import * as fs from "node:fs";
import * as path from "node:path";

interface LanguageItem {
  hint?: string;
  message: string;
  invalidMessage?: string;
  dirForPrompts?: {
    current: string;
    target: string;
  };
  toggleOptions?: {
    active: string;
    inactive: string;
  };
  selectOptions?: {
    [key: string]: { title: string; desc?: string };
  };
}

export interface Language {
  programName: LanguageItem;
  shouldOverride: LanguageItem;
  organizationName: LanguageItem;
  programCrateName: LanguageItem;
  programAddress: LanguageItem;
  programFramework: LanguageItem;
  clients: LanguageItem;
  jsClientPackageName: LanguageItem;
  rustClientCrateName: LanguageItem;
  errors: {
    operationCancelled: string;
    cannotOverrideDirectory: string;
    solanaKeygenNotFound: string;
  };
  defaultToggleOptions: {
    active: string;
    inactive: string;
  };
  instructions: {
    select: string;
    multiselect: string;
  };
  infos: {
    scaffolding: string;
    generatingKeypair: string;
    done: string;
  };
}

/**
 *
 * This function is used to link obtained locale with correct locale file in order to make locales reusable
 *
 * @param locale the obtained locale
 * @returns locale that linked with correct name
 */
function linkLocale(locale: string) {
  let linkedLocale: string;
  try {
    // @ts-ignore
    linkedLocale = Intl.getCanonicalLocales(locale)[0];
  } catch (error) {
    console.log(`${error.toString()}\n`);
  }
  switch (linkedLocale) {
    case "zh-TW":
    case "zh-HK":
    case "zh-MO":
      linkedLocale = "zh-Hant";
      break;
    case "zh-CN":
    case "zh-SG":
      linkedLocale = "zh-Hans";
      break;
    default:
      linkedLocale = locale;
  }

  return linkedLocale;
}

function getLocale() {
  const shellLocale =
    process.env.LC_ALL || // POSIX locale environment variables
    process.env.LC_MESSAGES ||
    process.env.LANG ||
    Intl.DateTimeFormat().resolvedOptions().locale || // Built-in ECMA-402 support
    "en-US"; // Default fallback

  return linkLocale(shellLocale.split(".")[0].replace("_", "-"));
}

export function getLanguage() {
  const locale = getLocale();

  // Note here __dirname would not be transpiled,
  // so it refers to the __dirname of the file `<repositoryRoot>/outfile.cjs`
  const localesRoot = path.resolve(__dirname, "locales");
  const languageFilePath = path.resolve(localesRoot, `${locale}.json`);
  const doesLanguageExist = fs.existsSync(languageFilePath);

  const lang: Language = doesLanguageExist
    ? require(languageFilePath)
    : require(path.resolve(localesRoot, "en-US.json"));

  return lang;
}