Country Name Retrieval

/**
 * Get country name by country code
 * @param code - Alpha-2, Alpha-3, or Numeric country code
 * @param lang - ISO 639-1 language code
 * @param options - Selection options for name variants
 * @returns Country name(s) or undefined if not found
 */
function getName(
  code: string | number | Alpha2Code | Alpha3Code,
  lang: string,
  options?: GetNameOptions
): string | string[] | undefined;

interface GetNameOptions {
  select: 'official' | 'alias' | 'all';
}

const countries = require("i18n-iso-countries");

// Basic usage (returns official name)
console.log(countries.getName("US", "en")); // "United States of America"
console.log(countries.getName("DE", "fr")); // "Allemagne"

// Using different code formats
console.log(countries.getName("USA", "en")); // "United States of America" (Alpha-3)
console.log(countries.getName("840", "en")); // "United States of America" (Numeric)
console.log(countries.getName(840, "en"));   // "United States of America" (Numeric as number)

// Selecting specific name variants
console.log(countries.getName("GB", "en", { select: "official" })); // "United Kingdom"
console.log(countries.getName("GB", "en", { select: "alias" }));    // "UK"
console.log(countries.getName("GB", "en", { select: "all" }));      // ["United Kingdom", "UK", "Great Britain"]

// Countries without aliases return the official name for all variants
console.log(countries.getName("LT", "en", { select: "official" })); // "Lithuania"
console.log(countries.getName("LT", "en", { select: "alias" }));    // "Lithuania"
console.log(countries.getName("LT", "en", { select: "all" }));      // ["Lithuania"]

// Multiple languages
console.log(countries.getName("JP", "en")); // "Japan"
console.log(countries.getName("JP", "de")); // "Japan"
console.log(countries.getName("JP", "fr")); // "Japon"
console.log(countries.getName("JP", "zh")); // "日本"

/**
 * Get all country names for a language
 * @param lang - ISO 639-1 language code
 * @param options - Selection options for name variants
 * @returns Object mapping Alpha-2 codes to country names
 */
function getNames(
  lang: string,
  options?: GetNameOptions
): LocalizedCountryNames<GetNameOptions>;

type LocalizedCountryNames<T extends GetNameOptions> = {
  [alpha2Key: string]: CountryName<T>;
};

type CountryName<T extends GetNameOptions> = T extends { select: 'all' } 
  ? string[] 
  : string;

const countries = require("i18n-iso-countries");

// Get all official country names in English
const englishNames = countries.getNames("en");
console.log(englishNames.US); // "United States of America"
console.log(englishNames.FR); // "France"
console.log(englishNames.DE); // "Germany"

// Get all country names with aliases
const namesWithAliases = countries.getNames("en", { select: "all" });
console.log(namesWithAliases.GB); // ["United Kingdom", "UK", "Great Britain"]
console.log(namesWithAliases.US); // ["United States of America"]

// Get all aliases (falls back to official if no alias exists)
const aliases = countries.getNames("en", { select: "alias" });
console.log(aliases.GB); // "UK"
console.log(aliases.US); // "United States of America"

// Different languages
const germanNames = countries.getNames("de");
console.log(germanNames.US); // "Vereinigte Staaten von Amerika"
console.log(germanNames.GB); // "Vereinigtes Königreich"

const frenchNames = countries.getNames("fr");
console.log(frenchNames.US); // "États-Unis"
console.log(frenchNames.CN); // "Chine"

const countries = require("i18n-iso-countries");

// Register required languages
countries.registerLocale(require("i18n-iso-countries/langs/en.json"));
countries.registerLocale(require("i18n-iso-countries/langs/fr.json"));

// Now you can use getName() and getNames() with these languages
console.log(countries.getName("US", "en")); // Works
console.log(countries.getName("US", "de")); // Returns undefined (not registered)