summaryrefslogtreecommitdiff
path: root/includes/api/ApiMain.php
blob: b7e118cf13f196fdc6efc5ff5b1242ab06c39355 (plain)
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
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
<?php
/**
 *
 *
 * Created on Sep 4, 2006
 *
 * Copyright © 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @defgroup API API
 */

if ( !defined( 'MEDIAWIKI' ) ) {
	// Eclipse helper - will be ignored in production
	require_once( 'ApiBase.php' );
}

/**
 * This is the main API class, used for both external and internal processing.
 * When executed, it will create the requested formatter object,
 * instantiate and execute an object associated with the needed action,
 * and use formatter to print results.
 * In case of an exception, an error message will be printed using the same formatter.
 *
 * To use API from another application, run it using FauxRequest object, in which
 * case any internal exceptions will not be handled but passed up to the caller.
 * After successful execution, use getResult() for the resulting data.
 *
 * @ingroup API
 */
class ApiMain extends ApiBase {

	/**
	 * When no format parameter is given, this format will be used
	 */
	const API_DEFAULT_FORMAT = 'xmlfm';

	/**
	 * List of available modules: action name => module class
	 */
	private static $Modules = array(
		'login' => 'ApiLogin',
		'logout' => 'ApiLogout',
		'query' => 'ApiQuery',
		'expandtemplates' => 'ApiExpandTemplates',
		'parse' => 'ApiParse',
		'opensearch' => 'ApiOpenSearch',
		'feedcontributions' => 'ApiFeedContributions',
		'feedwatchlist' => 'ApiFeedWatchlist',
		'help' => 'ApiHelp',
		'paraminfo' => 'ApiParamInfo',
		'rsd' => 'ApiRsd',
		'compare' => 'ApiComparePages',

		// Write modules
		'purge' => 'ApiPurge',
		'rollback' => 'ApiRollback',
		'delete' => 'ApiDelete',
		'undelete' => 'ApiUndelete',
		'protect' => 'ApiProtect',
		'block' => 'ApiBlock',
		'unblock' => 'ApiUnblock',
		'move' => 'ApiMove',
		'edit' => 'ApiEditPage',
		'upload' => 'ApiUpload',
		'filerevert' => 'ApiFileRevert',
		'emailuser' => 'ApiEmailUser',
		'watch' => 'ApiWatch',
		'patrol' => 'ApiPatrol',
		'import' => 'ApiImport',
		'userrights' => 'ApiUserrights',
	);

	/**
	 * List of available formats: format name => format class
	 */
	private static $Formats = array(
		'json' => 'ApiFormatJson',
		'jsonfm' => 'ApiFormatJson',
		'php' => 'ApiFormatPhp',
		'phpfm' => 'ApiFormatPhp',
		'wddx' => 'ApiFormatWddx',
		'wddxfm' => 'ApiFormatWddx',
		'xml' => 'ApiFormatXml',
		'xmlfm' => 'ApiFormatXml',
		'yaml' => 'ApiFormatYaml',
		'yamlfm' => 'ApiFormatYaml',
		'rawfm' => 'ApiFormatJson',
		'txt' => 'ApiFormatTxt',
		'txtfm' => 'ApiFormatTxt',
		'dbg' => 'ApiFormatDbg',
		'dbgfm' => 'ApiFormatDbg',
		'dump' => 'ApiFormatDump',
		'dumpfm' => 'ApiFormatDump',
	);

	/**
	 * List of user roles that are specifically relevant to the API.
	 * array( 'right' => array ( 'msg'    => 'Some message with a $1',
	 *                           'params' => array ( $someVarToSubst ) ),
	 *                          );
	 */
	private static $mRights = array(
		'writeapi' => array(
			'msg' => 'Use of the write API',
			'params' => array()
		),
		'apihighlimits'	=> array(
			'msg' => 'Use higher limits in API queries (Slow queries: $1 results; Fast queries: $2 results). The limits for slow queries also apply to multivalue parameters.',
			'params' => array( ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 )
		)
	);

