Add find nearest feature

Signed-off-by: Fred Boniface <fred@fjla.uk>

src/services/ldb.services.js

@@ -179,10 +179,11 @@ async function getReasonCode(code) {
 }
 
 async function getNearestStations(lat, long) {
+  
   logger.debug(`ldbService.getNearestStations: Fetching nearest stations`)
   let pipeline = findStationsByDistancePipeline(4, lat, long)
   try {
-    return await db.queryAggregate(pipeline)
+    return await db.queryAggregate("stations", pipeline)
   } catch (err) {
     logger.error(err, `ldbService.getNearestStations`)
   }

src/utils/ldbPipeline.utils.ts

@@ -1,11 +1,13 @@
-export function findStationsByDistancePipeline(count: number, latitude: number, longitude: number) {
-  return [
+export function findStationsByDistancePipeline(count: number, latitude: string, longitude: string) {
+  const numericLatitude = parseFloat(latitude)
+  const numericLongitude = parseFloat(longitude)
+  const pipeline = [
     {
       '$geoNear': {
         'near': {
           'type': 'Point', 
           'coordinates': [
-            longitude, latitude
+            numericLongitude, numericLatitude
           ]
         }, 
         'distanceField': 'distance'
@@ -39,4 +41,7 @@ export function findStationsByDistancePipeline(count: number, latitude: number,
       }
     }
   ]
+
+  //console.log(JSON.stringify(pipeline))
+  return pipeline
 }