Add near

Author: jason-fox

iot-devices/lib/ngsi-ld.js

@@ -0,0 +1,86 @@
+
+
+const BASE_PATH = process.env.CONTEXT_BROKER || 'http://localhost:1026/ngsi-ld/v1';
+const JSON_LD_HEADER = 'application/ld+json';
+const Context = process.env.IOTA_JSON_LD_CONTEXT || 'http://context/ngsi-context.jsonld';
+const LinkHeader = '<' + Context + '>; rel="http://www.w3.org/ns/json-ld#context"; type="application/ld+json">';
+
+
+async function parse(response) {
+    let text = '';
+    try {
+        text = await response.text();
+        const data = JSON.parse(text);
+        return data;
+    } catch (err) {
+        return text;
+    }
+}
+
+function setHeaders(accessToken, link, contentType) {
+    const headers = {};
+    if (accessToken) {
+        // If the system has been secured and we have logged in,
+        // add the access token to the request to the PEP Proxy
+        headers['X-Auth-Token'] = accessToken;
+    }
+    if (link) {
+        headers.Link = link;
+    }
+    if (contentType) {
+        headers['Content-Type'] = contentType || JSON_LD_HEADER;
+    }
+    return headers;
+}
+
+// This is a promise to make an HTTP GET request to the
+// /ngsi-ld/v1/entities/ end point
+function listEntities(opts, headers = {}) {
+
+    console.log(`${BASE_PATH}/entities/?${new URLSearchParams(opts)}`)
+    return fetch(`${BASE_PATH}/entities/?${new URLSearchParams(opts)}`, {
+        method: 'GET',
+        headers
+    })
+        .then((r) => parse(r).then((data) => ({ status: r.status, body: data })))
+        .then((data) => {
+            if (data.status !== 200) {
+                throw new Error(data.body);
+            }
+            return data.body;
+        });
+}
+
+
+exports.findNeighbour = async function (lat, lng, type){
+	const headers = setHeaders(null, LinkHeader);
+	const entities = await listEntities(
+            {
+                type,
+                pick: 'id',
+                limit: 2,
+                geometry: "Point",
+                coordinates: `[${lat},${lng}]`,
+                georel: "near;maxDistance==8000"
+            },
+            headers
+        );
+
+	return entities[1].id;
+}
+
+exports.findTargetInField = async function (type, locatedAt){
+	const headers = setHeaders(null, LinkHeader);
+	const entities = await listEntities(
+            {
+                type,
+                pick: 'id,location',
+                limit: 6
+            },
+            headers
+        );
+
+	console.log(entities);
+}
+
+

iot-devices/models/devices.js

@@ -10,6 +10,7 @@ const debug = require('debug')('devices:devices');
 const Northbound = require('../controllers/iot/northbound');
 const Emitter = require('../lib/emitter');
 const Writer = require('../lib/writer');
+const NgsiLd = require('../lib/ngsi-ld')
 
 // A series of constants used by our set of devices
 
@@ -321,7 +322,7 @@ function fireAnimalCollars() {
 function sendAnimalCollarReadings() {
   const deviceIds = myCache.keys();
   _.forEach(deviceIds, (deviceId) => {
-    getDeviceState(deviceId).then((state) => {
+    getDeviceState(deviceId).then( async (state) => {
       const isSensor = true;
       let targetRate;
 
@@ -380,6 +381,8 @@ function sendAnimalCollarReadings() {
           state.s = getStatusCode(state.d);
           if (state.o) {
             state.o++;
+            const coords = state.gps.split(',')
+            state.near = await NgsiLd.findNeighbour(coords[0], coords[1], 'Animal')
           }
           setDeviceState(deviceId, toUltraLight(state), isSensor);
           break;