feat: add shelter filter by geolocation radius (#93)

src/shelter/ShelterSearch.ts

@@ -1,5 +1,6 @@
 import { Prisma } from '@prisma/client';
 
+import { calculateGeolocationBounds } from '@/utils/utils';
 import { SupplyPriority } from 'src/supply/types';
 import { PrismaService } from '../prisma/prisma.service';
 import {
@@ -129,11 +130,31 @@ class ShelterSearch {
     };
   }
 
+  get geolocation(): Prisma.ShelterWhereInput {
+    if (!this.formProps.geolocation) return {};
+
+    const { minLat, maxLat, minLong, maxLong } = calculateGeolocationBounds(
+      this.formProps.geolocation,
+    );
+
+    return {
+      latitude: {
+        gte: minLat,
+        lte: maxLat,
+      },
+      longitude: {
+        gte: minLong,
+        lte: maxLong,
+      },
+    };
+  }
+
   get query(): Prisma.ShelterWhereInput {
     if (Object.keys(this.formProps).length === 0) return {};
     const queryData = {
       AND: [
         this.cities,
+        this.geolocation,
         { OR: this.search },
         { OR: this.shelterStatus },
         this.priority(this.formProps.supplyIds),

src/shelter/types/search.types.ts

@@ -21,6 +21,14 @@ export type ShelterTagType = z.infer<typeof ShelterTagTypeSchema>;
 
 export type ShelterTagInfo = z.infer<typeof ShelterTagInfoSchema>;
 
+export const GeolocationFilterSchema = z.object({
+  latitude: z.coerce.number(),
+  longitude: z.coerce.number(),
+  radiusInMeters: z.coerce.number(),
+});
+
+export type GeolocationFilter = z.infer<typeof GeolocationFilterSchema>;
+
 export const ShelterSearchPropsSchema = z.object({
   search: z.string().optional(),
   priority: z.preprocess(
@@ -32,6 +40,7 @@ export const ShelterSearchPropsSchema = z.object({
   shelterStatus: z.array(ShelterStatusSchema).optional(),
   tags: ShelterTagInfoSchema.nullable().optional(),
   cities: z.array(z.string()).optional(),
+  geolocation: GeolocationFilterSchema.optional(),
 });
 
 export type ShelterSearchProps = z.infer<typeof ShelterSearchPropsSchema>;

src/utils/utils.ts

@@ -1,4 +1,5 @@
 import { Logger } from '@nestjs/common';
+import { GeolocationFilter } from 'src/shelter/types/search.types';
 
 class ServerResponse<T> {
   readonly message: string;
@@ -75,10 +76,45 @@ function deepMerge(target: Record<string, any>, source: Record<string, any>) {
   }
 }
 
+interface Coordinates {
+  maxLat: number;
+  minLat: number;
+  maxLong: number;
+  minLong: number;
+}
+
+function calculateGeolocationBounds({
+  latitude,
+  longitude,
+  radiusInMeters,
+}: GeolocationFilter): Coordinates {
+  const earthRadius = 6371000;
+
+  const latRad = (latitude * Math.PI) / 180;
+
+  const radiusRad = radiusInMeters / earthRadius;
+
+  const maxLat = latitude + radiusRad * (180 / Math.PI);
+  const minLat = latitude - radiusRad * (180 / Math.PI);
+
+  const deltaLong = Math.asin(Math.sin(radiusRad) / Math.cos(latRad));
+
+  const maxLong = longitude + deltaLong * (180 / Math.PI);
+  const minLong = longitude - deltaLong * (180 / Math.PI);
+
+  return {
+    maxLat,
+    minLat,
+    maxLong,
+    minLong,
+  };
+}
+
 export {
   ServerResponse,
-  removeNotNumbers,
-  getSessionData,
-  deepMerge,
+  calculateGeolocationBounds,
   capitalize,
+  deepMerge,
+  getSessionData,
+  removeNotNumbers,
 };