1 <?php
2 
3 /**
4  * DokuWiki fulltextsearch functions using the index
5  *
6  * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
7  * @author     Andreas Gohr <andi@splitbrain.org>
8  */
9 
10 use dokuwiki\Utf8\Asian;
11 use dokuwiki\Search\Indexer;
12 use dokuwiki\Extension\Event;
13 use dokuwiki\Utf8\Clean;
14 use dokuwiki\Utf8\PhpString;
15 use dokuwiki\Utf8\Sort;
16 
17 /**
18  * create snippets for the first few results only
19  */
20 if (!defined('FT_SNIPPET_NUMBER')) define('FT_SNIPPET_NUMBER', 15);
21 
22 /**
23  * The fulltext search
24  *
25  * Returns a list of matching documents for the given query
26  *
27  * refactored into ft_pageSearch(), _ft_pageSearch() and trigger_event()
28  *
29  * @param string     $query
30  * @param array      $highlight
31  * @param string     $sort
32  * @param int|string $after  only show results with mtime after this date, accepts timestap or strtotime arguments
33  * @param int|string $before only show results with mtime before this date, accepts timestap or strtotime arguments
34  *
35  * @return array
36  */
37 function ft_pageSearch($query, &$highlight, $sort = null, $after = null, $before = null)
38 {
39 
40     if ($sort === null) {
41         $sort = 'hits';
42     }
43     $data = [
44         'query' => $query,
45         'sort' => $sort,
46         'after' => $after,
47         'before' => $before
48     ];
49     $data['highlight'] =& $highlight;
50 
51     return Event::createAndTrigger('SEARCH_QUERY_FULLPAGE', $data, '_ft_pageSearch');
52 }
53 
54 /**
55  * Returns a list of matching documents for the given query
56  *
57  * @author Andreas Gohr <andi@splitbrain.org>
58  * @author Kazutaka Miyasaka <kazmiya@gmail.com>
59  *
60  * @param array $data event data
61  * @return array matching documents
62  */
63 function _ft_pageSearch(&$data)
64 {
65     $Indexer = idx_get_indexer();
66 
67     // parse the given query
68     $q = ft_queryParser($Indexer, $data['query']);
69     $data['highlight'] = $q['highlight'];
70 
71     if (empty($q['parsed_ary'])) return [];
72 
73     // lookup all words found in the query
74     $lookup = $Indexer->lookup($q['words']);
75 
76     // get all pages in this dokuwiki site (!: includes nonexistent pages)
77     $pages_all = [];
78     foreach ($Indexer->getPages() as $id) {
79         $pages_all[$id] = 0; // base: 0 hit
80     }
81 
82     // process the query
83     $stack = [];
84     foreach ($q['parsed_ary'] as $token) {
85         switch (substr($token, 0, 3)) {
86             case 'W+:':
87             case 'W-:':
88             case 'W_:': // word
89                 $word    = substr($token, 3);
90                 if (isset($lookup[$word])) {
91                     $stack[] = (array)$lookup[$word];
92                 }
93                 break;
94             case 'P+:':
95             case 'P-:': // phrase
96                 $phrase = substr($token, 3);
97                 // since phrases are always parsed as ((W1)(W2)...(P)),
98                 // the end($stack) always points at the pages that contain
99                 // all words in this phrase
100                 $pages  = $stack ? end($stack) : [];
101                 $pages_matched = [];
102                 foreach (array_keys($pages) as $id) {
103                     $evdata = [
104                         'id' => $id,
105                         'phrase' => $phrase,
106                         'text' => rawWiki($id)
107                     ];
108                     $evt = new Event('FULLTEXT_PHRASE_MATCH', $evdata);
109                     if ($evt->advise_before() && $evt->result !== true) {
110                         $text = PhpString::strtolower($evdata['text']);
111                         if (strpos($text, $phrase) !== false) {
112                             $evt->result = true;
113                         }
114                     }
115                     $evt->advise_after();
116                     if ($evt->result === true) {
117                         $pages_matched[$id] = 0; // phrase: always 0 hit
118                     }
119                 }
120                 $stack[] = $pages_matched;
121                 break;
122             case 'N+:':
123             case 'N-:': // namespace
124                 $ns = cleanID(substr($token, 3)) . ':';
125                 $pages_matched = [];
126                 foreach (array_keys($pages_all) as $id) {
127                     if (strpos($id, $ns) === 0) {
128                         $pages_matched[$id] = 0; // namespace: always 0 hit
