summaryrefslogtreecommitdiffstats
path: root/vendor/guzzlehttp/psr7/src/UriResolver.php
blob: 540db5290a9d075f776c1fe0709d19cb5e09cff4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
<?php

namespace GuzzleHttp\Psr7;

use Psr\Http\Message\UriInterface;

/**
 * Resolves a URI reference in the context of a base URI and the opposite way.
 *
 * @author Tobias Schultze
 *
 * @link https://tools.ietf.org/html/rfc3986#section-5
 */
final class UriResolver
{
    /**
     * Removes dot segments from a path and returns the new path.
     *
     * @param string $path
     *
     * @return string
     *
     * @link http://tools.ietf.org/html/rfc3986#section-5.2.4
     */
    public static function removeDotSegments($path)
    {
        if ($path === '' || $path === '/') {
            return $path;
        }

        $results = [];
        $segments = explode('/', $path);
        foreach ($segments as $segment) {
            if ($segment === '..') {
                array_pop($results);
            } elseif ($segment !== '.') {
                $results[] = $segment;
            }
        }

        $newPath = implode('/', $results);

        if ($path[0] === '/' && (!isset($newPath[0]) || $newPath[0] !== '/')) {
            // Re-add the leading slash if necessary for cases like "/.."
            $newPath = '/' . $newPath;
        } elseif ($newPath !== '' && ($segment === '.' || $segment === '..')) {
            // Add the trailing slash if necessary
            // If newPath is not empty, then $segment must be set and is the last segment from the foreach
            $newPath .= '/';
        }

        return $newPath;
    }

    /**
     * Converts the relative URI into a new URI that is resolved against the base URI.
     *
     * @param UriInterface $base Base URI
     * @param UriInterface $rel  Relative URI
     *
     * @return UriInterface
     *
     * @link http://tools.ietf.org/html/rfc3986#section-5.2
     */
    public static function resolve(UriInterface $base, UriInterface $rel)
    {
        if ((string) $rel === '') {
            // we can simply return the same base URI instance for this same-document reference
            return $base;
        }

        if ($rel->getScheme() != '') {
            return $rel->withPath(self::removeDotSegments($rel->getPath()));
        }

        if ($rel->getAuthority() != '') {
            $targetAuthority = $rel->getAuthority();
            $targetPath = self::removeDotSegments($rel->getPath());
            $targetQuery = $rel->getQuery();
        } else {
            $targetAuthority = $base->getAuthority();
            if ($rel->getPath() === '') {
                $targetPath = $base->getPath();
                $targetQuery = $rel->getQuery() != '' ? $rel->getQuery() : $base->getQuery();
            } else {
                if ($rel->getPath()[0] === '/') {
                    $targetPath = $rel->getPath();
                } else {
                    if ($targetAuthority != '' && $base->getPath() === '') {
                        $targetPath = '/' . $rel->getPath();
                    } else {
                        $lastSlashPos = strrpos($base->getPath(), '/');
                        if ($lastSlashPos === false) {
                            $targetPath = $rel->getPath();
                        } else {
                            $targetPath = substr($base->getPath(), 0, $lastSlashPos + 1) . $rel->getPath();
                        }
                    }
                }
                $targetPath = self::removeDotSegments($targetPath);
                $targetQuery = $rel->getQuery();
            }
        }

        return new Uri(Uri::composeComponents(
            $base->getScheme(),
            $targetAuthority,
            $targetPath,
            $targetQuery,
            $rel->getFragment()
        ));
    }

