/* eslint-disable no-unused-vars */
'use strict';

// Ref: http://javascript.tutorialhorizon.com/2014/09/20/organizing-your-expressjs-routes-in-separate-files/

const express = require('express');
require('express-async-errors');
const rateLimit = require('express-rate-limit')

const debug = require('debug')('agm:server'),
  compression = require('compression'),
  path = require('path'),
  fs = require('fs-extra'),
  http = require('http'),
  https = require('node:http2'), // Use Node's https for HTTP2 support instead of 3rd party spdy (for Node <=v14)
  app = express(),
  env = require('./helpers/env'),
  { checkUser } = require('./middlewares/app_validator.js'),
  { ErrorHandler } = require('./middlewares/error_handler.js'),
  errorHandler = require('error-handler').errorHandler;

http.globalAgent.maxSockets = Infinity;
const MAX_REQ_BDY_MB = env.MAX_REQ_BDY_MB || '150mb'

// Load ENV vars specified in the .env file (within the same folder)
debug("Is in Production: ", env.PRODUCTION);
app.isProd = env.PRODUCTION;

process.setMaxListeners(0);
errorHandler && (errorHandler.registerUnCaughtProcessErrorsHandler(process, path.join(__dirname, 'agm_server.rlog')));

require('./helpers/db/connect.js')();

app.set('trust proxy', env.APP_RATE_TRUST_PROXIES /* number of proxies between user and server */);

if (!env.PRODUCTION && (env.INV_IMG_VIR_DIR && env.INV_UPLOAD_DIR)) {
  // Map static resources, cached for 8 hours
  app.use(env.INV_IMG_VIR_DIR, express.static(env.INV_UPLOAD_DIR, { maxAge: 31557600 }));
}

// for parsing application/x-www-form-urlencoded
app.use(express.urlencoded({ limit: MAX_REQ_BDY_MB, extended: true, parameterLimit: 100000 }));

// Rate limiting middleware. Define a rate limiter
const apiLimiter = rateLimit({
  windowMs: (env.APP_RATE_MINS || 15) * 60 * 1000, // 15 minutes
  max: env.APP_RATE_REQS || 100, // Limit each IP to 100 requests per windowMs
  skipFailedRequests: env.APP_RATE_SKIPFAIL || true, // Skip failed requests
  message: {
    error: "Too many requests, please try again later."
  }
});

// Apply the rate limiter to all routes in this router
app.use(apiLimiter);

// Handle webhook events from Stripe
require('./routes/subscription_webhooks')(express, app);

function shouldCompress(req, res) {
  if (req.headers['x-no-compression']) {
    return false; // don't compress responses with this request header
  }
  // fallback to standard filter function
  return compression.filter(req, res);
}
// Enable the compression middleware  
app.use(compression({ filter: shouldCompress }));

// Parsers for POST JSON data
app.use(express.json({ limit: MAX_REQ_BDY_MB }));

// Allow all CORS requests
// Ref at http://restlet.com/company/blog/2015/12/15/understanding-and-using-cors
app.use(function (req, res, next) {
  res.setHeader('Access-Control-Allow-Origin', '*');
  res.setHeader('Access-Control-Allow-Headers', 'Origin, Methods, X-Requested-With, Content-Type, Content-Disposition, Accept');
  res.setHeader('Access-Control-Allow-Methods', 'POST, GET, PATCH, DELETE, OPTIONS');
  next();
});

async function setupRoutes() {
  // const resLogger = async (req, res, next) => {
  //   debug('Request:', req.url);
  //   next();
  // };

  // Handle routes with middelware functions
  app.use(checkUser/*, resLogger*/);

  // REGISTER OUR ROUTES
  require('./routes')(app);

  app.use(ErrorHandler);

  app.get('/*', (req, res) => {
    // console.log(req.path);
    res.status(404).send({ status: 404, error: 'Not found' }).end();
  });

  // Avoid logging aborted requests
  // Ref: https://github.com/nodejs/help/issues/2155
  app.use((err, req, res, next) => {
    if (err && err.code === 'ECONNABORTED') {
      res.status(400).end();  // Don't process this error any further to avoid its logging
    } else
      next(err);
  });
}

/**
 * Preload some common libs, ussually written in ESM modules that require asynchronously loaded or import.. 
 * instead of using requires in CommonJS ones.
 */
async function preloadLibs() {
  let mod = await import('@mickeyjohn/geodesy/utm.js');
  app.locals.UTM = mod.default;
  app.locals.LatLonUTM = mod.LatLon;  // More accuracy, for converting from ll to utm
  app.locals.Dms = mod.Dms;

  mod = await import('@mickeyjohn/geodesy/latlon-spherical.js');
  app.locals.LatLonSP = mod.default;
}

async function ensureFolders() {
  try {
    await fs.ensureDir(env.INV_UPLOAD_DIR);
    await fs.ensureDir(env.UNZIP_DIR);
    await fs.ensureDir(env.REPORT_DIR);
    await fs.ensureDir(env.TEMP_DIR);
    await fs.ensureDir(env.AREAS_UPLOAD_DIR);
  } catch (error) {
    debug(error);
  }
}

const port = env.AGM_PORT || '4000';

// Create a secure HTTPS - HTTP2 server
https.createSecureServer({ key: fs.readFileSync(env.SSL_KEY), cert: fs.readFileSync(env.SSL_CERT), allowHTTP1: true }, app)
  .listen(port, async (error) => {
    const onAppErr = (err) => {
      debug(error);
      process.exit(1);
    }
    if (error) return onAppErr(error);

    try {
      await ensureFolders();
      await preloadLibs();
      await setupRoutes();

      // Start Job Importer queue consumer
      const jobQueuer = require('./helpers/job_queue').getInstance();
      jobQueuer.start();

      console.log(`Server is running on port ${port}`)

      debug(`HTTPS-v2 Agmission Server listening on port ${port}`);
    } catch (error) {
      onAppErr(error);
    }
  });