	/**
	 * @var ApiFormatBase
	 */
	private $mPrinter;

	private $mModules, $mModuleNames, $mFormats, $mFormatNames;
	private $mResult, $mAction, $mShowVersions, $mEnableWrite, $mRequest;
	private $mInternalMode, $mSquidMaxage, $mModule;

	private $mCacheMode = 'private';
	private $mCacheControl = array();

	/**
	 * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
	 *
	 * @param $request WebRequest - if this is an instance of FauxRequest, errors are thrown and no printing occurs
	 * @param $enableWrite bool should be set to true if the api may modify data
	 */
	public function __construct( $request, $enableWrite = false ) {
		$this->mInternalMode = ( $request instanceof FauxRequest );

		// Special handling for the main module: $parent === $this
		parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );

		if ( !$this->mInternalMode ) {
			// Impose module restrictions.
			// If the current user cannot read,
			// Remove all modules other than login
			global $wgUser;

			if ( $request->getVal( 'callback' ) !== null ) {
				// JSON callback allows cross-site reads.
				// For safety, strip user credentials.
				wfDebug( "API: stripping user credentials for JSON callback\n" );
				$wgUser = new User();
			}
		}

		global $wgAPIModules; // extension modules
		$this->mModules = $wgAPIModules + self::$Modules;

		$this->mModuleNames = array_keys( $this->mModules );
		$this->mFormats = self::$Formats;
		$this->mFormatNames = array_keys( $this->mFormats );

		$this->mResult = new ApiResult( $this );
		$this->mShowVersions = false;
		$this->mEnableWrite = $enableWrite;

		$this->mRequest = &$request;

		$this->mSquidMaxage = - 1; // flag for executeActionWithErrorHandling()
		$this->mCommit = false;
	}

	/**
	 * Return true if the API was started by other PHP code using FauxRequest
	 * @return bool
	 */
	public function isInternalMode() {
		return $this->mInternalMode;
	}

	/**
	 * Return the request object that contains client's request
	 * @return WebRequest
	 */
	public function getRequest() {
		return $this->mRequest;
	}

	/**
	 * Get the ApiResult object associated with current request
	 *
	 * @return ApiResult
	 */
	public function getResult() {
		return $this->mResult;
	}

	/**
	 * Get the API module object. Only works after executeAction()
	 *
	 * @return ApiBase
	 */
	public function getModule() {
		return $this->mModule;
	}

	/**
	 * Get the result formatter object. Only works after setupExecuteAction()
	 *
	 * @return ApiFormatBase
	 */
	public function getPrinter() {
		return $this->mPrinter;
	}

	/**
	 * Set how long the response should be cached.
	 *
	 * @param $maxage
	 */
	public function setCacheMaxAge( $maxage ) {
		$this->setCacheControl( array(
			'max-age' => $maxage,
			's-maxage' => $maxage
		) );
	}

	/**
	 * Set the type of caching headers which will be sent.
	 *
	 * @param $mode String One of:
	 *    - 'public':     Cache this object in public caches, if the maxage or smaxage
	 *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
	 *         not provided by any of these means, the object will be private.
	 *    - 'private':    Cache this object only in private client-side caches.
	 *    - 'anon-public-user-private': Make this object cacheable for logged-out
	 *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
	 *         set consistently for a given URL, it cannot be set differently depending on
	 *         things like the contents of the database, or whether the user is logged in.
	 *
	 *  If the wiki does not allow anonymous users to read it, the mode set here
	 *  will be ignored, and private caching headers will always be sent. In other words,
	 *  the "public" mode is equivalent to saying that the data sent is as public as a page
	 *  view.
	 *
	 *  For user-dependent data, the private mode should generally be used. The
	 *  anon-public-user-private mode should only be used where there is a particularly
	 *  good performance reason for caching the anonymous response, but where the
	 *  response to logged-in users may differ, or may contain private data.
	 *
	 *  If this function is never called, then the default will be the private mode.
	 */
	public function setCacheMode( $mode ) {
		if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
			wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
			// Ignore for forwards-compatibility
			return;
		}

		if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
			// Private wiki, only private headers
			if ( $mode !== 'private' ) {
				wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
				return;
			}
		}

		wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
		$this->mCacheMode = $mode;
	}

