<?php
/**
 * webtrees: online genealogy
 * Copyright (C) 2019 webtrees development team
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */
declare(strict_types=1);

namespace Fisharebest\Webtrees;

use Exception;
use Fisharebest\Webtrees\Functions\Functions;
use Fisharebest\Webtrees\Functions\FunctionsDate;
use Fisharebest\Webtrees\Functions\FunctionsImport;
use Fisharebest\Webtrees\Functions\FunctionsPrint;
use Illuminate\Database\Capsule\Manager as DB;
use stdClass;

/**
 * A GEDCOM object.
 */
class GedcomRecord
{
    const RECORD_TYPE = 'UNKNOWN';
    const ROUTE_NAME  = 'record';

    /** @var string The record identifier */
    protected $xref;

    /** @var Tree  The family tree to which this record belongs */
    protected $tree;

    /** @var string  GEDCOM data (before any pending edits) */
    protected $gedcom;

    /** @var string|null  GEDCOM data (after any pending edits) */
    protected $pending;

    /** @var Fact[] facts extracted from $gedcom/$pending */
    protected $facts;

    /** @var bool Can we display details of this record to Auth::PRIV_PRIVATE */
    private $disp_public;

    /** @var bool Can we display details of this record to Auth::PRIV_USER */
    private $disp_user;

    /** @var bool Can we display details of this record to Auth::PRIV_NONE */
    private $disp_none;

    /** @var string[][] All the names of this individual */
    protected $getAllNames;

    /** @var int|null Cached result */
    protected $getPrimaryName;

    /** @var int|null Cached result */
    protected $getSecondaryName;

    /** @var GedcomRecord[][] Allow getInstance() to return references to existing objects */
    public static $gedcom_record_cache;

    /** @var stdClass[][] Fetch all pending edits in one database query */
    public static $pending_record_cache;

    /**
     * Create a GedcomRecord object from raw GEDCOM data.
     *
     * @param string      $xref
     * @param string      $gedcom  an empty string for new/pending records
     * @param string|null $pending null for a record with no pending edits,
     *                             empty string for records with pending deletions
     * @param Tree        $tree
     */
    public function __construct(string $xref, string $gedcom, $pending, Tree $tree)
    {
        $this->xref    = $xref;
        $this->gedcom  = $gedcom;
        $this->pending = $pending;
        $this->tree    = $tree;

        $this->parseFacts();
    }

    /**
     * Split the record into facts
     *
     * @return void
     */
    private function parseFacts()
    {
        // Split the record into facts
        if ($this->gedcom) {
            $gedcom_facts = preg_split('/\n(?=1)/s', $this->gedcom);
            array_shift($gedcom_facts);
        } else {
            $gedcom_facts = [];
        }
        if ($this->pending) {
            $pending_facts = preg_split('/\n(?=1)/s', $this->pending);
            array_shift($pending_facts);
        } else {
            $pending_facts = [];
        }

        $this->facts = [];

        foreach ($gedcom_facts as $gedcom_fact) {
            $fact = new Fact($gedcom_fact, $this, md5($gedcom_fact));
            if ($this->pending !== null && !in_array($gedcom_fact, $pending_facts)) {
                $fact->setPendingDeletion();
            }
            $this->facts[] = $fact;
        }
        foreach ($pending_facts as $pending_fact) {
            if (!in_array($pending_fact, $gedcom_facts)) {
                $fact = new Fact($pending_fact, $this, md5($pending_fact));
                $fact->setPendingAddition();
                $this->facts[] = $fact;
            }
        }
    }

    /**
     * Get an instance of a GedcomRecord object. For single records,
     * we just receive the XREF. For bulk records (such as lists
     * and search results) we can receive the GEDCOM data as well.
     *
     * @param string      $xref
     * @param Tree        $tree
     * @param string|null $gedcom
     *
     * @throws Exception
     *
     * @return GedcomRecord|Individual|Family|Source|Repository|Media|Note|null
     */
    public static function getInstance(string $xref, Tree $tree, string $gedcom = null)
    {
        $tree_id = $tree->id();

        // Is this record already in the cache?
        if (isset(self::$gedcom_record_cache[$xref][$tree_id])) {
            return self::$gedcom_record_cache[$xref][$tree_id];
        }

