(_ => {
    require("dotenv").config();

    const root_path = process.cwd();
    const express = require("express");
    const errorHandler = require('express-error-handler');
    const path = require("path");
    const http = require("http");
    const middlewares = require(path.join(root_path, "src", "middlewares"));
    const _404 = require(path.join(root_path, "src", "middlewares", "404"));
    const _public = path.join(root_path, "public");
    const _storage = path.join(root_path, "storage", "image");
    const router = require(path.join(root_path, "src", "router"));
    const app = express();

    app.set("view engine", "ejs");
    // app.set("view cache", true);
    app.set("views", path.join(root_path, "resources", "views"));
    app.use(middlewares)
    app.use("/", express.static(_public));
    app.use("/storage/image", express.static(_storage));
    app.use("/", router);
    app.use(_404)
    app.use(errorHandler({
        debug: true,
        log: true,
    }));

    // * 使用內建的 cluster 做管理
    const cluster = require("cluster");
    const os = require("os");
    const cpus = os.cpus().length;

    if (cluster.isMaster && cpus.length > 1) {
        for (let i = 0; i < (cpus - 1); i++) {
            cluster.fork();
        };

        cluster.on("exit", (worker: any, code: any, signal: any) => {
            console.log(`Worker ${worker.process.pid} died with code: ${code}, and signal: ${signal}`);
            console.log('Starting a new worker');
            cluster.fork();
        });

        const signals = ["SIGINT", "SIGTERM", "SIGHUP"];
        signals.forEach(signal => {
            process.on(signal, () => {
                console.log(`Received ${signal}, shutting down master process...`);
                for (const id in cluster.workers) {
                    console.log(`Killing worker ${cluster.workers[id].process.pid}`);
                    cluster.workers[id].kill("SIGTERM");
                }
                process.exit(0);
            });
        });
    } else {
        http.createServer(app).listen(process.env.HOST_PORT, () => {
            console.log(`========== [MODE ${process.env.ENV}] [PORT ${process.env.HOST_PORT}] ==========`);
        });
    };
})();