server.js

const express = require('express')
const fileUpload = require('express-fileupload')
const bodyParser = require('body-parser');
const cors = require('cors');
const morgan = require('morgan');
const { MongoClient, ObjectId } = require('mongodb');
const app = express();
const { promises: fs } = require('fs');
const { spawn } = require('child_process');
const history = require('connect-history-api-fallback');
const cron = require('node-cron');
const aggregations = require('./aggregations.js');
const { OAuth2Client } = require('google-auth-library');
require('dotenv').config();
const console = require('console');
const { $push } = require('mongo-dot-notation');

async function exists (path) {  
  try {
    await fs.access(path)
    return true
  } catch {
    return false
  }
}

// Function to run a Python script and return a Promise
function runPythonScript(scriptPath, args = []) {
  return new Promise((resolve, reject) => {
    const pythonProcess = spawn('python3', [scriptPath, ...args]);

    pythonProcess.stdout.on('data', (data) => {
      console.log(`stdout from ${scriptPath}: ${data}`);
    });

    pythonProcess.stderr.on('data', (data) => {
      console.error(`stderr from ${scriptPath}: ${data}`);
    });

    pythonProcess.on('close', (code) => {
      console.log(`${scriptPath} process exited with code ${code}`);
      if (code === 0) {
        resolve();
      } else {
        reject(new Error(`${scriptPath} process exited with code ${code}`));
      }
    });
  });
}

const deleteFiles = async (audioID) => {
  const peaksPath = 'peaks/' + audioID + '.json';
  const spectrogramsPath = 'spectrograms/' + audioID;
  const mp3Path = 'audio/mp3/' + audioID + '.mp3';
  const wavPath = 'audio/wav/' + audioID + '.wav';
  const opusPath = 'audio/opus/' + audioID + '.opus';
  const peaksPathExists = await exists(peaksPath);
  const spectrogramsPathExists = await exists(spectrogramsPath);
  const mp3PathExists = await exists(mp3Path);
  const wavPathExists = await exists(wavPath);
  const opusPathExists = await exists(opusPath);
  if (peaksPathExists) {
    fs.unlink(peaksPath)
  }
  if (spectrogramsPathExists) {
    fs.rm(spectrogramsPath, { recursive: true, force: true })
  }
  if (mp3PathExists) {
    fs.unlink(mp3Path)
  }
  if (wavPathExists) {
    fs.unlink(wavPath)
  }
  if (opusPathExists) {
    fs.unlink(opusPath)
  }
}

const getSuffix = mimetype => {
  // TODO add other audio file types
  const end = mimetype.split('/')[1];
  if (end === 'mpeg') {
    return '.mp3'
  } else if (end === 'wav' || end === 'x-wav') {
    return '.wav'
  } else if (end === 'm4a' || end === 'x-m4a') {
    return '.m4a'
  } else if (end === 'flac' || end === 'x-flac') {
    return '.flac'
  } else if (end === 'ogg' || end === 'x-ogg') {
    return '.opus'
  } else if (end === 'opus' || end === 'x-opus') {
    return '.opus'
  }
};

cron.schedule('0 0 * * *', () => {
  spawn('python3', ['delete_unlinked_audio.py'])
})

// schedule a cron job to backup every day
cron.schedule('0 0 * * *', () => {
  spawn('python3', ['backups/backup_mongo.py'])
});

app.use(fileUpload({
  createParentPath: true
}))
app.use(history({
  htmlAcceptHeaders: ['text/html']
}))

app.use(cors({
  origin: '*'
}));
app.use(bodyParser({
  limit: '1000mb'
}))
app.use(express.json({
  type: ['application/json', 'text/plain']
}));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
  extended: true
}));
app.use(morgan('dev'));

const apiTimeout = 600000;
app.use((req, res, next) => {
  // Set the timeout for all HTTP requests
  req.setTimeout(apiTimeout, () => {
    let err = new Error('Request Timeout');
    err.status = 408;
    next(err);
  });
  // Set the server response timeout for all HTTP requests
  res.setTimeout(apiTimeout, () => {
    let err = new Error('Service Unavailable');
    err.status = 503;
    next(err);
  });
  next();
});
const settings = 'retryWrites=true&w=majority';
const webAddress = 'swara.f5cuf.mongodb.net/swara';
const password = process.env.PASSWORD;
const username = process.env.USER_NAME;
const login = `srv://${username}:${password}`;
const uri = `mongodb+${login}@${webAddress}?${settings}`;

const runServer = async () => {
  try {
    const client = await MongoClient.connect(uri, { useUnifiedTopology: true });    
    console.log('Connected to Database')
    const db = client.db('swara');
    const transcriptions = db.collection('transcriptions');
    const audioFiles = db.collection('audioFiles');
    const audioEvents = db.collection('audioEvents');
    const musicians = db.collection('musicians');
    const eventTypes = db.collection('audioEventTypes');
    const ragas = db.collection('ragas');
    const instruments = db.collection('instruments');
    const location = db.collection('location');
    const performanceSections = db.collection('performanceSections');
    const audioRecordings = db.collection('audioRecordings');
    const users = db.collection('users');
    const phonemes = db.collection('phonemes');
    const collections = db.collection('collections');
    const gharanas = db.collection('gharanas');
      
    app.post('/insertNewTranscription', async (req, res) => {
      // creates new transcription entry in transcriptions collection
      try {
        const insert = req.body;
        insert['dateCreated'] = new Date(insert.dateCreated);
        insert['dateModified'] = new Date(insert.dateModified);
        
        const result = await transcriptions.insertOne(req.body)

