import * as fs from "node:fs";
import { fileURLToPath } from "node:url";
import { dirname } from "node:path";
import * as os from "node:os";
import cluster from "node:cluster";
import net from "node:net";
import repl from "node:repl";
import chalk from "chalk";
import chalkTemplate from "chalk-template";
import semver from "semver";

import Logger from "@/services/logger.js";
import loadConfig from "@/config/load.js";
import type { Config } from "@/config/types.js";
import { lessThan } from "@/prelude/array.js";
import { envOption } from "../env.js";
import { showMachineInfo } from "@/misc/show-machine-info.js";
import { db, initDb } from "../db/postgre.js";

const _filename = fileURLToPath(import.meta.url);
const _dirname = dirname(_filename);

const meta = JSON.parse(
	fs.readFileSync(`${_dirname}/../../../../built/meta.json`, "utf-8"),
);

const logger = new Logger("core", "cyan");
const bootLogger = logger.createSubLogger("boot", "magenta", false);

const themeColor = chalk.hex("#31748f");

function greet() {
	if (!envOption.quiet) {
		console.log(
			chalkTemplate`--- ${os.hostname()} {gray (PID: ${process.pid.toString()})} ---`,
		);
	}

	bootLogger.info(`Iceshrimp v${meta.version}, initializing...`, null, true);
}

/**
 * Init master process
 */
export async function masterMain() {
	let config!: Config;

	// initialize app
	try {
		greet();
		showEnvironment();
		await showMachineInfo(bootLogger);
		showNodejsVersion();
		config = loadConfigBoot();
		await connectDb();
		if (config.shellAddress !== undefined)
			spawnShell(config.shellAddress);
	} catch (e) {
		bootLogger.error("Fatal error occurred during initialization", null, true);
		bootLogger.error(e);
		process.exit(1);
	}

	bootLogger.succ("Iceshrimp initialized");

	if (!envOption.disableClustering) {
		await spawnWorkers(config.clusterLimit);
	}

	bootLogger.succ(
		`Now listening on port ${config.port} on ${config.url} - using ${config.domain}`,
		null,
		true,
	);

	if (!envOption.noDaemons && !config.onlyQueueProcessor) {
		import("../daemons/server-stats.js").then((x) => x.default());
		import("../daemons/queue-stats.js").then((x) => x.default());
		import("../daemons/janitor.js").then((x) => x.default());
	}
}

function showEnvironment(): void {
	const env = process.env.NODE_ENV;
	const logger = bootLogger.createSubLogger("env");
	logger.info(
		typeof env === "undefined" ? "NODE_ENV is not set" : `NODE_ENV: ${env}`,
	);

	if (env !== "production") {
		logger.warn("The environment is not in production mode.");
		logger.warn("DO NOT USE FOR PRODUCTION PURPOSE!", null, true);
	}
}

function showNodejsVersion(): void {
	const nodejsLogger = bootLogger.createSubLogger("nodejs");

	nodejsLogger.info(`Version ${process.version} detected.`);

	const minVersion = fs
		.readFileSync(`${_dirname}/../../../../.node-version`, "utf-8")
		.trim();
	if (semver.lt(process.version, minVersion)) {
		nodejsLogger.error(`At least Node.js ${minVersion} required!`);
		process.exit(1);
	}
}

function loadConfigBoot(): Config {
	const configLogger = bootLogger.createSubLogger("config");
	let config;

	try {
		config = loadConfig();
	} catch (exception) {
		if (exception.code === "ENOENT") {
			configLogger.error("Configuration file not found", null, true);
			process.exit(1);
		} else if (e instanceof Error) {
			configLogger.error(e.message);
			process.exit(1);
		}
		throw exception;
	}

	configLogger.succ("Loaded");

	return config;
}

async function connectDb(): Promise<void> {
	const dbLogger = bootLogger.createSubLogger("db");

	// Try to connect to DB
	try {
		dbLogger.info("Connecting...");
		await initDb();
		const v = await db
			.query("SHOW server_version")
			.then((x) => x[0].server_version);
		dbLogger.succ(`Connected: v${v}`);
	} catch (e) {
		dbLogger.error("Cannot connect", null, true);
		dbLogger.error(e);
		process.exit(1);
	}
}

async function spawnWorkers(limit = 1) {
	const workers = Math.min(limit, os.cpus().length);
	bootLogger.info(`Starting ${workers} worker${workers === 1 ? "" : "s"}...`);
	await Promise.all([...Array(workers)].map(spawnWorker));
	bootLogger.succ("All workers started");
}

function spawnWorker(): Promise<void> {
	return new Promise((res) => {
		const worker = cluster.fork();
		worker.on("message", (message) => {
			if (message === "listenFailed") {
				bootLogger.error("The server Listen failed due to the previous error.");
				process.exit(1);
			}
			if (message !== "ready") return;
			res();
		});
	});
}

function spawnShell(address: number | string) {
	logger.info(`Spawning debug shell on ${address}`);
	if (typeof address == "string") {
		try {
			fs.unlinkSync(address);
		} catch {}
	}
	net
		.createServer()
		.unref()
		.listen(address)
		.on("connection", (socket) => {
			const r = repl.start({ input: socket, output: socket });
			socket.on("close", () => r.close());
			socket.on("error", () => r.close());
			r.on("close", () => socket.destroy());
			if (!envOption.disableClustering) {
				r.defineCommand("worker", (iid) => {
					r.close();
					const id = parseInt(iid.trim());
					cluster.workers[id].send("debug-shell", socket);
				});
			}
		})
		.on("error", (error) => logger.error(error));
}
