db-operations.js

function fetchNearestCops(db, coordinates, callback) {
  db.collection('policeData').createIndex({
    "location": "2dsphere"
  }, function () {
    db.collection("policeData").find({
      location: {
        $near: {
          $geometry: {
            type: "Point",
            coordinates: coordinates
          },
          $maxDistance: 2000
        }
      }
    }).toArray(function (err, results) {
      if (err) {
        console.log(err)
      } else {
        callback(results);
      }
    });
  });
}

function fetchCopDetails(db, userId, callback) {
  db.collection('policeData').findOne({
    userId: userId,
  }, function (err, results) {
    if (err) return console.log(err);
    callback({
      copId: results.userId,
      displayName: results.displayName,
      phone: results.phone,
      location: results.location,
    });
  })
}

function saveRequest(db, issueId, requestTime, location, citizenId, status, callback) {
  db.collection('requestsData').insert({
    "_id": issueId,
    "requestTime": requestTime,
    "location": location,
    "citizenId": citizenId,
    "status": status
  }, function (err, results) {
    if (err) {
      console.log(err);
    } else {
      callback(results);
    }
  });
}

function updateRequest(db, requestId, copId, status, callback) {
  db.collection('requestsData').update({
    "_id": requestId //Perform update for the given requestId
  }, {
      $set: {
        "status": status, //Update status to 'engaged'
        "copId": copId  //save cop's userId
      }
    }, function (err, results) {
      if (err) {
        console.log(err);
      } else {
        callback("Issue updated")
      }
    });
}

function fetchRequests(db, callback) {
  db.collection('requestsData').find({}, {
    requestTime: true,
    status: true,
    location: true
  }).toArray(function (err, results) {
    if (err) {
      console.log(err)
    } else {
      callback(results);
    }
  });
}

exports.fetchRequests = fetchRequests;
exports.updateRequest = updateRequest;
exports.saveRequest = saveRequest;
exports.fetchNearestCops = fetchNearestCops;
exports.fetchCopDetails = fetchCopDetails;