129                     }
130                 }
131                 $stack[] = $pages_matched;
132                 break;
133             case 'AND': // and operation
134                 $pages = array_splice($stack, -2);
135                 if ($pages === []) {
136                     break;
137                 }
138                 $stack[] = ft_resultCombine($pages);
139                 break;
140             case 'OR':  // or operation
141                 $pages = array_splice($stack, -2);
142                 if ($pages === []) {
143                     break;
144                 }
145                 $stack[] = ft_resultUnite($pages);
146                 break;
147             case 'NOT': // not operation (unary)
148                 $pages   = array_pop($stack);
149                 $stack[] = ft_resultComplement([$pages_all, $pages]);
150                 break;
151         }
152     }
153     $docs = array_pop($stack);
154 
155     if (empty($docs)) return [];
156 
157     // check: settings, acls, existence
158     foreach (array_keys($docs) as $id) {
159         if (isHiddenPage($id) || auth_quickaclcheck($id) < AUTH_READ || !page_exists($id, '', false)) {
160             unset($docs[$id]);
161         }
162     }
163 
164     $docs = _ft_filterResultsByTime($docs, $data['after'], $data['before']);
165 
166     if ($data['sort'] === 'mtime') {
167         uksort($docs, 'ft_pagemtimesorter');
168     } else {
169         // sort docs by count
170         uksort($docs, 'ft_pagesorter');
171         arsort($docs);
172     }
173 
174     return $docs;
175 }
176 
177 /**
178  * Returns the backlinks for a given page
179  *
180  * Uses the metadata index.
181  *
182  * @param string $id           The id for which links shall be returned
183  * @param bool   $ignore_perms Ignore the fact that pages are hidden or read-protected
184  * @return array The pages that contain links to the given page
185  */
186 function ft_backlinks($id, $ignore_perms = false)
187 {
188     $result = idx_get_indexer()->lookupKey('relation_references', $id);
189 
190     if ($result === []) return $result;
191 
192     // check ACL permissions
193     foreach (array_keys($result) as $idx) {
194         if (
195             (!$ignore_perms && (
196                 isHiddenPage($result[$idx]) || auth_quickaclcheck($result[$idx]) < AUTH_READ
197             )) || !page_exists($result[$idx], '', false)
198         ) {
199             unset($result[$idx]);
200         }
201     }
202 
203     Sort::sort($result);
204     return $result;
205 }
206 
207 /**
208  * Returns the pages that use a given media file
209  *
210  * Uses the relation media metadata property and the metadata index.
211  *
212  * Note that before 2013-07-31 the second parameter was the maximum number of results and
213  * permissions were ignored. That's why the parameter is now checked to be explicitely set
214  * to true (with type bool) in order to be compatible with older uses of the function.
215  *
216  * @param string $id           The media id to look for
217  * @param bool   $ignore_perms Ignore hidden pages and acls (optional, default: false)
218  * @return array A list of pages that use the given media file
219  */
220 function ft_mediause($id, $ignore_perms = false)
221 {
222     $result = idx_get_indexer()->lookupKey('relation_media', $id);
223 
224     if ($result === []) return $result;
225 
226     // check ACL permissions
227     foreach (array_keys($result) as $idx) {
228         if (
229             (!$ignore_perms && (
230                     isHiddenPage($result[$idx]) || auth_quickaclcheck($result[$idx]) < AUTH_READ
231                 )) || !page_exists($result[$idx], '', false)
232         ) {
233             unset($result[$idx]);
234         }
235     }
236 
237     Sort::sort($result);
238     return $result;
239 }
240 
241 
242 /**
243  * Quicksearch for pagenames
244  *
245  * By default it only matches the pagename and ignores the
246  * namespace. This can be changed with the second parameter.
247  * The third parameter allows to search in titles as well.
248  *
249  * The function always returns titles as well
250  *
251  * @triggers SEARCH_QUERY_PAGELOOKUP
252  * @author   Andreas Gohr <andi@splitbrain.org>
253  * @author   Adrian Lang <lang@cosmocode.de>
254  *
255  * @param string     $id       page id
256  * @param bool       $in_ns    match against namespace as well?
257  * @param bool       $in_title search in title?
