<?php

namespace Friends\Mf2;

use DOMDocument;
use DOMElement;
use DOMXPath;
use DOMNode;
use DOMNodeList;
use \Exception;
use SplObjectStorage;
use stdClass;

/**
 * Parse Microformats2
 *
 * Functional shortcut for the commonest cases of parsing microformats2 from HTML.
 *
 * Example usage:
 *
 *     use Mf2;
 *     $output = Mf2\parse('<span class="h-card">Barnaby Walters</span>');
 *     echo json_encode($output, JSON_PRETTY_PRINT);
 *
 * Produces:
 *
 *     {
 *      "items": [
 *       {
 *        "type": ["h-card"],
 *        "properties": {
 *         "name": ["Barnaby Walters"]
 *        }
 *       }
 *      ],
 *      "rels": {}
 *     }
 *
 * @param string|DOMDocument $input The HTML string or DOMDocument object to parse
 * @param string             $url The URL the input document was found at, for relative URL resolution
 * @param bool               $convertClassic whether or not to convert classic microformats
 * @return array Canonical MF2 array structure
 */
function parse( $input, $url = null, $convertClassic = true ) {
	$parser = new Parser( $input, $url );
	return $parser->parse( $convertClassic );
}

/**
 * Fetch microformats2
 *
 * Given a URL, fetches it (following up to 5 redirects) and, if the content-type appears to be HTML, returns the parsed
 * microformats2 array structure.
 *
 * Not that even if the response code was a 4XX or 5XX error, if the content-type is HTML-like then it will be parsed
 * all the same, as there are legitimate cases where error pages might contain useful microformats (for example a deleted
 * h-entry resulting in a 410 Gone page with a stub h-entry explaining the reason for deletion). Look in $curlInfo['http_code']
 * for the actual value.
 *
 * @param string $url The URL to fetch
 * @param bool   $convertClassic (optional, default true) whether or not to convert classic microformats
 * @param array  $curlInfo (optional) the results of curl_getinfo will be placed in this variable for debugging
 * @return array|null canonical microformats2 array structure on success, null on failure
 */
function fetch( $url, $convertClassic = true, &$curlInfo = null ) {
	// Friends modification: use wp_safe_remote_get() instead of curl directly.
	$response = wp_safe_remote_get(
		$url,
		array(
			'timeout'     => 20,
			'redirection' => 5,
			'headers'     => array(
				'Accept: text/html',
			),
		)
	);
	if ( 200 !== wp_remote_retrieve_response_code( $response ) ) {
		return null;
	}
	$html = wp_remote_retrieve_body( $response );
	$headers = wp_remote_retrieve_headers( $response );

	if ( stripos( $headers['content-type'], 'html' ) === false ) {
		// The content was not delivered as HTML, do not attempt to parse it.
		return null;
	}

	// ensure the final URL is used to resolve relative URLs
	$url = $response['http_response']->get_response_object()->url;
	// end modification.
	return parse( $html, $url, $convertClassic );
}

/**
 * Unicode to HTML Entities
 *
 * @param string $input String containing characters to convert into HTML entities
 * @return string
 */
function unicodeToHtmlEntities( $input ) {
	return \mb_convert_encoding( $input, 'HTML-ENTITIES', \mb_detect_encoding( $input ) );
}

/**
 * Collapse Whitespace
 *
 * Collapses any sequences of whitespace within a string into a single space
 * character.
 *
 * @deprecated since v0.2.3
 * @param string $str
 * @return string
 */
function collapseWhitespace( $str ) {
	return preg_replace( '/[\s|\n]+/', ' ', $str );
}

function unicodeTrim( $str ) {
	// this is cheating. TODO: find a better way if this causes any problems
	$str = str_replace( \mb_convert_encoding( '&nbsp;', 'UTF-8', 'HTML-ENTITIES' ), ' ', $str );
	$str = preg_replace( '/^\s+/', '', $str );
	return preg_replace( '/\s+$/', '', $str );
}

/**
 * Microformat Name From Class string
 *
 * Given the value of @class, get the relevant mf classnames (e.g. h-card,
 * p-name).
 *
 * @param string $class A space delimited list of classnames
 * @param string $prefix The prefix to look for
 * @return string|array The prefixed name of the first microfomats class found or false
 */
function mfNamesFromClass( $class, $prefix = 'h-' ) {
	$class = str_replace( array( ' ', '	', "\n" ), ' ', $class );
	$classes = explode( ' ', $class );
	$classes = preg_grep( '#^(h|p|u|dt|e)-([a-z0-9]+-)?[a-z]+(-[a-z]+)*$#', $classes );
	$matches = array();

	foreach ( $classes as $classname ) {
		$compare_classname = ' ' . $classname;
		$compare_prefix = ' ' . $prefix;
		if ( strstr( $compare_classname, $compare_prefix ) !== false && ( $compare_classname != $compare_prefix ) ) {
			$matches[] = ( $prefix === 'h-' ) ? $classname : substr( $classname, strlen( $prefix ) );
		}
	}

	return $matches;
}

/**
 * Get Nested µf Property Name From Class
 *
 * Returns all the p-, u-, dt- or e- prefixed classnames it finds in a
 * space-separated string.
 *
 * @param string $class
 * @return array
 */
function nestedMfPropertyNamesFromClass( $class ) {
	$prefixes = array( 'p-', 'u-', 'dt-', 'e-' );
	$propertyNames = array();

	$class = str_replace( array( ' ', '	', "\n" ), ' ', $class );
	foreach ( explode( ' ', $class ) as $classname ) {
		foreach ( $prefixes as $prefix ) {
			// Check if $classname is a valid property classname for $prefix.
			if ( \mb_substr( $classname, 0, \mb_strlen( $prefix ) ) == $prefix && $classname != $prefix ) {
				$propertyName = \mb_substr( $classname, \mb_strlen( $prefix ) );
				$propertyNames[ $propertyName ][] = $prefix;
			}
		}
	}

	foreach ( $propertyNames as $property => $prefixes ) {
		$propertyNames[ $property ] = array_unique( $prefixes );
	}

	return $propertyNames;
}

/**
 * Wraps mfNamesFromClass to handle an element as input (common)
 *
 * @param DOMElement $e The element to get the classname for
 * @param string     $prefix The prefix to look for
 * @return mixed See return value of mf2\Parser::mfNameFromClass()
 */
function mfNamesFromElement( \DOMElement $e, $prefix = 'h-' ) {
	$class = $e->getAttribute( 'class' );
	return mfNamesFromClass( $class, $prefix );
}

/**
 * Wraps nestedMfPropertyNamesFromClass to handle an element as input
 */
function nestedMfPropertyNamesFromElement( \DOMElement $e ) {
	$class = $e->getAttribute( 'class' );
	return nestedMfPropertyNamesFromClass( $class );
}

/**
 * Converts various time formats to HH:MM
 *
 * @param string $time The time to convert
 * @return string
 */
function convertTimeFormat( $time ) {
	$hh = $mm = $ss = '';
	preg_match( '/(\d{1,2}):?(\d{2})?:?(\d{2})?(a\.?m\.?|p\.?m\.?)?/i', $time, $matches );

	// If no am/pm is specified:
	if ( empty( $matches[4] ) ) {
		return $time;
	} else {
		// Otherwise, am/pm is specified.
		$meridiem = strtolower( str_replace( '.', '', $matches[4] ) );

		// Hours.
		$hh = $matches[1];

		// Add 12 to hours if pm applies.
		if ( $meridiem == 'pm' && ( $hh < 12 ) ) {
			$hh += 12;
		}

		$hh = str_pad( $hh, 2, '0', STR_PAD_LEFT );

		// Minutes.
		$mm = ( empty( $matches[2] ) ) ? '00' : $matches[2];

		// Seconds, only if supplied.
		if ( ! empty( $matches[3] ) ) {
			$ss = $matches[3];
		}

		if ( empty( $ss ) ) {
			return sprintf( '%s:%s', $hh, $mm );
		} else {
			return sprintf( '%s:%s:%s', $hh, $mm, $ss );
		}
	}
}

/**
 * Normalize an ordinal date to YYYY-MM-DD
 * This function should only be called after validating the $dtValue
 * matches regex \d{4}-\d{2}
 *
 * @param string $dtValue
 * @return string
 */
function normalizeOrdinalDate( $dtValue ) {
	list($year, $day) = explode( '-', $dtValue, 2 );
	$day = intval( $day );
	if ( $day < 367 && $day > 0 ) {
		$date = \DateTime::createFromFormat( 'Y-z', $dtValue );
		$date->modify( '-1 day' ); // 'z' format is zero-based so need to adjust
		if ( $date->format( 'Y' ) === $year ) {
			return $date->format( 'Y-m-d' );
		}
	}
	return '';
}

/**
 * If a date value has a timezone offset, normalize it.
 *
 * @param string $dtValue
 * @return string isolated, normalized TZ offset for implied TZ for other dt- properties
 */
function normalizeTimezoneOffset( &$dtValue ) {
	preg_match( '/Z|[+-]\d{1,2}:?(\d{2})?$/i', $dtValue, $matches );

	if ( empty( $matches ) ) {
		return null;
	}

	$timezoneOffset = null;

	if ( $matches[0] != 'Z' ) {
		$timezoneString = str_replace( ':', '', $matches[0] );
		$plus_minus = substr( $timezoneString, 0, 1 );
		$timezoneOffset = substr( $timezoneString, 1 );
		if ( strlen( $timezoneOffset ) <= 2 ) {
			$timezoneOffset .= '00';
		}
		$timezoneOffset = str_pad( $timezoneOffset, 4, 0, STR_PAD_LEFT );
		$timezoneOffset = $plus_minus . $timezoneOffset;
		$dtValue = preg_replace( '/Z?[+-]\d{1,2}:?(\d{2})?$/i', $timezoneOffset, $dtValue );
	}

	return $timezoneOffset;
}

function applySrcsetUrlTransformation( $srcset, $transformation ) {
	return implode(
		', ',
		array_filter(
			array_map(
				function ( $srcsetPart ) use ( $transformation ) {
					$parts = explode( " \t\n\r\0\x0B", trim( $srcsetPart ), 2 );
					$parts[0] = rtrim( $parts[0] );

					if ( empty( $parts[0] ) ) {
						return false; }

					$parts[0] = call_user_func( $transformation, $parts[0] );

					return $parts[0] . ( empty( $parts[1] ) ? '' : ' ' . $parts[1] );
				},
				explode( ',', trim( $srcset ) )
			)
		)
	);
}

