<?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 1.4-dev
 * @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
 */

/**
 * Parses XML into something sane
 *
 *
 * This class can be overloaded with {@see SimplePie::set_parser_class()}
 *
 * @package SimplePie
 * @subpackage Parsing
 */
class SimplePie_Parser
{
	var $error_code;
	var $error_string;
	var $current_line;
	var $current_column;
	var $current_byte;
	var $separator = ' ';
	var $namespace = array('');
	var $element = array('');
	var $xml_base = array('');
	var $xml_base_explicit = array(false);
	var $xml_lang = array('');
	var $data = array();
	var $datas = array(array());
	var $current_xhtml_construct = -1;
	var $encoding;
	protected $registry;

	public function set_registry(SimplePie_Registry $registry)
	{
		$this->registry = $registry;
	}

	public function parse(&$data, $encoding)
	{
		// Use UTF-8 if we get passed US-ASCII, as every US-ASCII character is a UTF-8 character
		if (strtoupper($encoding) === 'US-ASCII')
		{
			$this->encoding = 'UTF-8';
		}
		else
		{
			$this->encoding = $encoding;
		}

		// Strip BOM:
		// UTF-32 Big Endian BOM
		if (substr($data, 0, 4) === "\x00\x00\xFE\xFF")
		{
			$data = substr($data, 4);
		}
		// UTF-32 Little Endian BOM
		elseif (substr($data, 0, 4) === "\xFF\xFE\x00\x00")
		{
			$data = substr($data, 4);
		}
		// UTF-16 Big Endian BOM
		elseif (substr($data, 0, 2) === "\xFE\xFF")
		{
			$data = substr($data, 2);
		}
		// UTF-16 Little Endian BOM
		elseif (substr($data, 0, 2) === "\xFF\xFE")
		{
			$data = substr($data, 2);
		}
		// UTF-8 BOM
		elseif (substr($data, 0, 3) === "\xEF\xBB\xBF")
		{
			$data = substr($data, 3);
		}

		if (substr($data, 0, 5) === '<?xml' && strspn(substr($data, 5, 1), "\x09\x0A\x0D\x20") && ($pos = strpos($data, '?>')) !== false)
		{
			$declaration = $this->registry->create('XML_Declaration_Parser', array(substr($data, 5, $pos - 5)));
			if ($declaration->parse())
			{
				$data = substr($data, $pos + 2);
				$data = '<?xml version="' . $declaration->version . '" encoding="' . $encoding . '" standalone="' . (($declaration->standalone) ? 'yes' : 'no') . '"?>' . $data;
			}
			else
			{
				$this->error_string = 'SimplePie bug! Please report this!';
				return false;
			}
		}

		$return = true;

		static $xml_is_sane = null;
		if ($xml_is_sane === null)
		{
			$parser_check = xml_parser_create();
			xml_parse_into_struct($parser_check, '<foo>&amp;</foo>', $values);
			xml_parser_free($parser_check);
			$xml_is_sane = isset($values[0]['value']);
		}

		// Create the parser
		if ($xml_is_sane)
		{
			$xml = xml_parser_create_ns($this->encoding, $this->separator);
			xml_parser_set_option($xml, XML_OPTION_SKIP_WHITE, 1);
			xml_parser_set_option($xml, XML_OPTION_CASE_FOLDING, 0);
			xml_set_object($xml, $this);
			xml_set_character_data_handler($xml, 'cdata');
			xml_set_element_handler($xml, 'tag_open', 'tag_close');

