refactor(server): reverse geocoding (#2167)

* refactor(server): reverse geocoding

* fix: nullable results

server/libs/infra/src/repositories/geocoding.repository.ts

@@ -0,0 +1,44 @@
+import { GeoPoint, ReverseGeocodeResult } from '@app/domain';
+import { localGeocodingConfig } from '@app/infra';
+import { Injectable, Logger } from '@nestjs/common';
+import { getName } from 'i18n-iso-countries';
+import geocoder, { AddressObject, InitOptions } from 'local-reverse-geocoder';
+import { promisify } from 'util';
+
+export interface AdminCode {
+  name: string;
+  asciiName: string;
+  geoNameId: string;
+}
+
+export type GeoData = AddressObject & {
+  admin1Code?: AdminCode | string;
+  admin2Code?: AdminCode | string;
+};
+
+const init = (options: InitOptions): Promise<void> => new Promise<void>((resolve) => geocoder.init(options, resolve));
+const lookup = promisify<GeoPoint[], number, AddressObject[][]>(geocoder.lookUp).bind(geocoder);
+
+@Injectable()
+export class GeocodingRepository {
+  private logger = new Logger(GeocodingRepository.name);
+
+  async init(): Promise<void> {
+    await init(localGeocodingConfig);
+  }
+
+  async reverseGeocode(point: GeoPoint): Promise<ReverseGeocodeResult> {
+    this.logger.debug(`Request: ${point.latitude},${point.longitude}`);
+
+    const [address] = await lookup([point], 1);
+    this.logger.verbose(`Raw: ${JSON.stringify(address, null, 2)}`);
+
+    const { countryCode, name: city, admin1Code, admin2Code } = address[0] as GeoData;
+    const country = getName(countryCode, 'en');
+    const stateParts = [(admin2Code as AdminCode)?.name, (admin1Code as AdminCode)?.name].filter((name) => !!name);
+    const state = stateParts.length > 0 ? stateParts.join(', ') : null;
+    this.logger.debug(`Normalized: ${JSON.stringify({ country, state, city })}`);
+
+    return { country, state, city };
+  }
+}