xref: /webtrees/app/Tree.php (revision 3e983931fdde6db78f1490364106d7d46e77dea7)
1<?php
2/**
3 * webtrees: online genealogy
4 * Copyright (C) 2017 webtrees development team
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
15 */
16namespace Fisharebest\Webtrees;
17
18use Fisharebest\Webtrees\Functions\FunctionsExport;
19use Fisharebest\Webtrees\Functions\FunctionsImport;
20use PDOException;
21
22/**
23 * Provide an interface to the wt_gedcom table.
24 */
25class Tree {
26	/** @var int The tree's ID number */
27	private $tree_id;
28
29	/** @var string The tree's name */
30	private $name;
31
32	/** @var string The tree's title */
33	private $title;
34
35	/** @var int[] Default access rules for facts in this tree */
36	private $fact_privacy;
37
38	/** @var int[] Default access rules for individuals in this tree */
39	private $individual_privacy;
40
41	/** @var integer[][] Default access rules for individual facts in this tree */
42	private $individual_fact_privacy;
43
44	/** @var Tree[] All trees that we have permission to see. */
45	private static $trees;
46
47	/** @var string[] Cached copy of the wt_gedcom_setting table. */
48	private $preferences = [];
49
50	/** @var string[][] Cached copy of the wt_user_gedcom_setting table. */
51	private $user_preferences = [];
52
53	/**
54	 * Create a tree object. This is a private constructor - it can only
55	 * be called from Tree::getAll() to ensure proper initialisation.
56	 *
57	 * @param int    $tree_id
58	 * @param string $tree_name
59	 * @param string $tree_title
60	 */
61	private function __construct($tree_id, $tree_name, $tree_title) {
62		$this->tree_id                 = $tree_id;
63		$this->name                    = $tree_name;
64		$this->title                   = $tree_title;
65		$this->fact_privacy            = [];
66		$this->individual_privacy      = [];
67		$this->individual_fact_privacy = [];
68
69		// Load the privacy settings for this tree
70		$rows = Database::prepare(
71			"SELECT SQL_CACHE xref, tag_type, CASE resn WHEN 'none' THEN :priv_public WHEN 'privacy' THEN :priv_user WHEN 'confidential' THEN :priv_none WHEN 'hidden' THEN :priv_hide END AS resn" .
72			" FROM `##default_resn` WHERE gedcom_id = :tree_id"
73		)->execute([
74			'priv_public' => Auth::PRIV_PRIVATE,
75			'priv_user'   => Auth::PRIV_USER,
76			'priv_none'   => Auth::PRIV_NONE,
77			'priv_hide'   => Auth::PRIV_HIDE,
78			'tree_id'     => $this->tree_id,
79		])->fetchAll();
80
81		foreach ($rows as $row) {
82			if ($row->xref !== null) {
83				if ($row->tag_type !== null) {
84					$this->individual_fact_privacy[$row->xref][$row->tag_type] = (int) $row->resn;
85				} else {
86					$this->individual_privacy[$row->xref] = (int) $row->resn;
87				}
88			} else {
89				$this->fact_privacy[$row->tag_type] = (int) $row->resn;
90			}
91		}
92	}
93
94	/**
95	 * The ID of this tree
96	 *
97	 * @return int
98	 */
99	public function getTreeId() {
100		return $this->tree_id;
101	}
102
103	/**
104	 * The name of this tree
105	 *
106	 * @return string
107	 */
108	public function getName() {
109		return $this->name;
110	}
111
112	/**
113	 * The name of this tree
114	 *
115	 * @return string
116	 */
117	public function getNameHtml() {
118		return Html::escape($this->name);
119	}
120
121	/**
122	 * The name of this tree
123	 *
124	 * @return string
125	 */
126	public function getNameUrl() {
127		return rawurlencode($this->name);
128	}
129
130	/**
131	 * The title of this tree
132	 *
133	 * @return string
134	 */
135	public function getTitle() {
136		return $this->title;
137	}
138
139	/**
140	 * The title of this tree, with HTML markup
141	 *
142	 * @return string
143	 */
144	public function getTitleHtml() {
145		return '<span dir="auto">' . Html::escape($this->title) . '</span>';
146	}
147
148	/**
149	 * The fact-level privacy for this tree.
