<?php

/*

 * This file is part of the Assetic package, an OpenSky project.

 *

 * (c) 2010-2011 OpenSky Project Inc

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */

namespace Assetic\Factory\Resource;

/**

 * Coalesces multiple directories together into one merged resource.

 *

 * @author Kris Wallsmith <kris.wallsmith@gmail.com>

 */

class CoalescingDirectoryResource implements IteratorResourceInterface

{

    private $directories;

    public function __construct($directories)

    {

        $this->directories = array();

        foreach ($directories as $directory) {

            $this->addDirectory($directory);

        }

    }

    public function addDirectory(IteratorResourceInterface $directory)

    {

        $this->directories[] = $directory;

    }

    public function isFresh($timestamp)

    {

        foreach ($this->getFileResources() as $file) {

            if (!$file->isFresh($timestamp)) {

                return false;

            }

        }

        return true;

    }

    public function getContent()

    {

        $parts = array();

        foreach ($this->getFileResources() as $file) {

            $parts[] = $file->getContent();

        }

        return implode("\n", $parts);

    }

    /**

     * Returns a string to uniquely identify the current resource.

     *

     * @return string An identifying string

     */

    public function __toString()

    {

        $parts = array();

        foreach ($this->directories as $directory) {

            $parts[] = (string) $directory;

        }

        return implode(',', $parts);

    }

    public function getIterator()

    {

        return new \ArrayIterator($this->getFileResources());

    }

    /**

     * Returns the relative version of a filename.

     *

     * @param ResourceInterface $file      The file

     * @param ResourceInterface $directory The directory

     *

     * @return string The name to compare with files from other directories

     */

    protected function getRelativeName(ResourceInterface $file, ResourceInterface $directory)

    {

        return substr((string) $file, strlen((string) $directory));

    }

    /**

     * Performs the coalesce.

     *

     * @return array An array of file resources

     */

    private function getFileResources()

    {

        $paths = array();

        foreach ($this->directories as $directory) {

            foreach ($directory as $file) {

                $relative = $this->getRelativeName($file, $directory);

                if (!isset($paths[$relative])) {

                    $paths[$relative] = $file;

                }

            }

        }

        return array_values($paths);

    }

}