        const userID = insert.userID;
        const query = { _id: ObjectId(userID) };
        // const update = { transcriptions: $push(result.insertedId) };
        const update = { $push: { transcriptions: result.insertedId } };
        await users.updateOne(query, update);
        res.send(JSON.stringify(result));
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.post('/updateTranscription', async (req, res) => {
      // updates a transcription
      const updateObj = {};
      Object.keys(req.body).forEach(key => {
        if (key !== '_id') updateObj[key] = req.body[key]
      });
      updateObj['dateModified'] = new Date();
      updateObj['dateCreated'] = new Date(updateObj['dateCreated'])
      const query = { '_id': ObjectId(req.body._id) };
      const update = { '$set': updateObj };
      try {
        const result = await transcriptions.updateOne(query, update);
        result['dateModified'] = updateObj['dateModified']
        res.send(JSON.stringify(result))
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.get('/getAllCollections', async (req, res) => {
      try {
        const result = await collections.find().toArray();
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.get('/getAllMusicians', async (req, res) => {
      try {
        const result = await musicians.find().toArray();
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.get('/getAllGharanas', async (req, res) => {
      try {
        const result = await gharanas.find().toArray();
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.get('/getAllTranscriptions', async (req, res) => {
      try {
        const userID = JSON.parse(req.query.userID);
        const sortKey = JSON.parse(req.query.sortKey);
        let newPermissions = false;
        const reqNP = req.query.newPermissions;
        if (reqNP && reqNP !== 'undefined') {
          newPermissions = JSON.parse(req.query.newPermissions);
        }
        let secondarySortKey = undefined;
        if (sortKey === 'family_name') secondarySortKey = 'given_name';
        const sortDir = JSON.parse(req.query.sortDir);
        const proj = {
          title: 1,
          dateCreated: 1,
          dateModified: 1,
          location: 1,
          _id: 1,
          durTot: 1,
          raga: 1,
          userID: 1,
          permissions: 1,
          name: 1,
          family_name: 1,
          given_name: 1,
          audioID: 1,
          instrumentation: 1,
          explicitPermissions: 1,
          soloist: 1,
          soloInstrument: 1
        }
        let query;
        if (!newPermissions) {
          query = {
            '$or': [
              {
                '$or': [
                  { 'permissions': 'Public' },
                  { 'permissions': 'Publicly Editable' }
                ]
              },
              { 'userID': userID },
            ]
          };
        } else {
          query = {
            $or: [
              { "explicitPermissions.publicView": true },
              { "explicitPermissions.edit": userID },
              { "explicitPermissions.view": userID },
              { "userID": userID }
            ]
          };
        }
        const sort = {};
        sort[sortKey] = sortDir;
        if (secondarySortKey) sort[secondarySortKey] = sortDir;
        const result = await transcriptions
          .find(query)
          .collation({ 'locale': 'en' })
          .sort(sort)
          .project(proj)
          .toArray();
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.get('/getAllTranscriptionsOfAudioFile', async (req, res) => {
      const query = {
        audioID: req.query.audioID,
        $or: [
          { userID: req.query.userID },
          { permissions: { $in: ['Public', 'Publicly Editable'] } }
        ]
      };
      const projection = {
        title: 1,
        dateCreated: 1,
        dateModified: 1,
        location: 1,
        _id: 1,
        durTot: 1,
        raga: 1,
        userID: 1,
        permissions: 1,
        name: 1,
        family_name: 1,
        given_name: 1,
        audioID: 1,
        instrumentation: 1,
        explicitPermissions: 1
      };
      try {
        const result = await transcriptions.find(query)
          .project(projection).toArray();
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.get('/nameFromUserID', async (req, res) => {
      // retrieve a user's name from their associated userID in the users db
      const query = {
        _id: ObjectId(JSON.parse(req.query.userID))
      };
      try {
        const result = await users.findOne(query);
        res.send(await JSON.stringify(result.name))
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.get('/allUsers', async (req, res) => {
      try {
        const result = await users.find().toArray();
        res.send(await JSON.stringify(result))
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.get('/getAllAudioRecordingMetadata', async (req, res) => {
      // get all relevent data for audio files
      const projection = {
        performers: 1,
        musicians: 1,
        raags: 1,
        _id: 1,
        duration: 1,
        fundamental: 1,
        fileNumber: 1,
        year: 1,
        saEstimate: 1,
        saVerified: 1,
        octOffset: 1,
        parentID: 1,
        parentTitle: 1,
        parentTrackNumber: 1,
        userID: 1,
        explicitPermissions: 1
      }
      try {
        const out = await audioRecordings.find().project(projection).toArray();
        res.json(out)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.post('/saveMultiQuery', async (req, res) => {
      const userID = req.body.userID;
      if (!userID || userID.length !== 24) {
        console.log(userID)
        return res.status(400).send('Invalid userID: ' + userID);
      }
      const query = { _id: ObjectId(userID) };
      const multiQueryObj = {};
      multiQueryObj['queries'] = req.body.queries;
      multiQueryObj['dateCreated'] = new Date();
      multiQueryObj['options'] = req.body.options;
      multiQueryObj['transcriptionID'] = req.body.transcriptionID;
      multiQueryObj['title'] = req.body.title;
      const uniqueID = new ObjectId();
      multiQueryObj['_id'] = uniqueID;
      try {
        const result = await users.updateOne(query, { $push: { 
          multiQueries: multiQueryObj 
        } });
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }

    });

    app.delete('/deleteQuery', async (req, res) => {
      const query = { _id: ObjectId(req.body.userID) };
      const mQueryID = ObjectId(req.body.queryID);

      try {
        const result = await users.updateOne(query, {
          $pull: { multiQueries: { _id: mQueryID } }
        });
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.post('/createCollection', async (req, res) => {
      // create a new collection
      try {
        // get the user's name from their userID
        const query = { _id: ObjectId(req.body.userID) };
        const projection = { projection: { _id: 0, name: 1 } };
        const result = await users.findOne(query, projection);
        const name = result.name;
        // create the collection
        const collection = req.body;
        collection['dateCreated'] = new Date();
        collection['dateModified'] = new Date();
        collection['userName'] = name;
        const result2 = await collections.insertOne(collection);
        res.json(result2)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.delete('/deleteCollection', async (req, res) => {
      // delete a collection
      try {
        const query = { _id: ObjectId(req.body._id) };
        const result = await collections.deleteOne(query);
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.post('/updateCollection', async (req, res) => {
      // update a collection
      try {
        const query = { _id: ObjectId(req.body._id) };
        // copy to updates, and remove _id
        const updates = req.body;
        delete updates._id;
        const update = { $set: updates };
        const result = await collections.updateOne(query, update);
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.get('/getAllAudioEventMetadata', async (req, res) => {
      // retreive metadata for all audio events
      try {
        const result = await audioEvents.find().sort({
          'name': 1
        }).toArray();
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.post('/getOneTranscription', async (req, res) => {
      // retreive a particular transcription. If _id is 0, return first one.
      if (req.body._id === 0) {
        try {
          const result = await transcriptions.find().sort({ "_id": 1 }).next();
          res.json(result)
        } catch (err) {
          console.error(err);
          res.status(500).send(err);
        }
      } else {
        try {
          const query = { '_id': ObjectId(req.body._id) };
          const result = await transcriptions.findOne(query);
          res.send(JSON.stringify(result))
        } catch (err) {
          console.error(err);
          res.status(500).send(err);
        }  
      }
    });
    
    app.get('/pieceExists', async (req, res) => { 
      try {
        const query = { _id: ObjectId(req.query._id) };
        const result = await transcriptions.countDocuments(query) > 0;
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    });

    app.delete('/oneTranscription', async (req, res) => {
      // delete a particular transcription
      try {
        const query = { "_id": ObjectId(req.body._id) };
        const result = await transcriptions.deleteOne(query);
        