150	 *
151	 * @return int[]
152	 */
153	public function getFactPrivacy() {
154		return $this->fact_privacy;
155	}
156
157	/**
158	 * The individual-level privacy for this tree.
159	 *
160	 * @return int[]
161	 */
162	public function getIndividualPrivacy() {
163		return $this->individual_privacy;
164	}
165
166	/**
167	 * The individual-fact-level privacy for this tree.
168	 *
169	 * @return integer[][]
170	 */
171	public function getIndividualFactPrivacy() {
172		return $this->individual_fact_privacy;
173	}
174
175	/**
176	 * Get the tree’s configuration settings.
177	 *
178	 * @param string $setting_name
179	 * @param string $default
180	 *
181	 * @return string
182	 */
183	public function getPreference($setting_name, $default = '') {
184		if (empty($this->preferences)) {
185			$this->preferences = Database::prepare(
186				"SELECT SQL_CACHE setting_name, setting_value FROM `##gedcom_setting` WHERE gedcom_id = ?"
187			)->execute([$this->tree_id])->fetchAssoc();
188		}
189
190		if (array_key_exists($setting_name, $this->preferences)) {
191			return $this->preferences[$setting_name];
192		} else {
193			return $default;
194		}
195	}
196
197	/**
198	 * Set the tree’s configuration settings.
199	 *
200	 * @param string $setting_name
201	 * @param string $setting_value
202	 *
203	 * @return $this
204	 */
205	public function setPreference($setting_name, $setting_value) {
206		if ($setting_value !== $this->getPreference($setting_name)) {
207			Database::prepare(
208				"REPLACE INTO `##gedcom_setting` (gedcom_id, setting_name, setting_value)" .
209				" VALUES (:tree_id, :setting_name, LEFT(:setting_value, 255))"
210			)->execute([
211				'tree_id'       => $this->tree_id,
212				'setting_name'  => $setting_name,
213				'setting_value' => $setting_value,
214			]);
215
216			$this->preferences[$setting_name] = $setting_value;
217
218			Log::addConfigurationLog('Tree preference "' . $setting_name . '" set to "' . $setting_value . '"', $this);
219		}
220
221		return $this;
222	}
223
224	/**
225	 * Get the tree’s user-configuration settings.
226	 *
227	 * @param User        $user
228	 * @param string      $setting_name
229	 * @param string|null $default
230	 *
231	 * @return string
232	 */
233	public function getUserPreference(User $user, $setting_name, $default = null) {
234		// There are lots of settings, and we need to fetch lots of them on every page
235		// so it is quicker to fetch them all in one go.
236		if (!array_key_exists($user->getUserId(), $this->user_preferences)) {
237			$this->user_preferences[$user->getUserId()] = Database::prepare(
238				"SELECT SQL_CACHE setting_name, setting_value FROM `##user_gedcom_setting` WHERE user_id = ? AND gedcom_id = ?"
239			)->execute([$user->getUserId(), $this->tree_id])->fetchAssoc();
240		}
241
242		if (array_key_exists($setting_name, $this->user_preferences[$user->getUserId()])) {
243			return $this->user_preferences[$user->getUserId()][$setting_name];
244		} else {
245			return $default;
246		}
247	}
248
249	/**
250	 * Set the tree’s user-configuration settings.
251	 *
252	 * @param User    $user
253	 * @param string  $setting_name
254	 * @param string  $setting_value
255	 *
256	 * @return $this
257	 */
258	public function setUserPreference(User $user, $setting_name, $setting_value) {
259		if ($this->getUserPreference($user, $setting_name) !== $setting_value) {
260			// Update the database
261			if ($setting_value === null) {
262				Database::prepare(
263					"DELETE FROM `##user_gedcom_setting` WHERE gedcom_id = :tree_id AND user_id = :user_id AND setting_name = :setting_name"
264				)->execute([
265					'tree_id'      => $this->tree_id,
266					'user_id'      => $user->getUserId(),
267					'setting_name' => $setting_name,
268				]);
269			} else {
270				Database::prepare(
271					"REPLACE INTO `##user_gedcom_setting` (user_id, gedcom_id, setting_name, setting_value) VALUES (:user_id, :tree_id, :setting_name, LEFT(:setting_value, 255))"
272				)->execute([
273					'user_id'       => $user->getUserId(),
274					'tree_id'       => $this->tree_id,
275					'setting_name'  => $setting_name,
276					'setting_value' => $setting_value,
277				]);
278			}
279			// Update our cache
280			$this->user_preferences[$user->getUserId()][$setting_name] = $setting_value;
281			// Audit log of changes
282			Log::addConfigurationLog('Tree preference "' . $setting_name . '" set to "' . $setting_value . '" for user "' . $user->getUserName() . '"', $this);
283		}
284
285		return $this;
286	}
287
288	/**
289	 * Can a user accept changes for this tree?
