<?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\Asset;

use Assetic\Filter\FilterInterface;

/**
 * Represents an asset loaded via an HTTP request.
 *
 * @author Kris Wallsmith <kris.wallsmith@gmail.com>
 */
class HttpAsset extends BaseAsset
{
    private $sourceUrl;
    private $ignoreErrors;

    /**
     * Constructor.
     *
     * @param string $sourceUrl The source URL
     * @param array  $filters   An array of filters
     *
     * @throws InvalidArgumentException If the first argument is not an URL
     */
    public function __construct($sourceUrl, $filters = array(), $ignoreErrors = false)
    {
        if (0 === strpos($sourceUrl, '//')) {
            $sourceUrl = 'http:'.$sourceUrl;
        } elseif (false === strpos($sourceUrl, '://')) {
            throw new \InvalidArgumentException(sprintf('"%s" is not a valid URL.', $sourceUrl));
        }

        $this->sourceUrl = $sourceUrl;
        $this->ignoreErrors = $ignoreErrors;

        list($scheme, $url) = explode('://', $sourceUrl, 2);
        list($host, $path) = explode('/', $url, 2);

        parent::__construct($filters, $scheme.'://'.$host, $path);
    }

    public function load(FilterInterface $additionalFilter = null)
    {
        if (false === $content = @file_get_contents($this->sourceUrl)) {
            if ($this->ignoreErrors) {
                return;
            } else {
                throw new \RuntimeException(sprintf('Unable to load asset from URL "%s"', $this->sourceUrl));
            }
        }

        $this->doLoad($content, $additionalFilter);
    }

    public function getLastModified()
    {
        if (false !== @file_get_contents($this->sourceUrl, false, stream_context_create(array('http' => array('method' => 'HEAD'))))) {
            foreach ($http_response_header as $header) {
                if (0 === stripos($header, 'Last-Modified: ')) {
                    list(, $mtime) = explode(':', $header, 2);

                    return strtotime(trim($mtime));
                }
            }
        }
    }
}
