<?php

namespace Drupal\Core\Language;

use Drupal\Core\StringTranslation\TranslatableMarkup;

/**
 * An object containing the information for an interface language.
 *
 * @see \Drupal\Core\Language\LanguageManager::getLanguage()
 */
class Language implements LanguageInterface {

  /**
   * The values to use to instantiate the default language.
   *
   * @var array
   */
  public static $defaultValues = [
    'id' => 'en',
    'name' => 'English',
    'direction' => self::DIRECTION_LTR,
    'weight' => 0,
    'locked' => FALSE,
  ];

  // Properties within the Language are set up as the default language.

  /**
   * The human readable English name.
   *
   * @var string
   */
  protected $name = '';

  /**
   * The ID, langcode.
   *
   * @var string
   */
  protected $id = '';

  /**
   * The direction, left-to-right, or right-to-left.
   *
   * Defined using constants, either self::DIRECTION_LTR or self::DIRECTION_RTL.
   *
   * @var int
   */
  protected $direction = self::DIRECTION_LTR;

  /**
   * The weight, used for ordering languages in lists, like selects or tables.
   *
   * @var int
   */
  protected $weight = 0;

  /**
   * Locked indicates a language used by the system, not an actual language.
   *
   * Examples of locked languages are, LANGCODE_NOT_SPECIFIED, und, and
   * LANGCODE_NOT_APPLICABLE, zxx, which are usually shown in language selects
   * but hidden in places like the Language configuration and cannot be deleted.
   *
   * @var bool
   */
  protected $locked = FALSE;

  /**
   * Constructs a new class instance.
   *
   * @param array $values
   *   An array of property values, keyed by property name, used to construct
   *   the language.
   */
  public function __construct(array $values = []) {
    // Set all the provided properties for the language.
    foreach ($values as $key => $value) {
      if (property_exists($this, $key)) {
        $this->{$key} = $value;
      }
    }
    // If some values were not set, set sane defaults of a predefined language.
    if (!isset($values['name']) || !isset($values['direction'])) {
      $predefined = LanguageManager::getStandardLanguageList();
      if (isset($predefined[$this->id])) {
        if (!isset($values['name'])) {
          $this->name = $predefined[$this->id][0];
        }
        if (!isset($values['direction']) && isset($predefined[$this->id][2])) {
          $this->direction = $predefined[$this->id][2];
        }
      }
    }
  }

  /**
   * {@inheritdoc}
   */
  public function getName() {
    return $this->name;
  }

  /**
   * {@inheritdoc}
   */
  public function getId() {
    return $this->id;
  }

  /**
   * {@inheritdoc}
   */
  public function getDirection() {
    return $this->direction;
  }

  /**
   * {@inheritdoc}
   */
  public function getWeight() {
    return $this->weight;
  }

  /**
   * {@inheritdoc}
   */
  public function isDefault() {
    return static::getDefaultLangcode() == $this->getId();
  }

  /**
   * {@inheritdoc}
   */
  public function isLocked() {
    return (bool) $this->locked;
  }

  /**
   * Sort language objects.
   *
   * @param \Drupal\Core\Language\LanguageInterface[] $languages
   *   The array of language objects keyed by langcode.
   */
  public static function sort(&$languages) {
    uasort($languages, function (LanguageInterface $a, LanguageInterface $b) {
      $a_weight = $a->getWeight();
      $b_weight = $b->getWeight();
      if ($a_weight == $b_weight) {
        $a_name = $a->getName();
        $b_name = $b->getName();
        // If either name is a TranslatableMarkup object it can not be converted
        // to a string. This is because translation requires a sorted list of
        // languages thereby causing an infinite loop. Determine the order based
        // on ID if this is the case.
        if ($a_name instanceof TranslatableMarkup || $b_name instanceof TranslatableMarkup) {
          $a_name = $a->getId();
          $b_name = $b->getId();
        }
        return strnatcasecmp($a_name, $b_name);
      }
      return ($a_weight < $b_weight) ? -1 : 1;
    });
  }

  /**
   * Gets the default langcode.
   *
   * @return string
   *   The current default langcode.
   */
  protected static function getDefaultLangcode() {
    $language = \Drupal::service('language.default')->get();
    return $language->getId();
  }

}