        // Do we need to fetch the record from the database?
        if ($gedcom === null) {
            $gedcom = static::fetchGedcomRecord($xref, $tree_id);
        }

        // If we can edit, then we also need to be able to see pending records.
        if (Auth::isEditor($tree)) {
            if (!isset(self::$pending_record_cache[$tree_id])) {
                // Fetch all pending records in one database query
                self::$pending_record_cache[$tree_id] = [];
                $rows = DB::table('change')
                    ->where('gedcom_id', '=', $tree_id)
                    ->where('status', '=', 'pending')
                    ->orderBy('change_id')
                    ->select(['xref', 'new_gedcom'])
                    ->get();

                foreach ($rows as $row) {
                    self::$pending_record_cache[$tree_id][$row->xref] = $row->new_gedcom;
                }
            }

            $pending = self::$pending_record_cache[$tree_id][$xref] ?? null;
        } else {
            // There are no pending changes for this record
            $pending = null;
        }

        // No such record exists
        if ($gedcom === null && $pending === null) {
            return null;
        }

        // No such record, but a pending creation exists
        if ($gedcom === null) {
            $gedcom = '';
        }

        // Create the object
        if (preg_match('/^0 @(' . Gedcom::REGEX_XREF . ')@ (' . Gedcom::REGEX_TAG . ')/', $gedcom . $pending, $match)) {
            $xref = $match[1]; // Collation - we may have requested I123 and found i123
            $type = $match[2];
        } elseif (preg_match('/^0 (HEAD|TRLR)/', $gedcom . $pending, $match)) {
            $xref = $match[1];
            $type = $match[1];
        } elseif ($gedcom . $pending) {
            throw new Exception('Unrecognized GEDCOM record: ' . $gedcom);
        } else {
            // A record with both pending creation and pending deletion
            $type = static::RECORD_TYPE;
        }

        switch ($type) {
            case 'INDI':
                $record = new Individual($xref, $gedcom, $pending, $tree);
                break;
            case 'FAM':
                $record = new Family($xref, $gedcom, $pending, $tree);
                break;
            case 'SOUR':
                $record = new Source($xref, $gedcom, $pending, $tree);
                break;
            case 'OBJE':
                $record = new Media($xref, $gedcom, $pending, $tree);
                break;
            case 'REPO':
                $record = new Repository($xref, $gedcom, $pending, $tree);
                break;
            case 'NOTE':
                $record = new Note($xref, $gedcom, $pending, $tree);
                break;
            default:
                $record = new self($xref, $gedcom, $pending, $tree);
                break;
        }

        // Store it in the cache
        self::$gedcom_record_cache[$xref][$tree_id] = $record;

        return $record;
    }

    /**
     * Fetch data from the database
     *
     * @param string $xref
     * @param int    $tree_id
     *
     * @return null|string
     */
    protected static function fetchGedcomRecord(string $xref, int $tree_id)
    {
        // We don't know what type of object this is. Try each one in turn.
        $data = Individual::fetchGedcomRecord($xref, $tree_id);
        if ($data !== null) {
            return $data;
        }
        $data = Family::fetchGedcomRecord($xref, $tree_id);
        if ($data !== null) {
            return $data;
        }
        $data = Source::fetchGedcomRecord($xref, $tree_id);
        if ($data !== null) {
            return $data;
        }
        $data = Repository::fetchGedcomRecord($xref, $tree_id);
        if ($data !== null) {
            return $data;
        }
        $data = Media::fetchGedcomRecord($xref, $tree_id);
        if ($data !== null) {
            return $data;
        }
        $data = Note::fetchGedcomRecord($xref, $tree_id);
        if ($data !== null) {
            return $data;
        }

        // Some other type of record...
        return DB::table('other')
            ->where('o_file', '=', $tree_id)
            ->where('o_id', '=', $xref)
            ->value('o_gedcom');
    }

    /**
     * Get the XREF for this record
     *
     * @return string
     */
    public function xref(): string
    {
        return $this->xref;
    }

    /**
     * Get the tree to which this record belongs
     *
     * @return Tree
     */
    public function tree(): Tree
    {
        return $this->tree;
    }

