const http = require('https'); // or 'https' for https:// URLs
const fs = require('fs');
const yauzl = require('yauzl');

const baseURL = 'https://download.geonames.org/export/dump/';
const downloadGeonameFile = (filename) => {
  const writeStream = fs.createWriteStream(filename);
  const fileURL = `${baseURL}${filename}`;

  console.log(`Downloading ${fileURL}`);
  http.get(fileURL, (response) => {
    response.pipe(writeStream);
    writeStream.on('finish', () => {
      writeStream.close();
      console.log(`Download complete: ${filename}`);
    });
  });
};

downloadGeonameFile('admin1CodesASCII.txt');
downloadGeonameFile('admin2Codes.txt');

const txtFilename = 'cities1000.txt';
const zipFilename = 'cities1000.zip';
const zipFile = fs.createWriteStream(zipFilename);
http.get(`${baseURL}${zipFilename}`, (response) => {
  response.pipe(zipFile);

  zipFile.on('finish', () => {
    zipFile.close();
    console.log('Download Completed');

    yauzl.open(zipFilename, { lazyEntries: true }, (err, zipfile) => {
      if (err) throw err;
      zipfile.readEntry();
      zipfile.on('entry', (entry) => {
        if (entry.fileName === txtFilename) {
          const txtFile = fs.createWriteStream(entry.fileName);
          zipfile.openReadStream(entry, (err, readStream) => {
            if (err) {
              throw err;
            }
            readStream.on('end', function () {
              zipfile.readEntry();
            });
            readStream.pipe(txtFile);
          });
        }
      });
    });
  });
});