<?php

/*
 * This file is part of Twig.
 *
 * (c) 2009 Fabien Potencier
 * (c) 2009 Armin Ronacher
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * Marks a section of a template as being reusable.
 *
 * <pre>
 *  {% block head %}
 *    <link rel="stylesheet" href="style.css" />
 *    <title>{% block title %}{% endblock %} - My Webpage</title>
 *  {% endblock %}
 * </pre>
 */
class Twig_TokenParser_Block extends Twig_TokenParser
{
  public function parse(Twig_Token $token)
  {
    $lineno = $token->getLine();
    $stream = $this->parser->getStream();
    $name = $stream->expect(Twig_Token::NAME_TYPE)->getValue();
    if ($this->parser->hasBlock($name)) {
      throw new Twig_Error_Syntax(sprintf("The block '$name' has already been defined line %d", $this->parser->getBlock($name)->getLine()), $stream->getCurrent()->getLine(), $stream->getFilename());
    }
    $this->parser->setBlock($name, $block = new Twig_Node_Block($name, new Twig_Node([]), $lineno));
    $this->parser->pushLocalScope();
    $this->parser->pushBlockStack($name);

    if ($stream->nextIf(Twig_Token::BLOCK_END_TYPE)) {
      $body = $this->parser->subparse([$this, 'decideBlockEnd'], true);
      if ($token = $stream->nextIf(Twig_Token::NAME_TYPE)) {
        $value = $token->getValue();

        if ($value != $name) {
          throw new Twig_Error_Syntax(sprintf('Expected endblock for block "%s" (but "%s" given)', $name, $value), $stream->getCurrent()->getLine(), $stream->getFilename());
        }
      }
    } else {
      $body = new Twig_Node([new Twig_Node_Print($this->parser->getExpressionParser()->parseExpression(), $lineno)]);
    }
    $stream->expect(Twig_Token::BLOCK_END_TYPE);

    $block->setNode('body', $body);
    $this->parser->popBlockStack();
    $this->parser->popLocalScope();

    return new Twig_Node_BlockReference($name, $lineno, $this->getTag());
  }

  public function decideBlockEnd(Twig_Token $token)
  {
    return $token->test('endblock');
  }

  public function getTag()
  {
    return 'block';
  }
}