    /**
     * Returns the target URI as a relative reference from the base URI.
     *
     * This method is the counterpart to resolve():
     *
     *    (string) $target === (string) UriResolver::resolve($base, UriResolver::relativize($base, $target))
     *
     * One use-case is to use the current request URI as base URI and then generate relative links in your documents
     * to reduce the document size or offer self-contained downloadable document archives.
     *
     *    $base = new Uri('http://example.com/a/b/');
     *    echo UriResolver::relativize($base, new Uri('http://example.com/a/b/c'));  // prints 'c'.
     *    echo UriResolver::relativize($base, new Uri('http://example.com/a/x/y'));  // prints '../x/y'.
     *    echo UriResolver::relativize($base, new Uri('http://example.com/a/b/?q')); // prints '?q'.
     *    echo UriResolver::relativize($base, new Uri('http://example.org/a/b/'));   // prints '//example.org/a/b/'.
     *
     * This method also accepts a target that is already relative and will try to relativize it further. Only a
     * relative-path reference will be returned as-is.
     *
     *    echo UriResolver::relativize($base, new Uri('/a/b/c'));  // prints 'c' as well
     *
     * @param UriInterface $base   Base URI
     * @param UriInterface $target Target URI
     *
     * @return UriInterface The relative URI reference
     */
    public static function relativize(UriInterface $base, UriInterface $target)
    {
        if ($target->getScheme() !== '' &&
            ($base->getScheme() !== $target->getScheme() || $target->getAuthority() === '' && $base->getAuthority() !== '')
        ) {
            return $target;
        }

        if (Uri::isRelativePathReference($target)) {
            // As the target is already highly relative we return it as-is. It would be possible to resolve
            // the target with `$target = self::resolve($base, $target);` and then try make it more relative
            // by removing a duplicate query. But let's not do that automatically.
            return $target;
        }

        if ($target->getAuthority() !== '' && $base->getAuthority() !== $target->getAuthority()) {
            return $target->withScheme('');
        }

        // We must remove the path before removing the authority because if the path starts with two slashes, the URI
        // would turn invalid. And we also cannot set a relative path before removing the authority, as that is also
        // invalid.
        $emptyPathUri = $target->withScheme('')->withPath('')->withUserInfo('')->withPort(null)->withHost('');

        if ($base->getPath() !== $target->getPath()) {
            return $emptyPathUri->withPath(self::getRelativePath($base, $target));
        }

        if ($base->getQuery() === $target->getQuery()) {
            // Only the target fragment is left. And it must be returned even if base and target fragment are the same.
            return $emptyPathUri->withQuery('');
        }

        // If the base URI has a query but the target has none, we cannot return an empty path reference as it would
        // inherit the base query component when resolving.
        if ($target->getQuery() === '') {
            $segments = explode('/', $target->getPath());
            $lastSegment = end($segments);

            return $emptyPathUri->withPath($lastSegment === '' ? './' : $lastSegment);
        }

        return $emptyPathUri;
    }

    private static function getRelativePath(UriInterface $base, UriInterface $target)
    {
        $sourceSegments = explode('/', $base->getPath());
        $targetSegments = explode('/', $target->getPath());
        array_pop($sourceSegments);
        $targetLastSegment = array_pop($targetSegments);
        foreach ($sourceSegments as $i => $segment) {
            if (isset($targetSegments[$i]) && $segment === $targetSegments[$i]) {
                unset($sourceSegments[$i], $targetSegments[$i]);
            } else {
                break;
            }
        }
        $targetSegments[] = $targetLastSegment;
        $relativePath = str_repeat('../', count($sourceSegments)) . implode('/', $targetSegments);

        // A reference to am empty last segment or an empty first sub-segment must be prefixed with "./".
        // This also applies to a segment with a colon character (e.g., "file:colon") that cannot be used
        // as the first segment of a relative-path reference, as it would be mistaken for a scheme name.
        if ('' === $relativePath || false !== strpos(explode('/', $relativePath, 2)[0], ':')) {
            $relativePath = "./$relativePath";
        } elseif ('/' === $relativePath[0]) {
            if ($base->getAuthority() != '' && $base->getPath() === '') {
                // In this case an extra slash is added by resolve() automatically. So we must not add one here.
                $relativePath = ".$relativePath";
            } else {
                $relativePath = "./$relativePath";
            }
        }

        return $relativePath;
    }

    private function __construct()
    {
        // cannot be instantiated
    }
}