258  * @param int|string $after    only show results with mtime after this date, accepts timestap or strtotime arguments
259  * @param int|string $before   only show results with mtime before this date, accepts timestap or strtotime arguments
260  *
261  * @return string[]
262  */
263 function ft_pageLookup($id, $in_ns = false, $in_title = false, $after = null, $before = null)
264 {
265     $data = [
266         'id' => $id,
267         'in_ns' => $in_ns,
268         'in_title' => $in_title,
269         'after' => $after,
270         'before' => $before
271     ];
272     $data['has_titles'] = true; // for plugin backward compatibility check
273     return Event::createAndTrigger('SEARCH_QUERY_PAGELOOKUP', $data, '_ft_pageLookup');
274 }
275 
276 /**
277  * Returns list of pages as array(pageid => First Heading)
278  *
279  * @param array &$data event data
280  * @return string[]
281  */
282 function _ft_pageLookup(&$data)
283 {
284     // split out original parameters
285     $id = $data['id'];
286     $Indexer = idx_get_indexer();
287     $parsedQuery = ft_queryParser($Indexer, $id);
288     if (count($parsedQuery['ns']) > 0) {
289         $ns = cleanID($parsedQuery['ns'][0]) . ':';
290         $id = implode(' ', $parsedQuery['highlight']);
291     }
292     if (count($parsedQuery['notns']) > 0) {
293         $notns = cleanID($parsedQuery['notns'][0]) . ':';
294         $id = implode(' ', $parsedQuery['highlight']);
295     }
296 
297     $in_ns    = $data['in_ns'];
298     $in_title = $data['in_title'];
299     $cleaned = cleanID($id);
300 
301     $Indexer = idx_get_indexer();
302     $page_idx = $Indexer->getPages();
303 
304     $pages = [];
305     if ($id !== '' && $cleaned !== '') {
306         foreach ($page_idx as $p_id) {
307             if ((strpos($in_ns ? $p_id : noNSorNS($p_id), $cleaned) !== false)) {
308                 if (!isset($pages[$p_id]))
309                     $pages[$p_id] = p_get_first_heading($p_id, METADATA_DONT_RENDER);
310             }
311         }
312         if ($in_title) {
313             foreach ($Indexer->lookupKey('title', $id, '_ft_pageLookupTitleCompare') as $p_id) {
314                 if (!isset($pages[$p_id]))
315                     $pages[$p_id] = p_get_first_heading($p_id, METADATA_DONT_RENDER);
316             }
317         }
318     }
319 
320     if (isset($ns)) {
321         foreach (array_keys($pages) as $p_id) {
322             if (strpos($p_id, $ns) !== 0) {
323                 unset($pages[$p_id]);
324             }
325         }
326     }
327     if (isset($notns)) {
328         foreach (array_keys($pages) as $p_id) {
329             if (strpos($p_id, $notns) === 0) {
330                 unset($pages[$p_id]);
331             }
332         }
333     }
334 
335     // discard hidden pages
336     // discard nonexistent pages
337     // check ACL permissions
338     foreach (array_keys($pages) as $idx) {
339         if (
340             !isVisiblePage($idx) || !page_exists($idx) ||
341             auth_quickaclcheck($idx) < AUTH_READ
342         ) {
343             unset($pages[$idx]);
344         }
345     }
346 
347     $pages = _ft_filterResultsByTime($pages, $data['after'], $data['before']);
348 
349     uksort($pages, 'ft_pagesorter');
350     return $pages;
351 }
352 
353 
354 /**
355  * @param array      $results search results in the form pageid => value
356  * @param int|string $after   only returns results with mtime after this date, accepts timestap or strtotime arguments
357  * @param int|string $before  only returns results with mtime after this date, accepts timestap or strtotime arguments
358  *
359  * @return array
360  */
361 function _ft_filterResultsByTime(array $results, $after, $before)
362 {
363     if ($after || $before) {
364         $after = is_int($after) ? $after : strtotime($after);
365         $before = is_int($before) ? $before : strtotime($before);
366 
367         foreach (array_keys($results) as $id) {
368             $mTime = filemtime(wikiFN($id));
369             if ($after && $after > $mTime) {
370                 unset($results[$id]);
371                 continue;
372             }
373             if ($before && $before < $mTime) {
374                 unset($results[$id]);
375             }
376         }
377     }
378 
379     return $results;
380 }
381 
382 /**
383  * Tiny helper function for comparing the searched title with the title
384  * from the search index. This function is a wrapper around stripos with
385  * adapted argument order and return value.
