import { readFile } from "node:fs/promises";
import { basename } from "node:path";
import {
	RPCClient,
	ActivityStatus,
	ActivityType,
	DisplayType,
} from "@monicode/discord-rpc";

let client;
let config;
let lastArtUrl = null;
let lastData = null;
let intentionallyClosed = false;
let reconnectTimer = null;

// Cache: local file path → { url, uploadedAt }
const artCache = new Map();
const CACHE_TTL_MS = 50 * 60 * 1000; // 50 minutes (uploads expire at 60min)

function getCachedArtUrl(artUrl) {
	if (!artUrl || !artUrl.startsWith("file://")) return artUrl;
	const filePath = new URL(artUrl).pathname;
	const cached = artCache.get(filePath);
	if (cached && Date.now() - cached.uploadedAt < CACHE_TTL_MS) {
		return cached.url;
	}
	return null;
}

async function uploadArt(artUrl) {
	const filePath = new URL(artUrl).pathname;
	try {
		const fileData = await readFile(filePath);
		let filename = basename(filePath);
		if (!filename.includes(".")) {
			filename += ".png";
		}
		const form = new FormData();
		form.append("file", new Blob([fileData]), filename);

		const res = await fetch("https://tmpfiles.org/api/v1/upload", {
			method: "POST",
			body: form,
		});
		if (!res.ok) {
			console.error(`[discord] tmpfiles.org upload failed: ${res.status}`);
			return null;
		}

		const json = await res.json();
		const url = json.data.url.replace("tmpfiles.org/", "tmpfiles.org/dl/");
		artCache.set(filePath, { url, uploadedAt: Date.now() });
		console.log(`[discord] Uploaded art to ${url}`);
		return url;
	} catch (err) {
		console.error(`[discord] Failed to upload art: ${err.message}`);
		return null;
	}
}

async function connect() {
	client = new RPCClient(config.clientId, false);
	await client.init();
	console.log("[discord] Connected to Discord RPC");
}

function scheduleReconnect(delayMs = 5000) {
	if (intentionallyClosed || reconnectTimer) return;
	console.log(`[discord] Scheduling reconnect in ${delayMs / 1000}s...`);
	reconnectTimer = setTimeout(async () => {
		reconnectTimer = null;
		if (intentionallyClosed) return;
		try {
			await connect();
			console.log("[discord] Reconnected to Discord RPC");
			if (lastData) {
				await onData(lastData);
			}
		} catch (err) {
			console.error(`[discord] Reconnect failed: ${err.message}`);
			scheduleReconnect(Math.min(delayMs * 2, 60000));
		}
	}, delayMs);
}

export async function init(cfg) {
	if (!cfg || !cfg.clientId) {
		throw new Error("Missing config/discord.json (needs clientId)");
	}
	config = cfg;
	intentionallyClosed = false;

	await connect();
}

export async function onData(data) {
	if (!client) return;
	lastData = data;

	const artistString = data.artists.map((a) => a.artistName).join(", ");
	const paused = data.playbackStatus !== "Playing";

	function buildActivity(imageUrl, forceNoTimestamps = false) {
		const activity = new ActivityStatus(
			config.name ?? "Music",
			ActivityType.LISTENING,
		);
		activity.setDetails(data.trackName);
		activity.setState(paused ? "Paused" : `by ${artistString}`);
		activity.setStatusDisplayType(DisplayType.DETAILS);

		if (!paused && !forceNoTimestamps) {
			const endMs = new Date(data.expiry).getTime();
			const startMs = endMs - data.duration * 1000;
			activity.setTimestamps({
				start: Math.floor(startMs / 1000),
				end: Math.floor(endMs / 1000),
			});
		}

		const largeImage = imageUrl || config.largeImage || undefined;
		if (largeImage) {
			activity.setAssets({
				large_image: largeImage,
				large_text: data.releaseName || undefined,
			});
		}

		if (config.buttons?.length) {
			activity.setButtons(config.buttons);
		}
		return activity;
	}

	// Use cached URL if available, otherwise fallback
	const artUrl = data.artUrl || lastArtUrl;
	const cachedUrl = getCachedArtUrl(artUrl);

	// On seek, send a completely different activity so Discord resets timestamps
	if (data.seeked && !paused) {
		try {
			client.setActivity(
				new ActivityStatus("Idle", ActivityType.LISTENING),
			);
		} catch {
			// ignore
		}
		await new Promise((r) => setTimeout(r, 250));
	}

	try {
		client.setActivity(buildActivity(cachedUrl, false));
	} catch (err) {
		console.error(`[discord] Failed to set activity: ${err.message}`);
		client = null;
		scheduleReconnect();
		return;
	}

	// If artUrl is a local file and wasn't cached, upload in background and update
	if (artUrl?.startsWith("file://") && !cachedUrl) {
		uploadArt(artUrl).then((url) => {
			if (url && client) {
				try {
					client.setActivity(buildActivity(url, false));
				} catch {
					// ignore
				}
			}
		});
	}

	if (data.artUrl) lastArtUrl = data.artUrl;
}

export function onClear() {
	intentionallyClosed = true;
	lastData = null;
	if (reconnectTimer) {
		clearTimeout(reconnectTimer);
		reconnectTimer = null;
	}
	if (!client) return;
	try {
		client.close();
		console.log("[discord] Cleared activity (player gone)");
	} catch {
		// ignore
	}
	client = null;
}