/**
 * Microformats2 Parser
 *
 * A class which holds state for parsing microformats2 from HTML.
 *
 * Example usage:
 *
 *     use Mf2;
 *     $parser = new Mf2\Parser('<p class="h-card">Barnaby Walters</p>');
 *     $output = $parser->parse();
 */
class Parser {
	/** @var string The baseurl (if any) to use for this parse */
	public $baseurl;

	/** @var DOMXPath object which can be used to query over any fragment*/
	public $xpath;

	/** @var DOMDocument */
	public $doc;

	/** @var SplObjectStorage */
	protected $parsed;

	/**
	 * @var bool
	 */
	public $jsonMode;

	/** @var boolean Whether to include experimental language parsing in the result */
	public $lang = false;

	/** @var bool Whether to include alternates object (dropped from spec in favor of rel-urls) */
	public $enableAlternates = false;

	/**
	 * Elements upgraded to mf2 during backcompat
	 *
	 * @var SplObjectStorage
	 */
	protected $upgraded;

	/**
	 * Whether to convert classic microformats
	 *
	 * @var bool
	 */
	public $convertClassic;

	/**
	 * Constructor
	 *
	 * @param DOMDocument|string $input The data to parse. A string of HTML or a DOMDocument
	 * @param string             $url The URL of the parsed document, for relative URL resolution
	 * @param boolean            $jsonMode Whether or not to use a stdClass instance for an empty `rels` dictionary. This breaks PHP looping over rels, but allows the output to be correctly serialized as JSON.
	 */
	public function __construct( $input, $url = null, $jsonMode = false ) {
		libxml_use_internal_errors( true );
		set_error_handler( '__return_null' );
		if ( is_string( $input ) ) {
			if ( class_exists( 'Masterminds\\HTML5' ) ) {
					$doc = new \Masterminds\HTML5( array( 'disable_html_ns' => true ) );
					$doc = $doc->loadHTML( $input );
			} else {
				$doc = new DOMDocument();
				$doc->loadHTML( unicodeToHtmlEntities( $input ) );
			}
		} elseif ( is_a( $input, 'DOMDocument' ) ) {
			$doc = clone $input;
		} else {
			$doc = new DOMDocument();
			$doc->loadHTML( '' );
		}
		restore_error_handler();

		$this->xpath = new DOMXPath( $doc );

		$baseurl = $url;
		foreach ( $this->xpath->query( '//base[@href]' ) as $base ) {
			$baseElementUrl = $base->getAttribute( 'href' );

			if ( parse_url( $baseElementUrl, PHP_URL_SCHEME ) === null ) {
				$baseurl = resolveUrl( $url, $baseElementUrl );
			} else {
				$baseurl = $baseElementUrl;
			}
			break;
		}

		// Ignore <template> elements as per the HTML5 spec
		foreach ( $this->xpath->query( '//template' ) as $templateEl ) {
			$templateEl->parentNode->removeChild( $templateEl );
		}

		$this->baseurl = $baseurl;
		$this->doc = $doc;
		$this->parsed = new SplObjectStorage();
		$this->upgraded = new SplObjectStorage();
		$this->jsonMode = $jsonMode;
	}

	private function elementPrefixParsed( \DOMElement $e, $prefix ) {
		if ( ! $this->parsed->contains( $e ) ) {
			$this->parsed->attach( $e, array() );
		}

		$prefixes = $this->parsed[ $e ];
		$prefixes[] = $prefix;
		$this->parsed[ $e ] = $prefixes;
	}

	/**
	 * Determine if the element has already been parsed
	 *
	 * @param DOMElement $e
	 * @param string     $prefix
	 * @return bool
	 */
	private function isElementParsed( \DOMElement $e, $prefix ) {
		if ( ! $this->parsed->contains( $e ) ) {
			return false;
		}

		$prefixes = $this->parsed[ $e ];

		if ( ! in_array( $prefix, $prefixes ) ) {
			return false;
		}

		return true;
	}

	/**
	 * Determine if the element's specified property has already been upgraded during backcompat
	 *
	 * @param DOMElement $el
	 * @param string     $property
	 * @return bool
	 */
	private function isElementUpgraded( \DOMElement $el, $property ) {
		if ( $this->upgraded->contains( $el ) ) {
			if ( in_array( $property, $this->upgraded[ $el ] ) ) {
				return true;
			}
		}

		return false;
	}

	private function resolveChildUrls( DOMElement $el ) {
		$hyperlinkChildren = $this->xpath->query( './/*[@src or @href or @data]', $el );

		foreach ( $hyperlinkChildren as $child ) {
			if ( $child->hasAttribute( 'href' ) ) {
				$child->setAttribute( 'href', $this->resolveUrl( $child->getAttribute( 'href' ) ) );
			}
			if ( $child->hasAttribute( 'src' ) ) {
				$child->setAttribute( 'src', $this->resolveUrl( $child->getAttribute( 'src' ) ) );
			}
			if ( $child->hasAttribute( 'srcset' ) ) {
				$child->setAttribute( 'srcset', applySrcsetUrlTransformation( $child->getAttribute( 'href' ), array( $this, 'resolveUrl' ) ) );
			}
			if ( $child->hasAttribute( 'data' ) ) {
				$child->setAttribute( 'data', $this->resolveUrl( $child->getAttribute( 'data' ) ) );
			}
		}
	}

	/**
	 * The following two methods implements plain text parsing.
	 *
	 * @param DOMElement $element
	 * @param bool       $implied
	 * @see https://wiki.zegnat.net/media/textparsing.html
	 **/
	public function textContent( DOMElement $element, $implied = false ) {
				return preg_replace(
					'/(^[\t\n\f\r ]+| +(?=\n)|(?<=\n) +| +(?= )|[\t\n\f\r ]+$)/',
					'',
					$this->elementToString( $element, $implied )
				);
	}
	private function elementToString( DOMElement $input, $implied = false ) {
			$output = '';
		foreach ( $input->childNodes as $child ) {
			if ( $child->nodeType === XML_TEXT_NODE ) {
					$output .= str_replace( array( "\t", "\n", "\r" ), ' ', $child->textContent );
			} elseif ( $child->nodeType === XML_ELEMENT_NODE ) {
					$tagName = strtoupper( $child->tagName );
				if ( in_array( $tagName, array( 'SCRIPT', 'STYLE' ) ) ) {
						continue;
				} elseif ( $tagName === 'IMG' ) {
					if ( $child->hasAttribute( 'alt' ) ) {
							$output .= ' ' . trim( $child->getAttribute( 'alt' ), "\t\n\f\r " ) . ' ';
					} elseif ( ! $implied && $child->hasAttribute( 'src' ) ) {
							$output .= ' ' . $this->resolveUrl( trim( $child->getAttribute( 'src' ), "\t\n\f\r " ) ) . ' ';
					}
				} elseif ( $tagName === 'BR' ) {
						$output .= "\n";
				} elseif ( $tagName === 'P' ) {
							$output .= "\n" . $this->elementToString( $child );
				} else {
						$output .= $this->elementToString( $child );
				}
			}
		}
			return $output;
	}

	/**
	 * This method parses the language of an element
	 *
	 * @param DOMElement $el
	 * @access public
	 * @return string
	 */
	public function language( DOMElement $el ) {
		// element has a lang attribute; use it
		if ( $el->hasAttribute( 'lang' ) ) {
			return unicodeTrim( $el->getAttribute( 'lang' ) );
		}

		if ( $el->tagName == 'html' ) {
			// we're at the <html> element and no lang; check <meta> http-equiv Content-Language
			foreach ( $this->xpath->query( './/meta[@http-equiv]' ) as $node ) {
				if ( $node->hasAttribute( 'http-equiv' ) && $node->hasAttribute( 'content' ) && strtolower( $node->getAttribute( 'http-equiv' ) ) == 'content-language' ) {
					return unicodeTrim( $node->getAttribute( 'content' ) );
				}
			}
		} elseif ( $el->parentNode instanceof DOMElement ) {
			// check the parent node
			return $this->language( $el->parentNode );
		}

		return '';
	} // end method language()

	// TODO: figure out if this has problems with sms: and geo: URLs
	public function resolveUrl( $url ) {
		// If the URL is seriously malformed it’s probably beyond the scope of this
		// parser to try to do anything with it.
		if ( parse_url( $url ) === false ) {
			return $url;
		}

		// per issue #40 valid URLs could have a space on either side
		$url = trim( $url );

		$scheme = parse_url( $url, PHP_URL_SCHEME );

		if ( empty( $scheme ) and ! empty( $this->baseurl ) ) {
			return resolveUrl( $this->baseurl, $url );
		} else {
			return $url;
		}
	}