386  *
387  * @param string $search searched title
388  * @param string $title  title from index
389  * @return bool
390  */
391 function _ft_pageLookupTitleCompare($search, $title)
392 {
393     if (Clean::isASCII($search)) {
394         $pos = stripos($title, $search);
395     } else {
396         $pos = PhpString::strpos(
397             PhpString::strtolower($title),
398             PhpString::strtolower($search)
399         );
400     }
401 
402     return $pos !== false;
403 }
404 
405 /**
406  * Sort pages based on their namespace level first, then on their string
407  * values. This makes higher hierarchy pages rank higher than lower hierarchy
408  * pages.
409  *
410  * @param string $a
411  * @param string $b
412  * @return int Returns < 0 if $a is less than $b; > 0 if $a is greater than $b, and 0 if they are equal.
413  */
414 function ft_pagesorter($a, $b)
415 {
416     $ac = count(explode(':', $a));
417     $bc = count(explode(':', $b));
418     if ($ac < $bc) {
419         return -1;
420     } elseif ($ac > $bc) {
421         return 1;
422     }
423     return Sort::strcmp($a, $b);
424 }
425 
426 /**
427  * Sort pages by their mtime, from newest to oldest
428  *
429  * @param string $a
430  * @param string $b
431  *
432  * @return int Returns < 0 if $a is newer than $b, > 0 if $b is newer than $a and 0 if they are of the same age
433  */
434 function ft_pagemtimesorter($a, $b)
435 {
436     $mtimeA = filemtime(wikiFN($a));
437     $mtimeB = filemtime(wikiFN($b));
438     return $mtimeB - $mtimeA;
439 }
440 
441 /**
442  * Creates a snippet extract
443  *
444  * @author Andreas Gohr <andi@splitbrain.org>
445  * @triggers FULLTEXT_SNIPPET_CREATE
446  *
447  * @param string $id page id
448  * @param array $highlight
449  * @return mixed
450  */
451 function ft_snippet($id, $highlight)
452 {
453     $text = rawWiki($id);
454     $text = str_replace("\xC2\xAD", '', $text);
455      // remove soft-hyphens
456     $evdata = [
457         'id'        => $id,
458         'text'      => &$text,
459         'highlight' => &$highlight,
460         'snippet'   => ''
461     ];
462 
463     $evt = new Event('FULLTEXT_SNIPPET_CREATE', $evdata);
464     if ($evt->advise_before()) {
465         $match = [];
466         $snippets = [];
467         $utf8_offset = 0;
468         $offset = 0;
469         $end = 0;
470         $len = PhpString::strlen($text);
471 
472         // build a regexp from the phrases to highlight
473         $re1 = '(' .
474             implode(
475                 '|',
476                 array_map(
477                     'ft_snippet_re_preprocess',
478                     array_map(
479                         'preg_quote_cb',
480                         array_filter((array) $highlight)
481                     )
482                 )
483             ) .
484             ')';
485         $re2 = "$re1.{0,75}(?!\\1)$re1";
486         $re3 = "$re1.{0,45}(?!\\1)$re1.{0,45}(?!\\1)(?!\\2)$re1";
487 
488         for ($cnt = 4; $cnt--;) {
489             if (0) {
490             } elseif (preg_match('/' . $re3 . '/iu', $text, $match, PREG_OFFSET_CAPTURE, $offset)) {
491             } elseif (preg_match('/' . $re2 . '/iu', $text, $match, PREG_OFFSET_CAPTURE, $offset)) {
492             } elseif (preg_match('/' . $re1 . '/iu', $text, $match, PREG_OFFSET_CAPTURE, $offset)) {
493             } else {
494                 break;
495             }
496 
497             [$str, $idx] = $match[0];
498 
499             // convert $idx (a byte offset) into a utf8 character offset
500             $utf8_idx = PhpString::strlen(substr($text, 0, $idx));
501             $utf8_len = PhpString::strlen($str);
502 
503             // establish context, 100 bytes surrounding the match string
504             // first look to see if we can go 100 either side,
505             // then drop to 50 adding any excess if the other side can't go to 50,