    /**
     * Application code should access data via Fact objects.
     * This function exists to support old code.
     *
     * @return string
     */
    public function gedcom()
    {
        return $this->pending ?? $this->gedcom;
    }

    /**
     * Does this record have a pending change?
     *
     * @return bool
     */
    public function isPendingAddition(): bool
    {
        return $this->pending !== null;
    }

    /**
     * Does this record have a pending deletion?
     *
     * @return bool
     */
    public function isPendingDeletion(): bool
    {
        return $this->pending === '';
    }

    /**
     * Generate a URL to this record.
     *
     * @return string
     */
    public function url(): string
    {
        return route(static::ROUTE_NAME, [
            'xref' => $this->xref(),
            'ged'  => $this->tree->name(),
        ]);
    }

    /**
     * Work out whether this record can be shown to a user with a given access level
     *
     * @param int $access_level
     *
     * @return bool
     */
    private function canShowRecord(int $access_level): bool
    {
        // This setting would better be called "$ENABLE_PRIVACY"
        if (!$this->tree->getPreference('HIDE_LIVE_PEOPLE')) {
            return true;
        }

        // We should always be able to see our own record (unless an admin is applying download restrictions)
        if ($this->xref() === $this->tree->getUserPreference(Auth::user(), 'gedcomid') && $access_level === Auth::accessLevel($this->tree)) {
            return true;
        }

        // Does this record have a RESN?
        if (strpos($this->gedcom, "\n1 RESN confidential") !== false) {
            return Auth::PRIV_NONE >= $access_level;
        }
        if (strpos($this->gedcom, "\n1 RESN privacy") !== false) {
            return Auth::PRIV_USER >= $access_level;
        }
        if (strpos($this->gedcom, "\n1 RESN none") !== false) {
            return true;
        }

        // Does this record have a default RESN?
        $individual_privacy = $this->tree->getIndividualPrivacy();
        if (isset($individual_privacy[$this->xref()])) {
            return $individual_privacy[$this->xref()] >= $access_level;
        }

        // Privacy rules do not apply to admins
        if (Auth::PRIV_NONE >= $access_level) {
            return true;
        }

        // Different types of record have different privacy rules
        return $this->canShowByType($access_level);
    }

    /**
     * Each object type may have its own special rules, and re-implement this function.
     *
     * @param int $access_level
     *
     * @return bool
     */
    protected function canShowByType(int $access_level): bool
    {
        $fact_privacy = $this->tree->getFactPrivacy();

        if (isset($fact_privacy[static::RECORD_TYPE])) {
            // Restriction found
            return $fact_privacy[static::RECORD_TYPE] >= $access_level;
        }

        // No restriction found - must be public:
        return true;
    }

    /**
     * Can the details of this record be shown?
     *
     * @param int|null $access_level
     *
     * @return bool
     */
    public function canShow(int $access_level = null): bool
    {
        if ($access_level === null) {
            $access_level = Auth::accessLevel($this->tree);
        }

        // CACHING: this function can take three different parameters,
        // and therefore needs three different caches for the result.
        switch ($access_level) {
            case Auth::PRIV_PRIVATE: // visitor
                if ($this->disp_public === null) {
                    $this->disp_public = $this->canShowRecord(Auth::PRIV_PRIVATE);
                }

                return $this->disp_public;
            case Auth::PRIV_USER: // member
                if ($this->disp_user === null) {
                    $this->disp_user = $this->canShowRecord(Auth::PRIV_USER);
                }

                return $this->disp_user;
            case Auth::PRIV_NONE: // admin
                if ($this->disp_none === null) {
                    $this->disp_none = $this->canShowRecord(Auth::PRIV_NONE);
                }

                return $this->disp_none;
            case Auth::PRIV_HIDE: // hidden from admins
                // We use this value to bypass privacy checks. For example,
                // when downloading data or when calculating privacy itself.
                return true;
            default:
                // Should never get here.
                return false;
        }
    }

