<?php

/**

 * SimplePie

 *

 * A PHP-Based RSS and Atom Feed Framework.

 * Takes the hard work out of managing a complete RSS/Atom solution.

 *

 * Copyright (c) 2004-2012, Ryan Parman, Geoffrey Sneddon, Ryan McCue, and contributors

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without modification, are

 * permitted provided that the following conditions are met:

 *

 * 	* Redistributions of source code must retain the above copyright notice, this list of

 * 	  conditions and the following disclaimer.

 *

 * 	* Redistributions in binary form must reproduce the above copyright notice, this list

 * 	  of conditions and the following disclaimer in the documentation and/or other materials

 * 	  provided with the distribution.

 *

 * 	* Neither the name of the SimplePie Team nor the names of its contributors may be used

 * 	  to endorse or promote products derived from this software without specific prior

 * 	  written permission.

 *

 * 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 HOLDERS

 * AND 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.

 *

 * @package SimplePie

 * @version 1.3.1

 * @copyright 2004-2012 Ryan Parman, Geoffrey Sneddon, Ryan McCue

 * @author Ryan Parman

 * @author Geoffrey Sneddon

 * @author Ryan McCue

 * @link http://simplepie.org/ SimplePie

 * @license http://www.opensource.org/licenses/bsd-license.php BSD License

 */

/**

 * Used for feed auto-discovery

 *

 *

 * This class can be overloaded with {@see SimplePie::set_locator_class()}

 *

 * @package SimplePie

 */

class SimplePie_Locator

{

	var $useragent;

	var $timeout;

	var $file;

	var $local = array();

	var $elsewhere = array();

	var $cached_entities = array();

	var $http_base;

	var $base;

	var $base_location = 0;

	var $checked_feeds = 0;

	var $max_checked_feeds = 10;

	protected $registry;

	public function __construct(SimplePie_File $file, $timeout = 10, $useragent = null, $max_checked_feeds = 10)

	{

		$this->file = $file;

		$this->useragent = $useragent;

		$this->timeout = $timeout;

		$this->max_checked_feeds = $max_checked_feeds;

		if (class_exists('DOMDocument'))

		{

			$this->dom = new DOMDocument();

			set_error_handler(array('SimplePie_Misc', 'silence_errors'));

			$this->dom->loadHTML($this->file->body);

			restore_error_handler();

		}

		else

		{

			$this->dom = null;

		}

	}

	public function set_registry(SimplePie_Registry $registry)

	{

		$this->registry = $registry;

	}

	public function find($type = SIMPLEPIE_LOCATOR_ALL, &$working)

	{

		if ($this->is_feed($this->file))

		{

			return $this->file;

		}

		if ($this->file->method & SIMPLEPIE_FILE_SOURCE_REMOTE)

		{

			$sniffer = $this->registry->create('Content_Type_Sniffer', array($this->file));

			if ($sniffer->get_type() !== 'text/html')

			{

				return null;

			}

		}

		if ($type & ~SIMPLEPIE_LOCATOR_NONE)

		{

			$this->get_base();

		}

		if ($type & SIMPLEPIE_LOCATOR_AUTODISCOVERY && $working = $this->autodiscovery())

		{

			return $working[0];

		}

		if ($type & (SIMPLEPIE_LOCATOR_LOCAL_EXTENSION | SIMPLEPIE_LOCATOR_LOCAL_BODY | SIMPLEPIE_LOCATOR_REMOTE_EXTENSION | SIMPLEPIE_LOCATOR_REMOTE_BODY) && $this->get_links())

		{

			if ($type & SIMPLEPIE_LOCATOR_LOCAL_EXTENSION && $working = $this->extension($this->local))

			{

				return $working;

			}

			if ($type & SIMPLEPIE_LOCATOR_LOCAL_BODY && $working = $this->body($this->local))

			{

				return $working;

			}

			if ($type & SIMPLEPIE_LOCATOR_REMOTE_EXTENSION && $working = $this->extension($this->elsewhere))