        // also, remove from user's transcriptions array
        const userID = req.body.userID;
        const query2 = { _id: ObjectId(userID) };
        const tID = ObjectId(req.body._id);
        const result2 = await users.updateOne(query2, { $pull: { 
          transcriptions: { $in: [tID] } 
        } });
        console.log(userID)
        console.log(query2)
        console.log(result2)
        res.json(result);
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }    
    });

    app.delete('/deleteRecording', async (req, res) => {
      // delete a particular recording
      try {
        const query1 = { "_id": ObjectId(req.body._id) };
        const found1 = await audioRecordings.findOne(query1);
        const parentID = found1.parentID;
        const result1 = await audioRecordings.deleteOne(query1);
        // also delete recording from audioevent, if rec has associated audio
        // event
        // if parentID is not null
        if (parentID) {

          const query2 = { "_id": ObjectId(parentID) };
          const projection = { 'recordings': 1, '_id': 0 };
          const result2 = await audioEvents.findOne(query2, projection);
          const recordings = result2.recordings;
          const newRecordings = {};
          let count = 0;
          for (let idx in recordings) {
            if (recordings[idx].audioFileId.toString() !== req.body._id) {
              newRecordings[count] = recordings[idx];
              if (newRecordings[count].parentTrackNumber !== count) {
                newRecordings[count].parentTrackNumber = count;
                // update in audioRecordings collection
                const query = { 
                  '_id': ObjectId(newRecordings[count].audioFileId) 
                };
                const update = { $set: { 'parentTrackNumber': count } };
                await audioRecordings.updateOne(query, update);
              }
              count++;
            }
          }
          
          result2.recordings = newRecordings;
          const result3 = await audioEvents.updateOne(query2, { 
            $set: {recordings: newRecordings}
          });
          // if no recs left, delete audio event
          let result4 = undefined;
          if (Object.keys(newRecordings).length === 0) {
            result4 = await audioEvents.deleteOne(query2);
          }
          if (result4 !== undefined) {
            res.json({ result1, result2, result3, result4 });
          } else {
            res.json({ result1, result2, result3 });
          }
        } else {
          res.json(result1);
        }

        const peaksPath = 'peaks/' + req.body._id + '.json';
        const spectrogramsPath = 'spectrograms/' + req.body._id;
        const mp3Path = 'audio/mp3/' + req.body._id + '.mp3';
        const wavPath = 'audio/wav/' + req.body._id + '.wav';
        const opusPath = 'audio/opus/' + req.body._id + '.opus';
        const peaksPathExists = await exists(peaksPath);
        const spectrogramsPathExists = await exists(spectrogramsPath);
        const mp3PathExists = await exists(mp3Path);
        const wavPathExists = await exists(wavPath);
        const opusPathExists = await exists(opusPath);
        if (peaksPathExists) {
          fs.unlink(peaksPath)
        }
        if (spectrogramsPathExists) {
          fs.rm(spectrogramsPath, { recursive: true, force: true })
        }
        if (mp3PathExists) {
          fs.unlink(mp3Path)
        }
        if (wavPathExists) {
          fs.unlink(wavPath)
        }
        if (opusPathExists) {
          fs.unlink(opusPath)
        }
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }    
    });

    app.delete('/deleteAudioEvent', async (req, res) => {
      // delete a particular audio event
      try {
        const query = { "_id": ObjectId(req.body._id) };
        const projection = { 'recordings': 1, '_id': 0 };
        const result = await audioEvents.findOne(query, projection);
        const recordings = result.recordings;
        const idxs = Object.keys(recordings);
        idxs.forEach(async idx => {
          const recID = recordings[idx].audioFileId?.toString();
          //  remove from audioRecordings collection
          const query = { '_id': ObjectId(recID) };
          const result = await audioRecordings.deleteOne(query);
          console.log(result)
          // remove from peaks folder
          const peaksPath = 'peaks/' + recID + '.json';
          const spectrogramsPath = 'spectrograms' + recID;
          const mp3Path = 'audio/mp3/' + recID + '.mp3';
          const wavPath = 'audio/wav/' + recID + '.wav';
          const opusPath = 'audio/opus/' + recID + '.opus';
          const peaksPathExists = await exists(peaksPath);
          const spectrogramsPathExists = await exists(spectrogramsPath);
          const mp3PathExists = await exists(mp3Path);
          const wavPathExists = await exists(wavPath);
          const opusPathExists = await exists(opusPath);
          if (peaksPathExists) {
            fs.unlink(peaksPath)
          }
          if (spectrogramsPathExists) {
            fs.rm(spectrogramsPath, { recursive: true, force: true })
          }
          if (mp3PathExists) {
            fs.unlink(mp3Path)
          }
          if (wavPathExists) {
            fs.unlink(wavPath)
          }
          if (opusPathExists) {
            fs.unlink(opusPath)
          }
        })
        const delResult = await audioEvents.deleteOne(query);
        console.log(delResult)
        res.json(delResult);
        // res.json('not deleted _id ' + req.body._id);
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.post('/getAudioDBEntry', async (req, res) => {
      // retrieve a particular entry from the audioFiles db
      try {
        const query = { '_id': ObjectId(req.body._id) };
        const result = await audioFiles.findOne(query);
        res.json(result);
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }    
    });

    app.get('/getSortedMusicians', async (req, res) => {
      //Get all names of all musicians from db, sorted
      const sorts = { 'Last Name': 1, 'First Name': 1, 'Middle Name': 1};
      const proj = { 'Initial Name': 1, _id: 0 };
      if (req.query.verbose === 'true') {
        proj['First Name'] = 1;
        proj['Last Name'] = 1;
        proj['Middle Name'] = 1;
      }
      try {
        let result = await musicians.find().sort(sorts).project(proj).toArray();
        const output = req.query.verbose === 'true' ? 
          result : 
          result.map(r => r['Initial Name']);
        res.json(output)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.get('/getGharana', async (req, res) => {
      //gets gharana of a particular musician
      const initName = JSON.parse(req.query.initName);
      const query = { 'Initial Name': initName };
      const projection = { projection: { Gharana: 1, _id: 0 } };
      try {
        const result = musicians.findOne(query, projection);
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }    
    });

    app.get('/getInstruments', async (req, res) => {
      // get names of all instruments, or instruments  of particular kind (if 
      // melody is true)
      const proj = { name: 1, _id: 0 };
      if (req.query.melody) {
        const query = { 'kind': 'melody' };
        try {
          const result = await instruments.find(query).project(proj).toArray();
          res.json(result.map(r => r.name))
        } catch (err) {
          console.error(err);
          res.status(500).send(err);
        }        
      } else {
        try {
          const result = await instruments.find().project(proj).toArray();
          res.json(result.map(r => r.name))
        } catch (err) {
          console.error(err);
          res.status(500).send(err);
        }
      }
    });

    app.get('/verifySpectrogram', async (req, res) => {
      // verify that spectrogram exists for a particular recording
      const dir = 'spectrograms/' + req.query.id + '/0';
      try {
        const files = await fs.readdir(dir);
        res.json(files.length > 0)
      } catch (err) {
        if (err.code === 'ENOENT') {
          res.json(false)
        } else {
          console.error(err);
          res.status(500).send(err);
        }
        
