const fs = require('fs');
const jsonfile = require('jsonfile');
const readline = require('readline');

const removeDoubleQuotes = (value) => value.replaceAll('"', '');

const txtToJson = (filename, columnNameMapping = {}, jsonFilePath) => {
  const txtFilePath = `./${filename}.txt`;
  jsonFilePath = jsonFilePath || `./${filename}.json`;
  let entries = [],
    i = 0,
    lineValues;
  const mappedColumnIndexes = Object.keys(columnNameMapping).map((index) =>
    parseInt(index)
  );

  readline
    .createInterface({
      input: fs.createReadStream(txtFilePath),
      output: process.stdout,
      terminal: false,
    })
    .on('line', function (line) {
      lineValues = line.split('\t');
      if (i !== 0) {
        entries.push(
          lineValues.reduce((entry, value, valueIndex) => {
            if (mappedColumnIndexes.includes(valueIndex)) {
              entry[columnNameMapping[valueIndex]] = removeDoubleQuotes(value);
            }

            return entry;
          }, {})
        );
      }
      i++;
    })
    .on('close', function () {
      console.log(`Writing ${i} entries to ${jsonFilePath}`);
      jsonfile.writeFile(jsonFilePath, entries, { spaces: 2 }, function (err) {
        if (err) {
          console.error(err);
        }
      });
    });
};

// geonameid         : integer id of record in geonames database
// name              : name of geographical point (utf8) varchar(200)
// asciiname         : name of geographical point in plain ascii characters, varchar(200)
// alternatenames    : alternatenames, comma separated, ascii names automatically transliterated, convenience attribute from alternatename table, varchar(10000)
// latitude          : latitude in decimal degrees (wgs84)
// longitude         : longitude in decimal degrees (wgs84)
// feature class     : see http://www.geonames.org/export/codes.html, char(1)
// feature code      : see http://www.geonames.org/export/codes.html, varchar(10)
// country code      : ISO-3166 2-letter country code, 2 characters
// cc2               : alternate country codes, comma separated, ISO-3166 2-letter country code, 200 characters
// admin1 code       : fipscode (subject to change to iso code), see exceptions below, see file admin1Codes.txt for display names of this code; varchar(20)
// admin2 code       : code for the second administrative division, a county in the US, see file admin2Codes.txt; varchar(80)
// admin3 code       : code for third level administrative division, varchar(20)
// admin4 code       : code for fourth level administrative division, varchar(20)
// population        : bigint (8 byte int)
// elevation         : in meters, integer
// dem               : digital elevation model, srtm3 or gtopo30, average elevation of 3''x3'' (ca 90mx90m) or 30''x30'' (ca 900mx900m) area in meters, integer. srtm processed by cgiar/ciat.
// timezone          : the iana timezone id (see file timeZone.txt) varchar(40)
// modification date : date of last modification in yyyy-MM-dd format
txtToJson(
  'cities1000',
  {
    8: 'country',
    1: 'name',
    4: 'lat',
    5: 'lng',
    10: 'admin1',
    11: 'admin2',
  },
  './cities.json'
);

txtToJson(
  'admin1CodesASCII',
  {
    0: 'code',
    1: 'name',
  },
  './admin1.json'
);

txtToJson(
  'admin2Codes',
  {
    0: 'code',
    1: 'name',
  },
  './admin2.json'
);