	/**
	 * @deprecated since 1.17 Private caching is now the default, so there is usually no
	 * need to call this function. If there is a need, you can use
	 * $this->setCacheMode('private')
	 */
	public function setCachePrivate() {
		$this->setCacheMode( 'private' );
	}

	/**
	 * Set directives (key/value pairs) for the Cache-Control header.
	 * Boolean values will be formatted as such, by including or omitting
	 * without an equals sign.
	 *
	 * Cache control values set here will only be used if the cache mode is not
	 * private, see setCacheMode().
	 *
	 * @param $directives array
	 */
	public function setCacheControl( $directives ) {
		$this->mCacheControl = $directives + $this->mCacheControl;
	}

	/**
	 * Make sure Vary: Cookie and friends are set. Use this when the output of a request
	 * may be cached for anons but may not be cached for logged-in users.
	 *
	 * WARNING: This function must be called CONSISTENTLY for a given URL. This means that a
	 * given URL must either always or never call this function; if it sometimes does and
	 * sometimes doesn't, stuff will break.
	 *
	 * @deprecated since 1.17 Use setCacheMode( 'anon-public-user-private' )
	 */
	public function setVaryCookie() {
		$this->setCacheMode( 'anon-public-user-private' );
	}

	/**
	 * Create an instance of an output formatter by its name
	 *
	 * @param $format string
	 *
	 * @return ApiFormatBase
	 */
	public function createPrinterByName( $format ) {
		if ( !isset( $this->mFormats[$format] ) ) {
			$this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
		}
		return new $this->mFormats[$format] ( $this, $format );
	}

	/**
	 * Execute api request. Any errors will be handled if the API was called by the remote client.
	 */
	public function execute() {
		$this->profileIn();
		if ( $this->mInternalMode ) {
			$this->executeAction();
		} else {
			$this->executeActionWithErrorHandling();
		}

		$this->profileOut();
	}

	/**
	 * Execute an action, and in case of an error, erase whatever partial results
	 * have been accumulated, and replace it with an error message and a help screen.
	 */
	protected function executeActionWithErrorHandling() {
		// In case an error occurs during data output,
		// clear the output buffer and print just the error information
		ob_start();

		try {
			$this->executeAction();
		} catch ( Exception $e ) {
			// Log it
			if ( $e instanceof MWException ) {
				wfDebugLog( 'exception', $e->getLogMessage() );
			}

			// Handle any kind of exception by outputing properly formatted error message.
			// If this fails, an unhandled exception should be thrown so that global error
			// handler will process and log it.

			$errCode = $this->substituteResultWithError( $e );

			// Error results should not be cached
			$this->setCacheMode( 'private' );

			$response = $this->getRequest()->response();
			$headerStr = 'MediaWiki-API-Error: ' . $errCode;
			if ( $e->getCode() === 0 ) {
				$response->header( $headerStr );
			} else {
				$response->header( $headerStr, true, $e->getCode() );
			}

			// Reset and print just the error message
			ob_clean();

			// If the error occured during printing, do a printer->profileOut()
			$this->mPrinter->safeProfileOut();
			$this->printResult( true );
		}