      }
    });

    app.get('/verifyMelograph', async (req, res) => {
      // verify that melograph exists for a particular recording
      const dir = 'melographs/' + req.query.id;
      try {
        const files = await fs.readdir(dir);
        res.json(files.length > 0)
      } catch (err) {
        if (err.code === 'ENOENT') {
          res.json(false)
        } else {
          console.error(err);
          res.status(500).send(err);
        }
      }
    });

    app.get('/getRagaNames', async (req, res) => {
      // gets names of all ragas
      const proj = { 'name': 1, _id: 0 };
      const sortRule = { 'name': 1 };
      try {
        let result = await ragas.find().sort(sortRule).project(proj).toArray();
        const names = await result.map(r => r.name);
        res.json(names)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }    
    });

    app.get('/getLocationObject', async (req, res) => {
      // gets location object
      try {
        const result = await location.findOne({}, { projection: { _id: 0 } });
        res.json(result);
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.get('/getEventTypes', async (req, res) => {
      // retrieve list of all possible event types
      const projection = { 'type': 1, _id: 0 };
      try {
        const result = await eventTypes.find().project(projection).toArray();
        res.json(result.map(r => r.type))
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }    
    });

    app.get('/getPerformanceSections', async (req, res) => {
      // retrieve list of all possible performance sections
      const proj = { 'name': 1, _id: 0 };
      try {
        const result = await performanceSections.find().project(proj).toArray();
        res.json(result.map(r => r.name));
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.get('/getNumberOfSpectrograms', async (req, res) => {
      // returns the number of spectrograms that the app needs to load
      const dir = 'spectrograms/' + req.query.id + '/0';
      try {  
        const files = await fs.readdir(dir);
        res.json(files.length)  
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.post('/updateVisibility', async (req, res) => {
      // update the visibility of either a transcription, recording, or 
      // audioEvent
      if (req.body.artifactType === 'transcription') {
        try {
          const query = { _id: ObjectId(req.body._id) };
          const update = { $set: { 
            "explicitPermissions": req.body.explicitPermissions 
          } };
          const result = await transcriptions.updateOne(query, update);
          res.json(result)
        } catch (err) {
          console.error(err);
          res.status(500).send(err);
        }
      } else if (req.body.artifactType === 'audioRecording') {
        try {
          const q = { _id: ObjectId(req.body._id) };
          const up = { $set: { 
            "explicitPermissions": req.body.explicitPermissions 
          } };
          const options = { returnOriginal: false };
          const result = await audioRecordings.findOneAndUpdate(q, up, options);
          console.log(result)
          const parentID = result.value.parentID;
          const key = result.value.parentTrackNumber;
          const query2 = { _id: ObjectId(parentID) };
          const path = `recordings.${key}.explicitPermissions`;
          const update2 = { $set: { [path]: req.body.explicitPermissions } };
          const result2 = await audioEvents.updateOne(query2, update2);
          res.json({ result, result2 })
        } catch (err) {
          console.error(err);
          res.status(500).send(err);
        }
      } else if (req.body.artifactType === 'audioEvent') {
        console.log(req.body)
        try {
          const query = { _id: ObjectId(req.body._id) };
          const update = { $set: { 
            "explicitPermissions": req.body.explicitPermissions 
          } };
          const result = await audioEvents.findOneAndUpdate(query, update);
          const audioEvent = result.value;
          for (let recording of Object.values(audioEvent.recordings)) {
            const query = { _id: ObjectId(recording.audioFileId) };
            const update = { $set: { 
              "explicitPermissions": req.body.explicitPermissions 
            } };
            await audioRecordings.findOneAndUpdate(query, update);
          }
          res.json(result)
        } catch (err) {
          console.error(err);
          res.status(500).send(err);
        }
      }

    });

    // app.post('/makeVisualizationData', async (req, res) => {
    //   // generate visualization data for the given recording ID
    //   const script1 = './visualization_scripts/generate_melograph.py';
    //   const script2 = './visualization_scripts/make_spec_data.py';
    //   try {
    //     await Promise.all([
    //       runPythonScript(script1, [req.body.recId]),
    //       runPythonScript(script2, [req.body.recId])
    //     ])
    //   } catch (err) {
    //     console.error(err);
    //     res.status(500).send(err);
    //   }
    // })
    
    app.post('/makeSpectrograms', async (req, res) => {
      // generate spectrograms for the given recording ID and tonic estimate  
      const makingSpecs = spawn(
        'python3', 
        ['generate_log_spectrograms.py', req.body.recId, req.body.saEst]
      );
      try {
        makingSpecs.stdout.on('data', data => {
          console.log(`stdout: ${data}`)
        });
        
        makingSpecs.stderr.on('data', data => {
          console.error(`stderr: ${data}`)
        });
        await makingSpecs.on('close', (msg) => {
          console.log(msg)
          res.json('made the spectrograms')
        })
      } catch (err) {
        console.error(err)
      }
    })

    app.post('/makeMelograph', async (req, res) => {
      res.setTimeout(10 * 60 * 1000); // 10 minutes
      const makingMelograph = spawn(
        'python3', 
        ['generate_melograph.py', req.body.recId, req.body.saEst]
      );
      try {
        makingMelograph.stdout.on('data', data => {
          console.log(`stdout: ${data}`)
        });
        
        makingMelograph.stderr.on('data', data => {
          console.error(`stderr: ${data}`)
        });
        // await makingMelograph.on('close', (msg) => {
        //   console.log(msg)
        //   res.json('made the melograph')
        // })
        await new Promise((resolve, reject) => {
          makingMelograph.on('close', (msg) => {
            console.log(msg);
            resolve();
          });
    
          makingMelograph.on('error', (err) => {
            console.error(err);
            reject(err);
          });
        });
        res.json('made the melograph')
      } catch (err) {
        console.error(err)
      }
    })

    app.get('/getAudioEvent', async (req, res) => {
      try {
        const result = await audioEvents.findOne({
          _id: ObjectId(req.query._id)
        });
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.get('/getAudioRecording', async (req, res) => {
      try {
        const result = await audioRecordings.findOne({
          _id: ObjectId(req.query._id)
        });
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.post('/initializeAudioEvent', async (req, res) => {
      // Creates a new (empty) AudioEvent mongDB entry, and receives back a 
      // unique _id for use throughout the upload / metadata entry process.
      const userID = req.body.userID;
      const insertion = {
        userID: userID,
        permissions: "Public",
        explicitPermissions: {
          publicView: true,
          edit: [],
          view: []
        },
      };
      if (req.body.name) insertion.name = req.body.name;
      if (req.body.eventType) insertion['event type'] = req.body.eventType;
      try {
        const result = await audioEvents.insertOne(insertion);
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.delete('/cleanEmptyDoc', async (req, res) => {
      const query = { _id: ObjectId(req.body._id) };
      const projection = { projection: { _id: 0 } };
      try {
        const result = await audioEvents.findOne(query, projection)
        if (Object.keys(result).length <= 2) {
          const output = await audioEvents.deleteOne(query);
          res.json(output)
        }
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }    
    })

    app.post('/saveAudioMetadata', async (req, res) => {
      const parentId = ObjectId(req.body._id);
      const myUpdates = req.body.updates;
      const addMusicians = req.body.addMusicians;
      const query = { _id: parentId };
      const update = { $set: myUpdates };
      const options = { upsert: true };
      console.log(addMusicians)
      try {
        if (addMusicians.length > 0) {
          const [result1, result2] = await Promise.all([
            audioEvents.updateOne(query, update, options),
            musicians.insertMany(addMusicians)
          ])
          res.json({ result1, result2 });
        } else {
          const result = await audioEvents.updateOne(query, update, options);
          res.json(result);
        }
        aggregations.generateAudioRecordingsDB();
        
