iso3166-1/src/index.js

var read      = require('fs').readFileSync
var gunzip    = require('zlib-browserify').gunzipSync
var join      = require('path').join

var countries = read(join(__dirname, '../data', '/countries.json.gz'))
var ISOCodes  = JSON.parse(gunzip(countries).toString())

module.exports = (function iso3166() {
  var state = ''

  /**
   * Convert an ISO 3166-1 alpha-3 code to alpha-2
   *
   * @param  {String} alpha3 USA
   * @return {String}
   */
  var to2 = function to2(alpha3) {
    if (alpha3 && alpha3.length > 1) state = alpha3
    if (state.length !== 3) return state
    return ISOCodes.filter(function(row) {
      return row.alpha3 === state
    })[0].alpha2
  }

  /**
   * Convert an ISO 3166-1 alpha-2 code to alpha-3
   *
   * @param  {String} alpha2 US
   * @return {String}
   */
  var to3 = function to3(alpha2) {
    if (alpha2 && alpha2.length > 1) state = alpha2
    if (state.length !== 2) return state
    return ISOCodes.filter(function(row) {
      return row.alpha2 === state
    })[0].alpha3
  }

  /**
   * Prepare an ISO 3166-1 alpha-2 or alpha-3 code
   * for conversion.
   *
   * @param  {String} code USA
   * @return {Function}
   */
  var from = function from(code) {
    if (typeof code !== 'string') return state
    state = code.toUpperCase()
    return this
  }

  /**
   * Prepare an ISO 3166-1 alpha-2 and ISO 639-1 pair
   * for conversion.
   *
   * @param  {String} locale en-US
   * @return {Function}
   */
  var fromLocale = function fromLocale(locale) {
    if (typeof locale !== 'string') return state
    state = locale.split('-').pop().toUpperCase()
    return this
  }

  /**
   * Return an Object containing key/val pair of
   * ISO 3166-1 alpha-2 and alpha-3 codes.
   *
   * @return {Object}
   */
  var list = function list() {
    return ISOCodes
  }

  /**
   * Return true if input is a known ISO 3166-1 alpha-2
   * code, false otherwise.
   *
   * @param  {String} alpha2
   * @return {Boolean}
  */
  var is2 = function is2(alpha2) {
    return ISOCodes.some(function(row) {
      return row.alpha2 === alpha2
    })
  }

  /**
   * Return true if input is a known ISO 3166-1 alpha-3
   * code, false otherwise.
   *
   * @param  {String} alpha3
   * @return {Boolean}
  */
  var is3 = function is3(alpha3) {
    return ISOCodes.some(function(row) {
      return row.alpha3 === alpha3
    })
  }

  return {
    to2:        to2,
    to3:        to3,
    from:       from,
    fromLocale: fromLocale,
    list:       list,
    is2:        is2,
    is3:        is3
  }
})()