/*
This uses json-server, but with the module approach: https://github.com/typicode/json-server#module
Downside: You can't pass the json-server command line options.
Instead, can override some defaults by passing a config object to jsonServer.defaults();
You have to check the source code to set some items.
Examples:
Validation/Customization: https://github.com/typicode/json-server/issues/266
Delay: https://github.com/typicode/json-server/issues/534
ID: https://github.com/typicode/json-server/issues/613#issuecomment-325393041
Relevant source code: https://github.com/typicode/json-server/blob/master/src/cli/run.js
*/

/* eslint-disable no-console */
const fs = require("fs");
const jsonServer = require("json-server");
const server = jsonServer.create();
const path = require("path");
const dbPath = path.join(__dirname, "db.json");
const router = jsonServer.router(dbPath);
let maxId = getMaxId(dbPath);

// Can pass a limited number of options to this to override (some) defaults. See https://github.com/typicode/json-server#api
const middlewares = jsonServer.defaults({
  // Display json-server's built in homepage when json-server starts.
  static: "node_modules/json-server/public"
});

// Set default middlewares (logger, static, cors and no-cache)
server.use(middlewares);

// To handle POST, PUT and PATCH you need to use a body-parser. Using JSON Server's bodyParser
server.use(jsonServer.bodyParser);

// Simulate delay on all requests
server.use(function(req, res, next) {
  setTimeout(next, 2000);
});

// Declaring custom routes below. Add custom routes before JSON Server router

// Add createdAt to all POSTS
server.use((req, res, next) => {
  //if (req.method === "POST") {
  //  req.body.createdAt = Date.now();
  //}
  // Continue to JSON Server router
  next();
});

//create
server.post("/users/", function(req, res, next) {
  const error = validateUser(req.body);
  if (error) {
    res.status(400).send(error);
  } else {
    req.body.id = maxId;
    //req.body.slug = createSlug(req.body.title); // Generate a slug for new courses.
    next();
  }
});

//update
server.put("/users", function(req, res, next) {
  const error = validateUser(req.body);
  if (error) {
    res.status(400).send(error);
  } else {
    req.body.id = req.body.id;
    next();
  }
});

// Use default router
server.use(router);

// Start server
const port = 3001;
server.listen(port, () => {
  console.log(`JSON Server is running on port ${port}`);
});

// Centralized logic

// Returns a URL friendly slug
function createSlug(value) {
  return value
    .replace(/[^a-z0-9_]+/gi, "-")
    .replace(/^-|-$/g, "")
    .toLowerCase();
}

function validateUser(user) {
  if (!user.id || user.id === 0) {
    maxId = maxId + 1;
    user.id = maxId;
  } else if (user.id < 0 || user.id > maxId) {
    return "Invalid User Id";
  }

  if (!user.firstName) return "First Name is required.";
  if (!user.lastName) return "Last Name is required.";
  if (user.hoursPerWeek <= 0) return "Hours Per Week must be a positive integer";
  return "";
}

function getMaxId(dbPath) {
  let rawData = fs.readFileSync(dbPath);
  let data = JSON.parse(rawData);
  let userArray = data.users;
  return Math.max.apply(
    Math,
    userArray.map(function(o) {
      return o.id;
    })
  );
}