feat(geo): make geo a package instead of service (#161)

packages/geo/src/geo.ts

@@ -0,0 +1,69 @@
+import { readFile } from 'node:fs/promises';
+import path from 'node:path';
+import type { ReaderModel } from '@maxmind/geoip2-node';
+import { Reader } from '@maxmind/geoip2-node';
+
+const filename = 'GeoLite2-City.mmdb';
+// From api or worker package
+const dbPath = path.join(__dirname, `../../../packages/geo/${filename}`);
+// From local package
+const dbPathLocal = path.join(__dirname, `../${filename}`);
+
+let reader: ReaderModel | null = null;
+
+async function loadDatabase(dbPath: string) {
+  try {
+    const dbBuffer = await readFile(dbPath);
+    reader = Reader.openBuffer(dbBuffer);
+    console.log('GeoLite2-City.mmdb loaded (dist)');
+  } catch (error) {
+    try {
+      const dbBuffer = await readFile(dbPathLocal);
+      reader = Reader.openBuffer(dbBuffer);
+      console.log('GeoLite2-City.mmdb loaded (local)');
+    } catch (error) {
+      console.error('GeoLite2-City.mmdb not found');
+    }
+  }
+}
+
+export interface GeoLocation {
+  country: string | undefined;
+  city: string | undefined;
+  region: string | undefined;
+  longitude: number | undefined;
+  latitude: number | undefined;
+}
+
+const DEFAULT_GEO: GeoLocation = {
+  country: undefined,
+  city: undefined,
+  region: undefined,
+  longitude: undefined,
+  latitude: undefined,
+};
+
+const ignore = ['127.0.0.1', '::1'];
+
+export async function getGeoLocation(ip?: string): Promise<GeoLocation> {
+  if (!ip || ignore.includes(ip)) {
+    return DEFAULT_GEO;
+  }
+
+  if (!reader) {
+    await loadDatabase(dbPath);
+  }
+
+  try {
+    const response = await reader?.city(ip);
+    return {
+      city: response?.city?.names.en,
+      country: response?.country?.isoCode,
+      region: response?.subdivisions?.[0]?.names.en,
+      longitude: response?.location?.longitude,
+      latitude: response?.location?.latitude,
+    };
+  } catch (error) {
+    return DEFAULT_GEO;
+  }
+}