    /**
     * Can the name of this record be shown?
     *
     * @param int|null $access_level
     *
     * @return bool
     */
    public function canShowName(int $access_level = null): bool
    {
        if ($access_level === null) {
            $access_level = Auth::accessLevel($this->tree);
        }

        return $this->canShow($access_level);
    }

    /**
     * Can we edit this record?
     *
     * @return bool
     */
    public function canEdit(): bool
    {
        return Auth::isManager($this->tree) || Auth::isEditor($this->tree) && strpos($this->gedcom, "\n1 RESN locked") === false;
    }

    /**
     * Remove private data from the raw gedcom record.
     * Return both the visible and invisible data. We need the invisible data when editing.
     *
     * @param int $access_level
     *
     * @return string
     */
    public function privatizeGedcom(int $access_level)
    {
        if ($access_level == Auth::PRIV_HIDE) {
            // We may need the original record, for example when downloading a GEDCOM or clippings cart
            return $this->gedcom;
        }

        if ($this->canShow($access_level)) {
            // The record is not private, but the individual facts may be.

            // Include the entire first line (for NOTE records)
            [$gedrec] = explode("\n", $this->gedcom, 2);

            // Check each of the facts for access
            foreach ($this->facts([], false, $access_level) as $fact) {
                $gedrec .= "\n" . $fact->gedcom();
            }

            return $gedrec;
        }

        // We cannot display the details, but we may be able to display
        // limited data, such as links to other records.
        return $this->createPrivateGedcomRecord($access_level);
    }

    /**
     * Generate a private version of this record
     *
     * @param int $access_level
     *
     * @return string
     */
    protected function createPrivateGedcomRecord(int $access_level): string
    {
        return '0 @' . $this->xref . '@ ' . static::RECORD_TYPE . "\n1 NOTE " . I18N::translate('Private');
    }

    /**
     * Convert a name record into sortable and full/display versions. This default
     * should be OK for simple record types. INDI/FAM records will need to redefine it.
     *
     * @param string $type
     * @param string $value
     * @param string $gedcom
     *
     * @return void
     */
    protected function addName(string $type, string $value, string $gedcom)
    {
        $this->getAllNames[] = [
            'type'   => $type,
            'sort'   => preg_replace_callback('/([0-9]+)/', function (array $matches): string {
                return str_pad($matches[0], 10, '0', STR_PAD_LEFT);
            }, $value),
            'full'   => '<span dir="auto">' . e($value) . '</span>',
            // This is used for display
            'fullNN' => $value,
            // This goes into the database
        ];
    }

    /**
     * Get all the names of a record, including ROMN, FONE and _HEB alternatives.
     * Records without a name (e.g. FAM) will need to redefine this function.
     * Parameters: the level 1 fact containing the name.
     * Return value: an array of name structures, each containing
     * ['type'] = the gedcom fact, e.g. NAME, TITL, FONE, _HEB, etc.
     * ['full'] = the name as specified in the record, e.g. 'Vincent van Gogh' or 'John Unknown'
     * ['sort'] = a sortable version of the name (not for display), e.g. 'Gogh, Vincent' or '@N.N., John'
     *
     * @param int    $level
     * @param string $fact_type
     * @param Fact[] $facts
     *
     * @return void
     */
    protected function extractNamesFromFacts(int $level, string $fact_type, array $facts)
    {
        $sublevel    = $level + 1;
        $subsublevel = $sublevel + 1;
        foreach ($facts as $fact) {
            if (preg_match_all("/^{$level} ({$fact_type}) (.+)((\n[{$sublevel}-9].+)*)/m", $fact->gedcom(), $matches, PREG_SET_ORDER)) {
                foreach ($matches as $match) {
                    // Treat 1 NAME / 2 TYPE married the same as _MARNM
                    if ($match[1] == 'NAME' && strpos($match[3], "\n2 TYPE married") !== false) {
                        $this->addName('_MARNM', $match[2], $fact->gedcom());
                    } else {
                        $this->addName($match[1], $match[2], $fact->gedcom());
                    }
                    if ($match[3] && preg_match_all("/^{$sublevel} (ROMN|FONE|_\w+) (.+)((\n[{$subsublevel}-9].+)*)/m", $match[3], $submatches, PREG_SET_ORDER)) {
                        foreach ($submatches as $submatch) {
                            $this->addName($submatch[1], $submatch[2], $match[3]);
                        }
                    }
                }
            }
        }
    }