290	 *
291	 * @param User $user
292	 *
293	 * @return bool
294	 */
295	public function canAcceptChanges(User $user) {
296		return Auth::isModerator($this, $user);
297	}
298
299	/**
300	 * Fetch all the trees that we have permission to access.
301	 *
302	 * @return Tree[]
303	 */
304	public static function getAll() {
305		if (self::$trees === null) {
306			self::$trees = [];
307			$rows        = Database::prepare(
308				"SELECT SQL_CACHE g.gedcom_id AS tree_id, g.gedcom_name AS tree_name, gs1.setting_value AS tree_title" .
309				" FROM `##gedcom` g" .
310				" LEFT JOIN `##gedcom_setting`      gs1 ON (g.gedcom_id=gs1.gedcom_id AND gs1.setting_name='title')" .
311				" LEFT JOIN `##gedcom_setting`      gs2 ON (g.gedcom_id=gs2.gedcom_id AND gs2.setting_name='imported')" .
312				" LEFT JOIN `##gedcom_setting`      gs3 ON (g.gedcom_id=gs3.gedcom_id AND gs3.setting_name='REQUIRE_AUTHENTICATION')" .
313				" LEFT JOIN `##user_gedcom_setting` ugs ON (g.gedcom_id=ugs.gedcom_id AND ugs.setting_name='canedit' AND ugs.user_id=?)" .
314				" WHERE " .
315				"  g.gedcom_id>0 AND (" . // exclude the "template" tree
316				"    EXISTS (SELECT 1 FROM `##user_setting` WHERE user_id=? AND setting_name='canadmin' AND setting_value=1)" . // Admin sees all
317				"   ) OR (" .
318				"    (gs2.setting_value = 1 OR ugs.setting_value = 'admin') AND (" . // Allow imported trees, with either:
319				"     gs3.setting_value <> 1 OR" . // visitor access
320				"     IFNULL(ugs.setting_value, 'none')<>'none'" . // explicit access
321				"   )" .
322				"  )" .
323				" ORDER BY g.sort_order, 3"
324			)->execute([Auth::id(), Auth::id()])->fetchAll();
325			foreach ($rows as $row) {
326				self::$trees[] = new self((int) $row->tree_id, $row->tree_name, $row->tree_title);
327			}
328		}
329
330		return self::$trees;
331	}
332
333	/**
334	 * Find the tree with a specific ID.
335	 *
336	 * @param int $tree_id
337	 *
338	 * @throws \DomainException
339	 *
340	 * @return Tree
341	 */
342	public static function findById($tree_id) {
343		foreach (self::getAll() as $tree) {
344			if ($tree->tree_id == $tree_id) {
345				return $tree;
346			}
347		}
348		throw new \DomainException;
349	}
350
351	/**
352	 * Find the tree with a specific name.
353	 *
354	 * @param string $tree_name
355	 *
356	 * @return Tree|null
357	 */
358	public static function findByName($tree_name) {
359		foreach (self::getAll() as $tree) {
360			if ($tree->name === $tree_name) {
361				return $tree;
362			}
363		}
364
365		return null;
366	}
367
368	/**
369	 * Create arguments to select_edit_control()
370	 * Note - these will be escaped later
371	 *
372	 * @return string[]
373	 */
374	public static function getIdList() {
375		$list = [];
376		foreach (self::getAll() as $tree) {
377			$list[$tree->tree_id] = $tree->title;
378		}
379
380		return $list;
381	}
382
383	/**
384	 * Create arguments to select_edit_control()
385	 * Note - these will be escaped later
386	 *
387	 * @return string[]
388	 */
389	public static function getNameList() {
390		$list = [];
391		foreach (self::getAll() as $tree) {
392			$list[$tree->name] = $tree->title;
393		}
394
395		return $list;
396	}
397
398	/**
399	 * Create a new tree
400	 *
401	 * @param string $tree_name
402	 * @param string $tree_title
403	 *
404	 * @return Tree
405	 */
406	public static function create($tree_name, $tree_title) {
407		try {
408			// Create a new tree
409			Database::prepare(
410				"INSERT INTO `##gedcom` (gedcom_name) VALUES (?)"
