index.js

// Dependencies
const express = require('express');
const path = require("path");
const PythonShell = require('python-shell');
const fs = require('fs');
const csvWriter = require("csv-write-stream");
const _ = require('lodash');
const bodyParser = require('body-parser');
const csv = require('csvtojson');
const jsonfile = require('jsonfile');

let app = express();
let writer = csvWriter({ sendHeaders: false });

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

app.set('port', (process.env.PORT || 7101))

// Add headers
app.use(function (req, res, next) {
  res.setHeader('Access-Control-Allow-Origin', '*');
  res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE');
  res.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type');
  res.setHeader('Access-Control-Allow-Credentials', true);
  next();
});

// For Rendering HTML
app.get('/', function (req, res) {
  res.sendFile(path.join(__dirname + '/dev/index.html'));
})
app.use(express.static(__dirname + '/dev'));

app.listen(app.get('port'), function () {
  console.log("Node app is running at http://localhost:" + app.get('port'))
})

// POST endpoint for requesting trials
app.post('/trials', function (req, res, next) {
  console.log("trials post request received");

  let subjCode = req.body.subjCode;
  let sessionId = req.body.sessionId;
  console.log(req.body);

  let trials = [];
  fs.readdir('./trials', (err, filenames) => {
    filenames = filenames.filter(filename =>
      filename.startsWith("trials_drawing_")
    );
    let filename = filenames[Math.floor(Math.random()*filenames.length)];
    csv({delimiter: ','})
    .fromFile('./trials/'+filename)
    .on('json',(jsonObj)=>{
        trials.push(jsonObj);
    })
    .on('done',(error)=>{
      trials.forEach((trial) => {
        trial.file = filename;
      });

      // Parses to lines of questions to a shuffled array of questions
      let questions = _.shuffle(fs.readFileSync('IRQ_questions.txt').toString().replace(/\r/g, '\n').split('\n')).filter((line) => {return line.replace(/ /g, '').length > 0 });
      let ReadingQu1 = _.shuffle(fs.readFileSync('reading_questions_1.txt').toString().replace(/\r/g, '\n').split('\n').filter((line) => {return line.replace(/ /g, '').length > 0 }));
      let ReadingQu2 = _.shuffle(fs.readFileSync('reading_questions_2.txt').toString().replace(/\r/g, '\n').split('\n').filter((line) => {return line.replace(/ /g, '').length > 0 }));

      console.log(trials)
      res.send({ success: true, trials: trials, questions, ReadingQu: [ReadingQu1, ReadingQu2] });
    })
  })
})


// POST endpoint for receiving trial responses
app.post('/data', function (req, res, next) {
  console.log('data post request received');

  // Create new data folder if does not exist
  let response = req.body;
  fs.access('./data', (err) => {
    if (err && err.code === 'ENOENT') {
      fs.mkdir('./data', () => {
        next();
      });
    }
    else next();
  });

},
  (req, res, next) => {
    let response = req.body;
    let path = 'data/' + response.workerId + '_data.json';
    fs.access(path, (err) => {
      if (err && err.code === 'ENOENT') {
        jsonfile.writeFile(path, { trials: [] }, (err) => {
          if (err) {
            res.send({ success: false });
            return next(err);
          }
          next();
        })
      }
      else next();
    })
  },
  (req, res, next) => {
    // Write response to json
    let response = req.body;
    let path = 'data/' + response.workerId + '_data.json';
    console.log(response);
    jsonfile.readFile(path, (err, obj) => {
      if (err) {
        res.send({ success: false });
        return next(err);
      }
      obj.trials.push(response);
      jsonfile.writeFile(path, obj, (err) => {
        if (err) {
          res.send({ success: false });
          return next(err);
        }
        res.send({ success: true });
      })
    })
  });