	// Parsing Functions

	/**
	 * Parse value-class/value-title on an element, joining with $separator if
	 * there are multiple.
	 *
	 * @param \DOMElement $e
	 * @param string      $separator = '' if multiple value-title elements, join with this string
	 * @return string|null the parsed value or null if value-class or -title aren’t in use
	 */
	public function parseValueClassTitle( \DOMElement $e, $separator = '' ) {
		$valueClassElements = $this->xpath->query( './*[contains(concat(" ", @class, " "), " value ")]', $e );

		if ( $valueClassElements->length !== 0 ) {
			// Process value-class stuff
			$val = '';
			foreach ( $valueClassElements as $el ) {
				$val .= $this->textContent( $el );
			}

			return unicodeTrim( $val );
		}

		$valueTitleElements = $this->xpath->query( './*[contains(concat(" ", @class, " "), " value-title ")]', $e );

		if ( $valueTitleElements->length !== 0 ) {
			// Process value-title stuff
			$val = '';
			foreach ( $valueTitleElements as $el ) {
				$val .= $el->getAttribute( 'title' );
			}

			return unicodeTrim( $val );
		}

		// No value-title or -class in this element
		return null;
	}

	/**
	 * Given an element with class="p-*", get its value
	 *
	 * @param DOMElement $p The element to parse
	 * @return string The plaintext value of $p, dependant on type
	 * @todo Make this adhere to value-class
	 */
	public function parseP( \DOMElement $p ) {
		$classTitle = $this->parseValueClassTitle( $p, ' ' );

		if ( $classTitle !== null ) {
			return $classTitle;
		}

		$this->resolveChildUrls( $p );

		if ( $p->tagName == 'img' and $p->hasAttribute( 'alt' ) ) {
			$pValue = $p->getAttribute( 'alt' );
		} elseif ( $p->tagName == 'area' and $p->hasAttribute( 'alt' ) ) {
			$pValue = $p->getAttribute( 'alt' );
		} elseif ( ( $p->tagName == 'abbr' or $p->tagName == 'link' ) and $p->hasAttribute( 'title' ) ) {
			$pValue = $p->getAttribute( 'title' );
		} elseif ( in_array( $p->tagName, array( 'data', 'input' ) ) and $p->hasAttribute( 'value' ) ) {
			$pValue = $p->getAttribute( 'value' );
		} else {
			$pValue = $this->textContent( $p );
		}

		return $pValue;
	}

	/**
	 * Given an element with class="u-*", get the value of the URL
	 *
	 * @param DOMElement $u The element to parse
	 * @return string The plaintext value of $u, dependant on type
	 * @todo make this adhere to value-class
	 */
	public function parseU( \DOMElement $u ) {
		if ( ( $u->tagName == 'a' or $u->tagName == 'area' or $u->tagName == 'link' ) and $u->hasAttribute( 'href' ) ) {
			$uValue = $u->getAttribute( 'href' );
		} elseif ( in_array( $u->tagName, array( 'img', 'audio', 'video', 'source' ) ) and $u->hasAttribute( 'src' ) ) {
			$uValue = $u->getAttribute( 'src' );
		} elseif ( $u->tagName == 'video' and ! $u->hasAttribute( 'src' ) and $u->hasAttribute( 'poster' ) ) {
			$uValue = $u->getAttribute( 'poster' );
		} elseif ( $u->tagName == 'object' and $u->hasAttribute( 'data' ) ) {
			$uValue = $u->getAttribute( 'data' );
		} elseif ( ( $classTitle = $this->parseValueClassTitle( $u ) ) !== null ) {
				$uValue = $classTitle;
		} elseif ( ( $u->tagName == 'abbr' or $u->tagName == 'link' ) and $u->hasAttribute( 'title' ) ) {
			$uValue = $u->getAttribute( 'title' );
		} elseif ( in_array( $u->tagName, array( 'data', 'input' ) ) and $u->hasAttribute( 'value' ) ) {
			$uValue = $u->getAttribute( 'value' );
		} else {
			$uValue = $this->textContent( $u );
		}
				return $this->resolveUrl( $uValue );
	}

	/**
	 * Given an element with class="dt-*", get the value of the datetime as a php date object
	 *
	 * @param DOMElement $dt The element to parse
	 * @param array      $dates Array of dates processed so far
	 * @param string     $impliedTimezone
	 * @return string The datetime string found
	 */
	public function parseDT( \DOMElement $dt, &$dates = array(), &$impliedTimezone = null ) {
		// Check for value-class pattern
		$valueClassChildren = $this->xpath->query( './*[contains(concat(" ", @class, " "), " value ") or contains(concat(" ", @class, " "), " value-title ")]', $dt );
		$dtValue = false;

		if ( $valueClassChildren->length > 0 ) {
			// They’re using value-class
			$dateParts = array();

			foreach ( $valueClassChildren as $e ) {
				if ( strstr( ' ' . $e->getAttribute( 'class' ) . ' ', ' value-title ' ) ) {
					$title = $e->getAttribute( 'title' );
					if ( ! empty( $title ) ) {
						$dateParts[] = $title;
					}
				} elseif ( $e->tagName == 'img' or $e->tagName == 'area' ) {
					// Use @alt
					$alt = $e->getAttribute( 'alt' );
					if ( ! empty( $alt ) ) {
						$dateParts[] = $alt;
					}
				} elseif ( $e->tagName == 'data' ) {
					// Use @value, otherwise innertext
					$value = $e->hasAttribute( 'value' ) ? $e->getAttribute( 'value' ) : unicodeTrim( $e->nodeValue );
					if ( ! empty( $value ) ) {
						$dateParts[] = $value;
					}
				} elseif ( $e->tagName == 'abbr' ) {
					// Use @title, otherwise innertext
					$title = $e->hasAttribute( 'title' ) ? $e->getAttribute( 'title' ) : unicodeTrim( $e->nodeValue );
					if ( ! empty( $title ) ) {
						$dateParts[] = $title;
					}
				} elseif ( $e->tagName == 'del' or $e->tagName == 'ins' or $e->tagName == 'time' ) {
					// Use @datetime if available, otherwise innertext
					$dtAttr = ( $e->hasAttribute( 'datetime' ) ) ? $e->getAttribute( 'datetime' ) : unicodeTrim( $e->nodeValue );
					if ( ! empty( $dtAttr ) ) {
						$dateParts[] = $dtAttr;
					}
				} else {
					if ( ! empty( $e->nodeValue ) ) {
						$dateParts[] = unicodeTrim( $e->nodeValue );
					}
				}
			}

			// Look through dateParts
			$datePart = '';
			$timePart = '';
			$timezonePart = '';
			foreach ( $dateParts as $part ) {
				// Is this part a full ISO8601 datetime?
				if ( preg_match( '/^\d{4}-\d{2}-\d{2}[ T]\d{2}:\d{2}(:\d{2})?(Z|[+-]\d{2}:?\d{2})?$/', $part ) ) {
					// Break completely, we’ve got our value.
					$dtValue = $part;
					break;
				} else {
					// Is the current part a valid time(+TZ?) AND no other time representation has been found?
					if ( ( preg_match( '/^\d{1,2}:\d{2}(:\d{2})?(Z|[+-]\d{1,2}:?\d{2})?$/', $part ) or preg_match( '/^\d{1,2}(:\d{2})?(:\d{2})?[ap]\.?m\.?$/i', $part ) ) and empty( $timePart ) ) {
						$timePart = $part;

						$timezoneOffset = normalizeTimezoneOffset( $timePart );
						if ( ! $impliedTimezone && $timezoneOffset ) {
							$impliedTimezone = $timezoneOffset;
						}
						// Is the current part a valid date AND no other date representation has been found?
					} elseif ( preg_match( '/^\d{4}-\d{2}-\d{2}$/', $part ) and empty( $datePart ) ) {
						$datePart = $part;
						// Is the current part a valid ordinal date AND no other date representation has been found?
					} elseif ( preg_match( '/^\d{4}-\d{3}$/', $part ) and empty( $datePart ) ) {
						$datePart = normalizeOrdinalDate( $part );
						// Is the current part a valid timezone offset AND no other timezone part has been found?
					} elseif ( preg_match( '/^(Z|[+-]\d{1,2}:?(\d{2})?)$/', $part ) and empty( $timezonePart ) ) {
						$timezonePart = $part;

						$timezoneOffset = normalizeTimezoneOffset( $timezonePart );
						if ( ! $impliedTimezone && $timezoneOffset ) {
							$impliedTimezone = $timezoneOffset;
						}
						// Current part already represented by other VCP parts; do nothing with it
					} else {
						continue;
					}

					if ( ! empty( $datePart ) && ! in_array( $datePart, $dates ) ) {
						$dates[] = $datePart;
					}

					if ( ! empty( $timezonePart ) && ! empty( $timePart ) ) {
						$timePart .= $timezonePart;
					}

					$dtValue = '';

					if ( empty( $datePart ) && ! empty( $timePart ) ) {
						$timePart = convertTimeFormat( $timePart );
						$dtValue = unicodeTrim( $timePart );
					} elseif ( ! empty( $datePart ) && empty( $timePart ) ) {
						$dtValue = rtrim( $datePart, 'T' );
					} else {
						$timePart = convertTimeFormat( $timePart );
						$dtValue = rtrim( $datePart, 'T' ) . ' ' . unicodeTrim( $timePart );
					}
				}
			}
		} else {
			// Not using value-class (phew).
			if ( $dt->tagName == 'img' or $dt->tagName == 'area' ) {
				// Use @alt
				// Is it an entire dt?
				$alt = $dt->getAttribute( 'alt' );
				if ( ! empty( $alt ) ) {
					$dtValue = $alt;
				}
			} elseif ( in_array( $dt->tagName, array( 'data' ) ) ) {
				// Use @value, otherwise innertext
				// Is it an entire dt?
				$value = $dt->getAttribute( 'value' );
				if ( ! empty( $value ) ) {
					$dtValue = $value;
				} else {
					$dtValue = $this->textContent( $dt );
				}
			} elseif ( $dt->tagName == 'abbr' ) {
				// Use @title, otherwise innertext
				// Is it an entire dt?
				$title = $dt->getAttribute( 'title' );
				if ( ! empty( $title ) ) {
					$dtValue = $title;
				} else {
					$dtValue = $this->textContent( $dt );
				}
			} elseif ( $dt->tagName == 'del' or $dt->tagName == 'ins' or $dt->tagName == 'time' ) {
				// Use @datetime if available, otherwise innertext
				// Is it an entire dt?
				$dtAttr = $dt->getAttribute( 'datetime' );
				if ( ! empty( $dtAttr ) ) {
					$dtValue = $dtAttr;
				} else {
					$dtValue = $this->textContent( $dt );
				}
			} else {
				$dtValue = $this->textContent( $dt );
			}

			// if the dtValue is not just YYYY-MM-DD
			if ( ! preg_match( '/^(\d{4}-\d{2}-\d{2})$/', $dtValue ) ) {
				// no implied timezone set and dtValue has a TZ offset, use un-normalized TZ offset
				preg_match( '/Z|[+-]\d{1,2}:?(\d{2})?$/i', $dtValue, $matches );
				if ( ! $impliedTimezone && ! empty( $matches[0] ) ) {
					$impliedTimezone = $matches[0];
				}
			}

			$dtValue = unicodeTrim( $dtValue );

			// Store the date part so that we can use it when assembling the final timestamp if the next one is missing a date part
			if ( preg_match( '/(\d{4}-\d{2}-\d{2})/', $dtValue, $matches ) ) {
				$dates[] = $matches[0];
			}
		}

