api calculate the time gap between the sensor data

src/controllers/tanksController.js

@@ -668,7 +668,7 @@ exports.IotDevice = async (req, reply) => {
 
     // create a new tank document with the current date and time
     const currentDate = new Date();
-    const date = currentDate.toLocaleDateString('en-IN');
+    const date = currentDate.toISOString();  // save the date as an ISO string
     const time = currentDate.toLocaleTimeString('en-IN', {hour12:false, timeZone: 'Asia/Kolkata' });
     const tank = new IotData({ hardwareId, tankHeight, maxLevel, minLevel, mode, date, time });
 
@@ -713,3 +713,33 @@ exports.getIotD = async(req, reply) => {
     throw boom.boomify(err);
   }
 }
+
+
+exports.getLatestData = async (req, reply) => {
+  try {
+    const hardwareId = req.params.hardwareId;
+
+    // get the latest two tank documents for the current hardwareId sorted in descending order of date and time
+    const latestTanks = await IotData.find({ hardwareId }).sort({ date: -1, time: -1 }).limit(2);
+
+    // if the number of documents for the current hardwareId is less than two, return an error response
+    if (latestTanks.length < 2) {
+      return reply.code(404).send({ error: 'Not enough data' });
+    }
+
+    // calculate the time difference between the latest and previous documents
+    const latestDate = new Date(latestTanks[0].date);
+    const previousDate = new Date(latestTanks[1].date);
+    const latestTime = latestTanks[0].time.split('.')[0]; // remove milliseconds
+    const previousTime = latestTanks[1].time.split('.')[0]; // remove milliseconds
+    latestDate.setHours(parseInt(latestTime.substring(0, 2)), parseInt(latestTime.substring(3, 5)), parseInt(latestTime.substring(6, 8)));
+    previousDate.setHours(parseInt(previousTime.substring(0, 2)), parseInt(previousTime.substring(3, 5)), parseInt(previousTime.substring(6, 8)));
+    const timeDiff = (latestDate.getTime() - previousDate.getTime()) / 1000; // convert from milliseconds to seconds
+    console.log(latestDate,previousDate,latestTime,previousTime,timeDiff)
+    reply.code(200).send({ timeDiff });
+  
+  } catch (err) {
+    // send an error response
+    reply.code(500).send({ error: err.message });
+  }
+};

src/routes/tanksRoute.js

@@ -372,6 +372,35 @@ module.exports = function (fastify, opts, next) {
         handler: tanksController.getIotD,
       });
       
+      fastify.route({
+        method: "GET",
+        url: "/api/calculateTimedifference/:hardwareId",
+        schema: {
+          tags: ["Tank"],
+          summary: "This is for calculating the time gap between iot data",
+          params: {
+            required: ["hardwareId"],
+            type: "object",
+            properties: {
+              hardwareId: {
+                type: "string",
+                description: "hardwareId",
+              },
+            },
+          },
+         // querystring: {
+        //    tankName: {type: 'string'}
+       //   },
+          security: [
+            {
+              basicAuth: [],
+            },
+          ],
+        },
+        preHandler: fastify.auth([fastify.authenticate]),
+        handler: tanksController.getLatestData,
+      });
+
 
     next();
 }