506             $pre = min($utf8_idx - $utf8_offset, 100);
507             $post = min($len - $utf8_idx - $utf8_len, 100);
508 
509             if ($pre > 50 && $post > 50) {
510                 $pre = 50;
511                 $post = 50;
512             } elseif ($pre > 50) {
513                 $pre = min($pre, 100 - $post);
514             } elseif ($post > 50) {
515                 $post = min($post, 100 - $pre);
516             } elseif ($offset == 0) {
517                 // both are less than 50, means the context is the whole string
518                 // make it so and break out of this loop - there is no need for the
519                 // complex snippet calculations
520                 $snippets = [$text];
521                 break;
522             }
523 
524             // establish context start and end points, try to append to previous
525             // context if possible
526             $start = $utf8_idx - $pre;
527             $append = ($start < $end) ? $end : false;  // still the end of the previous context snippet
528             $end = $utf8_idx + $utf8_len + $post;      // now set it to the end of this context
529 
530             if ($append) {
531                 $snippets[count($snippets) - 1] .= PhpString::substr($text, $append, $end - $append);
532             } else {
533                 $snippets[] = PhpString::substr($text, $start, $end - $start);
534             }
535 
536             // set $offset for next match attempt
537             // continue matching after the current match
538             // if the current match is not the longest possible match starting at the current offset
539             // this prevents further matching of this snippet but for possible matches of length
540             // smaller than match length + context (at least 50 characters) this match is part of the context
541             $utf8_offset = $utf8_idx + $utf8_len;
542             $offset = $idx + strlen(PhpString::substr($text, $utf8_idx, $utf8_len));
543             $offset = Clean::correctIdx($text, $offset);
544         }
545 
546         $m = "\1";
547         $snippets = preg_replace('/' . $re1 . '/iu', $m . '$1' . $m, $snippets);
548         $snippet = preg_replace(
549             '/' . $m . '([^' . $m . ']*?)' . $m . '/iu',
550             '<strong class="search_hit">$1</strong>',
551             hsc(implode('... ', $snippets))
552         );
553 
554         $evdata['snippet'] = $snippet;
555     }
556     $evt->advise_after();
557     unset($evt);
558 
559     return $evdata['snippet'];
560 }
561 
562 /**
563  * Wraps a search term in regex boundary checks.
564  *
565  * @param string $term
566  * @return string
567  */
568 function ft_snippet_re_preprocess($term)
569 {
570     // do not process asian terms where word boundaries are not explicit
571     if (Asian::isAsianWords($term)) return $term;
572 
573     if (UTF8_PROPERTYSUPPORT) {
574         // unicode word boundaries
575         // see http://stackoverflow.com/a/2449017/172068
576         $BL = '(?<!\pL)';
577         $BR = '(?!\pL)';
578     } else {
579         // not as correct as above, but at least won't break
580         $BL = '\b';
581         $BR = '\b';
582     }
583 
584     if (str_starts_with($term, '\\*')) {
585         $term = substr($term, 2);
586     } else {
587         $term = $BL . $term;
588     }
589 
590     if (str_ends_with($term, '\\*')) {
591         $term = substr($term, 0, -2);
592     } else {
593         $term .= $BR;
594     }
595 
596     if ($term == $BL || $term == $BR || $term == $BL . $BR) $term = '';
597     return $term;
598 }
599 
600 /**
601  * Combine found documents and sum up their scores
602  *
603  * This function is used to combine searched words with a logical
604  * AND. Only documents available in all arrays are returned.
