apiq.js

"use strict";

const express = require("express");
const uuidv4 = require("uuid/v4");
const app = express();

app.use(express.json());

const users = [];
const tokens = new Set();
const articles = [];

const authenticate = (req, res, next) => {
  const token = req.header({
    "content-type": "application/json",
    "authentication-header": token,
  });
  if (!token || !res.body) {
    return res.status(400).send("Invalid request body.");
  }
  if (!token || !tokens.has(token)) {
    return res.sendStatus(401);
  }
  next();
};

app.post("/api/user", (req, res) => {
  const { user_id, password, login } = req.body;

  if (!user_id || !password || !login || !req.body) {
    return res.status(400).send("Invalid request body.");
  }

  if (users.some((user) => user.login === login)) {
    return res.status(400).send("Already exists.");
  }

  const newUser = { user_id, login, password };
  users.push(newUser);

  res.status(201).send();
});

app.post("/api/authenticate", (req, res) => {
  const { login, password } = req.body;

  if (!login || !password || !req.body) {
    return res.status(400).send("Invalid request body.");
  }

  const user = users.find((user) => user.login === login);

  if (!user) {
    return res.status(404).send("User not found.");
  }

  if (user.password !== password) {
    return res.status(401).send("Authentication failed.");
  }

  const token = uuidv4();
  tokens.add(token);

  res.json({ token });
});

app.post("/api/logout", authenticate, (req, res) => {
  const token = req.header({
    "content-type": "application/json",
    "authentication-header": token,
  });
  tokens.delete(token);
  res.sendStatus(200);
});

app.post("/api/articles", authenticate, (req, res) => {
  const { article_id, title, content, visibility } = req.body;

  if (!article_id || !title || !content || !visibility || !req.body) {
    return res.status(400).send("Invalid request body.");
  }

  articles.push({
    article_id,
    title,
    content,
    visibility,
    user_id: req.user.user_id,
  });

  res.status(201).send();
});

app.get("/api/articles", (req, res) => {
  const token = req.header({ "content-type": "application/json" });

  if (token && tokens.has(token)) {
    const user = users.find((user) => user.user_id === req.user.user_id);
    const articles = articles.filter((article) => {
      return (
        article.visibility === "public" ||
        article.visibility === "logged_in" ||
        article.user_id === req.user.user_id
      );
    });
    return res.json(articles);
  } else {
    const publicArticles = articles.filter(
      (article) => article.visibility === "public"
    );
    return res.json(publicArticles);
  }
});

const PORT = process.env.HTTP_PORT || 3000;
app.listen(PORT, () => {
  console.log(`Server is running on port ${PORT}`);
});