Add count parameter for getLatestMeasurements (#588)

* Add count parameter for getLatestMeasurements

* Add projection and restructure lastMeasurements

* add tests and doc for count measurement feature

Co-authored-by: Umut Tas <[email protected]>

Author: mpfeil

docker-compose.yml

@@ -15,4 +15,4 @@ services:
       # - ./dumps/measurements:/exports/measurements
       - ./.scripts/mongodb/osem_admin.sh:/docker-entrypoint-initdb.d/osem_admin.sh
       # - ./.scripts/mongodb/osem_seed_boxes.sh:/docker-entrypoint-initdb.d/osem_seed_boxes.sh
-      # - ./.scripts/mongodb/osem_seed_measurements.sh:/docker-entrypoint-initdb.d/osem_seed_measurements.sh
+      # - ./.scripts/mongodb/osem_seed_measurements.sh:/docker-entrypoint-initdb.d/osem_seed_measurements.sh

packages/api/lib/controllers/measurementsController.js

@@ -19,6 +19,7 @@ const
  * @apiGroup Measurements
  * @apiName getLatestMeasurements
  * @apiUse BoxIdParam
+ * @apiParam {NumberNumber=1-100} [count] Number of measurements to be retrieved for every sensor.
  */
 /**
  * @api {get} /boxes/:senseBoxId/sensors/:sensorId Get latest measurements of a sensor
@@ -35,7 +36,30 @@ const getLatestMeasurements = async function getLatestMeasurements (req, res, ne
   let box;
 
   try {
-    box = await Box.findBoxById(req._userParams.boxId, { onlyLastMeasurements: true });
+    if (req._userParams.count) {
+      box = await Box.findBoxById(req._userParams.boxId, {
+        populate: false,
+        onlyLastMeasurements: false,
+        count: req._userParams.count,
+        projection: {
+          name: 1,
+          lastMeasurementAt: 1,
+          sensors: 1,
+          grouptag: 1
+        }
+      });
+
+      const measurements = await Measurement.findLatestMeasurementsForSensorsWithCount(box, req._userParams.count);
+      for (let index = 0; index < box.sensors.length; index++) {
+        const sensor = box.sensors[index];
+        const values = measurements.find(elem => elem._id.equals(sensor._id));
+        sensor['lastMeasurements'] = values;
+      }
+    } else {
+      box = await Box.findBoxById(req._userParams.boxId, {
+        onlyLastMeasurements: true
+      });
+    }
   } catch (err) {
     handleError(err, next);
 
@@ -413,6 +437,7 @@ module.exports = {
     retrieveParameters([
       { predef: 'boxId', required: true },
       { predef: 'sensorId' },
+      { name: 'count', dataType: 'Integer', min: 1, max: 100, required: false },
       { name: 'onlyValue', required: false }
     ]),
     getLatestMeasurements

packages/models/src/measurement/measurement.js

@@ -86,6 +86,59 @@ measurementSchema.statics.findLatestMeasurementsForSensors = function findLatest
     .exec();
 };
 
+measurementSchema.statics.findLatestMeasurementsForSensorsWithCount = function findLatestMeasurementsForSensorsWithCount (box, count) {
+  const match = {
+    $or: []
+  };
+  for (let index = 0; index < box.sensors.length; index++) {
+    const sensor = box.sensors[index];
+    match.$or.push({
+      sensor_id: sensor._id
+    });
+  }
+
+  return this.aggregate([
+    {
+      $match: match,
+    },
+    {
+      $sort: {
+        createdAt: -1,
+      },
+    },
+    {
+      $limit: count * box.sensors.length,
+    },
+    {
+      $group: {
+        _id: '$sensor_id',
+        measurements: {
+          $push: {
+            value: '$value',
+            createdAt: '$createdAt',
+          }
+        },
+        fromDate: {
+          $last: '$createdAt',
+        },
+        toDate: {
+          $first: '$createdAt',
+        },
+      },
+    },
+    {
+      $project: {
+        _id: 1,
+        measurements: {
+          $slice: ['$measurements', count],
+        },
+        fromDate: 1,
+        toDate: 1,
+      },
+    },
+  ]).exec();
+};
+
 measurementSchema.statics.getMeasurementsStream = function getMeasurementsStream ({ fromDate, toDate, sensorId }) {
   const queryLimit = 10000;
 

tests/tests/007-download-data-test.js

@@ -194,6 +194,18 @@ describe('downloading data', function () {
         });
     });
 
+    it('should return the sensors of a box with 3 measurements for /boxes/:boxid/sensors?count=3 GET', function () {
+      return chakram.get(`${BASE_URL}/boxes/${boxIds[0]}/sensors?count=3`)
+        .then(function (response) {
+          expect(response).to.have.status(200);
+          expect(response).to.have.header('content-type', 'application/json; charset=utf-8');
+          expect(response).to.have.schema(boxSensorsSchema);
+          expect(response.body.sensors[0].lastMeasurements.measurements.length).to.be.equal(3);
+
+          return chakram.wait();
+        });
+    });
+
     it('should return a single sensor of a box for /boxes/:boxid/sensors/:sensorId GET', function () {
       return chakram.get(`${BASE_URL}/boxes/${boxes[0]._id}/sensors/${boxes[0].sensors[0]._id}`)
         .then(function (response) {