		// Send cache headers after any code which might generate an error, to
		// avoid sending public cache headers for errors.
		$this->sendCacheHeaders();

		if ( $this->mPrinter->getIsHtml() && !$this->mPrinter->isDisabled() ) {
			echo wfReportTime();
		}

		ob_end_flush();
	}

	protected function sendCacheHeaders() {
		global $wgUseXVO, $wgOut, $wgVaryOnXFP;
		$response = $this->getRequest()->response();

		if ( $this->mCacheMode == 'private' ) {
			$response->header( 'Cache-Control: private' );
			return;
		}

		if ( $this->mCacheMode == 'anon-public-user-private' ) {
			$xfp = $wgVaryOnXFP ? ', X-Forwarded-Proto' : '';
			$response->header( 'Vary: Accept-Encoding, Cookie' . $xfp );
			if ( $wgUseXVO ) {
				if ( $wgVaryOnXFP ) {
					$wgOut->addVaryHeader( 'X-Forwarded-Proto' );
				}
				$response->header( $wgOut->getXVO() );
				if ( $wgOut->haveCacheVaryCookies() ) {
					// Logged in, mark this request private
					$response->header( 'Cache-Control: private' );
					return;
				}
				// Logged out, send normal public headers below
			} elseif ( session_id() != '' ) {
				// Logged in or otherwise has session (e.g. anonymous users who have edited)
				// Mark request private
				$response->header( 'Cache-Control: private' );
				return;
			} // else no XVO and anonymous, send public headers below
		}
		
		// Send public headers
		if ( $wgVaryOnXFP ) {
			$response->header( 'Vary: Accept-Encoding, X-Forwarded-Proto' );
			if ( $wgUseXVO ) {
				// Bleeeeegh. Our header setting system sucks
				$response->header( 'X-Vary-Options: Accept-Encoding;list-contains=gzip, X-Forwarded-Proto' );
			}
		}

		// If nobody called setCacheMaxAge(), use the (s)maxage parameters
		if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
			$this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
		}
		if ( !isset( $this->mCacheControl['max-age'] ) ) {
			$this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
		}

		if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
			// Public cache not requested
			// Sending a Vary header in this case is harmless, and protects us
			// against conditional calls of setCacheMaxAge().
			$response->header( 'Cache-Control: private' );
			return;
		}

		$this->mCacheControl['public'] = true;

		// Send an Expires header
		$maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
		$expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
		$response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );

		// Construct the Cache-Control header
		$ccHeader = '';
		$separator = '';
		foreach ( $this->mCacheControl as $name => $value ) {
			if ( is_bool( $value ) ) {
				if ( $value ) {
					$ccHeader .= $separator . $name;
					$separator = ', ';
				}
			} else {
				$ccHeader .= $separator . "$name=$value";
				$separator = ', ';
			}
		}

		$response->header( "Cache-Control: $ccHeader" );
	}

	/**
	 * Replace the result data with the information about an exception.
	 * Returns the error code
	 * @param $e Exception
	 * @return string
	 */
	protected function substituteResultWithError( $e ) {
		$result = $this->getResult();
		// Printer may not be initialized if the extractRequestParams() fails for the main module
		if ( !isset ( $this->mPrinter ) ) {
			// The printer has not been created yet. Try to manually get formatter value.
			$value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
			if ( !in_array( $value, $this->mFormatNames ) ) {
				$value = self::API_DEFAULT_FORMAT;
			}

			$this->mPrinter = $this->createPrinterByName( $value );
			if ( $this->mPrinter->getNeedsRawData() ) {
				$result->setRawMode();
			}
		}

		if ( $e instanceof UsageException ) {
			// User entered incorrect parameters - print usage screen
			$errMessage = $e->getMessageArray();

			// Only print the help message when this is for the developer, not runtime
			if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
				ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
			}

		} else {
			global $wgShowSQLErrors, $wgShowExceptionDetails;
			// Something is seriously wrong
			if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
				$info = 'Database query error';
			} else {
				$info = "Exception Caught: {$e->getMessage()}";
			}

			$errMessage = array(
				'code' => 'internal_api_error_' . get_class( $e ),
				'info' => $info,
			);
			ApiResult::setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : '' );
		}

