<?php

namespace Symfony\Components\CssSelector\Node;

use Symfony\Components\CssSelector\SyntaxError;

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien.potencier@symfony-project.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * PseudoNode represents a "selector:ident" node.
 *
 * This component is a port of the Python lxml library,
 * which is copyright Infrae and distributed under the BSD license.
 *
 * @package    Symfony
 * @subpackage Components_CssSelector
 * @author     Fabien Potencier <fabien.potencier@symfony-project.com>
 */
class PseudoNode implements NodeInterface
{
  static protected $unsupported = array(
    'indeterminate', 'first-line', 'first-letter',
    'selection', 'before', 'after', 'link', 'visited',
    'active', 'focus', 'hover',
  );

  protected $element;
  protected $type;
  protected $ident;

  /**
   * @throws SyntaxError When incorrect PseudoNode type is given
   */
  public function __construct($element, $type, $ident)
  {
    $this->element = $element;

    if (!in_array($type, array(':', '::')))
    {
      throw new SyntaxError(sprintf('The PseudoNode type can only be : or :: (%s given).', $type));
    }

    $this->type = $type;
    $this->ident = $ident;
  }

  public function __toString()
  {
    return sprintf('%s[%s%s%s]', __CLASS__, $this->element, $this->type, $this->ident);
  }

  /**
   * @throws SyntaxError When unsupported or unknown pseudo-class is found
   */
  public function toXpath()
  {
    $el_xpath = $this->element->toXpath();

    if (in_array($this->ident, self::$unsupported))
    {
      throw new SyntaxError(sprintf("The pseudo-class %s is unsupported", $this->ident));
    }
    $method = 'xpath_'.str_replace('-', '_', $this->ident);
    if (!method_exists($this, $method))
    {
      throw new SyntaxError(sprintf("The pseudo-class %s is unknown", $this->ident));
    }

    return $this->$method($el_xpath);
  }

  protected function xpath_checked($xpath)
  {
    // FIXME: is this really all the elements?
    $xpath->addCondition("(@selected or @checked) and (name(.) = 'input' or name(.) = 'option')");

    return $xpath;
  }

  /**
   * @throws SyntaxError If this element is the root element
   */
  protected function xpath_root($xpath)
  {
    // if this element is the root element
    throw new SyntaxError();
  }

  protected function xpath_first_child($xpath)
  {
    $xpath->addStarPrefix();
    $xpath->addNameTest();
    $xpath->addCondition('position() = 1');

    return $xpath;
  }

  protected function xpath_last_child($xpath)
  {
    $xpath->addStarPrefix();
    $xpath->addNameTest();
    $xpath->addCondition('position() = last()');

    return $xpath;
  }

  protected function xpath_first_of_type($xpath)
  {
    if ($xpath->getElement() == '*')
    {
      throw new SyntaxError("*:first-of-type is not implemented");
    }
    $xpath->addStarPrefix();
    $xpath->addCondition('position() = 1');

    return $xpath;
  }

  /**
   * @throws SyntaxError Because *:last-of-type is not implemented
   */
  protected function xpath_last_of_type($xpath)
  {
    if ($xpath->getElement() == '*')
    {
      throw new SyntaxError("*:last-of-type is not implemented");
    }
    $xpath->addStarPrefix();
    $xpath->addCondition('position() = last()');

    return $xpath;
  }

  protected function xpath_only_child($xpath)
  {
    $xpath->addNameTest();
    $xpath->addStarPrefix();
    $xpath->addCondition('last() = 1');

    return $xpath;
  }

  /**
   * @throws SyntaxError Because *:only-of-type is not implemented
   */
  protected function xpath_only_of_type($xpath)
  {
    if ($xpath->getElement() == '*')
    {
      throw new SyntaxError("*:only-of-type is not implemented");
    }
    $xpath->addCondition('last() = 1');

    return $xpath;
  }

  protected function xpath_empty($xpath)
  {
    $xpath->addCondition("not(*) and not(normalize-space())");

    return $xpath;
  }
}