A CLI node script for syncing https://github.com/dr5hn/countries-states-cities-database/blob/master/countries%2Bstates%2Bcities.json to a Firebase Cloud Firestore

populateFirestore.js

const admin = require('firebase-admin');
const fs = require('fs');
const { geohashForLocation } = require('geofire-common');

// Initialize Firebase Admin
const serviceAccount = require('./firebase-adminsdk.json');
admin.initializeApp({
  credential: admin.credential.cert(serviceAccount)
});
const db = admin.firestore();

// Helper functions
const generateSlug = (...parts) => parts.map(part => part.toLowerCase().replace(/[\s\W-]+/g, '-')).join('-');
const sleep = (milliseconds) => new Promise(resolve => setTimeout(resolve, milliseconds));

const lastProcessedSlugFile = './lastProcessedSlug.txt';

const saveLastProcessedSlug = (slug) => {
  fs.writeFileSync(lastProcessedSlugFile, slug);
};

const readLastProcessedSlug = () => {
  try {
    return fs.readFileSync(lastProcessedSlugFile, 'utf8');
  } catch (e) {
    return null; // If file doesn't exist, start from the beginning
  }
};

// Populate Firestore with geohash
const populateFirestore = async (data) => {
  const lastProcessedSlug = readLastProcessedSlug();
  let hasReachedLastProcessed = lastProcessedSlug === null;

  for (const country of data) {
    const countrySlug = generateSlug(country.region, country.subregion, country.name);
    for (const state of country.states) {
      const stateSlug = generateSlug(countrySlug, state.name);
      for (const city of state.cities) {
        const citySlug = generateSlug(stateSlug, city.name);
        
        if (!hasReachedLastProcessed && citySlug === lastProcessedSlug) {
          hasReachedLastProcessed = true;
        } else if (!hasReachedLastProcessed) {
          continue; // Skip until we reach the last processed
        }

        // Calculate geohash
        const geohash = geohashForLocation([parseFloat(city.latitude), parseFloat(city.longitude)]);

        const docRef = db.collection('locations').doc(citySlug);
        await docRef.set({
          region: country.region,
          subregion: country.subregion,
          country: country.name,
          state: state.name,
          city: city.name,
          latitude: city.latitude,
          longitude: city.longitude,
          slug: citySlug,
          geohash // Include geohash in document
        });
        console.log(`Added: ${citySlug}`);

        saveLastProcessedSlug(citySlug); // Save this slug as the last processed
        await sleep(500); // Wait to prevent hitting rate limits
      }
    }
  }
};

// Main function to read JSON and populate Firestore
const main = async () => {
  const data = JSON.parse(fs.readFileSync('./countries+states+cities.json', 'utf8'));
  await populateFirestore(data);
  console.log('Data population completed.');
};

main().catch(console.error);