		/**
		 * if $dtValue is only a time and there are recently parsed dates,
		 * form the full date-time using the most recently parsed dt- value
		 */
		if ( ( preg_match( '/^\d{1,2}:\d{2}(:\d{2})?(Z|[+-]\d{2}:?\d{2}?)?$/', $dtValue ) or preg_match( '/^\d{1,2}(:\d{2})?(:\d{2})?[ap]\.?m\.?$/i', $dtValue ) ) && ! empty( $dates ) ) {
			$timezoneOffset = normalizeTimezoneOffset( $dtValue );
			if ( ! $impliedTimezone && $timezoneOffset ) {
				$impliedTimezone = $timezoneOffset;
			}

			$dtValue = convertTimeFormat( $dtValue );
			$dtValue = end( $dates ) . ' ' . unicodeTrim( $dtValue );
		}

		return $dtValue;
	}

	/**
	 *  Given the root element of some embedded markup, return a string representing that markup
	 *
	 *  @param DOMElement $e The element to parse
	 *  @return string $e’s innerHTML
	 *
	 * @todo need to mark this element as e- parsed so it doesn’t get parsed as it’s parent’s e-* too
	 */
	public function parseE( \DOMElement $e ) {
		$classTitle = $this->parseValueClassTitle( $e );

		if ( $classTitle !== null ) {
			return $classTitle;
		}

		// Expand relative URLs within children of this element
		// TODO: as it is this is not relative to only children, make this .// and rerun tests
		$this->resolveChildUrls( $e );

		// Temporarily move all descendants into a separate DocumentFragment.
		// This way we can DOMDocument::saveHTML on the entire collection at once.
		// Running DOMDocument::saveHTML per node may add whitespace that isn't in source.
		// See https://stackoverflow.com/q/38317903
		$innerNodes = $e->ownerDocument->createDocumentFragment();
		while ( $e->hasChildNodes() ) {
			$innerNodes->appendChild( $e->firstChild );
		}
		$html = $e->ownerDocument->saveHtml( $innerNodes );
		// Put the nodes back in place.
		if ( $innerNodes->hasChildNodes() ) {
			$e->appendChild( $innerNodes );
		}

		$return = array(
			'html'  => unicodeTrim( $html ),
			'value' => $this->textContent( $e ),
		);

		if ( $this->lang ) {
			// Language
			if ( $html_lang = $this->language( $e ) ) {
				$return['lang'] = $html_lang;
			}
		}

		return $return;
	}

	private function removeTags( \DOMElement &$e, $tagName ) {
		while ( ( $r = $e->getElementsByTagName( $tagName ) ) && $r->length ) {
			$r->item( 0 )->parentNode->removeChild( $r->item( 0 ) );
		}
	}

	/**
	 * Recursively parse microformats
	 *
	 * @param DOMElement $e The element to parse
	 * @param bool       $is_backcompat Whether using backcompat parsing or not
	 * @param bool       $has_nested_mf Whether this microformat has a nested microformat
	 * @return array A representation of the values contained within microformat $e
	 */
	public function parseH( \DOMElement $e, $is_backcompat = false, $has_nested_mf = false ) {
		// If it’s already been parsed (e.g. is a child mf), skip
		if ( $this->parsed->contains( $e ) ) {
			return null;
		}

		// Get current µf name
		$mfTypes = mfNamesFromElement( $e, 'h-' );

		if ( ! $mfTypes ) {
			return null;
		}

		// Initalise var to store the representation in
		$return = array();
		$children = array();
		$dates = array();
		$prefixes = array();
		$impliedTimezone = null;

		if ( $e->tagName == 'area' ) {
			$coords = $e->getAttribute( 'coords' );
			$shape = $e->getAttribute( 'shape' );
		}

		// Handle p-*
		foreach ( $this->xpath->query( './/*[contains(concat(" ", @class) ," p-")]', $e ) as $p ) {
			// element is already parsed
			if ( $this->isElementParsed( $p, 'p' ) ) {
				continue;
				// backcompat parsing and element was not upgraded; skip it
			} elseif ( $is_backcompat && empty( $this->upgraded[ $p ] ) ) {
				$this->elementPrefixParsed( $p, 'p' );
				continue;
			}

			$prefixes[] = 'p-';
			$pValue = $this->parseP( $p );

			// Add the value to the array for it’s p- properties
			foreach ( mfNamesFromElement( $p, 'p-' ) as $propName ) {
				if ( ! empty( $propName ) ) {
					$return[ $propName ][] = $pValue;
				}
			}

			// Make sure this sub-mf won’t get parsed as a top level mf
			$this->elementPrefixParsed( $p, 'p' );
		}

		// Handle u-*
		foreach ( $this->xpath->query( './/*[contains(concat(" ",  @class)," u-")]', $e ) as $u ) {
			// element is already parsed
			if ( $this->isElementParsed( $u, 'u' ) ) {
				continue;
				// backcompat parsing and element was not upgraded; skip it
			} elseif ( $is_backcompat && empty( $this->upgraded[ $u ] ) ) {
				$this->elementPrefixParsed( $u, 'u' );
				continue;
			}

			$prefixes[] = 'u-';
			$uValue = $this->parseU( $u );

			// Add the value to the array for it’s property types
			foreach ( mfNamesFromElement( $u, 'u-' ) as $propName ) {
				$return[ $propName ][] = $uValue;
			}

			// Make sure this sub-mf won’t get parsed as a top level mf
			$this->elementPrefixParsed( $u, 'u' );
		}

		$temp_dates = array();

		// Handle dt-*
		foreach ( $this->xpath->query( './/*[contains(concat(" ", @class), " dt-")]', $e ) as $dt ) {
			// element is already parsed
			if ( $this->isElementParsed( $dt, 'dt' ) ) {
				continue;
				// backcompat parsing and element was not upgraded; skip it
			} elseif ( $is_backcompat && empty( $this->upgraded[ $dt ] ) ) {
				$this->elementPrefixParsed( $dt, 'dt' );
				continue;
			}

			$prefixes[] = 'dt-';
			$dtValue = $this->parseDT( $dt, $dates, $impliedTimezone );

			if ( $dtValue ) {
				// Add the value to the array for dt- properties
				foreach ( mfNamesFromElement( $dt, 'dt-' ) as $propName ) {
					$temp_dates[ $propName ][] = $dtValue;
				}
			}
			// Make sure this sub-mf won’t get parsed as a top level mf
			$this->elementPrefixParsed( $dt, 'dt' );
		}

		foreach ( $temp_dates as $propName => $data ) {
			foreach ( $data as $dtValue ) {
				// var_dump(preg_match('/[+-]\d{2}(\d{2})?$/i', $dtValue));
				if ( $impliedTimezone && preg_match( '/(Z|[+-]\d{2}:?(\d{2})?)$/i', $dtValue, $matches ) == 0 ) {
					$dtValue .= $impliedTimezone;
				}

				$return[ $propName ][] = $dtValue;
			}
		}

		// Handle e-*
		foreach ( $this->xpath->query( './/*[contains(concat(" ", @class)," e-")]', $e ) as $em ) {
			// element is already parsed
			if ( $this->isElementParsed( $em, 'e' ) ) {
				continue;
				// backcompat parsing and element was not upgraded; skip it
			} elseif ( $is_backcompat && empty( $this->upgraded[ $em ] ) ) {
				$this->elementPrefixParsed( $em, 'e' );
				continue;
			}

			$prefixes[] = 'e-';
			$eValue = $this->parseE( $em );

			if ( $eValue ) {
				// Add the value to the array for e- properties
				foreach ( mfNamesFromElement( $em, 'e-' ) as $propName ) {
					$return[ $propName ][] = $eValue;
				}
			}
			// Make sure this sub-mf won’t get parsed as a top level mf
			$this->elementPrefixParsed( $em, 'e' );
		}

		// Do we need to imply a name property?
		// if no explicit "name" property, and no other p-* or e-* properties, and no nested microformats,
		if ( ! array_key_exists( 'name', $return ) && ! in_array( 'p-', $prefixes ) && ! in_array( 'e-', $prefixes ) && ! $has_nested_mf && ! $is_backcompat ) {
			$name = false;
			// img.h-x[alt] or area.h-x[alt]
			if ( ( $e->tagName === 'img' || $e->tagName === 'area' ) && $e->hasAttribute( 'alt' ) ) {
				$name = $e->getAttribute( 'alt' );
				// abbr.h-x[title]
			} elseif ( $e->tagName === 'abbr' && $e->hasAttribute( 'title' ) ) {
				$name = $e->getAttribute( 'title' );
			} else {
				$xpaths = array(
					// .h-x>img:only-child[alt]:not([alt=""]):not[.h-*]
					'./img[not(contains(concat(" ", @class), " h-")) and count(../*) = 1 and @alt and string-length(@alt) != 0]',
					// .h-x>area:only-child[alt]:not([alt=""]):not[.h-*]
					'./area[not(contains(concat(" ", @class), " h-")) and count(../*) = 1 and @alt and string-length(@alt) != 0]',
					// .h-x>abbr:only-child[title]:not([title=""]):not[.h-*]
					'./abbr[not(contains(concat(" ", @class), " h-")) and count(../*) = 1 and @title and string-length(@title) != 0]',
					// .h-x>:only-child:not[.h-*]>img:only-child[alt]:not([alt=""]):not[.h-*]
					'./*[not(contains(concat(" ", @class), " h-")) and count(../*) = 1 and count(*) = 1]/img[not(contains(concat(" ", @class), " h-")) and @alt and string-length(@alt) != 0]',
					// .h-x>:only-child:not[.h-*]>area:only-child[alt]:not([alt=""]):not[.h-*]
					'./*[not(contains(concat(" ", @class), " h-")) and count(../*) = 1 and count(*) = 1]/area[not(contains(concat(" ", @class), " h-")) and @alt and string-length(@alt) != 0]',
					// .h-x>:only-child:not[.h-*]>abbr:only-child[title]:not([title=""]):not[.h-*]
					'./*[not(contains(concat(" ", @class), " h-")) and count(../*) = 1 and count(*) = 1]/abbr[not(contains(concat(" ", @class), " h-")) and @title and string-length(@title) != 0]',
				);
				foreach ( $xpaths as $xpath ) {
					$nameElement = $this->xpath->query( $xpath, $e );
					if ( $nameElement !== false && $nameElement->length === 1 ) {
						$nameElement = $nameElement->item( 0 );
						if ( $nameElement->tagName === 'img' || $nameElement->tagName === 'area' ) {
							$name = $nameElement->getAttribute( 'alt' );
						} else {
							$name = $nameElement->getAttribute( 'title' );
						}
						break;
					}
				}
			}
			if ( $name === false ) {
				$name = $this->textContent( $e, true );
			}
			$return['name'][] = unicodeTrim( $name );
		}