605  *
606  * based upon PEAR's PHP_Compat function for array_intersect_key()
607  *
608  * @param array $args An array of page arrays
609  * @return array
610  */
611 function ft_resultCombine($args)
612 {
613     $array_count = count($args);
614     if ($array_count == 1) {
615         return $args[0];
616     }
617 
618     $result = [];
619     if ($array_count > 1) {
620         foreach ($args[0] as $key => $value) {
621             $result[$key] = $value;
622             for ($i = 1; $i !== $array_count; $i++) {
623                 if (!isset($args[$i][$key])) {
624                     unset($result[$key]);
625                     break;
626                 }
627                 $result[$key] += $args[$i][$key];
628             }
629         }
630     }
631     return $result;
632 }
633 
634 /**
635  * Unites found documents and sum up their scores
636  *
637  * based upon ft_resultCombine() function
638  *
639  * @param array $args An array of page arrays
640  * @return array
641  *
642  * @author Kazutaka Miyasaka <kazmiya@gmail.com>
643  */
644 function ft_resultUnite($args)
645 {
646     $array_count = count($args);
647     if ($array_count === 1) {
648         return $args[0];
649     }
650 
651     $result = $args[0];
652     for ($i = 1; $i !== $array_count; $i++) {
653         foreach (array_keys($args[$i]) as $id) {
654             $result[$id] += $args[$i][$id];
655         }
656     }
657     return $result;
658 }
659 
660 /**
661  * Computes the difference of documents using page id for comparison
662  *
663  * nearly identical to PHP5's array_diff_key()
664  *
665  * @param array $args An array of page arrays
666  * @return array
667  *
668  * @author Kazutaka Miyasaka <kazmiya@gmail.com>
669  */
670 function ft_resultComplement($args)
671 {
672     $array_count = count($args);
673     if ($array_count === 1) {
674         return $args[0];
675     }
676 
677     $result = $args[0];
678     foreach (array_keys($result) as $id) {
679         for ($i = 1; $i !== $array_count; $i++) {
680             if (isset($args[$i][$id])) unset($result[$id]);
681         }
682     }
683     return $result;
684 }
685 
686 /**
687  * Parses a search query and builds an array of search formulas
688  *
689  * @author Andreas Gohr <andi@splitbrain.org>
690  * @author Kazutaka Miyasaka <kazmiya@gmail.com>
691  *
692  * @param Indexer $Indexer
693  * @param string                  $query search query
694  * @return array of search formulas
695  */
696 function ft_queryParser($Indexer, $query)
697 {
698     /**
699      * parse a search query and transform it into intermediate representation
700      *
701      * in a search query, you can use the following expressions:
702      *
703      *   words:
704      *     include
705      *     -exclude
706      *   phrases:
707      *     "phrase to be included"
708      *     -"phrase you want to exclude"
709      *   namespaces:
710      *     @include:namespace (or ns:include:namespace)
711      *     ^exclude:namespace (or -ns:exclude:namespace)
712      *   groups:
713      *     ()
714      *     -()
715      *   operators:
716      *     and ('and' is the default operator: you can always omit this)
717      *     or  (or pipe symbol '|', lower precedence than 'and')
718      *
719      * e.g. a query [ aa "bb cc" @dd:ee ] means "search pages which contain
720      *      a word 'aa', a phrase 'bb cc' and are within a namespace 'dd:ee'".
721      *      this query is equivalent to [ -(-aa or -"bb cc" or -ns:dd:ee) ]
722      *      as long as you don't mind hit counts.
723      *
724      * intermediate representation consists of the following parts:
725      *
726      *   ( )           - group
727      *   AND           - logical and
728      *   OR            - logical or
729      *   NOT           - logical not
730      *   W+:, W-:, W_: - word      (underscore: no need to highlight)
731      *   P+:, P-:      - phrase    (minus sign: logically in NOT group)
732      *   N+:, N-:      - namespace
733      */
734     $parsed_query = '';
735     $parens_level = 0;
736     $terms = preg_split(
737         '/(-?".*?")/u',
738         PhpString::strtolower($query),
739         -1,
740         PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY
741     );
742 
743     foreach ($terms as $term) {
744         $parsed = '';
745         if (preg_match('/^(-?)"(.+)"$/u', $term, $matches)) {
746             // phrase-include and phrase-exclude
747             $not = $matches[1] ? 'NOT' : '';
748             $parsed = $not . ft_termParser($Indexer, $matches[2], false, true);
749         } else {
750             // fix incomplete phrase
751             $term = str_replace('"', ' ', $term);
752 
753             // fix parentheses
754             $term = str_replace(')', ' ) ', $term);
755             $term = str_replace('(', ' ( ', $term);
756             $term = str_replace('- (', ' -(', $term);
757 
758             // treat pipe symbols as 'OR' operators
759             $term = str_replace('|', ' or ', $term);
760 
761             // treat ideographic spaces (U+3000) as search term separators
762             // FIXME: some more separators?
