<?php

define('GENERATE_TEMPLATES', false);

class L10N
{
  private $translations = [];
  const default_language = "en_US";
  private $language;
  private $l10n_template = [];

  public function __construct($desired_languages, $l10n_dir, $modules_path = null)
  {
    if (!isset($desired_languages)) {
      $desired_languages = "";
    }

    $l10n_dir = rtrim($l10n_dir, '/');
    $available_languages = array_filter(scandir($l10n_dir),
        function ($s) {
          return pathinfo($s, PATHINFO_EXTENSION) == "json";
        });
    $available_languages = array_map(
        function ($s) {
          return basename($s, ".json");
        },
        $available_languages);

    $desired_lang = $this->load_language_setting($modules_path);
    if ($desired_lang != "auto") {
      $desired_languages = $desired_lang;
    }
    $lang = $this->find_language($available_languages, $desired_languages);
    $this->language = $lang;
    if ($lang === L10N::default_language || !file_exists(join('/', [$l10n_dir, $lang . ".json"])) || !$this->load($lang, $l10n_dir, $modules_path)) {
      $this->language = L10N::default_language;
    }
  }

  function load($lang, $l10n_dir, $modules_path)
  {
    $modules_path = join('/', [rtrim($modules_path, '/'), $l10n_dir]);
    $files = [join('/', [$l10n_dir, $lang . ".json"])];
    if (is_dir($modules_path)) {
      foreach (scandir($modules_path) as $dir) {
        $file_path = join('/', [$modules_path, trim($dir, '/'), $lang . ".json"]);
        if (is_file($file_path)) {
          array_push($files, $file_path);
        }
      }
    }

    $jsonError = null;
    foreach ($files as $file) {
      $module_name = pathinfo(pathinfo($file, PATHINFO_DIRNAME), PATHINFO_BASENAME);
      if ($module_name == pathinfo($l10n_dir, PATHINFO_BASENAME)) {
        $module_name = "__core__";
      }
      $json = json_decode(file_get_contents($file), true);
      if (!is_array($json)) {
        $jsonError = json_last_error();
        continue;
      }
      $this->translations[$module_name] = $json['translations'];
    }
    return ($jsonError == null);
  }

  function save($lang)
  {
    $cfg = 'ncp-web.cfg';
    $line = file_get_contents( $cfg );
    $str  = '';
    if (preg_match('/^LANGUAGE_=\[(([_\w]+,)*[_\w]+)\]$/', $line, $matches)) {
      $options = explode(',', $matches[1]);
      foreach ($options as $option) {
        $opt = trim( $option, "_" );
        $str .= $opt == $lang ? '_' . $opt . '_,' : $opt . ',';
      }
    }
    $str = 'LANGUAGE_=[' . rtrim( $str, ',' ) . ']';
    return file_put_contents( $cfg , $str );
  }

  function load_template($module)
  {
    if (is_file("./l10n_templates/$module.json")) {
      $this->l10n_template[$module] =
          json_decode(file_get_contents("./l10n_templates/$module.json"), true)['translations'];
    } else {
      $this->l10n_template[$module] = [];
    }
  }

  function save_template($module)
  {
    $f_handle = fopen("./l10n_templates/$module.json", "w");
    fwrite($f_handle, json_encode(['translations' => $this->l10n_template[$module]]));
    fclose($f_handle);
  }

  public function __($text, $module = "__core__")
  {
    if (GENERATE_TEMPLATES) {
      $this->load_template($module);
      if (!isset($this->l10n_template[$module][$text])) {
        $this->l10n_template[$module][$text] = $text;
        $this->save_template($module);
      }
    }
    if (isset($this->translations[$module]) && isset($this->translations[$module][$text])) {
      return $this->translations[$module][$text];
    }
    return $text;
  }

  function find_language(array $available_languages, $desired_language)
  {

    $available_languages = array_flip($available_languages);
    $langs = [];
    preg_match_all('~([\w-]+)(?:[^,\d]+([\d.]+))?~', strtolower($desired_language), $matches, PREG_SET_ORDER);

    foreach ($matches as $match) {

      list($a, $b) = explode('-', $match[1]) + array('', '');
      $value = isset($match[2]) ? (float)$match[2] : 1.0;

      if (isset($available_languages[$match[1]])) {
        $langs[$match[1]] = $value;
        continue;
      }

      if (isset($available_languages[$a])) {
        $langs[$a] = $value - 0.1;
      }

    }
    arsort($langs);

    if (count($langs) == 0) {
      return L10N::default_language;
    }
    return array_keys($langs)[0];
  }

  function load_language_setting($modules_path)
  {
    $webui_config_file = 'ncp-web.cfg';
    $fh = fopen($webui_config_file, 'r')
    or exit('{ "output": "' . $webui_config_file . ' read error" }');
    $lang = "auto";
    while ($line = fgets($fh)) {
      // drop down menu
      if (preg_match('/^LANGUAGE_=\[(([_\w]+,)*[_\w]+)\]$/', $line, $matches)) {
        $options = explode(',', $matches[1]);
        foreach ($options as $option) {
          if ($option[0] == "_" && $option[count($option) - 1] == "_") {
            fclose($fh);
            $lang = trim($option, '_');
          }
        }
        fclose($fh);
        return $lang;
      }
    }
  }
}