<?php
/*
 *  $Id$
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

namespace Doctrine\ORM\Query\AST;

/**
 * Abstract class of an AST node
 *
 * @license http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link    www.doctrine-project.org
 * @since   2.0
 * @version $Revision: 3938 $
 * @author  Guilherme Blanco <guilhermeblanco@hotmail.com>
 * @author  Jonathan Wage <jonwage@gmail.com>
 * @author  Roman Borschel <roman@code-factory.org>
 */
abstract class Node
{
    /**
     * Double-dispatch method, supposed to dispatch back to the walker.
     * 
     * Implementation is not mandatory for all nodes.
     * 
     * @param $walker
     */
    public function dispatch($walker)
    {
        throw ASTException::noDispatchForNode($this);
    }
    
    /**
     * Dumps the AST Node into a string representation for information purpose only
     *
     * @return string
     */
    public function __toString()
    {
        return $this->dump($this);
    }
    
    public function dump($obj)
    {
        static $ident = 0;
        
        $str = '';
        
        if ($obj instanceof Node) {
            $str .= get_class($obj) . '(' . PHP_EOL;
            $props = get_object_vars($obj);
                
            foreach ($props as $name => $prop) {
                $ident += 4;
                $str .= str_repeat(' ', $ident) . '"' . $name . '": ' 
                      . $this->dump($prop) . ',' . PHP_EOL;
                $ident -= 4;
            }
                
            $str .= str_repeat(' ', $ident) . ')';
        } else if (is_array($obj)) {
            $ident += 4;
            $str .= 'array(';
            $some = false;
                
            foreach ($obj as $k => $v) {
                $str .= PHP_EOL . str_repeat(' ', $ident) . '"' 
                      . $k . '" => ' . $this->dump($v) . ',';
                $some = true;
            }
                
            $ident -= 4;
            $str .= ($some ? PHP_EOL . str_repeat(' ', $ident) : '') . ')';
        } else if (is_object($obj)) {
            $str .= 'instanceof(' . get_class($obj) . ')';
        } else {
            $str .= var_export($obj, true);
        }
          
        return $str;
    }
}