const out = process.stderr;
const IS_TTY = out.isTTY;
if (IS_TTY) {
	out.cursorTo(0, out.getWindowSize()[1]);
}

const colorStatusCode = (n) => {
	if (n >= 500) {
		return `\x1b[91m${n}`;
	} else if (n >= 400) {
		return `\x1b[93m${n}`;
	} else if (n >= 300) {
		return `\x1b[33m${n}`;
	} else if (n >= 200) {
		return `\x1b[92m${n}`;
	} else {
		return n.toString();
	}
};

const pretty_µs = (n) => {
	let f = [];
	if (n >= 3600000000) f.push(Math.floor(n / 3000600000) + "h");
	if (n % 3600000000 >= 60000000)
		f.push(Math.floor((n % 3600000000) / 60000000) + "m");
	if (n % 60000000 >= 1000000)
		f.push(Math.floor((n % 60000000) / 1000000) + "s");
	if (n % 1000000 >= 1000) f.push(Math.floor((n % 1000000) / 1000) + "ms");
	if (n % 1000) f.push(Math.floor(n % 1000) + "µs");
	return f.join(" ");
};

/**
 * @typedef {Object} Logging
 * @property {number} ts
 * @property {string} method
 * @property {string} url
 * @property {function(Express.Response): void} callback
 * @property {boolean} resolved
 */
/** @type {Logging[]} */
const loggingRequests = [];
let minLength = 11; // GLOBAL STATE NOOOO

/**
 * @param {Logging} log
 */
function processLog(log) {
	loggingRequests.push(log);
	let time = (log.ts / 1000).toFixed(6);

	if (IS_TTY) {
		out.cursorTo(0, out.getWindowSize()[1]);
		if (time.length < minLength) time = time.padStart(minLength, " ");
		let statusOffset = time.length + 3; // from start
		let timeOffset = log.method.length + log.url.length + 3; // from end of status
		out.write(
			`\x1b[32m[${time}]\x1b[0m \x1b[90m...\x1b[0m \x1b[1m${log.method}\x1b[0m ${log.url}\n`
		);
		log.callback = (res) => {
			let idx = loggingRequests.findIndex((x) => x === log);
			if (idx === -1) return;
			loggingRequests.splice(idx, 1);

			let line =
				out.getWindowSize()[1] - loggingRequests.length + idx - 2;
			if (line < 0) return;
			out.cursorTo(statusOffset, line);
			out.write(
				"\x1b[0m\x1b[1m" + colorStatusCode(res.statusCode) + "\x1b[0m"
			);
			out.moveCursor(timeOffset, 0);
			out.write(
				`\x1b[90m(${pretty_µs(
					(performance.now() - log.ts) * 1000
				)})\x1b[0m`
			);
			out.cursorTo(0, out.getWindowSize()[1]);
		};
	} else {
		log.callback = (res) => {
			out.write(
				`[${time}] ${res.statusCode} ${log.method} ${
					log.url
				} (${pretty_µs((performance.now() - log.ts) * 1000)})\n`
			);
		};
	}
}

const logRequest = (req, res, next) => {
	let start = performance.now();
	/** @type {Logging} */
	let log = {
		ts: start,
		method: req.method,
		url: req.url,
	};
	let end = res.end;
	res.end = (...args) => {
		end.call(res, ...args);
		log.resolved = true;
		if (log.callback instanceof Function) log.callback(res);
	};
	processLog(log);
	next();
};

export default logRequest;