<?php
namespace Curl;
use Curl\StringUtil;
class Url
{
private $baseUrl = null;
private $relativeUrl = null;
public function __construct($base_url, $relative_url = null)
{
$this->baseUrl = $base_url;
$this->relativeUrl = $relative_url;
}
public function __toString()
{
return $this->absolutizeUrl();
}
/**
* Remove dot segments.
*
* Interpret and remove the special "." and ".." path segments from a referenced path.
*/
public static function removeDotSegments($input)
{
// 1. The input buffer is initialized with the now-appended path
// components and the output buffer is initialized to the empty
// string.
$output = '';
// 2. While the input buffer is not empty, loop as follows:
while (!empty($input)) {
// A. If the input buffer begins with a prefix of "../" or "./",
// then remove that prefix from the input buffer; otherwise,
if (StringUtil::startsWith($input, '../')) {
$input = substr($input, 3);
} elseif (StringUtil::startsWith($input, './')) {
$input = substr($input, 2);
// 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,
} elseif (StringUtil::startsWith($input, '/./')) {
$input = substr($input, 2);
} elseif ($input === '/.') {
$input = '/';
// C. if the input buffer begins with a prefix of "/../" or "/..",
// where ".." is a complete path segment, then replace that
// prefix with "/" in the input buffer and remove the last
// segment and its preceding "/" (if any) from the output
// buffer; otherwise,
} elseif (StringUtil::startsWith($input, '/../')) {
$input = substr($input, 3);
$output = substr_replace($output, '', StringUtil::reversePosition($output, '/'));
} elseif ($input === '/..') {
$input = '/';
$output = substr_replace($output, '', StringUtil::reversePosition($output, '/'));
// D. if the input buffer consists only of "." or "..", then remove
// that from the input buffer; otherwise,
} elseif ($input === '.' || $input === '..') {
$input = '';
// E. move the first path segment in the input buffer to the end of
// the output buffer, including the initial "/" character (if
// any) and any subsequent characters up to, but not including,
// the next "/" character or the end of the input buffer.
} elseif (!(($pos = StringUtil::position($input, '/', 1)) === false)) {
$output .= substr($input, 0, $pos);
$input = substr_replace($input, '', 0, $pos);
} else {
$output .= $input;
$input = '';
}
}
// 3. Finally, the output buffer is returned as the result of
// remove_dot_segments.
return $output . $input;
}
/**
* Absolutize url.
*
* Combine the base and relative url into an absolute url.
*/
private function absolutizeUrl()
{
$b = $this->parseUrl($this->baseUrl);
if (!isset($b['path'])) {
$b['path'] = '/';
}
if ($this->relativeUrl === null) {
return $this->unparseUrl($b);
}
$r = $this->parseUrl($this->relativeUrl);
$r['authorized'] = isset($r['scheme']) || isset($r['host']) || isset($r['port'])
|| isset($r['user']) || isset($r['pass']);
$target = array();
if (isset($r['scheme'])) {
$target['scheme'] = $r['scheme'];
$target['host'] = isset($r['host']) ? $r['host'] : null;
$target['port'] = isset($r['port']) ? $r['port'] : null;
$target['user'] = isset($r['user']) ? $r['user'] : null;
$target['pass'] = isset($r['pass']) ? $r['pass'] : null;
$target['path'] = isset($r['path']) ? self::removeDotSegments($r['path']) : null;
$target['query'] = isset($r['query']) ? $r['query'] : null;
} else {
$target['scheme'] = isset($b['scheme']) ? $b['scheme'] : null;
if ($r['authorized']) {
$target['host'] = isset($r['host']) ? $r['host'] : null;
$target['port'] = isset($r['port']) ? $r['port'] : null;
$target['user'] = isset($r['user']) ? $r['user'] : null;
$target['pass'] = isset($r['pass']) ? $r['pass'] : null;
$target['path'] = isset($r['path']) ? self::removeDotSegments($r['path']) : null;
$target['query'] = isset($r['query']) ? $r['query'] : null;
} else {
$target['host'] = isset($b['host']) ? $b['host'] : null;
$target['port'] = isset($b['port']) ? $b['port'] : null;
$target['user'] = isset($b['user']) ? $b['user'] : null;
$target['pass'] = isset($b['pass']) ? $b['pass'] : null;
if (!isset($r['path']) || $r['path'] === '') {
$target['path'] = $b['path'];
$target['query'] = isset($r['query']) ? $r['query'] : (isset($b['query']) ? $b['query'] : null);
} else {
if (StringUtil::startsWith($r['path'], '/')) {
$target['path'] = self::removeDotSegments($r['path']);
} else {
$base = StringUtil::characterReversePosition($b['path'], '/', true);
if ($base === false) {
$base = '';
}
$target['path'] = self::removeDotSegments($base . '/' . $r['path']);
}
$target['query'] = isset($r['query']) ? $r['query'] : null;
}
}
}
if ($this->relativeUrl === '') {
$target['fragment'] = isset($b['fragment']) ? $b['fragment'] : null;
} else {
$target['fragment'] = isset($r['fragment']) ? $r['fragment'] : null;
}
$absolutized_url = $this->unparseUrl($target);
return $absolutized_url;
}
/**
* Parse url.
*
* Parse url into components of a URI as specified by RFC 3986.
*/
private function parseUrl($url)
{
// ALPHA = A-Z / a-z
$alpha = 'A-Za-z';
// DIGIT = 0-9
$digit = '0-9';
// unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"
$unreserved = $alpha . $digit . preg_quote('-._~');
// sub-delims = "!" / "$" / "&" / "'" / "(" / ")"
// / "*" / "+" / "," / ";" / "=" / "#"
$sub_delims = preg_quote('!$&\'()*+,;=#');
// HEXDIG = DIGIT / "A" / "B" / "C" / "D" / "E" / "F"
$hexdig = $digit . 'A-F';
// "The uppercase hexadecimal digits 'A' through 'F' are equivalent to
// the lowercase digits 'a' through 'f', respectively."
$hexdig .= 'a-f';
$pattern = '/(?:[^' . $unreserved . $sub_delims . preg_quote(':@%/?', '/') . ']++|%(?![' . $hexdig . ']{2}))/';
$url = preg_replace_callback(
$pattern,
function ($matches) {
return rawurlencode($matches[0]);
},
$url
);
return parse_url($url);
}
/**
* Unparse url.
*
* Combine url components into a url.
*/
private function unparseUrl($parsed_url)
{
$scheme = isset($parsed_url['scheme']) ? $parsed_url['scheme'] . '://' : '';
$user = isset($parsed_url['user']) ? $parsed_url['user'] : '';
$pass = isset($parsed_url['pass']) ? ':' . $parsed_url['pass'] : '';
$pass = ($user || $pass) ? $pass . '@' : '';
$host = isset($parsed_url['host']) ? $parsed_url['host'] : '';
$port = isset($parsed_url['port']) ? ':' . $parsed_url['port'] : '';
$path = isset($parsed_url['path']) ? $parsed_url['path'] : '';
$query = isset($parsed_url['query']) ? '?' . $parsed_url['query'] : '';
$fragment = isset($parsed_url['fragment']) ? '#' . $parsed_url['fragment'] : '';
$unparsed_url = $scheme . $user . $pass . $host . $port . $path . $query . $fragment;
return $unparsed_url;
}
}