			{

				return $working;

			}

			if ($type & SIMPLEPIE_LOCATOR_REMOTE_BODY && $working = $this->body($this->elsewhere))

			{

				return $working;

			}

		}

		return null;

	}

	public function is_feed($file)

	{

		if ($file->method & SIMPLEPIE_FILE_SOURCE_REMOTE)

		{

			$sniffer = $this->registry->create('Content_Type_Sniffer', array($file));

			$sniffed = $sniffer->get_type();

			if (in_array($sniffed, array('application/rss+xml', 'application/rdf+xml', 'text/rdf', 'application/atom+xml', 'text/xml', 'application/xml')))

			{

				return true;

			}

			else

			{

				return false;

			}

		}

		elseif ($file->method & SIMPLEPIE_FILE_SOURCE_LOCAL)

		{

			return true;

		}

		else

		{

			return false;

		}

	}

	public function get_base()

	{

		if ($this->dom === null)

		{

			throw new SimplePie_Exception('DOMDocument not found, unable to use locator');

		}

		$this->http_base = $this->file->url;

		$this->base = $this->http_base;

		$elements = $this->dom->getElementsByTagName('base');

		foreach ($elements as $element)

		{

			if ($element->hasAttribute('href'))

			{

				$base = $this->registry->call('Misc', 'absolutize_url', array(trim($element->getAttribute('href')), $this->http_base));

				if ($base === false)

				{

					continue;

				}

				$this->base = $base;

				$this->base_location = method_exists($element, 'getLineNo') ? $element->getLineNo() : 0;

				break;

			}

		}

	}

	public function autodiscovery()

	{

		$done = array();

		$feeds = array();

		$feeds = array_merge($feeds, $this->search_elements_by_tag('link', $done, $feeds));

		$feeds = array_merge($feeds, $this->search_elements_by_tag('a', $done, $feeds));

		$feeds = array_merge($feeds, $this->search_elements_by_tag('area', $done, $feeds));

		if (!empty($feeds))

		{

			return array_values($feeds);

		}

		else

		{

			return null;

		}

	}

	protected function search_elements_by_tag($name, &$done, $feeds)

	{

		if ($this->dom === null)

		{

			throw new SimplePie_Exception('DOMDocument not found, unable to use locator');

		}

		$links = $this->dom->getElementsByTagName($name);

		foreach ($links as $link)

		{

			if ($this->checked_feeds === $this->max_checked_feeds)

			{

				break;

			}

			if ($link->hasAttribute('href') && $link->hasAttribute('rel'))

			{

				$rel = array_unique($this->registry->call('Misc', 'space_seperated_tokens', array(strtolower($link->getAttribute('rel')))));

				$line = method_exists($link, 'getLineNo') ? $link->getLineNo() : 1;

				if ($this->base_location < $line)

				{

					$href = $this->registry->call('Misc', 'absolutize_url', array(trim($link->getAttribute('href')), $this->base));

				}

				else

				{

					$href = $this->registry->call('Misc', 'absolutize_url', array(trim($link->getAttribute('href')), $this->http_base));

				}

				if ($href === false)

				{

					continue;

				}

				if (!in_array($href, $done) && in_array('feed', $rel) || (in_array('alternate', $rel) && !in_array('stylesheet', $rel) && $link->hasAttribute('type') && in_array(strtolower($this->registry->call('Misc', 'parse_mime', array($link->getAttribute('type')))), array('application/rss+xml', 'application/atom+xml'))) && !isset($feeds[$href]))

				{

					$this->checked_feeds++;

					$headers = array(

						'Accept' => 'application/atom+xml, application/rss+xml, application/rdf+xml;q=0.9, application/xml;q=0.8, text/xml;q=0.8, text/html;q=0.7, unknown/unknown;q=0.1, application/unknown;q=0.1, */*;q=0.1',

					);