		$result->reset();
		$result->disableSizeCheck();
		// Re-add the id
		$requestid = $this->getParameter( 'requestid' );
		if ( !is_null( $requestid ) ) {
			$result->addValue( null, 'requestid', $requestid );
		}
		// servedby is especially useful when debugging errors
		$result->addValue( null, 'servedby', wfHostName() );
		$result->addValue( null, 'error', $errMessage );

		return $errMessage['code'];
	}

	/**
	 * Set up for the execution.
	 * @return array
	 */
	protected function setupExecuteAction() {
		// First add the id to the top element
		$result = $this->getResult();
		$requestid = $this->getParameter( 'requestid' );
		if ( !is_null( $requestid ) ) {
			$result->addValue( null, 'requestid', $requestid );
		}
		$servedby = $this->getParameter( 'servedby' );
		if ( $servedby ) {
			$result->addValue( null, 'servedby', wfHostName() );
		}

		$params = $this->extractRequestParams();

		$this->mShowVersions = $params['version'];
		$this->mAction = $params['action'];

		if ( !is_string( $this->mAction ) ) {
			$this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
		}

		return $params;
	}

	/**
	 * Set up the module for response
	 * @return ApiBase The module that will handle this action
	 */
	protected function setupModule() {
		// Instantiate the module requested by the user
		$module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
		$this->mModule = $module;

		$moduleParams = $module->extractRequestParams();

		// Die if token required, but not provided (unless there is a gettoken parameter)
		if ( isset( $moduleParams['gettoken'] ) ) {
			$gettoken = $moduleParams['gettoken'];
		} else {
			$gettoken = false;
		}

		$salt = $module->getTokenSalt();
		if ( $salt !== false && !$gettoken ) {
			if ( !isset( $moduleParams['token'] ) ) {
				$this->dieUsageMsg( array( 'missingparam', 'token' ) );
			} else {
				global $wgUser;
				if ( !$wgUser->matchEditToken( $moduleParams['token'], $salt, $this->getRequest() ) ) {
					$this->dieUsageMsg( 'sessionfailure' );
				}
			}
		}
		return $module;
	}

	/**
	 * Check the max lag if necessary
	 * @param $module ApiBase object: Api module being used
	 * @param $params Array an array containing the request parameters.
	 * @return boolean True on success, false should exit immediately
	 */
	protected function checkMaxLag( $module, $params ) {
		if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
			// Check for maxlag
			global $wgShowHostnames;
			$maxLag = $params['maxlag'];
			list( $host, $lag ) = wfGetLB()->getMaxLag();
			if ( $lag > $maxLag ) {
				$response = $this->getRequest()->response();

				$response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
				$response->header( 'X-Database-Lag: ' . intval( $lag ) );

				if ( $wgShowHostnames ) {
					$this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
				} else {
					$this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
				}
				return false;
			}
		}
		return true;
	}

	/**
	 * Check for sufficient permissions to execute
	 * @param $module ApiBase An Api module
	 */
	protected function checkExecutePermissions( $module ) {
		global $wgUser;
		if ( $module->isReadMode() && !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) &&
			!$wgUser->isAllowed( 'read' ) )
		{
			$this->dieUsageMsg( 'readrequired' );
		}
		if ( $module->isWriteMode() ) {
			if ( !$this->mEnableWrite ) {
				$this->dieUsageMsg( 'writedisabled' );
			}
			if ( !$wgUser->isAllowed( 'writeapi' ) ) {
				$this->dieUsageMsg( 'writerequired' );
			}
			if ( wfReadOnly() ) {
				$this->dieReadOnly();
			}
		}
	}

	/**
	 * Check POST for external response and setup result printer
	 * @param $module ApiBase An Api module
	 * @param $params Array an array with the request parameters
	 */
	protected function setupExternalResponse( $module, $params ) {
		// Ignore mustBePosted() for internal calls
		if ( $module->mustBePosted() && !$this->mRequest->wasPosted() ) {
			$this->dieUsageMsg( array( 'mustbeposted', $this->mAction ) );
		}

