<?php
/* 
 *  $Id: RegexpMapper.php,v 1.9 2004/03/15 17:11:15 hlellelid Exp $
 *
 * 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 please see
 * <http://phing.info>. 
 */

require_once 'phing/mappers/FileNameMapper.php';
include_once 'phing/util/StringHelper.php';
include_once 'phing/util/regexp/Regexp.php';

/**
 * Uses regular expressions to perform filename transformations.
 *
 * @author Andreas Aderhold <andi@binarycloud.com>
 * @author Hans Lellelid <hans@velum.net>
 * @version $Revision: 1.9 $
 * @package phing.mappers
 */
class RegexpMapper implements FileNameMapper {

    /**
     * @var string
     */
    private $to;
    
    /**
     * The Regexp engine.
     * @var Regexp
     */
    private $reg;

    function __construct() {                
        // instantiage regexp matcher here
        $this->reg = new Regexp();
    }

    /**
     * Sets the &quot;from&quot; pattern. Required.
     */
    function setFrom($from) {
        $this->reg->SetPattern($from);
    }

    /**
     * Sets the &quot;to&quot; pattern. Required.
     */
    function setTo($to) {
    
        // [HL] I'm changing the way this works for now to just use string
        //$this->to = StringHelper::toCharArray($to);
        
        $this->to = $to;
    }

    function main($sourceFileName) {
        if ($this->reg === null  || $this->to === null || !$this->reg->matches((string) $sourceFileName)) {
            return null;
        }
        return array($this->replaceReferences($sourceFileName));
    }

    /**
     * Replace all backreferences in the to pattern with the matched groups.
     * groups of the source.
     * @param string $source The source filename.
     */
    private function replaceReferences($source) {
        
        // FIXME
        // Can't we just use engine->replace() to handle this?  the Preg engine
        // will automatically convert \1 references to $1
        
        // the expression has already been processed (when ->matches() was run in Main())
        // so no need to pass $source again to the engine.
        $groups = (array) $this->reg->getGroups();            
        
        // replace \1 with value of $groups[1] and return the modified "to" string
        return preg_replace('/\\\([\d]+)/e', "\$groups[$1]", $this->to);            
    }
    
}