querySelector('input#playback-progress[aria-valuenow][aria-valuemax]');

	if (!artworkBase64Cache.defaultArtworkBase64) {
		artworkBase64Cache.defaultArtworkBase64 = await imageUrlToBase64(defaultArtwork);
	}
	const defaultArtworkBase64 = artworkBase64Cache.defaultArtworkBase64;

	if (!media) {
		pauseStartTime = null;
		return {
			details: "Nothing playing",
			state: "",
			paused: true,
			artworkBase64: defaultArtworkBase64
		};
	}

	const paused = media.paused || media.readyState <= 2;
	const metadata = navigator.mediaSession?.metadata || {};
	const title = metadata.title || media.title || "Unknown Title";
	const artist = metadata.artist || "Unknown Artist";
	const album = metadata.album || "Unknown Album";
	const artworkSrc = Array.isArray(metadata.artwork) && metadata.artwork[0]?.src
		? metadata.artwork[0].src
		: null;

	let artworkBase64 = null;
	const largeImageKey = artworkSrc?.replace(/\d+x\d+[a-z]*/i, '150x150bb'); // More robust for Apple Music artwork URLs

	if (largeImageKey) {
		if (artworkBase64Cache.lastArtworkUrl !== largeImageKey) {
			artworkBase64 = await imageUrlToBase64(largeImageKey);
			artworkBase64Cache.lastArtworkUrl = largeImageKey;
			artworkBase64Cache.lastArtworkBase64 = artworkBase64;
		} else {
			artworkBase64 = artworkBase64Cache.lastArtworkBase64;
		}
	}

	if (paused) {
		pauseStartTime ??= Date.now();
		if (Date.now() - pauseStartTime >= pausedTimeout) {
			return {
				details: "Nothing playing",
				state: "",
				paused: true,
				artworkBase64: defaultArtworkBase64
			};
		}
	} else {
		pauseStartTime = null;
	}

	const currentTime = timestampInput ? Number(timestampInput.getAttribute('aria-valuenow')) : media.currentTime || 0;
	const duration = timestampInput ? Number(timestampInput.getAttribute('aria-valuemax')) : media.duration || 0;
	const nowUnix = Math.floor(Date.now() / metadataFetchInterval);

	return {
		details: title,
		state: artist,
		album,
		paused,
		currentTime,
		startTimestamp: nowUnix - Math.floor(currentTime),
		endTimestamp: nowUnix + Math.floor(Math.max(0, duration - currentTime)),
		duration,
		artworkBase64
	};
}

async function sendNowPlaying() {
	if (!endpoint || !token) {
		console.warn("Endpoint or token not loaded.");
		return;
	}

	const data = await getNowPlayingData();
	if (!data) return;

	const { artworkBase64, details, state, ...noArtData } = data;


	try {
		await fetch(endpoint, {
			method: 'POST',
			headers: {
				'Content-Type': 'application/json',
				'Authorization': `Bearer ${token}`
			},
			body: JSON.stringify({ ...noArtData, details, state })
		});
		console.log('Now playing data sent:', details, '-', state);
	} catch (e) {
		console.error('Failed to send now playing:', e);
	}

	// Only send artwork when song changes
	const currentTrackKey = `${details} - ${state}`;
	if (artworkEndpoint && artworkBase64 && currentTrackKey !== lastSentArtworkKey) {
		try {
			await fetch(artworkEndpoint, {
				method: 'POST',
				headers: {
					'Content-Type': 'application/json',
					'Authorization': `Bearer ${token}`
				},
				body: JSON.stringify({
					image: artworkBase64
				})
			});
			lastSentArtworkKey = currentTrackKey;
			console.log('Artwork sent for:', currentTrackKey);
		} catch (e) {
			console.error('Failed to send artwork:', e);
		}
	}
}

function safeCall(fn) {
	try {
		fn().catch(e => {
			if (e.message?.includes("Extension context invalidated")) {
				console.warn("Extension context invalidated, clearing interval.");
				clearInterval(intervalId);
			} else {
				console.error("Unexpected async error:", e);
			}
		});
	} catch (e) {
		console.error("Unexpected sync error:", e);
	}
}
function startNowPlayingLoop() {
	if (!window._nowPlayingIntervalSet) {
		window._nowPlayingIntervalSet = true;
		intervalId = setInterval(() => safeCall(sendNowPlaying), metadataFetchInterval);
	}
}

if (!window._nowPlayingExtensionLogged) {
	console.log('Apple Music Now Playing Extension made by Sophia Atkinson with help from PreMiD contributors');
	window._nowPlayingExtensionLogged = true;
}

if (chrome?.storage?.sync) {
	chrome.storage.sync.get(['endpoint', 'artworkEndpoint', 'token'], result => {
		if (chrome.runtime.lastError) {
			console.error("Failed to load settings:", chrome.runtime.lastError.message);
			return;
		}
		({ endpoint, artworkEndpoint, token } = result);

		if (!endpoint || !token) {
			console.error("No endpoint/token configured.");
			return;
		}

		startNowPlayingLoop();
	});
} else {
	console.warn("Chrome extension APIs are not available. Please run this script as a Chrome extension.");
}
let lastUrl = location.href;

new MutationObserver(() => {
	if (location.href !== lastUrl) {
		console.log('[NowPlaying] Route change detected.');
		lastUrl = location.href;

		clearInterval(intervalId);
		window._nowPlayingIntervalSet = false;

		setTimeout(() => {
			if (!window._nowPlayingIntervalSet) startNowPlayingLoop();
		}, metadataFetchInterval);
	}
}).observe(document, { subtree: true, childList: true });