		// Check for u-photo
		if ( ! array_key_exists( 'photo', $return ) && ! $is_backcompat ) {

			$photo = $this->parseImpliedPhoto( $e );

			if ( $photo !== false ) {
				$return['photo'][] = $photo;
			}
		}

		// Do we need to imply a url property?
		// if no explicit "url" property, and no other explicit u-* properties, and no nested microformats
		if ( ! array_key_exists( 'url', $return ) && ! in_array( 'u-', $prefixes ) && ! $has_nested_mf && ! $is_backcompat ) {
			// a.h-x[href] or area.h-x[href]
			if ( ( $e->tagName === 'a' || $e->tagName === 'area' ) && $e->hasAttribute( 'href' ) ) {
				$return['url'][] = $this->resolveUrl( $e->getAttribute( 'href' ) );
			} else {
				$xpaths = array(
					// .h-x>a[href]:only-of-type:not[.h-*]
					'./a[not(contains(concat(" ", @class), " h-")) and count(../a) = 1 and @href]',
					// .h-x>area[href]:only-of-type:not[.h-*]
					'./area[not(contains(concat(" ", @class), " h-")) and count(../area) = 1 and @href]',
					// .h-x>:only-child:not[.h-*]>a[href]:only-of-type:not[.h-*]
					'./*[not(contains(concat(" ", @class), " h-")) and count(../*) = 1 and count(a) = 1]/a[not(contains(concat(" ", @class), " h-")) and @href]',
					// .h-x>:only-child:not[.h-*]>area[href]:only-of-type:not[.h-*]
					'./*[not(contains(concat(" ", @class), " h-")) and count(../*) = 1 and count(area) = 1]/area[not(contains(concat(" ", @class), " h-")) and @href]',
				);
				foreach ( $xpaths as $xpath ) {
					$url = $this->xpath->query( $xpath, $e );
					if ( $url !== false && $url->length === 1 ) {
						$return['url'][] = $this->resolveUrl( $url->item( 0 )->getAttribute( 'href' ) );
						break;
					}
				}
			}
		}

		// Make sure things are unique and in alphabetical order
		$mfTypes = array_unique( $mfTypes );
		sort( $mfTypes );

		// Properties should be an object when JSON serialised
		if ( empty( $return ) and $this->jsonMode ) {
			$return = new stdClass();
		}

		// Phew. Return the final result.
		$parsed = array(
			'type'       => $mfTypes,
			'properties' => $return,
		);

		if ( $this->lang ) {
			// Language
			if ( $html_lang = $this->language( $e ) ) {
				$parsed['lang'] = $html_lang;
			}
		}

		if ( ! empty( $shape ) ) {
			$parsed['shape'] = $shape;
		}

		if ( ! empty( $coords ) ) {
			$parsed['coords'] = $coords;
		}

		if ( ! empty( $children ) ) {
			$parsed['children'] = array_values( array_filter( $children ) );
		}
		return $parsed;
	}

	/**
	 * @see http://microformats.org/wiki/microformats2-parsing#parsing_for_implied_properties
	 */
	public function parseImpliedPhoto( \DOMElement $e ) {

		// img.h-x[src]
		if ( $e->tagName == 'img' ) {
			return $this->resolveUrl( $e->getAttribute( 'src' ) );
		}

		// object.h-x[data]
		if ( $e->tagName == 'object' && $e->hasAttribute( 'data' ) ) {
			return $this->resolveUrl( $e->getAttribute( 'data' ) );
		}

		$xpaths = array(
			// .h-x>img[src]:only-of-type:not[.h-*]
			'./img[not(contains(concat(" ", @class), " h-")) and count(../img) = 1 and @src]',
			// .h-x>object[data]:only-of-type:not[.h-*]
			'./object[not(contains(concat(" ", @class), " h-")) and count(../object) = 1 and @data]',
			// .h-x>:only-child:not[.h-*]>img[src]:only-of-type:not[.h-*]
			'./*[not(contains(concat(" ", @class), " h-")) and count(../*) = 1 and count(img) = 1]/img[not(contains(concat(" ", @class), " h-")) and @src]',
			// .h-x>:only-child:not[.h-*]>object[data]:only-of-type:not[.h-*]
			'./*[not(contains(concat(" ", @class), " h-")) and count(../*) = 1 and count(object) = 1]/object[not(contains(concat(" ", @class), " h-")) and @data]',
		);

		foreach ( $xpaths as $path ) {
			$els = $this->xpath->query( $path, $e );

			if ( $els !== false && $els->length === 1 ) {
				$el = $els->item( 0 );
				if ( $el->tagName == 'img' ) {
					return $this->resolveUrl( $el->getAttribute( 'src' ) );
				} elseif ( $el->tagName == 'object' ) {
					return $this->resolveUrl( $el->getAttribute( 'data' ) );
				}
			}
		}

		// no implied photo
		return false;
	}

	/**
	 * Parse rels and alternates
	 *
	 * Returns [$rels, $rel_urls, $alternates].
	 * For $rels and $rel_urls, if they are empty and $this->jsonMode = true, they will be returned as stdClass,
	 * optimizing for JSON serialization. Otherwise they will be returned as an empty array.
	 * Note that $alternates is deprecated in the microformats spec in favor of $rel_urls. $alternates only appears
	 * in parsed results if $this->enableAlternates = true.
	 *
	 * @return array|stdClass
	 */
	public function parseRelsAndAlternates() {
		$rels = array();
		$rel_urls = array();
		$alternates = array();

		// Iterate through all a, area and link elements with rel attributes
		foreach ( $this->xpath->query( '//a[@rel and @href] | //link[@rel and @href] | //area[@rel and @href]' ) as $hyperlink ) {
			// Parse the set of rels for the current link
			$linkRels = array_unique( array_filter( preg_split( '/[\t\n\f\r ]/', $hyperlink->getAttribute( 'rel' ) ) ) );
			if ( count( $linkRels ) === 0 ) {
				continue;
			}

			// Resolve the href
			$href = $this->resolveUrl( $hyperlink->getAttribute( 'href' ) );

			$rel_attributes = array();

			if ( $hyperlink->hasAttribute( 'media' ) ) {
				$rel_attributes['media'] = $hyperlink->getAttribute( 'media' );
			}

			if ( $hyperlink->hasAttribute( 'hreflang' ) ) {
				$rel_attributes['hreflang'] = $hyperlink->getAttribute( 'hreflang' );
			}

			if ( $hyperlink->hasAttribute( 'title' ) ) {
				$rel_attributes['title'] = $hyperlink->getAttribute( 'title' );
			}

			if ( $hyperlink->hasAttribute( 'type' ) ) {
				$rel_attributes['type'] = $hyperlink->getAttribute( 'type' );
			}

			if ( strlen( $hyperlink->textContent ) > 0 ) {
				$rel_attributes['text'] = $hyperlink->textContent;
			}

			if ( $this->enableAlternates ) {
				// If 'alternate' in rels, create 'alternates' structure, append
				if ( in_array( 'alternate', $linkRels ) ) {
					$alternates[] = array_merge(
						$rel_attributes,
						array(
							'url' => $href,
							'rel' => implode( ' ', array_diff( $linkRels, array( 'alternate' ) ) ),
						)
					);
				}
			}

			foreach ( $linkRels as $rel ) {
				if ( ! array_key_exists( $rel, $rels ) ) {
					$rels[ $rel ] = array( $href );
				} elseif ( ! in_array( $href, $rels[ $rel ] ) ) {
					$rels[ $rel ][] = $href;
				}
			}

			if ( ! array_key_exists( $href, $rel_urls ) ) {
				$rel_urls[ $href ] = array( 'rels' => array() );
			}

			// Add the attributes collected only if they were not already set
			$rel_urls[ $href ] = array_merge(
				$rel_attributes,
				$rel_urls[ $href ]
			);

			// Merge current rels with those already set
			$rel_urls[ $href ]['rels'] = array_merge(
				$rel_urls[ $href ]['rels'],
				$linkRels
			);
		}

		// Alphabetically sort the rels arrays after removing duplicates
		foreach ( $rel_urls as $href => $object ) {
			$rel_urls[ $href ]['rels'] = array_unique( $rel_urls[ $href ]['rels'] );
			sort( $rel_urls[ $href ]['rels'] );
		}

		if ( empty( $rels ) and $this->jsonMode ) {
			$rels = new stdClass();
		}

		if ( empty( $rel_urls ) and $this->jsonMode ) {
			$rel_urls = new stdClass();
		}

		return array( $rels, $rel_urls, $alternates );
	}

	/**
	 * Find rel=tag elements that don't have class=category and have an href.
	 * For each element, get the last non-empty URL segment. Append a <data>
	 * element with that value as the category. Uses the mf1 class 'category'
	 * which will then be upgraded to p-category during backcompat.
	 *
	 * @param DOMElement $el
	 */
	public function upgradeRelTagToCategory( DOMElement $el ) {
		$rel_tag = $this->xpath->query( './/a[contains(concat(" ",normalize-space(@rel)," ")," tag ") and not(contains(concat(" ", normalize-space(@class), " "), " category ")) and @href]', $el );

		if ( $rel_tag->length ) {
			foreach ( $rel_tag as $tempEl ) {
				$path = trim( parse_url( $tempEl->getAttribute( 'href' ), PHP_URL_PATH ), ' /' );
				$segments = explode( '/', $path );
				$value = array_pop( $segments );

				// build the <data> element
				$dataEl = $tempEl->ownerDocument->createElement( 'data' );
				$dataEl->setAttribute( 'class', 'category' );
				$dataEl->setAttribute( 'value', $value );