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.post('/addMusicianToDB', async (req, res) => {
      //adding new entry to musicians db
      const entry = { 
        'Initial Name': req.body.initName,
        'Gharana': req.body.gharana,
        'Full Name': req.body.fullName,
        'Instrument': req.body.instrument
      };
      try {
        const result = await musicians.insertOne(entry);
        res.json(result);
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.post('/addGharanaToDB', async (req, res) => {
      //adding new entry to gharanas db
      const entry = { 'name': req.body.name, 'members': req.body.members };
      try {
        const result = await gharanas.insertOne(entry);
        res.json(result);
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.post('/addCountryToDB', async (req, res) => {
      const country = req.body.country;
      const continent = req.body.continent;
      const update = { $set: { [`${continent}.${country}`]: [] } };
      const query = {};
      try {
        const result = await location.updateOne(query, update);
        res.json(result);
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      } 
    })

    app.post('/addCityToDB', async (req, res) => {
      const continent = req.body.continent;
      const country = req.body.country;
      const city = req.body.city;
      const update = { $push: { [`${continent}.${country}`]: city } };
      const query = {};
      try {
        const result = await location.updateOne(query, update);
        res.json(result);
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.post('/addRaagToDB', async (req, res) => {
      const d = new Date();
      const entry = { 'name': req.body.raag, 'updatedDate': d.toISOString() };
      try {
        const result = await ragas.insertOne(entry);
        res.json(result);
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.post('/updateSaEstimate', async (req, res) => {
      try {
        const verString = `recordings.${req.body.recIdx}.saVerified`;
        const estString = `recordings.${req.body.recIdx}.saEstimate`;
        const octString = `recordings.${req.body.recIdx}.octOffset`;
        const query = { _id: ObjectId(req.body.aeID) };
        const update = { $set: {} };
        update.$set[verString] = req.body.verified;
        update.$set[estString] = req.body.saEstimate;
        update.$set[octString] = req.body.octOffset;
        await audioEvents.updateOne(query, update);
        const otherQuery = { _id: ObjectId(req.body.recID) };
        const saEst = req.body.saEstimate;
        const ver = req.body.verified;
        const oct = req.body.octOffset;
        const setting = { saEstimate: saEst, saVerified: ver, octOffset: oct };
        const otherUpdate = { $set: setting };
        const oRes = await audioRecordings.updateOne(otherQuery, otherUpdate);
        res.json(oRes)
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.post('/updateAudioRecording', async (req, res) => {
      try {
        const query = { _id: ObjectId(req.body._id) };
        const isoDateString = new Date().toISOString();
        const update = { $set: {
          ...req.body.updates,
          dateModified: isoDateString
         } };
        const result = await audioRecordings.updateOne(query, update);
        if (req.body.ae_id !== undefined) {
          const aeUpdate = {};
          console.log(req.body.updates)
          Object.keys(req.body.updates).forEach(key => {
            console.log(key)
            aeUpdate[key] = JSON.parse(JSON.stringify(req.body.updates[key]));
          })
          aeUpdate['audioFileId'] = ObjectId(req.body._id);
          delete aeUpdate['_id'];

          const aeQuery = { _id: ObjectId(req.body.ae_id) };
          const aeUpdateKeys = Object.keys(aeUpdate);
          const aeUpdateFull = { $set: {} };
          aeUpdateKeys.forEach(key => {
            const path = `recordings.${req.body.parentTrackNum}.${key}`;
            aeUpdateFull.$set[path] = aeUpdate[key];
          });
          aeUpdateFull.$set['dateModified'] = isoDateString;
          await audioEvents.updateOne(aeQuery, aeUpdateFull);
        }
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.post('/updateTranscriptionTitle', async (req, res) => {
      try {
        const query = { _id: ObjectId(req.body.id) };
        const update = { $set: { title: req.body.title} };
        const result = await transcriptions.updateOne(query, update);
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.post('/updateTranscriptionPermissions', async (req, res) => {
      try {
        const query = { _id: ObjectId(req.body.id) };
        const update = { $set: { permissions: req.body.permissions} };
        const result = await transcriptions.updateOne(query, update);
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.post('/updateTranscriptionOwner', async (req, res) => {
      try {
        const query = { _id: ObjectId(req.body.transcriptionID) };
        const update = { $set: { 
          userID: req.body.userID,
          name: req.body.name,
          family_name: req.body.family_name,
          given_name: req.body.given_name
        } };
        const result = await transcriptions.updateOne(query, update);
        // remove from old user's transcriptions array
        const query2 = { _id: ObjectId(req.body.originalOwnerID) };
        const tID = ObjectId(req.body.transcriptionID);
        await users.updateOne(query2, { $pull: {
          transcriptions: { $in: [tID] }
        } });
        // add to new user's transcriptions array
        const query3 = { _id: ObjectId(req.body.userID) };
        await users.updateOne(query3, { $push: {
          transcriptions: tID
        } });
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.get('/loadQueries', async (req, res) => {
      try {
        const userID = req.query.userID;
        const transcriptionID = req.query.transcriptionID;
        const query = { _id: ObjectId(userID) };
        const projection = { projection: { multiQueries: 1, _id: 0 } };
        let user = await users.findOne(query, projection);
        let multiQueries = user.multiQueries;
        multiQueries = multiQueries.filter(q => {
          return q.transcriptionID === transcriptionID
        });
        res.json(multiQueries)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.get('/getVerifiedStatus', async (req, res) => {
      try {
        const query = { _id: ObjectId(req.query.aeID) };
        const verString = `$recordings.${req.query.recIdx}.saVerified`;
        const estString = `$recordings.${req.query.recIdx}.saEstimate`;
        const octOffset = `$recordings.${req.query.recIdx}.octOffset`;
        const projection = { '_id': 0 };
        projection['saEstimate'] = estString;
        projection['saVerified'] = verString;
        projection['octOffset'] = octOffset;
        const options = { projection: projection };
        const result = await audioEvents.findOne(query, options);
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.get('/getRaagRule', async (req, res) => {
      try {
        const query = { name: req.query.name };
        const projection = { _id: 0, rules: 1, updatedDate: 1 };
        const options = { projection: projection };
        const result = await ragas.findOne(query, options);
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.get('/getIpaVowels', async (req, res) => {
      try {
        const query = { type: 'vowel' };
        const projection = { _id: 0 };
        const options = { projection: projection };
        const result = await phonemes.find(query, options).toArray();
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })
    
    app.post('/addRecordingToCollection', async (req, res) => {
      try {
        // add recordingID to collections collection
        const query = { _id: ObjectId(req.body.colID) };