763             $term = preg_replace('/[ \x{3000}]+/u', ' ', $term);
764             $term = trim($term);
765             if ($term === '') continue;
766 
767             $tokens = explode(' ', $term);
768             foreach ($tokens as $token) {
769                 if ($token === '(') {
770                     // parenthesis-include-open
771                     $parsed .= '(';
772                     ++$parens_level;
773                 } elseif ($token === '-(') {
774                     // parenthesis-exclude-open
775                     $parsed .= 'NOT(';
776                     ++$parens_level;
777                 } elseif ($token === ')') {
778                     // parenthesis-any-close
779                     if ($parens_level === 0) continue;
780                     $parsed .= ')';
781                     $parens_level--;
782                 } elseif ($token === 'and') {
783                     // logical-and (do nothing)
784                 } elseif ($token === 'or') {
785                     // logical-or
786                     $parsed .= 'OR';
787                 } elseif (preg_match('/^(?:\^|-ns:)(.+)$/u', $token, $matches)) {
788                     // namespace-exclude
789                     $parsed .= 'NOT(N+:' . $matches[1] . ')';
790                 } elseif (preg_match('/^(?:@|ns:)(.+)$/u', $token, $matches)) {
791                     // namespace-include
792                     $parsed .= '(N+:' . $matches[1] . ')';
793                 } elseif (preg_match('/^-(.+)$/', $token, $matches)) {
794                     // word-exclude
795                     $parsed .= 'NOT(' . ft_termParser($Indexer, $matches[1]) . ')';
796                 } else {
797                     // word-include
798                     $parsed .= ft_termParser($Indexer, $token);
799                 }
800             }
801         }
802         $parsed_query .= $parsed;
803     }
804 
805     // cleanup (very sensitive)
806     $parsed_query .= str_repeat(')', $parens_level);
807     do {
808         $parsed_query_old = $parsed_query;
809         $parsed_query = preg_replace('/(NOT)?\(\)/u', '', $parsed_query);
810     } while ($parsed_query !== $parsed_query_old);
811     $parsed_query = preg_replace('/(NOT|OR)+\)/u', ')', $parsed_query);
812     $parsed_query = preg_replace('/(OR)+/u', 'OR', $parsed_query);
813     $parsed_query = preg_replace('/\(OR/u', '(', $parsed_query);
814     $parsed_query = preg_replace('/^OR|OR$/u', '', $parsed_query);
815     $parsed_query = preg_replace('/\)(NOT)?\(/u', ')AND$1(', $parsed_query);
816 
817     // adjustment: make highlightings right
818     $parens_level     = 0;
819     $notgrp_levels    = [];
820     $parsed_query_new = '';
821     $tokens = preg_split('/(NOT\(|[()])/u', $parsed_query, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);
822     foreach ($tokens as $token) {
823         if ($token === 'NOT(') {
824             $notgrp_levels[] = ++$parens_level;
825         } elseif ($token === '(') {
826             ++$parens_level;
827         } elseif ($token === ')') {
828             if ($parens_level-- === end($notgrp_levels)) array_pop($notgrp_levels);
829         } elseif (count($notgrp_levels) % 2 === 1) {
830             // turn highlight-flag off if terms are logically in "NOT" group
831             $token = preg_replace('/([WPN])\+\:/u', '$1-:', $token);
832         }
833         $parsed_query_new .= $token;
834     }
835     $parsed_query = $parsed_query_new;
836 
837     /**
838      * convert infix notation string into postfix (Reverse Polish notation) array
839      * by Shunting-yard algorithm
840      *
841      * see: http://en.wikipedia.org/wiki/Reverse_Polish_notation
842      * see: http://en.wikipedia.org/wiki/Shunting-yard_algorithm
843      */
844     $parsed_ary     = [];
845     $ope_stack      = [];
846     $ope_precedence = [')' => 1, 'OR' => 2, 'AND' => 3, 'NOT' => 4, '(' => 5];
847     $ope_regex      = '/([()]|OR|AND|NOT)/u';
848 
849     $tokens = preg_split($ope_regex, $parsed_query, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);
850     foreach ($tokens as $token) {
851         if (preg_match($ope_regex, $token)) {
852             // operator
853             $last_ope = end($ope_stack);
854             while ($last_ope !== false && $ope_precedence[$token] <= $ope_precedence[$last_ope] && $last_ope != '(') {
855                 $parsed_ary[] = array_pop($ope_stack);
856                 $last_ope = end($ope_stack);
857             }
858             if ($token == ')') {
859                 array_pop($ope_stack); // this array_pop always deletes '('
860             } else {
861                 $ope_stack[] = $token;
862             }
863         } else {
864             // operand
865             $token_decoded = str_replace(['OP', 'CP'], ['(', ')'], $token);