				// append as child of input element. this should ensure added element does get parsed inside e-*
				$el->appendChild( $dataEl );
			}
		}
	}

	/**
	 * Kicks off the parsing routine
	 *
	 * @param bool       $convertClassic whether to do backcompat parsing on microformats1. Defaults to true.
	 * @param DOMElement $context optionally specify an element from which to parse microformats
	 * @return array An array containing all the microformats found in the current document
	 */
	public function parse( $convertClassic = true, DOMElement $context = null ) {
		$this->convertClassic = $convertClassic;
		$mfs = $this->parse_recursive( $context );

		// Parse rels
		list($rels, $rel_urls, $alternates) = $this->parseRelsAndAlternates();

		$top = array(
			'items'    => array_values( array_filter( $mfs ) ),
			'rels'     => $rels,
			'rel-urls' => $rel_urls,
		);

		if ( $this->enableAlternates && count( $alternates ) ) {
			$top['alternates'] = $alternates;
		}

		return $top;
	}


	/**
	 * Parse microformats recursively
	 * Keeps track of whether inside a backcompat root or not
	 *
	 * @param DOMElement $context: node to start with
	 * @param int        $depth: recursion depth
	 * @return array
	 */
	public function parse_recursive( DOMElement $context = null, $depth = 0 ) {
		$mfs = array();
		$mfElements = $this->getRootMF( $context );

		foreach ( $mfElements as $node ) {
			$is_backcompat = ! $this->hasRootMf2( $node );

			if ( $this->convertClassic && $is_backcompat ) {
				$this->backcompat( $node );
			}

			$recurse = $this->parse_recursive( $node, $depth + 1 );

			// set bool flag for nested mf
			$has_nested_mf = ( $recurse );

			// parse for root mf
			$result = $this->parseH( $node, $is_backcompat, $has_nested_mf );

			// TODO: Determine if clearing this is required?
			$this->elementPrefixParsed( $node, 'h' );
			$this->elementPrefixParsed( $node, 'p' );
			$this->elementPrefixParsed( $node, 'u' );
			$this->elementPrefixParsed( $node, 'dt' );
			$this->elementPrefixParsed( $node, 'e' );

			// parseH returned a parsed result
			if ( $result ) {

				// merge recursive results into current results
				if ( $recurse ) {
					$result = array_merge_recursive( $result, $recurse );
				}

				// currently a nested mf; check if node is an mf property of parent
				if ( $depth > 0 ) {
					$temp_properties = nestedMfPropertyNamesFromElement( $node );

					// properties found; set up parsed result in 'properties'
					if ( ! empty( $temp_properties ) ) {

						foreach ( $temp_properties as $property => $prefixes ) {
							// Note: handling microformat nesting under multiple conflicting prefixes is not currently specified by the mf2 parsing spec.
							$prefixSpecificResult = $result;
							if ( in_array( 'p-', $prefixes ) ) {
								$prefixSpecificResult['value'] = ( ! is_array( $prefixSpecificResult['properties'] ) || empty( $prefixSpecificResult['properties']['name'][0] ) ) ? $this->parseP( $node ) : $prefixSpecificResult['properties']['name'][0];
							} elseif ( in_array( 'e-', $prefixes ) ) {
								$eParsedResult = $this->parseE( $node );
								$prefixSpecificResult['html'] = $eParsedResult['html'];
								$prefixSpecificResult['value'] = $eParsedResult['value'];
							} elseif ( in_array( 'u-', $prefixes ) ) {
								$prefixSpecificResult['value'] = ( ! is_array( $result['properties'] ) || empty( $result['properties']['url'] ) ) ? $this->parseU( $node ) : reset( $result['properties']['url'] );
							} elseif ( in_array( 'dt-', $prefixes ) ) {
								$parsed_property = $this->parseDT( $node );
								$prefixSpecificResult['value'] = ( $parsed_property ) ? $parsed_property : '';
							}

							$mfs['properties'][ $property ][] = $prefixSpecificResult;
						}

						// otherwise, set up in 'children'
					} else {
						$mfs['children'][] = $result;
					}
					// otherwise, top-level mf
				} else {
					$mfs[] = $result;
				}
			}
		}

		return $mfs;
	}


	/**
	 * Parse From ID
	 *
	 * Given an ID, parse all microformats which are children of the element with
	 * that ID.
	 *
	 * Note that rel values are still document-wide.
	 *
	 * If an element with the ID is not found, an empty skeleton mf2 array structure
	 * will be returned.
	 *
	 * @param string $id
	 * @param bool   $htmlSafe = false whether or not to HTML-encode angle brackets in non e-* properties
	 * @return array
	 */
	public function parseFromId( $id, $convertClassic = true ) {
		$matches = $this->xpath->query( "//*[@id='{$id}']" );

		if ( empty( $matches ) ) {
			return array(
				'items'      => array(),
				'rels'       => array(),
				'alternates' => array(),
			);
		}

		return $this->parse( $convertClassic, $matches->item( 0 ) );
	}

	/**
	 * Get the root microformat elements
	 *
	 * @param DOMElement $context
	 * @return DOMNodeList
	 */
	public function getRootMF( DOMElement $context = null ) {
		// start with mf2 root class name xpath
		$xpaths = array(
			'contains(concat(" ",normalize-space(@class)), " h-")',
		);

		// add mf1 root class names
		foreach ( $this->classicRootMap as $old => $new ) {
			$xpaths[] = '( contains(concat(" ",normalize-space(@class), " "), " ' . $old . ' ") )';
		}

		// final xpath with OR
		$xpath = '//*[' . implode( ' or ', $xpaths ) . ']';

		$mfElements = ( null === $context )
			? $this->xpath->query( $xpath )
			: $this->xpath->query( '.' . $xpath, $context );

		return $mfElements;
	}

	/**
	 * Apply the backcompat algorithm to upgrade mf1 classes to mf2.
	 * This method is called recursively.
	 *
	 * @param DOMElement $el
	 * @param string     $context
	 * @param bool       $isParentMf2
	 * @see http://microformats.org/wiki/microformats2-parsing#algorithm
	 */
	public function backcompat( DOMElement $el, $context = '', $isParentMf2 = false ) {

		if ( $context ) {
			$mf1Classes = array( $context );
		} else {
			$class = str_replace( array( "\t", "\n" ), ' ', $el->getAttribute( 'class' ) );
			$classes = array_filter( explode( ' ', $class ) );
			$mf1Classes = array_intersect( $classes, array_keys( $this->classicRootMap ) );
		}

		$elHasMf2 = $this->hasRootMf2( $el );

		foreach ( $mf1Classes as $classname ) {
			// special handling for specific properties
			switch ( $classname ) {
				case 'hentry':
					$this->upgradeRelTagToCategory( $el );

					$rel_bookmark = $this->xpath->query( './/a[contains(concat(" ",normalize-space(@rel)," ")," bookmark ") and @href]', $el );

					if ( $rel_bookmark->length ) {
						foreach ( $rel_bookmark as $tempEl ) {
							$this->addMfClasses( $tempEl, 'u-url' );
							$this->addUpgraded( $tempEl, array( 'bookmark' ) );
						}
					}
					break;

				case 'hreview':
					$item_and_vcard = $this->xpath->query( './/*[contains(concat(" ", normalize-space(@class), " "), " item ") and contains(concat(" ", normalize-space(@class), " "), " vcard ")]', $el );

					if ( $item_and_vcard->length ) {
						foreach ( $item_and_vcard as $tempEl ) {
							if ( ! $this->hasRootMf2( $tempEl ) ) {
								$this->backcompat( $tempEl, 'vcard' );
								$this->addMfClasses( $tempEl, 'p-item h-card' );
								$this->addUpgraded( $tempEl, array( 'item', 'vcard' ) );
							}
						}
					}

					$item_and_vevent = $this->xpath->query( './/*[contains(concat(" ", normalize-space(@class), " "), " item ") and contains(concat(" ", normalize-space(@class), " "), " vevent ")]', $el );

					if ( $item_and_vevent->length ) {
						foreach ( $item_and_vevent as $tempEl ) {
							if ( ! $this->hasRootMf2( $tempEl ) ) {
								$this->addMfClasses( $tempEl, 'p-item h-event' );
								$this->backcompat( $tempEl, 'vevent' );
								$this->addUpgraded( $tempEl, array( 'item', 'vevent' ) );
							}
						}
					}

					$item_and_hproduct = $this->xpath->query( './/*[contains(concat(" ", normalize-space(@class), " "), " item ") and contains(concat(" ", normalize-space(@class), " "), " hproduct ")]', $el );

					if ( $item_and_hproduct->length ) {
						foreach ( $item_and_hproduct as $tempEl ) {
							if ( ! $this->hasRootMf2( $tempEl ) ) {
								$this->addMfClasses( $tempEl, 'p-item h-product' );
								$this->backcompat( $tempEl, 'vevent' );
								$this->addUpgraded( $tempEl, array( 'item', 'hproduct' ) );
							}
						}
					}

					$this->upgradeRelTagToCategory( $el );
					break;

				case 'vevent':
					$location = $this->xpath->query( './/*[contains(concat(" ", normalize-space(@class), " "), " location ")]', $el );

					if ( $location->length ) {
						foreach ( $location as $tempEl ) {
							if ( ! $this->hasRootMf2( $tempEl ) ) {
								$this->addMfClasses( $tempEl, 'h-card' );
								$this->backcompat( $tempEl, 'vcard' );
							}
						}
					}
					break;
			}

			// root class has mf1 properties to be upgraded
			if ( isset( $this->classicPropertyMap[ $classname ] ) ) {
				// loop through each property of the mf1 root
				foreach ( $this->classicPropertyMap[ $classname ] as $property => $data ) {
					$propertyElements = $this->xpath->query( './/*[contains(concat(" ", normalize-space(@class), " "), " ' . $property . ' ")]', $el );

					// loop through each element with the property
					foreach ( $propertyElements as $propertyEl ) {
						$hasRootMf2 = $this->hasRootMf2( $propertyEl );