411			)->execute([$tree_name]);
412			$tree_id = Database::prepare("SELECT LAST_INSERT_ID()")->fetchOne();
413		} catch (PDOException $ex) {
414			DebugBar::addThrowable($ex);
415
416			// A tree with that name already exists?
417			return self::findByName($tree_name);
418		}
419
420		// Update the list of trees - to include this new one
421		self::$trees = null;
422		$tree        = self::findById($tree_id);
423
424		$tree->setPreference('imported', '0');
425		$tree->setPreference('title', $tree_title);
426
427		// Module privacy
428		Module::setDefaultAccess($tree_id);
429
430		// Set preferences from default tree
431		Database::prepare(
432			"INSERT INTO `##gedcom_setting` (gedcom_id, setting_name, setting_value)" .
433			" SELECT :tree_id, setting_name, setting_value" .
434			" FROM `##gedcom_setting` WHERE gedcom_id = -1"
435		)->execute([
436			'tree_id' => $tree_id,
437		]);
438
439		Database::prepare(
440			"INSERT INTO `##default_resn` (gedcom_id, tag_type, resn)" .
441			" SELECT :tree_id, tag_type, resn" .
442			" FROM `##default_resn` WHERE gedcom_id = -1"
443		)->execute([
444			'tree_id' => $tree_id,
445		]);
446
447		Database::prepare(
448			"INSERT INTO `##block` (gedcom_id, location, block_order, module_name)" .
449			" SELECT :tree_id, location, block_order, module_name" .
450			" FROM `##block` WHERE gedcom_id = -1"
451		)->execute([
452			'tree_id' => $tree_id,
453		]);
454
455		// Gedcom and privacy settings
456		$tree->setPreference('CONTACT_USER_ID', Auth::id());
457		$tree->setPreference('WEBMASTER_USER_ID', Auth::id());
458		$tree->setPreference('LANGUAGE', WT_LOCALE); // Default to the current admin’s language
459		switch (WT_LOCALE) {
460			case 'es':
461				$tree->setPreference('SURNAME_TRADITION', 'spanish');
462				break;
463			case 'is':
464				$tree->setPreference('SURNAME_TRADITION', 'icelandic');
465				break;
466			case 'lt':
467				$tree->setPreference('SURNAME_TRADITION', 'lithuanian');
468				break;
469			case 'pl':
470				$tree->setPreference('SURNAME_TRADITION', 'polish');
471				break;
472			case 'pt':
473			case 'pt-BR':
474				$tree->setPreference('SURNAME_TRADITION', 'portuguese');
475				break;
476			default:
477				$tree->setPreference('SURNAME_TRADITION', 'paternal');
478				break;
479		}
480
481		// Genealogy data
482		// It is simpler to create a temporary/unimported GEDCOM than to populate all the tables...
483		$john_doe = /* I18N: This should be a common/default/placeholder name of an individual. Put slashes around the surname. */ I18N::translate('John /DOE/');
484		$note     = I18N::translate('Edit this individual and replace their details with your own.');
485		Database::prepare("INSERT INTO `##gedcom_chunk` (gedcom_id, chunk_data) VALUES (?, ?)")->execute([
486			$tree_id,
487			"0 HEAD\n1 CHAR UTF-8\n0 @I1@ INDI\n1 NAME {$john_doe}\n1 SEX M\n1 BIRT\n2 DATE 01 JAN 1850\n2 NOTE {$note}\n0 TRLR\n",
488		]);
489
490		// Update our cache
491		self::$trees[$tree->tree_id] = $tree;
492
493		return $tree;
494	}
495
496	/**
497	 * Are there any pending edits for this tree, than need reviewing by a moderator.