        const update = { $push: { audioRecordings: req.body.recordingID } };
        const result = await collections.updateOne(query, update);
        // add colID to audioRecordings collection
        const query2 = { _id: ObjectId(req.body.recordingID) };
        const update2 = { $push: { collections: req.body.colID } };
        const result2 = await audioRecordings.updateOne(query2, update2);
        res.json({ result, result2 })
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.post('/addTranscriptionToCollection', async (req, res) => {
      try {
        // add recordingID to collections collection
        const query = { _id: ObjectId(req.body.colID) };
        const update = { $push: { transcriptions: req.body.transcriptionID } };
        const result = await collections.updateOne(query, update);
        // add colID to audioRecordings collection
        const query2 = { _id: ObjectId(req.body.transcriptionID) };
        const update2 = { $push: { collections: req.body.colID } };
        const result2 = await transcriptions.updateOne(query2, update2);
        res.json({ result, result2 })
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.post('/addAudioEventToCollection', async (req, res) => {
      try {
        // add recordingID to collections collection
        const query = { _id: ObjectId(req.body.colID) };
        const update = { $push: { audioEvents: req.body.audioEventID } };
        const result = await collections.updateOne(query, update);
        // add colID to audioRecordings collection
        const query2 = { _id: ObjectId(req.body.audioEventID) };
        const update2 = { $push: { collections: req.body.colID } };
        const result2 = await audioEvents.updateOne(query2, update2);
        res.json({ result, result2 })
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.post('/removeRecordingFromCollection', async (req, res) => {
      try {
        // remove recordingID from collections collection
        const query = { _id: ObjectId(req.body.colID) };
        const update = { $pull: { audioRecordings: req.body.recordingID } };
        const result = await collections.updateOne(query, update);
        // remove colID from audioRecordings collection
        const query2 = { _id: ObjectId(req.body.recordingID) };
        const update2 = { $pull: { collections: req.body.colID } };
        const result2 = await audioRecordings.updateOne(query2, update2);
        res.json({ result, result2 })
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.post('/removeTranscriptionFromCollection', async (req, res) => {
      try { 
        console.log(req.body)
        const query = { _id: ObjectId(req.body.colID) };
        const update = { $pull: { transcriptions: req.body.transcriptionID } };
        const result = await collections.updateOne(query, update);

        const query2 = { _id: ObjectId(req.body.transcriptionID) };
        const update2 = { $pull: { collections: req.body.colID } };
        const result2 = await transcriptions.updateOne(query2, update2);
        console.log(result, result2)
        res.json({ result, result2 })
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.post('/removeAudioEventFromCollection', async (req, res) => {
      try {
        const query = { _id: ObjectId(req.body.colID) };
        const update = { $pull: { audioEvents: req.body.audioEventID } };
        const result = await collections.updateOne(query, update);

        const query2 = { _id: ObjectId(req.body.audioEventID) };
        const update2 = { $pull: { collections: req.body.colID } };
        const result2 = await audioEvents.updateOne(query2, update2);
        res.json({ result, result2 })
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.post('/getRecsFromIds', async (req, res) => {
      try {
        const query = { _id: { $in: req.body.recIDs.map(id => ObjectId(id)) } };
        const result = await audioRecordings.find(query).toArray();
        console.log(result)
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.get('/getLooseRecordings', async (req, res) => {
      try {
        const query = { parentID: null };
        const result = await audioRecordings.find(query).toArray();
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.post('/getAEsFromIds', async (req, res) => {
      try {
        const query = { _id: { $in: req.body.aeIDs.map(id => ObjectId(id)) } };
        const result = await audioEvents.find(query).toArray();
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.post('/getTranscriptionsFromIds', async (req, res) => {
      try {
        const query = { 
          _id: { $in: req.body.transIDs.map(id => ObjectId(id)) },
          $or: [
            { "explicitPermissions.view": req.body.userID },
            { "explicitPermissions.publicView": true },
            { "userID": req.body.userID },
            { "explicitPermissions.edit": req.body.userID }
          ] 
        };
        const proj = {
          title: 1,
          dateCreated: 1,
          dateModified: 1,
          location: 1,
          transcriber: 1,
          _id: 1,
          performers: 1,
          durTot: 1,
          raga: 1,
          userID: 1,
          permissions: 1,
          name: 1,
          family_name: 1,
          given_name: 1,
          audioID: 1,
          instrumentation: 1,
          explicitPermissions: 1,
          soloist: 1
        }
        const result = await transcriptions.find(query).project(proj).toArray();
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.get('/getConsonants', async (req, res) => {
      try {
        const query = { type: 'consonant' };
        const projection = { _id: 0 };
        const options = { projection: projection };
        const result = await phonemes.find(query, options).toArray();
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.post('/saveRaagRules', async (req, res) => {
      try {
        const query = { name: req.body.name };
        const update = {
          $set: { rules: req.body.rules, updatedDate: req.body.date }
        };
        const options = { upsert: true };
        const result = await ragas.updateOne(query, update, options);
        res.json(result.acknowledged)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.post('/userLoginGoogle', async (req, res) => {
      try {
        const query = { sub: req.body.sub };
        const update = { $set: req.body };
        const options = { upsert: true, returnDocument: 'after' };
        const result = await users.findOneAndUpdate(query, update, options);
        res.json(result);
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.post('/agreeToWaiver', async (req, res) => {
      try {
        const query = { _id: ObjectId(req.body.userID) };
        const update = { $set: { waiverAgreed: true } };
        const options = { upsert: true };
        const result = await users.updateOne(query, update, options);
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.post('/handleGoogleAuthCode', async (req, res) => {
      
      try {
        let url = req.body.redirectURL;
        if (url[url.length-1] === '/') {
          url = url.slice(0, url.length-1);
        }
        if (url.slice(url.length-5, url.length) === 'logIn')[
          url = url.slice(0, url.length-6)
        ]
        console.log(url)
        const OAuthClient = new OAuth2Client({
          clientId: "324767655055-crhq76mdupavvrcedtde986glivug1nm.apps.googl" +
            "eusercontent.com",
          clientSecret: "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",
          redirectUri: url
        });
        let { tokens } = await OAuthClient.getToken(req.body.authCode);
        OAuthClient.setCredentials({ access_token: tokens.access_token });
        const userinfo = await OAuthClient.request({
          url: 'https://www.googleapis.com/oauth2/v3/userinfo'
        })
        res.json(userinfo.data)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.post('/cloneTranscription', async (req, res) => {
      try {

        const query = { _id: ObjectId(req.body.id) };
        const copy = await transcriptions.findOne(query);
        copy._id = new ObjectId();
        copy.title = req.body.title;
        copy.userID = req.body.newOwner;
        copy.permissions = req.body.permissions;
        copy.name = req.body.name;
        copy.family_name = req.body.family_name;
        copy.given_name = req.body.given_name;
        copy.dateModified = new Date();
        copy.dateCreated = new Date();
        if (req.body.explicitPermissions) {
          copy.explicitPermissions = req.body.explicitPermissions;
        }
        const result = await transcriptions.insertOne(copy);
        res.json(result);
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.get('/excelData', async (req, res) => {
      const id = req.query._id;
      const argvs = [
        'make_excel.py',
        id,
        `data/json/${id}.json`,
        `data/excel/${id}.xlsx`
      ];
      try {
        const pythonScript = spawn('python3', argvs);
        pythonScript.stdout.on('data', data => {
          console.log(`stdout: ${data}`)
        });
        
        pythonScript.stderr.on('data', data => {
          console.error(`stderr: ${data}`)
        });
        await pythonScript.on('close', () => {
          res.download(`data/excel/${id}.xlsx`);
        }) 
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.get('/jsonData', async (req, res) => {
      const id = req.query._id;
      const argvs = [
        'make_excel.py',
        id,
        `data/json/${id}.json`,
        `data/excel/${id}.xlsx`
      ];
      try {
        const pythonScript = spawn('python3', argvs);
        pythonScript.stdout.on('data', data => {
          console.log(`stdout: ${data}`)
        });
        