		// See if custom printer is used
		$this->mPrinter = $module->getCustomPrinter();
		if ( is_null( $this->mPrinter ) ) {
			// Create an appropriate printer
			$this->mPrinter = $this->createPrinterByName( $params['format'] );
		}

		if ( $this->mPrinter->getNeedsRawData() ) {
			$this->getResult()->setRawMode();
		}
	}

	/**
	 * Execute the actual module, without any error handling
	 */
	protected function executeAction() {
		$params = $this->setupExecuteAction();
		$module = $this->setupModule();

		$this->checkExecutePermissions( $module );

		if ( !$this->checkMaxLag( $module, $params ) ) {
			return;
		}

		if ( !$this->mInternalMode ) {
			$this->setupExternalResponse( $module, $params );
		}

		// Execute
		$module->profileIn();
		$module->execute();
		wfRunHooks( 'APIAfterExecute', array( &$module ) );
		$module->profileOut();

		if ( !$this->mInternalMode ) {
			// Print result data
			$this->printResult( false );
		}
	}

	/**
	 * Print results using the current printer
	 *
	 * @param $isError bool
	 */
	protected function printResult( $isError ) {
		$this->getResult()->cleanUpUTF8();
		$printer = $this->mPrinter;
		$printer->profileIn();

		/**
		 * If the help message is requested in the default (xmlfm) format,
		 * tell the printer not to escape ampersands so that our links do
		 * not break.
		 */
		$printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
				&& $printer->getFormat() == 'XML' && $printer->getIsHtml() );

		$printer->initPrinter( $isError );

		$printer->execute();
		$printer->closePrinter();
		$printer->profileOut();
	}

	/**
	 * @return bool
	 */
	public function isReadMode() {
		return false;
	}

	/**
	 * See ApiBase for description.
	 *
	 * @return array
	 */
	public function getAllowedParams() {
		return array(
			'format' => array(
				ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
				ApiBase::PARAM_TYPE => $this->mFormatNames
			),
			'action' => array(
				ApiBase::PARAM_DFLT => 'help',
				ApiBase::PARAM_TYPE => $this->mModuleNames
			),
			'version' => false,
			'maxlag'  => array(
				ApiBase::PARAM_TYPE => 'integer'
			),
			'smaxage' => array(
				ApiBase::PARAM_TYPE => 'integer',
				ApiBase::PARAM_DFLT => 0
			),
			'maxage' => array(
				ApiBase::PARAM_TYPE => 'integer',
				ApiBase::PARAM_DFLT => 0
			),
			'requestid' => null,
			'servedby'  => false,
		);
	}

	/**
	 * See ApiBase for description.
	 *
	 * @return array
	 */
	public function getParamDescription() {
		return array(
			'format' => 'The format of the output',
			'action' => 'What action you would like to perform. See below for module help',
			'version' => 'When showing help, include version for each module',
			'maxlag' => array(
				'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
				'To save actions causing any more site replication lag, this parameter can make the client',
				'wait until the replication lag is less than the specified value.',
				'In case of a replag error, a HTTP 503 error is returned, with the message like',
				'"Waiting for $host: $lag seconds lagged\n".',
				'See https://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
			),
			'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
			'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
			'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
			'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
		);
	}