						// if the element has not been upgraded and we're not inside an mf2 root, recurse
						if ( ! $this->isElementUpgraded( $propertyEl, $property ) && ! $isParentMf2 ) {
							$temp_context = ( isset( $data['context'] ) ) ? $data['context'] : null;
							$this->backcompat( $propertyEl, $temp_context, $hasRootMf2 );
							$this->addMfClasses( $propertyEl, $data['replace'] );
						}

						$this->addUpgraded( $propertyEl, $property );
					}
				}
			}

			if ( empty( $context ) && isset( $this->classicRootMap[ $classname ] ) && ! $elHasMf2 ) {
				$this->addMfClasses( $el, $this->classicRootMap[ $classname ] );
			}
		}

		return;
	}

	/**
	 * Add element + property as upgraded during backcompat
	 *
	 * @param DOMElement   $el
	 * @param string|array $property
	 */
	public function addUpgraded( DOMElement $el, $property ) {
		if ( ! is_array( $property ) ) {
			$property = array( $property );
		}

		// add element to list of upgraded elements
		if ( ! $this->upgraded->contains( $el ) ) {
			$this->upgraded->attach( $el, $property );
		} else {
			$this->upgraded[ $el ] = array_merge( $this->upgraded[ $el ], $property );
		}
	}

	/**
	 * Add the provided classes to an element.
	 * Does not add duplicate if class name already exists.
	 *
	 * @param DOMElement $el
	 * @param string     $classes
	 */
	public function addMfClasses( DOMElement $el, $classes ) {
		$existingClasses = str_replace( array( "\t", "\n" ), ' ', $el->getAttribute( 'class' ) );
		$existingClasses = array_filter( explode( ' ', $existingClasses ) );

		$addClasses = array_diff( explode( ' ', $classes ), $existingClasses );

		if ( $addClasses ) {
			$el->setAttribute( 'class', $el->getAttribute( 'class' ) . ' ' . implode( ' ', $addClasses ) );
		}
	}

	/**
	 * Check an element for mf2 h-* class, typically to determine if backcompat should be used
	 *
	 * @param DOMElement $el
	 */
	public function hasRootMf2( \DOMElement $el ) {
		$class = str_replace( array( "\t", "\n" ), ' ', $el->getAttribute( 'class' ) );
		$classes = array_filter( explode( ' ', $class ) );

		foreach ( $classes as $classname ) {
			if ( strpos( $classname, 'h-' ) === 0 ) {
				return true;
			}
		}

		return false;
	}

	/**
	 * Convert Legacy Classnames
	 *
	 * Adds microformats2 classnames into a document containing only legacy
	 * semantic classnames.
	 *
	 * @return Parser $this
	 */
	public function convertLegacy() {
		$doc = $this->doc;
		$xp = new DOMXPath( $doc );

		// replace all roots
		foreach ( $this->classicRootMap as $old => $new ) {
			foreach ( $xp->query( '//*[contains(concat(" ", @class, " "), " ' . $old . ' ") and not(contains(concat(" ", @class, " "), " ' . $new . ' "))]' ) as $el ) {
				$el->setAttribute( 'class', $el->getAttribute( 'class' ) . ' ' . $new );
			}
		}

		foreach ( $this->classicPropertyMap as $oldRoot => $properties ) {
			$newRoot = $this->classicRootMap[ $oldRoot ];
			foreach ( $properties as $old => $data ) {
				foreach ( $xp->query( '//*[contains(concat(" ", @class, " "), " ' . $oldRoot . ' ")]//*[contains(concat(" ", @class, " "), " ' . $old . ' ") and not(contains(concat(" ", @class, " "), " ' . $data['replace'] . ' "))]' ) as $el ) {
					$el->setAttribute( 'class', $el->getAttribute( 'class' ) . ' ' . $data['replace'] );
				}
			}
		}

		return $this;
	}

	/**
	 * XPath Query
	 *
	 * Runs an XPath query over the current document. Works in exactly the same
	 * way as DOMXPath::query.
	 *
	 * @param string  $expression
	 * @param DOMNode $context
	 * @return DOMNodeList
	 */
	public function query( $expression, $context = null ) {
		return $this->xpath->query( $expression, $context );
	}

	/**
	 * Classic Root Classname map
	 *
	 * @var array
	 */
	public $classicRootMap = array(
		'vcard'    => 'h-card',
		'hfeed'    => 'h-feed',
		'hentry'   => 'h-entry',
		'hrecipe'  => 'h-recipe',
		'hresume'  => 'h-resume',
		'vevent'   => 'h-event',
		'hreview'  => 'h-review',
		'hproduct' => 'h-product',
		'adr'      => 'h-adr',
	);

	/**
	 * Mapping of mf1 properties to mf2 and the context they're parsed with
	 *
	 * @var array
	 */
	public $classicPropertyMap = array(
		'vcard'    => array(
			'fn'                => array(
				'replace' => 'p-name',
			),
			'honorific-prefix'  => array(
				'replace' => 'p-honorific-prefix',
			),
			'given-name'        => array(
				'replace' => 'p-given-name',
			),
			'additional-name'   => array(
				'replace' => 'p-additional-name',
			),
			'family-name'       => array(
				'replace' => 'p-family-name',
			),
			'honorific-suffix'  => array(
				'replace' => 'p-honorific-suffix',
			),
			'nickname'          => array(
				'replace' => 'p-nickname',
			),
			'email'             => array(
				'replace' => 'u-email',
			),
			'logo'              => array(
				'replace' => 'u-logo',
			),
			'photo'             => array(
				'replace' => 'u-photo',
			),
			'url'               => array(
				'replace' => 'u-url',
			),
			'uid'               => array(
				'replace' => 'u-uid',
			),
			'category'          => array(
				'replace' => 'p-category',
			),
			'adr'               => array(
				'replace' => 'p-adr',
			),
			'extended-address'  => array(
				'replace' => 'p-extended-address',
			),
			'street-address'    => array(
				'replace' => 'p-street-address',
			),
			'locality'          => array(
				'replace' => 'p-locality',
			),
			'region'            => array(
				'replace' => 'p-region',
			),
			'postal-code'       => array(
				'replace' => 'p-postal-code',
			),
			'country-name'      => array(
				'replace' => 'p-country-name',
			),
			'label'             => array(
				'replace' => 'p-label',
			),
			'geo'               => array(
				'replace' => 'p-geo h-geo',
			),
			'latitude'          => array(
				'replace' => 'p-latitude',
			),
			'longitude'         => array(
				'replace' => 'p-longitude',
			),
			'tel'               => array(
				'replace' => 'p-tel',
			),
			'note'              => array(
				'replace' => 'p-note',
			),
			'bday'              => array(
				'replace' => 'dt-bday',
			),
			'key'               => array(
				'replace' => 'u-key',
			),
			'org'               => array(
				'replace' => 'p-org',
			),
			'organization-name' => array(
				'replace' => 'p-organization-name',
			),
			'organization-unit' => array(
				'replace' => 'p-organization-unit',
			),
			'title'             => array(
				'replace' => 'p-job-title',
			),
			'role'              => array(
				'replace' => 'p-role',
			),
			'tz'                => array(
				'replace' => 'p-tz',
			),
			'rev'               => array(
				'replace' => 'dt-rev',
			),
		),
		'hfeed'    => array(
			// nothing currently
		),
		'hentry'   => array(
			'entry-title'   => array(
				'replace' => 'p-name',
			),
			'entry-summary' => array(
				'replace' => 'p-summary',
			),
			'entry-content' => array(
				'replace' => 'e-content',
			),
			'published'     => array(
				'replace' => 'dt-published',
			),
			'updated'       => array(
				'replace' => 'dt-updated',
			),
			'author'        => array(
				'replace' => 'p-author h-card',
				'context' => 'vcard',
			),
			'category'      => array(
				'replace' => 'p-category',
			),
		),
		'hrecipe'  => array(
			'fn'           => array(
				'replace' => 'p-name',
			),
			'ingredient'   => array(
				'replace' => 'p-ingredient',
				/**
				 * TODO: hRecipe 'value' and 'type' child mf not parsing correctly currently.
				 * Per http://microformats.org/wiki/hRecipe#Property_details, they're experimental.
				 */
			),
			'yield'        => array(
				'replace' => 'p-yield',
			),
			'instructions' => array(
				'replace' => 'e-instructions',
			),
			'duration'     => array(
				'replace' => 'dt-duration',
			),
			'photo'        => array(
				'replace' => 'u-photo',
			),
			'summary'      => array(
				'replace' => 'p-summary',
			),
			'author'       => array(
				'replace' => 'p-author h-card',
				'context' => 'vcard',
			),
			'nutrition'    => array(
				'replace' => 'p-nutrition',
			),
			'category'     => array(
				'replace' => 'p-category',
			),
		),
		'hresume'  => array(
			'summary'     => array(
				'replace' => 'p-summary',
			),
			'contact'     => array(
				'replace' => 'p-contact h-card',
				'context' => 'vcard',
			),
			'education'   => array(
				'replace' => 'p-education h-event',
				'context' => 'vevent',
			),
			'experience'  => array(
				'replace' => 'p-experience h-event',
				'context' => 'vevent',
			),
			'skill'       => array(
				'replace' => 'p-skill',
			),
			'affiliation' => array(
				'replace' => 'p-affiliation h-card',
				'context' => 'vcard',
			),
		),
		'vevent'   => array(
			'summary'     => array(
				'replace' => 'p-name',
			),
			'dtstart'     => array(
				'replace' => 'dt-start',
			),
			'dtend'       => array(
				'replace' => 'dt-end',
			),
			'duration'    => array(
				'replace' => 'dt-duration',
			),
			'description' => array(
				'replace' => 'p-description',
			),
			'url'         => array(
				'replace' => 'u-url',
			),
			'category'    => array(
				'replace' => 'p-category',
			),
			'location'    => array(
				'replace' => 'h-card',
				'context' => 'vcard',
			),
			'geo'         => array(
				'replace' => 'p-location h-geo',
			),
		),
		'hreview'  => array(
			'summary'     => array(
				'replace' => 'p-name',
			),
			// fn: see item.fn below
			// photo: see item.photo below
			// url: see item.url below
			'item'        => array(
				'replace' => 'p-item h-item',
				'context' => 'item',
			),
			'reviewer'    => array(
				'replace' => 'p-author h-card',
				'context' => 'vcard',
			),
			'dtreviewed'  => array(
				'replace' => 'dt-published',
			),
			'rating'      => array(
				'replace' => 'p-rating',
			),
			'best'        => array(
				'replace' => 'p-best',
			),
			'worst'       => array(
				'replace' => 'p-worst',
			),
			'description' => array(
				'replace' => 'e-content',
			),
			'category'    => array(
				'replace' => 'p-category',
			),
		),
		'hproduct' => array(
			'fn'          => array(
				'replace' => 'p-name',
			),
			'photo'       => array(
				'replace' => 'u-photo',
			),
			'brand'       => array(
				'replace' => 'p-brand',
			),
			'category'    => array(
				'replace' => 'p-category',
			),
			'description' => array(
				'replace' => 'p-description',
			),
			'identifier'  => array(
				'replace' => 'u-identifier',
			),
			'url'         => array(
				'replace' => 'u-url',
			),
			'review'      => array(
				'replace' => 'p-review h-review',
			),
			'price'       => array(
				'replace' => 'p-price',
			),
		),
		'item'     => array(
			'fn'    => array(
				'replace' => 'p-name',
			),
			'url'   => array(
				'replace' => 'u-url',
			),
			'photo' => array(
				'replace' => 'u-photo',
			),
		),
		'adr'      => array(
			'post-office-box'  => array(
				'replace' => 'p-post-office-box',
			),
			'extended-address' => array(
				'replace' => 'p-extended-address',
			),
			'street-address'   => array(
				'replace' => 'p-street-address',
			),
			'locality'         => array(
				'replace' => 'p-locality',
			),
			'region'           => array(
				'replace' => 'p-region',
			),
			'postal-code'      => array(
				'replace' => 'p-postal-code',
			),
			'country-name'     => array(
				'replace' => 'p-country-name',
			),
		),
		'geo'      => array(
			'latitude'  => array(
				'replace' => 'p-latitude',
			),
			'longitude' => array(
				'replace' => 'p-longitude',
			),
		),
	);
}