    /**
     * Default for "other" object types
     *
     * @return void
     */
    public function extractNames()
    {
        $this->addName(static::RECORD_TYPE, $this->getFallBackName(), '');
    }

    /**
     * Derived classes should redefine this function, otherwise the object will have no name
     *
     * @return string[][]
     */
    public function getAllNames(): array
    {
        if ($this->getAllNames === null) {
            $this->getAllNames = [];
            if ($this->canShowName()) {
                // Ask the record to extract its names
                $this->extractNames();
                // No name found? Use a fallback.
                if (!$this->getAllNames) {
                    $this->addName(static::RECORD_TYPE, $this->getFallBackName(), '');
                }
            } else {
                $this->addName(static::RECORD_TYPE, I18N::translate('Private'), '');
            }
        }

        return $this->getAllNames;
    }

    /**
     * If this object has no name, what do we call it?
     *
     * @return string
     */
    public function getFallBackName(): string
    {
        return e($this->xref());
    }

    /**
     * Which of the (possibly several) names of this record is the primary one.
     *
     * @return int
     */
    public function getPrimaryName(): int
    {
        static $language_script;

        if ($language_script === null) {
            $language_script = I18N::languageScript(WT_LOCALE);
        }

        if ($this->getPrimaryName === null) {
            // Generally, the first name is the primary one....
            $this->getPrimaryName = 0;
            // ...except when the language/name use different character sets
            foreach ($this->getAllNames() as $n => $name) {
                if (I18N::textScript($name['sort']) === $language_script) {
                    $this->getPrimaryName = $n;
                    break;
                }
            }
        }

        return $this->getPrimaryName;
    }

    /**
     * Which of the (possibly several) names of this record is the secondary one.
     *
     * @return int
     */
    public function getSecondaryName(): int
    {
        if ($this->getSecondaryName === null) {
            // Generally, the primary and secondary names are the same
            $this->getSecondaryName = $this->getPrimaryName();
            // ....except when there are names with different character sets
            $all_names = $this->getAllNames();
            if (count($all_names) > 1) {
                $primary_script = I18N::textScript($all_names[$this->getPrimaryName()]['sort']);
                foreach ($all_names as $n => $name) {
                    if ($n != $this->getPrimaryName() && $name['type'] != '_MARNM' && I18N::textScript($name['sort']) != $primary_script) {
                        $this->getSecondaryName = $n;
                        break;
                    }
                }
            }
        }

        return $this->getSecondaryName;
    }

    /**
     * Allow the choice of primary name to be overidden, e.g. in a search result
     *
     * @param int|null $n
     *
     * @return void
     */
    public function setPrimaryName(int $n = null)
    {
        $this->getPrimaryName   = $n;
        $this->getSecondaryName = null;
    }

    /**
     * Allow native PHP functions such as array_unique() to work with objects
     *
     * @return string
     */
    public function __toString()
    {
        return $this->xref . '@' . $this->tree->id();
    }

    /**
     * Static helper function to sort an array of objects by name
     * Records whose names cannot be displayed are sorted at the end.
     *
     * @param GedcomRecord $x
     * @param GedcomRecord $y
     *
     * @return int
     */
    public static function compare(GedcomRecord $x, GedcomRecord $y)
    {
        if ($x->canShowName()) {
            if ($y->canShowName()) {
                return I18N::strcasecmp($x->getSortName(), $y->getSortName());
            }

            return -1; // only $y is private
        }

        if ($y->canShowName()) {
            return 1; // only $x is private
        }

        return 0; // both $x and $y private
    }

    /**
     * Get variants of the name
     *
     * @return string
     */
    public function getFullName()
    {
        if ($this->canShowName()) {
            $tmp = $this->getAllNames();

            return $tmp[$this->getPrimaryName()]['full'];
        }

        return I18N::translate('Private');
    }

    /**
     * Get a sortable version of the name. Do not display this!
     *
     * @return string
     */
    public function getSortName(): string
    {
        // The sortable name is never displayed, no need to call canShowName()
        $tmp = $this->getAllNames();