498	 *
499	 * @return bool
500	 */
501	public function hasPendingEdit() {
502		return (bool) Database::prepare(
503			"SELECT 1 FROM `##change` WHERE status = 'pending' AND gedcom_id = :tree_id"
504		)->execute([
505			'tree_id' => $this->tree_id,
506		])->fetchOne();
507	}
508
509	/**
510	 * Delete all the genealogy data from a tree - in preparation for importing
511	 * new data. Optionally retain the media data, for when the user has been
512	 * editing their data offline using an application which deletes (or does not
513	 * support) media data.
514	 *
515	 * @param bool $keep_media
516	 */
517	public function deleteGenealogyData($keep_media) {
518		Database::prepare("DELETE FROM `##gedcom_chunk` WHERE gedcom_id = ?")->execute([$this->tree_id]);
519		Database::prepare("DELETE FROM `##individuals`  WHERE i_file    = ?")->execute([$this->tree_id]);
520		Database::prepare("DELETE FROM `##families`     WHERE f_file    = ?")->execute([$this->tree_id]);
521		Database::prepare("DELETE FROM `##sources`      WHERE s_file    = ?")->execute([$this->tree_id]);
522		Database::prepare("DELETE FROM `##other`        WHERE o_file    = ?")->execute([$this->tree_id]);
523		Database::prepare("DELETE FROM `##places`       WHERE p_file    = ?")->execute([$this->tree_id]);
524		Database::prepare("DELETE FROM `##placelinks`   WHERE pl_file   = ?")->execute([$this->tree_id]);
525		Database::prepare("DELETE FROM `##name`         WHERE n_file    = ?")->execute([$this->tree_id]);
526		Database::prepare("DELETE FROM `##dates`        WHERE d_file    = ?")->execute([$this->tree_id]);
527		Database::prepare("DELETE FROM `##change`       WHERE gedcom_id = ?")->execute([$this->tree_id]);
528
529		if ($keep_media) {
530			Database::prepare("DELETE FROM `##link` WHERE l_file =? AND l_type<>'OBJE'")->execute([$this->tree_id]);
531		} else {
532			Database::prepare("DELETE FROM `##link`  WHERE l_file =?")->execute([$this->tree_id]);
533			Database::prepare("DELETE FROM `##media` WHERE m_file =?")->execute([$this->tree_id]);
534		}
535	}
536
537	/**
538	 * Delete everything relating to a tree
539	 */
540	public function delete() {
541		// If this is the default tree, then unset it
542		if (Site::getPreference('DEFAULT_GEDCOM') === $this->name) {
543			Site::setPreference('DEFAULT_GEDCOM', '');
544		}
545
546		$this->deleteGenealogyData(false);
547
548		Database::prepare("DELETE `##block_setting` FROM `##block_setting` JOIN `##block` USING (block_id) WHERE gedcom_id=?")->execute([$this->tree_id]);
549		Database::prepare("DELETE FROM `##block`               WHERE gedcom_id = ?")->execute([$this->tree_id]);
550		Database::prepare("DELETE FROM `##user_gedcom_setting` WHERE gedcom_id = ?")->execute([$this->tree_id]);
551		Database::prepare("DELETE FROM `##gedcom_setting`      WHERE gedcom_id = ?")->execute([$this->tree_id]);
552		Database::prepare("DELETE FROM `##module_privacy`      WHERE gedcom_id = ?")->execute([$this->tree_id]);
553		Database::prepare("DELETE FROM `##hit_counter`         WHERE gedcom_id = ?")->execute([$this->tree_id]);
554		Database::prepare("DELETE FROM `##default_resn`        WHERE gedcom_id = ?")->execute([$this->tree_id]);
555		Database::prepare("DELETE FROM `##gedcom_chunk`        WHERE gedcom_id = ?")->execute([$this->tree_id]);
556		Database::prepare("DELETE FROM `##log`                 WHERE gedcom_id = ?")->execute([$this->tree_id]);
557		Database::prepare("DELETE FROM `##gedcom`              WHERE gedcom_id = ?")->execute([$this->tree_id]);
558
559		// After updating the database, we need to fetch a new (sorted) copy
560		self::$trees = null;
561	}
562
563	/**
564	 * Export the tree to a GEDCOM file
565	 *
566	 * @param resource $stream
567	 */
568	public function exportGedcom($stream) {
569		$stmt = Database::prepare(
570			"SELECT i_gedcom AS gedcom, i_id AS xref, 1 AS n FROM `##individuals` WHERE i_file = :tree_id_1" .