	/**
	 * See ApiBase for description.
	 *
	 * @return array
	 */
	public function getDescription() {
		return array(
			'',
			'',
			'**********************************************************************************************************',
			'**                                                                                                      **',
			'**                      This is an auto-generated MediaWiki API documentation page                      **',
			'**                                                                                                      **',
			'**                                    Documentation and Examples:                                       **',
			'**                                 https://www.mediawiki.org/wiki/API                                    **',
			'**                                                                                                      **',
			'**********************************************************************************************************',
			'',
			'Status:                All features shown on this page should be working, but the API',
			'                       is still in active development, and may change at any time.',
			'                       Make sure to monitor our mailing list for any updates',
			'',
			'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
			'                       with the key "MediaWiki-API-Error" and then both the value of the',
			'                       header and the error code sent back will be set to the same value',
			'',
			'                       In the case of an invalid action being passed, these will have a value',
			'                       of "unknown_action"',
			'',
			'                       For more information see https://www.mediawiki.org/wiki/API:Errors_and_warnings',
			'',
			'Documentation:         https://www.mediawiki.org/wiki/API:Main_page',
			'FAQ                    https://www.mediawiki.org/wiki/API:FAQ',
			'Mailing list:          https://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
			'Api Announcements:     https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
			'Bugs & Requests:       https://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
			'',
			'',
			'',
			'',
			'',
		);
	}

	/**
	 * @return array
	 */
	public function getPossibleErrors() {
		return array_merge( parent::getPossibleErrors(), array(
			array( 'readonlytext' ),
			array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
			array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
			array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
			array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
		) );
	}

	/**
	 * Returns an array of strings with credits for the API
	 * @return array
	 */
	protected function getCredits() {
		return array(
			'API developers:',
			'    Roan Kattouw <Firstname>.<Lastname>@gmail.com (lead developer Sep 2007-present)',
			'    Victor Vasiliev - vasilvv at gee mail dot com',
			'    Bryan Tong Minh - bryan . tongminh @ gmail . com',
			'    Sam Reed - sam @ reedyboy . net',
			'    Yuri Astrakhan <Firstname><Lastname>@gmail.com (creator, lead developer Sep 2006-Sep 2007)',
			'',
			'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
			'or file a bug report at https://bugzilla.wikimedia.org/'
		);
	}

	/**
	 * Sets whether the pretty-printer should format *bold* and $italics$
	 *
	 * @param $help bool
	 */
	public function setHelp( $help = true ) {
		$this->mPrinter->setHelp( $help );
	}

	/**
	 * Override the parent to generate help messages for all available modules.
	 *
	 * @return string
	 */
	public function makeHelpMsg() {
		global $wgMemc, $wgAPICacheHelpTimeout;
		$this->setHelp();
		// Get help text from cache if present
		$key = wfMemcKey( 'apihelp', $this->getModuleName(),
			SpecialVersion::getVersion( 'nodb' ) .
			$this->getShowVersions() );
		if ( $wgAPICacheHelpTimeout > 0 ) {
			$cached = $wgMemc->get( $key );
			if ( $cached ) {
				return $cached;
			}
		}
		$retval = $this->reallyMakeHelpMsg();
		if ( $wgAPICacheHelpTimeout > 0 ) {
			$wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
		}
		return $retval;
	}

	/**
	 * @return mixed|string
	 */
	public function reallyMakeHelpMsg() {
		$this->setHelp();

		// Use parent to make default message for the main module
		$msg = parent::makeHelpMsg();

		$astriks = str_repeat( '*** ', 14 );
		$msg .= "\n\n$astriks Modules  $astriks\n\n";
		foreach ( array_keys( $this->mModules ) as $moduleName ) {
			$module = new $this->mModules[$moduleName] ( $this, $moduleName );
			$msg .= self::makeHelpMsgHeader( $module, 'action' );
			$msg2 = $module->makeHelpMsg();
			if ( $msg2 !== false ) {
				$msg .= $msg2;
			}
			$msg .= "\n";
		}

		$msg .= "\n$astriks Permissions $astriks\n\n";
		foreach ( self::$mRights as $right => $rightMsg ) {
			$groups = User::getGroupsWithPermission( $right );
			$msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
						"\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";