        return $tmp[$this->getPrimaryName()]['sort'];
    }

    /**
     * Get the full name in an alternative character set
     *
     * @return null|string
     */
    public function getAddName()
    {
        if ($this->canShowName() && $this->getPrimaryName() != $this->getSecondaryName()) {
            $all_names = $this->getAllNames();

            return $all_names[$this->getSecondaryName()]['full'];
        }

        return null;
    }

    /**
     * Format this object for display in a list
     *
     * @return string
     */
    public function formatList(): string
    {
        $html = '<a href="' . e($this->url()) . '" class="list_item">';
        $html .= '<b>' . $this->getFullName() . '</b>';
        $html .= $this->formatListDetails();
        $html .= '</a>';

        return $html;
    }

    /**
     * This function should be redefined in derived classes to show any major
     * identifying characteristics of this record.
     *
     * @return string
     */
    public function formatListDetails(): string
    {
        return '';
    }

    /**
     * Extract/format the first fact from a list of facts.
     *
     * @param string[] $facts
     * @param int      $style
     *
     * @return string
     */
    public function formatFirstMajorFact(array $facts, int $style): string
    {
        foreach ($this->facts($facts, true) as $event) {
            // Only display if it has a date or place (or both)
            if ($event->date()->isOK() && !$event->place()->isEmpty()) {
                $joiner = ' — ';
            } else {
                $joiner = '';
            }
            if ($event->date()->isOK() || !$event->place()->isEmpty()) {
                switch ($style) {
                    case 1:
                        return '<br><em>' . $event->label() . ' ' . FunctionsPrint::formatFactDate($event, $this, false, false) . $joiner . FunctionsPrint::formatFactPlace($event) . '</em>';
                    case 2:
                        return '<dl><dt class="label">' . $event->label() . '</dt><dd class="field">' . FunctionsPrint::formatFactDate($event, $this, false, false) . $joiner . FunctionsPrint::formatFactPlace($event) . '</dd></dl>';
                }
            }
        }

        return '';
    }

    /**
     * Find individuals linked to this record.
     *
     * @param string $link
     *
     * @return Individual[]
     */
    public function linkedIndividuals(string $link): array
    {
        $rows = Database::prepare(
            "SELECT i_id AS xref, i_gedcom AS gedcom" .
            " FROM `##individuals`" .
            " JOIN `##link` ON i_file = l_file AND i_id = l_from" .
            " LEFT JOIN `##name` ON i_file = n_file AND i_id = n_id AND n_num = 0" .
            " WHERE i_file = :tree_id AND l_type = :link AND l_to = :xref" .
            " ORDER BY n_sort COLLATE :collation"
        )->execute([
            'tree_id'   => $this->tree->id(),
            'link'      => $link,
            'xref'      => $this->xref,
            'collation' => I18N::collation(),
        ])->fetchAll();

        $list = [];
        foreach ($rows as $row) {
            $record = Individual::getInstance($row->xref, $this->tree, $row->gedcom);
            if ($record->canShowName()) {
                $list[] = $record;
            }
        }

        return $list;
    }

    /**
     * Find families linked to this record.
     *
     * @param string $link
     *
     * @return Family[]
     */
    public function linkedFamilies(string $link): array
    {
        $rows = Database::prepare(
            "SELECT f_id AS xref, f_gedcom AS gedcom" .
            " FROM `##families`" .
            " JOIN `##link` ON f_file = l_file AND f_id = l_from" .
            " LEFT JOIN `##name` ON f_file = n_file AND f_id = n_id AND n_num = 0" .
            " WHERE f_file = :tree_id AND l_type = :link AND l_to = :xref"
        )->execute([
            'tree_id' => $this->tree->id(),
            'link'    => $link,
            'xref'    => $this->xref,
        ])->fetchAll();

        $list = [];
        foreach ($rows as $row) {
            $record = Family::getInstance($row->xref, $this->tree, $row->gedcom);
            if ($record->canShowName()) {
                $list[] = $record;
            }
        }

        return $list;
    }

    /**
     * Find sources linked to this record.
     *
     * @param string $link
     *
     * @return Source[]
     */
    public function linkedSources(string $link): array
    {
        $rows = Database::prepare(
            "SELECT s_id AS xref, s_gedcom AS gedcom" .
            " FROM `##sources`" .
            " JOIN `##link` ON s_file = l_file AND s_id = l_from" .
            " WHERE s_file = :tree_id AND l_type = :link AND l_to = :xref" .
            " ORDER BY s_name COLLATE :collation"
        )->execute([
            'tree_id'   => $this->tree->id(),
            'link'      => $link,
            'xref'      => $this->xref,
            'collation' => I18N::collation(),
        ])->fetchAll();