        pythonScript.stderr.on('data', data => {
          console.error(`stderr: ${data}`)
        });
        await pythonScript.on('close', () => {
          res.download(`data/json/${id}.json`);
        }) 
      } catch (err) {
        console.error(err);
        res.status(500).send(err)
      }
    })

    app.get('/getInstrumentation', async (req, res) => {
      // from the audio recording.
      try {
        const audioID = ObjectId(JSON.parse(req.query.audioID));
        const query = { _id: audioID };
        const projection = { projection: { musicians: 1, _id: 0 } };
        const result = await audioRecordings.findOne(query, projection);
        const musicians = result.musicians;
        const keys = Object.keys(musicians);
        const sortOrder = ['Soloist', 'Accompanist'];
        const musiciansArr = keys
          .map(key => musicians[key])
          .filter(musician => sortOrder.includes(musician.role))
        const ordering = {};
        for (let i=0; i<sortOrder.length; i++) {
          ordering[sortOrder[i]] = i;
        }
        musiciansArr.sort((a, b) => ordering[a.role] - ordering[b.role]);
        const instrumentation = musiciansArr.map(m => m.instrument);
        res.json(instrumentation);
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.get('/getTranscriptionInstrumentation', async (req, res) => {
      // from the transcription.
      try {
        const transcriptionID = ObjectId(req.query.transcriptionID);
        const query = { _id: transcriptionID };
        console.log(query)
        const projection = { projection: { instrumentation: 1, _id: 0 } };
        const result = await transcriptions.findOne(query, projection);
        res.json(result.instrumentation);
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.post('/newUploadFile', async (req, res) => {
      try {
        if (!req.files) {
          res.send({ status: false, message: 'No file uploaded' });
        } else {
          const newId = await ObjectId();
          const dateModified = new Date().toISOString();
          const audioEventID = req.body.audioEventID;
          let recIdx = req.body.recIdx;
          const audioFile = req.files.audioFile;
          let parentTitle = undefined;
          let aeUserID = undefined;
          if (
            req.body.audioEventType === 'add' || 
            req.body.audioEventType === 'create'
            ) {
            const recPath = `recordings.${recIdx}`;
            const afIdPath = `${recPath}.audioFileId`;
            const datePath = `${recPath}.date`;
            const locationPath = `${recPath}.location`;
            const musiciansPath = `${recPath}.musicians`;
            const raagsPath = `${recPath}.raags`;
            const octOffsetPath = `${recPath}.octOffset`;
            const dateModifiedPath = `${recPath}.dateModified`
            const expPermissionsPath = `${recPath}.explicitPermissions`;
            const q = { _id: ObjectId(audioEventID) };
            const update = { $set: { 
              [afIdPath]: newId,
              [datePath]: {},
              [locationPath]: {},
              [musiciansPath]: {},
              [raagsPath]: {},
              [octOffsetPath]: 0,
              [dateModifiedPath]: dateModified,
              [expPermissionsPath]: {
                publicView: true,
                edit: [],
                view: []
              }         
            } };
            const op = { upsert: true, returnOriginal: false };
            const result = await audioEvents.findOneAndUpdate(q, update, op);
            parentTitle = result.value.name;
            aeUserID = result.value.userID;
            console.log(result.value)
          }
            // here we should also update the audioRecordings collection
            // with the new audio file, so as not to rely on the aggregation
            // which generates from audioEvents forever.
          await audioRecordings.insertOne({
            _id: newId,
            duration: 0,
            saEstimate: 0,
            saVerified: false,
            octOffset: 0,
            collections: [],
            musicians: {},
            title: '',
            date: {},
            location: {},
            raags: {},
            parentID: audioEventID,
            parentTitle: parentTitle,
            aeUserID: aeUserID,
            userID: req.body.userID,
            parentTrackNumber: recIdx,
            dateModified: dateModified,
            explicitPermissions: {
              publicView: true,
              edit: [],
              view: []
            }
          })

          const suffix = getSuffix(audioFile.mimetype);
          let fn = newId + suffix;
          audioFile.mv('./uploads/' + fn);
          if (suffix === '.opus') {
            const newFN = newId + '.wav';
            const spawnArgs = ['-i', './uploads/' + fn, './uploads/' + newFN];
            const convertToOpus = spawn('ffmpeg', spawnArgs)
            fn = newFN;
            convertToOpus.stderr.on('data', data => {
              console.error(`stderr: ${data}`)
            });
            convertToOpus.on('close', () => {
              console.log('opus conversion finished')
            })
          }
          const spawns = ['process_audio.py', fn, audioEventID, recIdx, newId];
          const processAudio = spawn('python3', spawns);
          processAudio.stderr.on('data', data => {
            console.error(`stderr: ${data}`)
          });
          processAudio.on('close', async () => {
            console.log('audio processing finished')
            const script1 = './visualization_scripts/generate_melograph.py';
            const script2 = './visualization_scripts/make_spec_data.py';
            try {
              await Promise.all([
                runPythonScript(script1, [newId]),
                runPythonScript(script2, [newId])
              ])
              res.send({
                status: true,
                message: 'File is uploaded',
                data: {
                  name: audioFile.name,
                  mimetype: audioFile.mimetype,
                  size: audioFile.size,
                  audioFileId: newId
                }
              });
            } catch (err) {
              console.error(err);
              res.status(500).send(err)
            }
          });
          // const script1 = './visualization_scripts/generate_melograph.py';
          // const script2 = './visualization_scripts/make_spec_data.py';
          // await Promise.all([
          //   runPythonScript(script1, [newId]),
          //   runPythonScript(script2, [newId])
          // ])
        }
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.get('/getEditableCollections', async (req, res) => {
      try {
        const query1 = { userID: JSON.parse(req.query.userID) };
        const query2 = { 'permissions.edit': JSON.parse(req.query.userID) };
        const query = { $or: [query1, query2] };
        const result = await collections.find(query).toArray();
        res.json(result)
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })
    
