Filter shelters by distance

Author: rohitrp

client/src/app/_services/shelters.service.ts

@@ -22,9 +22,21 @@ export class SheltersService {
     );
   }
 
-  public getAllShelters(): Observable<Shelter[]> {
+  public getLatLng(): Observable<any> {
+    return this.http.get(
+      'http://ip-api.com/json/'
+    );
+  }
+
+  public getAllShelters(lat, lng): Observable<Shelter[]> {
     return this.http.get<Shelter[]>(
-      `${this.apiBaseUrl}/shelters`
+      `${this.apiBaseUrl}/shelters`,
+      {
+        params: {
+          lat: lat,
+          lng: lng
+        }
+      }
     );
   }
 

client/src/app/shelters/shelter-card/shelter-card.component.html

@@ -26,6 +26,11 @@
               <a href="{{bingMapUrl}}" target="_blank" class="button is-outlined">Open in Bing Maps</a>
             </div>
           </div>
+          <div class="column is-4">
+            <div class="content">
+              <p>Approx <span class="has-text-weight-bold">{{shelter['distance']}} kms</span> away</p>
+            </div>
+          </div>
         </div>
       </div>
       <footer class="card-footer">

client/src/app/shelters/shelter-info/shelter-info.component.html

@@ -7,6 +7,9 @@
           <div class="card-content">
             <div class="columns">
               <div class="column is-4">
+                <p *ngIf="shelter['official']" class="has-text-success">
+                  <i class="fa fa-check"></i>&nbsp;Official Government Shelter
+                </p>
                 <p class="title">
                   {{ shelter.name }}
                 </p>

client/src/app/shelters/shelters.component.ts

@@ -27,12 +27,19 @@ export class SheltersComponent implements OnInit {
         (err) => this.alertService.error(err)
       );
 
-    this.shelterService.getAllShelters()
+    this.shelterService.getLatLng()
       .subscribe(
-        (res) => this.shelters = res,
-        (err) => this.alertService.error(err)
+        (res) => {
+          this.shelterService.getAllShelters(res.lat, res.lon)
+            .subscribe(
+              (res) => this.shelters = res,
+              (err) => this.alertService.error(err)
+            );
+        }
       );
 
+
+
     this.shelterService.getZipcodeStatus()
       .subscribe(
         (res) => this.zipcodeStatus = res[0],

server/api/shelters/routes/getShelterUsers.js

@@ -0,0 +1,16 @@
+const Shelter = require('../model/Shelter')
+const User = require('../../users/model/User')
+var ObjectId = require('mongoose').Types.ObjectId; 
+
+module.exports = {
+  method: 'GET',
+  path: '/api/shelters/{id}/users',
+  options: {
+    handler: async (request, h) => {
+      const shelter = await User.find({shelter: new ObjectId(request.params.id)}).lean()
+
+      return shelter;
+    },
+    description: 'Returns requested shelter info'
+  }
+}

server/api/shelters/routes/getShelters.js

@@ -1,19 +1,57 @@
 const Shelter = require('../model/Shelter')
 const User = require('../../users/model/User')
 
+function distance(lat1, lon1, shelter) {
+  const unit = 'K';
+  const lon2 = +shelter.lngLat.split(",")[0];
+  const lat2 = +shelter.lngLat.split(",")[1];
+
+  if ((lat1 == lat2) && (lon1 == lon2)) {
+    return 0;
+  }
+  else {
+    var radlat1 = Math.PI * lat1 / 180;
+    var radlat2 = Math.PI * lat2 / 180;
+    var theta = lon1 - lon2;
+    var radtheta = Math.PI * theta / 180;
+    var dist = Math.sin(radlat1) * Math.sin(radlat2) + Math.cos(radlat1) * Math.cos(radlat2) * Math.cos(radtheta);
+    if (dist > 1) {
+      dist = 1;
+    }
+    dist = Math.acos(dist);
+    dist = dist * 180 / Math.PI;
+    dist = dist * 60 * 1.1515;
+    if (unit === "K") { dist = dist * 1.609344 }
+    return dist.toFixed(2);
+  }
+}
+
 module.exports = {
   method: 'GET',
   path: '/api/shelters',
   options: {
     handler: async (request, h) => {
+      const userLat = +request.query.lat
+      const userLng = +request.query.lng
+
       const shelters = await Shelter.find({}).lean()
 
       for (let i = 0; i < shelters.length; i++) {
         const user = await User.findOne({ _id: shelters[i].user })
         shelters[i].user = user.email;
       }
 
-      return shelters;
+      const nearbyShelters = []
+
+      for (let i = 0; i < shelters.length; i++) {
+        const dist = distance(userLat, userLng, shelters[i]);
+        if ( dist < 50) {
+          shelters[i]['distance'] = dist
+          nearbyShelters.push(shelters[i])
+        }
+      }
+
+      return nearbyShelters;
     },
     description: 'Returns all shelters'
   }