866             $parsed_ary[] = $token_decoded;
867         }
868     }
869     $parsed_ary = array_values([...$parsed_ary, ...array_reverse($ope_stack)]);
870 
871     // cleanup: each double "NOT" in RPN array actually does nothing
872     $parsed_ary_count = count($parsed_ary);
873     for ($i = 1; $i < $parsed_ary_count; ++$i) {
874         if ($parsed_ary[$i] === 'NOT' && $parsed_ary[$i - 1] === 'NOT') {
875             unset($parsed_ary[$i], $parsed_ary[$i - 1]);
876         }
877     }
878     $parsed_ary = array_values($parsed_ary);
879 
880     // build return value
881     $q = [];
882     $q['query']      = $query;
883     $q['parsed_str'] = $parsed_query;
884     $q['parsed_ary'] = $parsed_ary;
885 
886     foreach ($q['parsed_ary'] as $token) {
887         if (strlen($token) < 3 || $token[2] !== ':') continue;
888         $body = substr($token, 3);
889 
890         switch (substr($token, 0, 3)) {
891             case 'N+:':
892                      $q['ns'][]        = $body; // for backward compatibility
893                 break;
894             case 'N-:':
895                      $q['notns'][]     = $body; // for backward compatibility
896                 break;
897             case 'W_:':
898                      $q['words'][]     = $body;
899                 break;
900             case 'W-:':
901                      $q['words'][]     = $body;
902                      $q['not'][]       = $body; // for backward compatibility
903                 break;
904             case 'W+:':
905                      $q['words'][]     = $body;
906                      $q['highlight'][] = $body;
907                      $q['and'][]       = $body; // for backward compatibility
908                 break;
909             case 'P-:':
910                      $q['phrases'][]   = $body;
911                 break;
912             case 'P+:':
913                      $q['phrases'][]   = $body;
914                      $q['highlight'][] = $body;
915                 break;
916         }
917     }
918     foreach (['words', 'phrases', 'highlight', 'ns', 'notns', 'and', 'not'] as $key) {
919         $q[$key] = empty($q[$key]) ? [] : array_values(array_unique($q[$key]));
920     }
921 
922     return $q;
923 }
924 
925 /**
926  * Transforms given search term into intermediate representation
927  *
928  * This function is used in ft_queryParser() and not for general purpose use.
929  *
930  * @author Kazutaka Miyasaka <kazmiya@gmail.com>
931  *
932  * @param Indexer $Indexer
933  * @param string                  $term
934  * @param bool                    $consider_asian
935  * @param bool                    $phrase_mode
936  * @return string
937  */
938 function ft_termParser($Indexer, $term, $consider_asian = true, $phrase_mode = false)
939 {
940     $parsed = '';
941     if ($consider_asian) {
942         // successive asian characters need to be searched as a phrase
943         $words = Asian::splitAsianWords($term);
944         foreach ($words as $word) {
945             $phrase_mode = $phrase_mode ? true : Asian::isAsianWords($word);
946             $parsed .= ft_termParser($Indexer, $word, false, $phrase_mode);
947         }
948     } else {
949         $term_noparen = str_replace(['(', ')'], ' ', $term);
950         $words = $Indexer->tokenizer($term_noparen, true);
951 
952         // W_: no need to highlight
953         if (empty($words)) {
954             $parsed = '()'; // important: do not remove
955         } elseif ($words[0] === $term) {
956             $parsed = '(W+:' . $words[0] . ')';
957         } elseif ($phrase_mode) {
958             $term_encoded = str_replace(['(', ')'], ['OP', 'CP'], $term);
959             $parsed = '((W_:' . implode(')(W_:', $words) . ')(P+:' . $term_encoded . '))';
960         } else {
961             $parsed = '((W+:' . implode(')(W+:', $words) . '))';
962         }
963     }
964     return $parsed;
965 }
966 
967 /**
968  * Recreate a search query string based on parsed parts, doesn't support negated phrases and `OR` searches
969  *
970  * @param array $and
971  * @param array $not
972  * @param array $phrases
973  * @param array $ns
974  * @param array $notns
975  *
976  * @return string
977  */
978 function ft_queryUnparser_simple(array $and, array $not, array $phrases, array $ns, array $notns)
979 {
980     $query = implode(' ', $and);
981     if ($not !== []) {
982         $query .= ' -' . implode(' -', $not);
983     }
984 
985     if ($phrases !== []) {
986         $query .= ' "' . implode('" "', $phrases) . '"';
987     }
988 
989     if ($ns !== []) {
990         $query .= ' @' . implode(' @', $ns);
991     }
992 
993     if ($notns !== []) {
994         $query .= ' ^' . implode(' ^', $notns);
995     }
996 
997     return $query;
998 }
999 
1000 //Setup VIM: ex: et ts=4 :
1001