server.js

const http = require('http');
const path = require('path');
const fs = require('fs');
const fsPromises = require('fs').promises;

const logEvents = require('./logEvents');
const EventEmitter = require('events');

class Emitter extends EventEmitter { };

const myEmitter = new Emitter();

//myEmitter.on('log', (msg) => logEvents(msg));
/*setTimeout(() => {
    myEmitter.emit('log', "Log event emitted!");
}, 2000);*/

/*
switch (req.url) {
    case '/':
        res.statusCode = 200;
        path = path.join(__dirname, "views", "index.html");
        fs.readFile(path, "utf8", (err, data) => {
            res.end(data);
        });
        break;
}
*/
myEmitter.on("log", (msg, fileName) => logEvents(msg, fileName));

const PORT = process.env.PORT || 3500;

const serveFile = async (filePath, contentType, response) => {
    try {
        const rawData = await fsPromises.readFile(
            filePath,
            !contentType.includes("image") ? "utf8" : ""
        );
        const data = contentType === "application/json" 
        ? JSON.parse(rawData) : rawData;
        response.writeHead(
            filePath.includes("404.html") ? 400 : 200, {"Content-Type": contentType});
        response.end(
            contentType === "application/json" ? JSON.stringify(data) : data
        );
    } catch (err) {
        console.log(err);
        myEmitter.emit("log", `${err.name}\t${err.message}`, "errLog.txt");
        response.statusCode = 500;
        response.end();
    }
}

const server = http.createServer((req, res) => {
    console.log(req.url, req.method);
    myEmitter.emit("log", `${req.url}\t${req.method}`, "reqLog.txt");

    const extension = path.extname(req.url);

    let contentType;

    switch (extension) {
        case ".css":
            contentType = "text/css";
            break;
        case ".js":
            contentType = "text/javascript";
            break;
        case ".json":
            contentType = "application/json";
            break;
        case ".jpeg":
            contentType = "image/jpeg";
            break;
        case ".png":
            contentType = "image/png";
            break;
        case ".txt":
            contentType = "text/plain";
            break;
        default:
            contentType = "text/html";
    }

    let filePath = 
        contentType === "text/html" && req.url === "/"
           ? path.join(__dirname, "views", "index.html")
           : contentType === "text/html" && req.url.slice(-1) === "/"
              ? path.join(__dirname, "views", "index.html")
              : contentType === "text/html"
                 ? path.join(__dirname, "views", req.url)
                 : path.join(__dirname, req.url);


    // makes .html extension not required in the browser
    if (!extension && req.url.slice(-1) !== "/") filePath += ".html";

    const fileExists = fs.existsSync(filePath);

    if(fileExists) {
        serveFile(filePath, contentType, res);
    } else {
        // 404
        // 301 redirect
        switch(path.parse(filePath).base) {
            case "old-page.html":
                res.writeHead(301, {"location": "/new-page.html"});
                res.end();
                break;
            case "www-page.html":
                res.writeHead(301, {"location": "/"});
                res.end();
                break;
            default:
                serveFile(path.join(__dirname, "views", "404.html"), "text/html", res);
        }
    }
   
});

server.listen(PORT, () => console.log(`Server running on port ${PORT}`));