// POST endpoint for receiving demographics responses
app.post('/demographics', function (req, res, next) {
  let demographics = req.body;
  console.log('demographics post request received');
  console.log(demographics);
  let path = 'demographics/' + demographics.subjCode + '_demographics.csv';

  fs.access('./demographics', (err) => {
    if (err && err.code === 'ENOENT') {
      fs.mkdir('./demographics', () => {
        next();
      });
    }
    else next();
  });

},
  (req, res, next) => {
    let demographics = req.body;
    let path = 'demographics/' + demographics.subjCode + '_demographics.csv';
    fs.access(path, (err) => {
      if (err && err.code === 'ENOENT') {
        jsonfile.writeFile(path, { trials: [] }, (err) => {
          if (err) {
            res.send({ success: false });
            return next(err);
          }
          next();
        })
      }
      else next();
    })
  }, (req, res, next) => {
    // Parses the trial response data to csv
    let demographics = req.body;
    let path = 'demographics/' + demographics.subjCode + '_demographics.csv';

    writer = csvWriter({ headers: ['subjCode', 'question', 'response'] });

    writer.pipe(fs.createWriteStream(path, { flags: 'w' }));
    demographics.responses.forEach((response) => {
      writer.write(response);
    });
    writer.end();

    res.send({ success: true });
  });


// POST endpoint for receiving image responses
app.post('/image', function (req, res, next) {
  console.log('image post request received');

  // Create new data folder if does not exist
  let response = req.body;
  fs.access('./data', (err) => {
    if (err && err.code === 'ENOENT') {
      fs.mkdir('./data', () => {
        next();
      });
    }
    else next();
  });

},
  (req, res, next) => {
    // Create new user folder if does not exist
    let response = req.body;
    fs.access('./data/' + response.workerId, (err) => {
      if (err && err.code === 'ENOENT') {
        fs.mkdir('./data/' + response.workerId, () => {
          next();
        });
      }
      else next();
    });
  },
  (req, res, next) => {
    // save as png
    let response = req.body;
    console.log(Object.keys(response))
    var base64Data = response.drawing.replace(/^data:image\/png;base64,/, "");

    fs.writeFile('./data/' + response.workerId+'/'+response.workerId+'_'+response.word_to_draw+'_'+response.trial_number+'.png', base64Data, 'base64', function (err) {
      if (err) {
        res.send({ success: false });
        return next(err);
      }
      res.send({ success: true });
    });
  });

  // POST endpoint for receiving trial responses
app.post('/IRQ', function (req, res) {
  console.log('IRQ post request received');

  // Parses the trial response data to csv
  let IRQ = req.body;
  console.log(IRQ);
  if (!fs.existsSync('IRQ')) {
    fs.mkdirSync('IRQ');
  }
  let path = 'IRQ/' + IRQ.subjCode + '_IRQ.csv';
  writer = csvWriter({ headers: ['subjCode', 'question', 'response'] });

  writer.pipe(fs.createWriteStream(path, { flags: 'w' }));
  IRQ.responses.forEach((response) => {
    console.log(response);
    writer.write(response);
  })
  writer.end();

  res.send({ success: true });
})

// POST endpoint for receiving trial responses
app.post('/ReadingQu', function (req, res) {
  console.log('ReadingQu post request received');

  // Parses the trial response data to csv
  let ReadingQu = req.body;
  console.log(ReadingQu);
  if (!fs.existsSync('ReadingQu')) {
    fs.mkdirSync('ReadingQu');
  }
  let path;
  if (ReadingQu.batch === 1) {
    path = 'ReadingQu/' + ReadingQu.subjCode + '_ReadingQu1.csv';
  } else if (ReadingQu.batch === 2) {
    path = 'ReadingQu/' + ReadingQu.subjCode + '_ReadingQu2.csv';
  }
  writer = csvWriter({ headers: ['subjCode', 'question', 'response'] });

  writer.pipe(fs.createWriteStream(path, { flags: 'w' }));
  ReadingQu.responses.forEach((response) => {
    writer.write(response);
  });
  writer.end();

  res.send({ success: true });
})