    // app.post('/upload-avatar', async (req, res) => {
    // // upload files, and send back progress, via axios (doesn't work with fetch)
    //   try {
    //     if (!req.files) {
    //       res.send({ status: false, message: 'No file uploaded' });
    //     } else {
    //       const parentId = req.body.parentID;
    //       const idx = req.body.idx;
    //       const avatar = req.files.avatar;
    //       const tempString = `recordings.${idx}.audioFileId`;
    //       const newId = await ObjectId();
    //       const query = { _id: ObjectId(parentId) };
    //       const update = { $set: { [tempString]: newId } };
    //       const options = { upsert: true };
    //       // first, find the existing audio event.
    //       // if there is another audio file already, use that id to search
    //       // the transcriptions db via the audioID field. For each transcription
    //       // found, update the audioID field to the new id. Then, delete any 
    //       // audio, spectrograms, melographs, and peaks files associated with 
    //       // the old id.
    //       // Then, delete the old id from the audioRecordings db.
    //       const ae = await audioEvents.findOne(query);
    //       if (ae.recordings && ae.recordings[idx]) {
    //         const oldId = ae.recordings[idx].audioFileId.toString();
    //         const tQuery = { audioID: oldId };
    //         const tUpdate = { $set: { audioID: newId } };
    //         const tOptions = { upsert: true };
    //         await transcriptions.updateMany(tQuery, tUpdate, tOptions);
    //         await deleteFiles(oldId);
    //         const arQuery = { _id: oldId };
    //         audioRecordings.deleteOne(arQuery);
    //       }
    //       await audioEvents.updateOne(query, update, options)
    //       const suffix = getSuffix(avatar.mimetype);
    //       let fn = newId + suffix;
    //       avatar.mv('./uploads/' + fn);
    //       if (suffix === '.opus') {
    //         const newFN = newId + '.wav';
    //         const spawnArgs = ['-i', './uploads/' + fn, './uploads/' + newFN];
    //         const convertToOpus = spawn('ffmpeg', spawnArgs)
    //         fn = newFN;
    //         convertToOpus.stderr.on('data', data => {
    //           console.error(`stderr: ${data}`)
    //         });
    //         convertToOpus.on('close', () => {
    //           console.log('opus conversion finished')
    //         })
    //       }
    //       const spawnArr = ['process_audio.py', fn, parentId, idx];
    //       const processAudio = spawn('python3', spawnArr);
    //       processAudio.stderr.on('data', data => {
    //         console.error(`stderr: ${data}`)
    //       });
    //       processAudio.on('close', () => {
    //         console.log('python closed, finally')
    //         res.send({
    //           status: true,
    //           message: 'File is uploaded',
    //           data: {
    //             name: avatar.name,
    //             mimetype: avatar.mimetype,
    //             size: avatar.size,
    //             audioFileId: newId
    //           }
    //         });
    //       });
    //       const script1 = './visualization_scripts/generate_melograph.py';
    //       const script2 = './visualization_scripts/make_spec_data.py';
    //       await Promise.all([
    //         runPythonScript(script1, [newId]),
    //         runPythonScript(script2, [newId])
    //       ])
    //     }
    //   } catch (err) {
    //     console.error(err)
    //     res.status(500).send(err);
    //   }
    // });

    app.get('/getSavedSettings', async (req, res) => {
      try {
        const query = { _id: ObjectId(req.query.userID) };
        const projection = { savedSettings: 1, _id: 0 };
        const result = await users.findOne(query, projection);
        if (result && result.savedSettings) {
          res.json(result.savedSettings)
        } else {
          res.json([])
        }
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.post('/saveDisplaySettings', async (req, res) => {
      try {
        const query = { _id: ObjectId(req.body.userID) };
        const user = await users.findOne(query);
        if (user) {
          if (user.savedSettings) {
            const update = { $push: { savedSettings: req.body.settings } };
            const result = await users.updateOne(query, update);
            res.json(result);
          } else {
            const update = { $set: { savedSettings: [req.body.settings] } };
            const result = await users.updateOne(query, update);
            res.json(result);
          }
        } else {
          res.status(404).send('User not found');
        }
        
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.post('/updateDisplaySettings', async (req, res) => {
      try {
        const { userId, uniqueId, settings } = req.body;
        const query = { _id: ObjectId(userId), 'savedSettings.uniqueId': uniqueId };
        const update = { $set: { 'savedSettings.$': settings } };
        const result = await users.updateOne(query, update);
        // console.log(userID, uniqueId, settings)
        if (result.matchedCount === 0) {
          res.status(404).send('User or display settings not found');
        } else {
          res.json(result);
        }
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    app.get('/getDefaultSettings', async (req, res) => {
      try {
        const query = { _id: ObjectId(req.query.userID) };
        const projection = { defaultSettingsID: 1, _id: 0 };
        const result = await users.findOne(query, projection);
        if (result && result.defaultSettingsID) {
          res.json(result.defaultSettingsID)
        } else {
          res.json('ffa38001-f592-4778-a91e-c4ef5c99b081')
        }
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.post('/setDefaultSettings', async (req, res) => {
      try {
        const query = { _id: ObjectId(req.body.userID) };
        const update = { $set: { defaultSettingsID: req.body.settingsID } };
        const result = await users.updateOne(query, update);
        res.json(result);
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.delete('/deleteDisplaySettings', async (req, res) => {
      try {
        const query = { _id: ObjectId(req.body.userId) };
        const savedSettings = { uniqueId: req.body.uniqueId };
        const update = { $pull: { savedSettings } };
        const result = await users.updateOne(query, update);
        res.json(result);
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    })

    app.post('/updateInstrumentation', async (req, res) => {
      try {
        // first get the transcription included in the query under 
        // the transcriptionID key.
        // then, update the instrumentation field of the transcription.
        // If the new length of instrumentation is less than the original,
        // delete the corresponding idxs from the following fields: 
        // instrumentation, phrases, phraseGrid, durArrayGrid, sectionCatGrid, 
        // and sectionStartsGrid.

        // If the new length of instrumentation is greater than the original,
        // add the new instrument name to the end of the instrumentation array.
        const { transcriptionID, instrumentation } = req.body;
        if (!transcriptionID || !instrumentation) {
          res.status(400).send('TranscriptionID and instrumentation are required');
        };
        const query = { _id: ObjectId(transcriptionID) };
        const transcription = await transcriptions.findOne(query);
        if (!transcription) {
          res.status(404).send('Transcription not found');
        }
        const originalInstrumentation = transcription.instrumentation;
        const originalLength = originalInstrumentation.length;
        const newLength = instrumentation.length;

        await transcriptions.updateOne(query, { $set: { instrumentation } });
        if (newLength < originalLength) {
          const fieldsToUpdate = [
            'instrumentation', 
            'phraseGrid', 
            'durArrayGrid', 
            'sectionCatGrid', 
            'sectionStartsGrid'
          ];
          const updateOps = fieldsToUpdate.map(field => ({
            [field]: transcription[field].slice(0, newLength)
          }));
          await transcriptions.updateOne(query, { 
            $set: Object.assign({}, ...updateOps) 
          });
        }
        // res.status(200).send('Instrumentation updated');
        res.json({ status: 200, message: 'Instrumentation updated' });
      } catch (err) {
        console.error(err);
        res.status(500).send(err);
      }
    });

    const setNoCache = res => {
      res.setHeader('Cache-Control', 'no-cache, no-store, must-revalidate');
      res.setHeader('Pragma', 'no-cache');
      res.setHeader('Expires', '0')
    };
    app.use('/audio', express.static('audio', { setHeaders: setNoCache }));
    app.use('/peaks', express.static('peaks', { setHeaders: setNoCache }));
    app.use('/test', express.static('test', { setHeaders: setNoCache }));
    app.use('/spectrograms', express.static('spectrograms', { 
      setHeaders: setNoCache 
    }))
    app.use('/spec_data', express.static('spec_data', {
      setHeaders: setNoCache
    }))
    app.use('/melographs', express.static('melographs', { 
      setHeaders: setNoCache 
    }));
    app.use('/', express.static('dist'))
    const server = app.listen(3000);
    server.timeout = 600000;
  } catch (err) {
    console.error(err)
  }
}

runServer();