function parseUriToComponents( $uri ) {
	$result = array(
		'scheme'    => null,
		'authority' => null,
		'path'      => null,
		'query'     => null,
		'fragment'  => null,
	);

	$u = parse_url( $uri );
	if ( ! $u ) {
		return $result;
	}

	if ( array_key_exists( 'scheme', $u ) ) {
		$result['scheme'] = $u['scheme'];
	}

	if ( array_key_exists( 'host', $u ) ) {
		if ( array_key_exists( 'user', $u ) ) {
			$result['authority'] = $u['user'];
		}
		if ( array_key_exists( 'pass', $u ) ) {
			$result['authority'] .= ':' . $u['pass'];
		}
		if ( array_key_exists( 'user', $u ) || array_key_exists( 'pass', $u ) ) {
			$result['authority'] .= '@';
		}
		$result['authority'] .= $u['host'];
		if ( array_key_exists( 'port', $u ) ) {
			$result['authority'] .= ':' . $u['port'];
		}
	}

	if ( array_key_exists( 'path', $u ) ) {
		$result['path'] = $u['path'];
	}

	if ( array_key_exists( 'query', $u ) ) {
		$result['query'] = $u['query'];
	}

	if ( array_key_exists( 'fragment', $u ) ) {
		$result['fragment'] = $u['fragment'];
	}

	return $result;
}

function resolveUrl( $baseURI, $referenceURI ) {
	$target = array(
		'scheme'    => null,
		'authority' => null,
		'path'      => null,
		'query'     => null,
		'fragment'  => null,
	);

	// 5.2.1 Pre-parse the Base URI
	// The base URI (Base) is established according to the procedure of
	// Section 5.1 and parsed into the five main components described in
	// Section 3
	$base = parseUriToComponents( $baseURI );

	// If base path is blank (http://example.com) then set it to /
	// (I can't tell if this is actually in the RFC or not, but seems like it makes sense)
	if ( $base['path'] == null ) {
		$base['path'] = '/';
	}

	// 5.2.2. Transform References

	// The URI reference is parsed into the five URI components
	// (R.scheme, R.authority, R.path, R.query, R.fragment) = parse(R);
	$reference = parseUriToComponents( $referenceURI );

	// A non-strict parser may ignore a scheme in the reference
	// if it is identical to the base URI's scheme.
	// TODO

	if ( $reference['scheme'] ) {
		$target['scheme'] = $reference['scheme'];
		$target['authority'] = $reference['authority'];
		$target['path'] = removeDotSegments( $reference['path'] );
		$target['query'] = $reference['query'];
	} else {
		if ( $reference['authority'] ) {
			$target['authority'] = $reference['authority'];
			$target['path'] = removeDotSegments( $reference['path'] );
			$target['query'] = $reference['query'];
		} else {
			if ( $reference['path'] == '' ) {
				$target['path'] = $base['path'];
				if ( $reference['query'] ) {
					$target['query'] = $reference['query'];
				} else {
					$target['query'] = $base['query'];
				}
			} else {
				if ( substr( $reference['path'], 0, 1 ) == '/' ) {
					$target['path'] = removeDotSegments( $reference['path'] );
				} else {
					$target['path'] = mergePaths( $base, $reference );
					$target['path'] = removeDotSegments( $target['path'] );
				}
				$target['query'] = $reference['query'];
			}
			$target['authority'] = $base['authority'];
		}
		$target['scheme'] = $base['scheme'];
	}
	$target['fragment'] = $reference['fragment'];

	// 5.3 Component Recomposition
	$result = '';
	if ( $target['scheme'] ) {
		$result .= $target['scheme'] . ':';
	}
	if ( $target['authority'] ) {
		$result .= '//' . $target['authority'];
	}
	$result .= $target['path'];
	if ( $target['query'] ) {
		$result .= '?' . $target['query'];
	}
	if ( $target['fragment'] ) {
		$result .= '#' . $target['fragment'];
	} elseif ( $referenceURI == '#' ) {
		$result .= '#';
	}
	return $result;
}

// 5.2.3 Merge Paths
function mergePaths( $base, $reference ) {
	// If the base URI has a defined authority component and an empty
	// path,
	if ( $base['authority'] && $base['path'] == null ) {
		// then return a string consisting of "/" concatenated with the
		// reference's path; otherwise,
		$merged = '/' . $reference['path'];
	} else {
		if ( ( $pos = strrpos( $base['path'], '/' ) ) !== false ) {
			// return a string consisting of the reference's path component
			// appended to all but the last segment of the base URI's path (i.e.,
			// excluding any characters after the right-most "/" in the base URI
			// path,
			$merged = substr( $base['path'], 0, $pos + 1 ) . $reference['path'];
		} else {
			// or excluding the entire base URI path if it does not contain
			// any "/" characters).
			$merged = $base['path'];
		}
	}
	return $merged;
}

// 5.2.4.A Remove leading ../ or ./
function removeLeadingDotSlash( &$input ) {
	if ( substr( $input, 0, 3 ) == '../' ) {
		$input = substr( $input, 3 );
	} elseif ( substr( $input, 0, 2 ) == './' ) {
		$input = substr( $input, 2 );
	}
}

// 5.2.4.B Replace leading /. with /
function removeLeadingSlashDot( &$input ) {
	if ( substr( $input, 0, 3 ) == '/./' ) {
		$input = '/' . substr( $input, 3 );
	} else {
		$input = '/' . substr( $input, 2 );
	}
}

// 5.2.4.C Given leading /../ remove component from output buffer
function removeOneDirLevel( &$input, &$output ) {
	if ( substr( $input, 0, 4 ) == '/../' ) {
		$input = '/' . substr( $input, 4 );
	} else {
		$input = '/' . substr( $input, 3 );
	}
	$output = substr( $output, 0, strrpos( $output, '/' ) );
}

// 5.2.4.D Remove . and .. if it's the only thing in the input
function removeLoneDotDot( &$input ) {
	if ( $input == '.' ) {
		$input = substr( $input, 1 );
	} else {
		$input = substr( $input, 2 );
	}
}

// 5.2.4.E Move one segment from input to output
function moveOneSegmentFromInput( &$input, &$output ) {
	if ( substr( $input, 0, 1 ) != '/' ) {
		$pos = strpos( $input, '/' );
	} else {
		$pos = strpos( $input, '/', 1 );
	}

	if ( $pos === false ) {
		$output .= $input;
		$input = '';
	} else {
		$output .= substr( $input, 0, $pos );
		$input = substr( $input, $pos );
	}
}

// 5.2.4 Remove Dot Segments
function removeDotSegments( $path ) {
	// 1.  The input buffer is initialized with the now-appended path
	// components and the output buffer is initialized to the empty
	// string.
	$input = $path;
	$output = '';

	$step = 0;

	// 2.  While the input buffer is not empty, loop as follows:
	while ( $input ) {
		$step++;

		if ( substr( $input, 0, 3 ) == '../' || substr( $input, 0, 2 ) == './' ) {
			// A.  If the input buffer begins with a prefix of "../" or "./",
			// then remove that prefix from the input buffer; otherwise,
			removeLeadingDotSlash( $input );
		} elseif ( substr( $input, 0, 3 ) == '/./' || $input == '/.' ) {
			// B.  if the input buffer begins with a prefix of "/./" or "/.",
			// where "." is a complete path segment, then replace that
			// prefix with "/" in the input buffer; otherwise,
			removeLeadingSlashDot( $input );
		} elseif ( substr( $input, 0, 4 ) == '/../' || $input == '/..' ) {
			// C.  if the input buffer begins with a prefix of "/../" or "/..",
			// where ".." is a complete path segment, then replace that
			// prefix with "/" in the input buffer and remove the last
			// segment and its preceding "/" (if any) from the output
			// buffer; otherwise,
			removeOneDirLevel( $input, $output );
		} elseif ( $input == '.' || $input == '..' ) {
			// D.  if the input buffer consists only of "." or "..", then remove
			// that from the input buffer; otherwise,
			removeLoneDotDot( $input );
		} else {
			// E.  move the first path segment in the input buffer to the end of
			// the output buffer and any subsequent characters up to, but not including,
			// the next "/" character or the end of the input buffer
			moveOneSegmentFromInput( $input, $output );
		}
	}

	return $output;
}