<?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.
 */

/**
 * Represents a for node.
 *
 * @package    twig
 * @author     Fabien Potencier <fabien@symfony.com>
 */
class Twig_Node_For extends Twig_Node
{
    protected $loop;

    public function __construct(Twig_Node_Expression_AssignName $keyTarget, Twig_Node_Expression_AssignName $valueTarget, Twig_Node_Expression $seq, Twig_Node_Expression $ifexpr = null, Twig_NodeInterface $body, Twig_NodeInterface $else = null, $lineno, $tag = null)
    {
        $body->setNode('_for_loop', $this->loop = new Twig_Node_ForLoop($lineno, $tag));

        if (null !== $ifexpr) {
            $body = new Twig_Node_If(new Twig_Node(array($ifexpr, $body)), null, $lineno, $tag);
        }

        parent::__construct(array('key_target' => $keyTarget, 'value_target' => $valueTarget, 'seq' => $seq, 'body' => $body, 'else' => $else), array('with_loop' => true, 'ifexpr' => null !== $ifexpr), $lineno, $tag);
    }

    /**
     * Compiles the node to PHP.
     *
     * @param Twig_Compiler A Twig_Compiler instance
     */
    public function compile(Twig_Compiler $compiler)
    {
        $compiler
            ->addDebugInfo($this)
            // the (array) cast bypasses a PHP 5.2.6 bug
            ->write("\$context['_parent'] = (array) \$context;\n")
            ->write("\$context['_seq'] = twig_ensure_traversable(")
            ->subcompile($this->getNode('seq'))
            ->raw(");\n")
        ;

        if (null !== $this->getNode('else')) {
            $compiler->write("\$context['_iterated'] = false;\n");
        }

        if ($this->getAttribute('with_loop')) {
            $compiler
                ->write("\$context['loop'] = array(\n")
                ->write("  'parent' => \$context['_parent'],\n")
                ->write("  'index0' => 0,\n")
                ->write("  'index'  => 1,\n")
                ->write("  'first'  => true,\n")
                ->write(");\n")
            ;

            if (!$this->getAttribute('ifexpr')) {
                $compiler
                    ->write("if (is_array(\$context['_seq']) || (is_object(\$context['_seq']) && \$context['_seq'] instanceof Countable)) {\n")
                    ->indent()
                    ->write("\$length = count(\$context['_seq']);\n")
                    ->write("\$context['loop']['revindex0'] = \$length - 1;\n")
                    ->write("\$context['loop']['revindex'] = \$length;\n")
                    ->write("\$context['loop']['length'] = \$length;\n")
                    ->write("\$context['loop']['last'] = 1 === \$length;\n")
                    ->outdent()
                    ->write("}\n")
                ;
            }
        }

        $this->loop->setAttribute('else', null !== $this->getNode('else'));
        $this->loop->setAttribute('with_loop', $this->getAttribute('with_loop'));
        $this->loop->setAttribute('ifexpr', $this->getAttribute('ifexpr'));

        $compiler
            ->write("foreach (\$context['_seq'] as ")
            ->subcompile($this->getNode('key_target'))
            ->raw(" => ")
            ->subcompile($this->getNode('value_target'))
            ->raw(") {\n")
            ->indent()
            ->subcompile($this->getNode('body'))
            ->outdent()
            ->write("}\n")
        ;

        if (null !== $this->getNode('else')) {
            $compiler
                ->write("if (!\$context['_iterated']) {\n")
                ->indent()
                ->subcompile($this->getNode('else'))
                ->outdent()
                ->write("}\n")
            ;
        }

        $compiler->write("\$_parent = \$context['_parent'];\n");

        // remove some "private" loop variables (needed for nested loops)
        $compiler->write('unset($context[\'_seq\'], $context[\'_iterated\'], $context[\''.$this->getNode('key_target')->getAttribute('name').'\'], $context[\''.$this->getNode('value_target')->getAttribute('name').'\'], $context[\'_parent\'], $context[\'loop\']);'."\n");

        // keep the values set in the inner context for variables defined in the outer context
        $compiler->write("\$context = array_merge(\$_parent, array_intersect_key(\$context, \$_parent));\n");
    }
}