		}

		$msg .= "\n$astriks Formats  $astriks\n\n";
		foreach ( array_keys( $this->mFormats ) as $formatName ) {
			$module = $this->createPrinterByName( $formatName );
			$msg .= self::makeHelpMsgHeader( $module, 'format' );
			$msg2 = $module->makeHelpMsg();
			if ( $msg2 !== false ) {
				$msg .= $msg2;
			}
			$msg .= "\n";
		}

		$msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";

		return $msg;
	}

	/**
	 * @param $module ApiBase
	 * @param $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
	 * @return string
	 */
	public static function makeHelpMsgHeader( $module, $paramName ) {
		$modulePrefix = $module->getModulePrefix();
		if ( strval( $modulePrefix ) !== '' ) {
			$modulePrefix = "($modulePrefix) ";
		}

		return "* $paramName={$module->getModuleName()} $modulePrefix*";
	}

	private $mCanApiHighLimits = null;

	/**
	 * Check whether the current user is allowed to use high limits
	 * @return bool
	 */
	public function canApiHighLimits() {
		if ( !isset( $this->mCanApiHighLimits ) ) {
			global $wgUser;
			$this->mCanApiHighLimits = $wgUser->isAllowed( 'apihighlimits' );
		}

		return $this->mCanApiHighLimits;
	}

	/**
	 * Check whether the user wants us to show version information in the API help
	 * @return bool
	 */
	public function getShowVersions() {
		return $this->mShowVersions;
	}

	/**
	 * Returns the version information of this file, plus it includes
	 * the versions for all files that are not callable proper API modules
	 *
	 * @return array
	 */
	public function getVersion() {
		$vers = array();
		$vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    https://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
		$vers[] = __CLASS__ . ': $Id$';
		$vers[] = ApiBase::getBaseVersion();
		$vers[] = ApiFormatBase::getBaseVersion();
		$vers[] = ApiQueryBase::getBaseVersion();
		return $vers;
	}

	/**
	 * Add or overwrite a module in this ApiMain instance. Intended for use by extending
	 * classes who wish to add their own modules to their lexicon or override the
	 * behavior of inherent ones.
	 *
	 * @param $mdlName String The identifier for this module.
	 * @param $mdlClass String The class where this module is implemented.
	 */
	protected function addModule( $mdlName, $mdlClass ) {
		$this->mModules[$mdlName] = $mdlClass;
	}

	/**
	 * Add or overwrite an output format for this ApiMain. Intended for use by extending
	 * classes who wish to add to or modify current formatters.
	 *
	 * @param $fmtName string The identifier for this format.
	 * @param $fmtClass ApiFormatBase The class implementing this format.
	 */
	protected function addFormat( $fmtName, $fmtClass ) {
		$this->mFormats[$fmtName] = $fmtClass;
	}

	/**
	 * Get the array mapping module names to class names
	 * @return array
	 */
	function getModules() {
		return $this->mModules;
	}

	/**
	 * Returns the list of supported formats in form ( 'format' => 'ClassName' )
	 *
	 * @since 1.18
	 * @return array
	 */
	public function getFormats() {
		return $this->mFormats;
	}
}

/**
 * This exception will be thrown when dieUsage is called to stop module execution.
 * The exception handling code will print a help screen explaining how this API may be used.
 *
 * @ingroup API
 */
class UsageException extends Exception {

	private $mCodestr;
	private $mExtraData;

	public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
		parent::__construct( $message, $code );
		$this->mCodestr = $codestr;
		$this->mExtraData = $extradata;
	}

	/**
	 * @return string
	 */
	public function getCodeString() {
		return $this->mCodestr;
	}

	/**
	 * @return array
	 */
	public function getMessageArray() {
		$result = array(
			'code' => $this->mCodestr,
			'info' => $this->getMessage()
		);
		if ( is_array( $this->mExtraData ) ) {
			$result = array_merge( $result, $this->mExtraData );
		}
		return $result;
	}

	/**
	 * @return string
	 */
	public function __toString() {
		return "{$this->getCodeString()}: {$this->getMessage()}";
	}
}