571			" UNION ALL " .
572			"SELECT f_gedcom AS gedcom, f_id AS xref, 2 AS n FROM `##families`    WHERE f_file = :tree_id_2" .
573			" UNION ALL " .
574			"SELECT s_gedcom AS gedcom, s_id AS xref, 3 AS n FROM `##sources`     WHERE s_file = :tree_id_3" .
575			" UNION ALL " .
576			"SELECT o_gedcom AS gedcom, o_id AS xref, 4 AS n FROM `##other`       WHERE o_file = :tree_id_4 AND o_type NOT IN ('HEAD', 'TRLR')" .
577			" UNION ALL " .
578			"SELECT m_gedcom AS gedcom, m_id AS xref, 5 AS n FROM `##media`       WHERE m_file = :tree_id_5" .
579			" ORDER BY n, LENGTH(xref), xref"
580		)->execute([
581			'tree_id_1' => $this->tree_id,
582			'tree_id_2' => $this->tree_id,
583			'tree_id_3' => $this->tree_id,
584			'tree_id_4' => $this->tree_id,
585			'tree_id_5' => $this->tree_id,
586		]);
587
588		$buffer = FunctionsExport::reformatRecord(FunctionsExport::gedcomHeader($this));
589		while (($row = $stmt->fetch()) !== false) {
590			$buffer .= FunctionsExport::reformatRecord($row->gedcom);
591			if (strlen($buffer) > 65535) {
592				fwrite($stream, $buffer);
593				$buffer = '';
594			}
595		}
596		fwrite($stream, $buffer . '0 TRLR' . WT_EOL);
597		$stmt->closeCursor();
598	}
599
600	/**
601	 * Import data from a gedcom file into this tree.
602	 *
603	 * @param string  $path       The full path to the (possibly temporary) file.
604	 * @param string  $filename   The preferred filename, for export/download.
605	 *
606	 * @throws \Exception
607	 */
608	public function importGedcomFile($path, $filename) {
609		// Read the file in blocks of roughly 64K. Ensure that each block
610		// contains complete gedcom records. This will ensure we don’t split
611		// multi-byte characters, as well as simplifying the code to import
612		// each block.
613
614		$file_data = '';
615		$fp        = fopen($path, 'rb');
616
617		// Don’t allow the user to cancel the request. We do not want to be left with an incomplete transaction.
618		ignore_user_abort(true);
619
620		Database::beginTransaction();
621		$this->deleteGenealogyData($this->getPreference('keep_media'));
622		$this->setPreference('gedcom_filename', $filename);
623		$this->setPreference('imported', '0');
624
625		while (!feof($fp)) {
626			$file_data .= fread($fp, 65536);
627			// There is no strrpos() function that searches for substrings :-(
628			for ($pos = strlen($file_data) - 1; $pos > 0; --$pos) {
629				if ($file_data[$pos] === '0' && ($file_data[$pos - 1] === "\n" || $file_data[$pos - 1] === "\r")) {
630					// We’ve found the last record boundary in this chunk of data
631					break;
632				}
633			}
634			if ($pos) {
635				Database::prepare(
636					"INSERT INTO `##gedcom_chunk` (gedcom_id, chunk_data) VALUES (?, ?)"
637				)->execute([$this->tree_id, substr($file_data, 0, $pos)]);
638				$file_data = substr($file_data, $pos);
639			}
640		}
641		Database::prepare(
642			"INSERT INTO `##gedcom_chunk` (gedcom_id, chunk_data) VALUES (?, ?)"
643		)->execute([$this->tree_id, $file_data]);
644
645		Database::commit();
646		fclose($fp);
647	}
648
649	/**
650	 * Generate a new XREF, unique across all family trees
651	 *
652	 * @return string
653	 */
654	public function getNewXref() {
655		$prefix = 'X';
656
657		$increment = 1.0;
658		do {
659			// Use LAST_INSERT_ID(expr) to provide a transaction-safe sequence. See
660			// http://dev.mysql.com/doc/refman/5.6/en/information-functions.html#function_last-insert-id
661			$statement = Database::prepare(
662				"UPDATE `##site_setting` SET setting_value = LAST_INSERT_ID(setting_value + :increment) WHERE setting_name = 'next_xref'"
663			);
664			$statement->execute([
665				'increment'   => (int) $increment,
666			]);
667
668			if ($statement->rowCount() === 0) {
669				// First time we've used this record type.
