index.js

const express = require("express");
const fs = require("fs");
const path = require("path");
const promisify = require("util.promisify");
const crypto = require("crypto");

const readFile = promisify(fs.readFile);
const writeFile = promisify(fs.writeFile);
const readDir = promisify(fs.readdir);
const unlink = promisify(fs.unlink);

console.log("Arguments", process.argv);

const app = express();

const getExistingFilesNames = async (files) => {
  const ret = [];
  for (let i = 0; i < files.length; ++i) {
    const file = await readFile(path.join(__dirname, "uploads", files[i]));
    const data = JSON.parse(file);

    ret.push(data.name + (data.pass ? "*" : ""));
  }

  return ret;
};
const getFileDiskName = (userName) => {
  const hasher = crypto.createHash("whirlpool");

  return hasher.update(userName).digest("hex");
};

{
  // loggers
  // log API request
  app.use((req, res, next) => {
    console.log("Request method", req.method, "received for", req.path);

    next();
  });
  // log empty file request(additional)
  app.get("/file", (req, res, next) => {
    console.log("Empty file requested");

    next();
  });
}

app.get("/file", async (req, res) => {
  const files = await readDir(path.join(__dirname, "uploads"));
  const names = await getExistingFilesNames(files);

  return res.json(names);
});

app.put("/file/:name/:content?", async (req, res) => {
  const hash = getFileDiskName(req.params.name);
  const obj = JSON.stringify({
    name: req.params.name,
    hash,
    content: req.params.content,
    pass: undefined,
  });

  try {
    await writeFile(path.join(__dirname, "uploads", `${hash}.txt`), obj);

    return res.send(req.params.content);
  } catch (error) {
    res.status(500);
    res.send(error.message);
  }
});

app.delete("/file/:name", async (req, res, next) => {
  const hash = getFileDiskName(req.params.name);
  const fileName = path.join(__dirname, "uploads", `${hash}.txt`);
  let content;
  try {
    content = JSON.parse(await readFile(fileName));
  } catch (err) {
    return res.status(403).send("File not found");
  }

  try {
    if (content.pass && req.query.pass === content.pass) {
      await unlink(fileName);
      return res.send(true);
    } else {
      if (!content.pass) {
        await unlink(fileName);
        return res.send(true);
      }
      res.status(403).send("File is Protected");
    }
  } catch (err) {
    res.status(500).send(err.message);
  }
});

app.post("/file/:name", async (req, res) => {
  const hash = getFileDiskName(req.params.name);
  const fileName = path.join(__dirname, "uploads", `${hash}.txt`);

  try {
    const content = JSON.parse(await readFile(fileName));
    if (content.pass && req.query.pass !== content.pass) {
      return res.status(403).send("File is Protected");
    }

    content.pass = req.query.pass;

    await writeFile(fileName, JSON.stringify(content));
    res.status(200).send("Password set");
  } catch (err) {
    res.status(500);
    res.send(err.message);
  }
});

app.get("/file/:name", async (req, res) => {
  const hash = getFileDiskName(req.params.name);
  const fileName = path.join(__dirname, "uploads", `${hash}.txt`);

  try {
    const content = JSON.parse(await readFile(fileName));
    if (content.pass && req.query.pass === content.pass) {
      return res.send(content.content);
    } else {
      if (!content.pass) {
        return res.send(content.content);
      }
      res.status(403).send("File is Protected");
    }
  } catch (err) {
    if (err.code === "ENOENT") {
      res.status(404).send("File not found");

      return;
    }

    res.status(500);
    res.send(err.message);
  }
});

app.listen(2000, () => {
  console.log("App is listening on", 2000);
});