			// Parse!
			if (!xml_parse($xml, $data, true))
			{
				$this->error_code = xml_get_error_code($xml);
				$this->error_string = xml_error_string($this->error_code);
				$return = false;
			}
			$this->current_line = xml_get_current_line_number($xml);
			$this->current_column = xml_get_current_column_number($xml);
			$this->current_byte = xml_get_current_byte_index($xml);
			xml_parser_free($xml);
			return $return;
		}
		else
		{
			libxml_clear_errors();
			$xml = new XMLReader();
			$xml->xml($data);
			while (@$xml->read())
			{
				switch ($xml->nodeType)
				{

					case constant('XMLReader::END_ELEMENT'):
						if ($xml->namespaceURI !== '')
						{
							$tagName = $xml->namespaceURI . $this->separator . $xml->localName;
						}
						else
						{
							$tagName = $xml->localName;
						}
						$this->tag_close(null, $tagName);
						break;
					case constant('XMLReader::ELEMENT'):
						$empty = $xml->isEmptyElement;
						if ($xml->namespaceURI !== '')
						{
							$tagName = $xml->namespaceURI . $this->separator . $xml->localName;
						}
						else
						{
							$tagName = $xml->localName;
						}
						$attributes = array();
						while ($xml->moveToNextAttribute())
						{
							if ($xml->namespaceURI !== '')
							{
								$attrName = $xml->namespaceURI . $this->separator . $xml->localName;
							}
							else
							{
								$attrName = $xml->localName;
							}
							$attributes[$attrName] = $xml->value;
						}
						$this->tag_open(null, $tagName, $attributes);
						if ($empty)
						{
							$this->tag_close(null, $tagName);
						}
						break;
					case constant('XMLReader::TEXT'):

					case constant('XMLReader::CDATA'):
						$this->cdata(null, $xml->value);
						break;
				}
			}
			if ($error = libxml_get_last_error())
			{
				$this->error_code = $error->code;
				$this->error_string = $error->message;
				$this->current_line = $error->line;
				$this->current_column = $error->column;
				return false;
			}
			else
			{
				return true;
			}
		}
	}

	public function get_error_code()
	{
		return $this->error_code;
	}

	public function get_error_string()
	{
		return $this->error_string;
	}

	public function get_current_line()
	{
		return $this->current_line;
	}

	public function get_current_column()
	{
		return $this->current_column;
	}

	public function get_current_byte()
	{
		return $this->current_byte;
	}

	public function get_data()
	{
		return $this->data;
	}

	public function tag_open($parser, $tag, $attributes)
	{
		list($this->namespace[], $this->element[]) = $this->split_ns($tag);

		$attribs = array();
		foreach ($attributes as $name => $value)
		{
			list($attrib_namespace, $attribute) = $this->split_ns($name);
			$attribs[$attrib_namespace][$attribute] = $value;
		}

		if (isset($attribs[SIMPLEPIE_NAMESPACE_XML]['base']))
		{
			$base = $this->registry->call('Misc', 'absolutize_url', array($attribs[SIMPLEPIE_NAMESPACE_XML]['base'], end($this->xml_base)));
			if ($base !== false)
			{
				$this->xml_base[] = $base;
				$this->xml_base_explicit[] = true;
			}
		}
		else
		{
			$this->xml_base[] = end($this->xml_base);
			$this->xml_base_explicit[] = end($this->xml_base_explicit);
		}

		if (isset($attribs[SIMPLEPIE_NAMESPACE_XML]['lang']))
		{
			$this->xml_lang[] = $attribs[SIMPLEPIE_NAMESPACE_XML]['lang'];
		}
		else
		{
			$this->xml_lang[] = end($this->xml_lang);
		}