670				Site::setPreference('next_xref', '1');
671				$num = 1;
672			} else {
673				$num = Database::prepare("SELECT LAST_INSERT_ID()")->fetchOne();
674			}
675
676			$xref = $prefix . $num;
677
678			// Records may already exist with this sequence number.
679			$already_used = Database::prepare(
680				"SELECT" .
681				" EXISTS (SELECT 1 FROM `##individuals` WHERE i_id = :i_id) OR" .
682				" EXISTS (SELECT 1 FROM `##families` WHERE f_id = :f_id) OR" .
683				" EXISTS (SELECT 1 FROM `##sources` WHERE s_id = :s_id) OR" .
684				" EXISTS (SELECT 1 FROM `##media` WHERE m_id = :m_id) OR" .
685				" EXISTS (SELECT 1 FROM `##other` WHERE o_id = :o_id) OR" .
686				" EXISTS (SELECT 1 FROM `##change` WHERE xref = :xref)"
687			)->execute([
688				'i_id' => $xref,
689				'f_id' => $xref,
690				's_id' => $xref,
691				'm_id' => $xref,
692				'o_id' => $xref,
693				'xref' => $xref,
694			])->fetchOne();
695
696			// This exponential increment allows us to scan over large blocks of
697			// existing data in a reasonable time.
698			$increment *= 1.01;
699		} while ($already_used !== '0');
700
701		return $xref;
702	}
703
704	/**
705	 * Create a new record from GEDCOM data.
706	 *
707	 * @param string $gedcom
708	 *
709	 * @throws \Exception
710	 *
711	 * @return GedcomRecord|Individual|Family|Note|Source|Repository|Media
712	 */
713	public function createRecord($gedcom) {
714		if (preg_match('/^0 @(' . WT_REGEX_XREF . ')@ (' . WT_REGEX_TAG . ')/', $gedcom, $match)) {
715			$xref = $match[1];
716			$type = $match[2];
717		} else {
718			throw new \Exception('Invalid argument to GedcomRecord::createRecord(' . $gedcom . ')');
719		}
720		if (strpos("\r", $gedcom) !== false) {
721			// MSDOS line endings will break things in horrible ways
722			throw new \Exception('Evil line endings found in GedcomRecord::createRecord(' . $gedcom . ')');
723		}
724
725		// webtrees creates XREFs containing digits. Anything else (e.g. “new”) is just a placeholder.
726		if (!preg_match('/\d/', $xref)) {
727			$xref   = $this->getNewXref();
728			$gedcom = preg_replace('/^0 @(' . WT_REGEX_XREF . ')@/', '0 @' . $xref . '@', $gedcom);
729		}
730
731		// Create a change record, if not already present
732		if (!preg_match('/\n1 CHAN/', $gedcom)) {
733			$gedcom .= "\n1 CHAN\n2 DATE " . date('d M Y') . "\n3 TIME " . date('H:i:s') . "\n2 _WT_USER " . Auth::user()->getUserName();
734		}
735
736		// Create a pending change
737		Database::prepare(
738			"INSERT INTO `##change` (gedcom_id, xref, old_gedcom, new_gedcom, user_id) VALUES (?, ?, '', ?, ?)"
739		)->execute([
740			$this->tree_id,
741			$xref,
742			$gedcom,
743			Auth::id(),
744		]);
745
746		Log::addEditLog('Create: ' . $type . ' ' . $xref);
747
748		// Accept this pending change
749		if (Auth::user()->getPreference('auto_accept')) {
750			FunctionsImport::acceptAllChanges($xref, $this->tree_id);
751		}
752		// Return the newly created record. Note that since GedcomRecord
753		// has a cache of pending changes, we cannot use it to create a
754		// record with a newly created pending change.
755		return GedcomRecord::getInstance($xref, $this, $gedcom);
756	}
757}
758