					$feed = $this->registry->create('File', array($href, $this->timeout, 5, $headers, $this->useragent));

					if ($feed->success && ($feed->method & SIMPLEPIE_FILE_SOURCE_REMOTE === 0 || ($feed->status_code === 200 || $feed->status_code > 206 && $feed->status_code < 300)) && $this->is_feed($feed))

					{

						$feeds[$href] = $feed;

					}

				}

				$done[] = $href;

			}

		}

		return $feeds;

	}

	public function get_links()

	{

		if ($this->dom === null)

		{

			throw new SimplePie_Exception('DOMDocument not found, unable to use locator');

		}

		$links = $this->dom->getElementsByTagName('a');

		foreach ($links as $link)

		{

			if ($link->hasAttribute('href'))

			{

				$href = trim($link->getAttribute('href'));

				$parsed = $this->registry->call('Misc', 'parse_url', array($href));

				if ($parsed['scheme'] === '' || preg_match('/^(http(s)|feed)?$/i', $parsed['scheme']))

				{

					if (method_exists($link, 'getLineNo') && $this->base_location < $link->getLineNo())

					{

						$href = $this->registry->call('Misc', 'absolutize_url', array(trim($link->getAttribute('href')), $this->base));

					}

					else

					{

						$href = $this->registry->call('Misc', 'absolutize_url', array(trim($link->getAttribute('href')), $this->http_base));

					}

					if ($href === false)

					{

						continue;

					}

					$current = $this->registry->call('Misc', 'parse_url', array($this->file->url));

					if ($parsed['authority'] === '' || $parsed['authority'] === $current['authority'])

					{

						$this->local[] = $href;

					}

					else

					{

						$this->elsewhere[] = $href;

					}

				}

			}

		}

		$this->local = array_unique($this->local);

		$this->elsewhere = array_unique($this->elsewhere);

		if (!empty($this->local) || !empty($this->elsewhere))

		{

			return true;

		}

		return null;

	}

	public function extension(&$array)

	{

		foreach ($array as $key => $value)

		{

			if ($this->checked_feeds === $this->max_checked_feeds)

			{

				break;

			}

			if (in_array(strtolower(strrchr($value, '.')), array('.rss', '.rdf', '.atom', '.xml')))

			{

				$this->checked_feeds++;

				$headers = array(

					'Accept' => 'application/atom+xml, application/rss+xml, application/rdf+xml;q=0.9, application/xml;q=0.8, text/xml;q=0.8, text/html;q=0.7, unknown/unknown;q=0.1, application/unknown;q=0.1, */*;q=0.1',

				);

				$feed = $this->registry->create('File', array($value, $this->timeout, 5, $headers, $this->useragent));

				if ($feed->success && ($feed->method & SIMPLEPIE_FILE_SOURCE_REMOTE === 0 || ($feed->status_code === 200 || $feed->status_code > 206 && $feed->status_code < 300)) && $this->is_feed($feed))

				{

					return $feed;

				}

				else

				{

					unset($array[$key]);

				}

			}

		}

		return null;

	}

	public function body(&$array)

	{

		foreach ($array as $key => $value)

		{

			if ($this->checked_feeds === $this->max_checked_feeds)

			{

				break;

			}

			if (preg_match('/(rss|rdf|atom|xml)/i', $value))

			{

				$this->checked_feeds++;

				$headers = array(

					'Accept' => 'application/atom+xml, application/rss+xml, application/rdf+xml;q=0.9, application/xml;q=0.8, text/xml;q=0.8, text/html;q=0.7, unknown/unknown;q=0.1, application/unknown;q=0.1, */*;q=0.1',

				);

				$feed = $this->registry->create('File', array($value, $this->timeout, 5, null, $this->useragent));

				if ($feed->success && ($feed->method & SIMPLEPIE_FILE_SOURCE_REMOTE === 0 || ($feed->status_code === 200 || $feed->status_code > 206 && $feed->status_code < 300)) && $this->is_feed($feed))

				{

					return $feed;

				}

				else

				{

					unset($array[$key]);

				}

			}

		}

		return null;

	}

}