		if ($this->current_xhtml_construct >= 0)
		{
			$this->current_xhtml_construct++;
			if (end($this->namespace) === SIMPLEPIE_NAMESPACE_XHTML)
			{
				$this->data['data'] .= '<' . end($this->element);
				if (isset($attribs['']))
				{
					foreach ($attribs[''] as $name => $value)
					{
						$this->data['data'] .= ' ' . $name . '="' . htmlspecialchars($value, ENT_COMPAT, $this->encoding) . '"';
					}
				}
				$this->data['data'] .= '>';
			}
		}
		else
		{
			$this->datas[] =& $this->data;
			$this->data =& $this->data['child'][end($this->namespace)][end($this->element)][];
			$this->data = array('data' => '', 'attribs' => $attribs, 'xml_base' => end($this->xml_base), 'xml_base_explicit' => end($this->xml_base_explicit), 'xml_lang' => end($this->xml_lang));
			if ((end($this->namespace) === SIMPLEPIE_NAMESPACE_ATOM_03 && in_array(end($this->element), array('title', 'tagline', 'copyright', 'info', 'summary', 'content')) && isset($attribs['']['mode']) && $attribs['']['mode'] === 'xml')
			|| (end($this->namespace) === SIMPLEPIE_NAMESPACE_ATOM_10 && in_array(end($this->element), array('rights', 'subtitle', 'summary', 'info', 'title', 'content')) && isset($attribs['']['type']) && $attribs['']['type'] === 'xhtml')
			|| (end($this->namespace) === SIMPLEPIE_NAMESPACE_RSS_20 && in_array(end($this->element), array('title')))
			|| (end($this->namespace) === SIMPLEPIE_NAMESPACE_RSS_090 && in_array(end($this->element), array('title')))
			|| (end($this->namespace) === SIMPLEPIE_NAMESPACE_RSS_10 && in_array(end($this->element), array('title'))))
			{
				$this->current_xhtml_construct = 0;
			}
		}
	}

	public function cdata($parser, $cdata)
	{
		if ($this->current_xhtml_construct >= 0)
		{
			$this->data['data'] .= htmlspecialchars($cdata, ENT_QUOTES, $this->encoding);
		}
		else
		{
			$this->data['data'] .= $cdata;
		}
	}

	public function tag_close($parser, $tag)
	{
		if ($this->current_xhtml_construct >= 0)
		{
			$this->current_xhtml_construct--;
			if (end($this->namespace) === SIMPLEPIE_NAMESPACE_XHTML && !in_array(end($this->element), array('area', 'base', 'basefont', 'br', 'col', 'frame', 'hr', 'img', 'input', 'isindex', 'link', 'meta', 'param')))
			{
				$this->data['data'] .= '</' . end($this->element) . '>';
			}
		}
		if ($this->current_xhtml_construct === -1)
		{
			$this->data =& $this->datas[count($this->datas) - 1];
			array_pop($this->datas);
		}

		array_pop($this->element);
		array_pop($this->namespace);
		array_pop($this->xml_base);
		array_pop($this->xml_base_explicit);
		array_pop($this->xml_lang);
	}

	public function split_ns($string)
	{
		static $cache = array();
		if (!isset($cache[$string]))
		{
			if ($pos = strpos($string, $this->separator))
			{
				static $separator_length;
				if (!$separator_length)
				{
					$separator_length = strlen($this->separator);
				}
				$namespace = substr($string, 0, $pos);
				$local_name = substr($string, $pos + $separator_length);
				if (strtolower($namespace) === SIMPLEPIE_NAMESPACE_ITUNES)
				{
					$namespace = SIMPLEPIE_NAMESPACE_ITUNES;
				}

				// Normalize the Media RSS namespaces
				if ($namespace === SIMPLEPIE_NAMESPACE_MEDIARSS_WRONG ||
					$namespace === SIMPLEPIE_NAMESPACE_MEDIARSS_WRONG2 ||
					$namespace === SIMPLEPIE_NAMESPACE_MEDIARSS_WRONG3 ||
					$namespace === SIMPLEPIE_NAMESPACE_MEDIARSS_WRONG4 ||
					$namespace === SIMPLEPIE_NAMESPACE_MEDIARSS_WRONG5 )
				{
					$namespace = SIMPLEPIE_NAMESPACE_MEDIARSS;
				}
				$cache[$string] = array($namespace, $local_name);
			}
			else
			{
				$cache[$string] = array('', $string);
			}
		}
		return $cache[$string];
	}
}
