server.js

'use strict';
RegExp.prototype.toJSON = RegExp.prototype.toString;

const debug = require('debug')('DICOM Server');
const express = require('express');
const bodyParser = require('body-parser');
const http = require('http');
const compress = require('compression');
//login
const cookieParser = require('cookie-parser');
const session = require('express-session');
const flash = require('connect-flash');
const mongodb = require('./models/mongodb');
const mongoose = require('mongoose');
const MongoStore = require('connect-mongo')({ session: session }); //eslint-disable-line @typescript-eslint/naming-convention
//
const fetch = require('node-fetch');
const os = require('os');
const { exec } = require('child_process');
require('dotenv').config();
const port = process.env.SERVER_PORT;
const app = express();

require('rootpath')();
debug('Start DICOM Server...');
app.use(compress());
app.use(flash());
app.use(express.static('public'));
app.use(bodyParser.urlencoded({
  extended: true
}));
app.use(bodyParser.json({ 
  "strict": false,
  "limit": "50mb"
}));
app.use(bodyParser.json({ 
  "type": "application/fhir+json",
  "limit": "50mb"
}));
app.use(bodyParser.text({ "type": "text/*" }));
//app.use(bodyParser.raw({ "type" : "multipart/related" , limit: "100gb"}));
app.use((err, req, res, next) => {
  // This check makes sure this is a JSON parsing issue, but it might be
  // coming from any middleware, not just body-parser:

  if (err instanceof SyntaxError && err.status === 400 && 'body' in err) {
    console.error(err);
    return res.status(400).json(require('./models/FHIR/httpMessage').handleError.exception(err.message)); // Bad request
  }

  next();
});
app.use(cookieParser());
//login
app.use(session({
  secret: 'micalasecret',
  resave: true,
  saveUninitialized: true,
  store: new MongoStore({
    mongooseConnection: mongoose.connection
  }),
  httpOnly: true
}));
//
//app.use(expressValidator());
app.use((req, res, next) => {
  res.header("Access-Control-Allow-Origin", "*");
  res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept ,Authorization, apikey, user-agent");
  res.header("Vary", "Origin");
  res.header("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE");
  res.header("Access-Control-Allow-Credentials", "true");
  res.header("Access-Control-Expose-Headers", "Content-Disposition");
  next();
});
//require('routes')(app);

//login
require("routes.js")(app);
app.engine('html', require('ejs').renderFile);
app.set("views", "public");

// If host is present, the server will accept connection on specific host, when
// host is omitted, use IPv6 (::) or IPv4 (0.0.0.0)
if (process.env.SERVER_HOST) {
  http.createServer(app).listen(port, process.env.SERVER_HOST, function () {
    console.log(`http server is listening on port:${port}`);
  });
} else {
  http.createServer(app).listen(port, function () {
    console.log(`http server is listening on port:${port}`);
  });
}


let osPlatform = os.platform().toLocaleLowerCase();
if (osPlatform.includes('linux')) {
  process.env.ENV = "linux";
} else if (osPlatform.includes('win')) {
  process.env.ENV = "windows";
}
process.env.USE_DCM2JPEG_PYTHONAPI = (process.env.USE_DCM2JPEG_PYTHONAPI=='true') ? true : false;

let condaPath = process.env.CONDA_PATH;
let condaEnvName = process.env.CONDA_GDCM_ENV_NAME;

(async ()=> {
  let isflaskRunning = false;
  if (process.env.USE_DCM2JPEG_PYTHONAPI) {
    try {
      let res = await fetch(`http://${process.env.DCM2JPEG_PYTHONAPI_HOST}:${process.env.DCM2JPEG_PYTHONAPI_PORT}/`);
      let resJson = await res.json();
      if (resJson.status) {
        isflaskRunning = true;
        console.log('the dcm2jpeg python flask api ready');  
      }
    } catch (e) { // eslint-disable-line no-empty

    }
    if (!isflaskRunning) {
      if (process.env.ENV == "windows") {
        let cmd = `python DICOM2JPEGAPI.py ${process.env.DCM2JPEG_PYTHONAPI_PORT}`;
        if (process.env.USE_CONDA === "true") cmd = `${condaPath} run -n ${condaEnvName} python DICOM2JPEGAPI.py ${process.env.DCM2JPEG_PYTHONAPI_PORT}`;
        exec(`${cmd}`, {
          cwd: process.cwd()
        }, function (err, stdout, stderr) {
          if (err) {
            console.error(err);
            process.exit(1);
          } else if (stderr) {
            console.error(stderr);
            process.exit(1);
          }
        });
      } else {
        exec(`python3 DICOM2JPEGAPI.py ${process.env.DCM2JPEG_PYTHONAPI_PORT}`, {
          cwd: process.cwd()
        }, function (err, stdout, stderr) {
          if (err) {
            console.error(err);
            process.exit(1);
          } else if (stderr) {
            console.error(stderr);
          }
        });
      }
    }
  }
})();

(()=> {
  let checkAPITimes = 0;
  if (process.env.USE_DCM2JPEG_PYTHONAPI) {
    let checkAPIInterval = setInterval(async ()=> {
      if (checkAPITimes >=30) {
        console.error("The dcm2jpeg python flask api set up failure");
        process.exit(1);
      }
      try {
        let res = await fetch(`http://${process.env.DCM2JPEG_PYTHONAPI_HOST}:${process.env.DCM2JPEG_PYTHONAPI_PORT}/`);
        console.log('the dcm2jpeg python flask api ready');
        clearInterval(checkAPIInterval);
      } catch (e) {
        checkAPITimes++;
      }
    } , 1000);
  }
})();

module.exports = app;