        $list = [];
        foreach ($rows as $row) {
            $record = Source::getInstance($row->xref, $this->tree, $row->gedcom);
            if ($record->canShowName()) {
                $list[] = $record;
            }
        }

        return $list;
    }

    /**
     * Find media objects linked to this record.
     *
     * @param string $link
     *
     * @return Media[]
     */
    public function linkedMedia(string $link): array
    {
        $rows = Database::prepare(
            "SELECT m_id AS xref, m_gedcom AS gedcom" .
            " FROM `##media`" .
            " JOIN `##link` ON m_file = l_file AND m_id = l_from" .
            " WHERE m_file = :tree_id AND l_type = :link AND l_to = :xref"
        )->execute([
            'tree_id' => $this->tree->id(),
            'link'    => $link,
            'xref'    => $this->xref,
        ])->fetchAll();

        $list = [];
        foreach ($rows as $row) {
            $record = Media::getInstance($row->xref, $this->tree, $row->gedcom);
            if ($record->canShowName()) {
                $list[] = $record;
            }
        }

        return $list;
    }

    /**
     * Find notes linked to this record.
     *
     * @param string $link
     *
     * @return Note[]
     */
    public function linkedNotes(string $link): array
    {
        $rows = Database::prepare(
            "SELECT o_id AS xref, o_gedcom AS gedcom" .
            " FROM `##other`" .
            " JOIN `##link` ON o_file = l_file AND o_id = l_from" .
            " LEFT JOIN `##name` ON o_file = n_file AND o_id = n_id AND n_num = 0" .
            " WHERE o_file = :tree_id AND o_type = 'NOTE' AND l_type = :link AND l_to = :xref" .
            " ORDER BY n_sort COLLATE :collation"
        )->execute([
            'tree_id'   => $this->tree->id(),
            'link'      => $link,
            'xref'      => $this->xref,
            'collation' => I18N::collation(),
        ])->fetchAll();

        $list = [];
        foreach ($rows as $row) {
            $record = Note::getInstance($row->xref, $this->tree, $row->gedcom);
            if ($record->canShowName()) {
                $list[] = $record;
            }
        }

        return $list;
    }

    /**
     * Find repositories linked to this record.
     *
     * @param string $link
     *
     * @return Repository[]
     */
    public function linkedRepositories(string $link): array
    {
        $rows = Database::prepare(
            "SELECT o_id AS xref, o_gedcom AS gedcom" .
            " FROM `##other`" .
            " JOIN `##link` ON o_file = l_file AND o_id = l_from" .
            " LEFT JOIN `##name` ON o_file = n_file AND o_id = n_id AND n_num = 0" .
            " WHERE o_file = :tree_id AND o_type = 'REPO' AND l_type = :link AND l_to = :xref" .
            " ORDER BY n_sort COLLATE :collation"
        )->execute([
            'tree_id'   => $this->tree->id(),
            'link'      => $link,
            'xref'      => $this->xref,
            'collation' => I18N::collation(),
        ])->fetchAll();

        $list = [];
        foreach ($rows as $row) {
            $record = Repository::getInstance($row->xref, $this->tree, $row->gedcom);
            if ($record->canShowName()) {
                $list[] = $record;
            }
        }

        return $list;
    }

    /**
     * Get all attributes (e.g. DATE or PLAC) from an event (e.g. BIRT or MARR).
     * This is used to display multiple events on the individual/family lists.
     * Multiple events can exist because of uncertainty in dates, dates in different
     * calendars, place-names in both latin and hebrew character sets, etc.
     * It also allows us to combine dates/places from different events in the summaries.
     *
     * @param string[] $events
     *
     * @return Date[]
     */
    public function getAllEventDates(array $events): array
    {
        $dates = [];
        foreach ($this->facts($events) as $event) {
            if ($event->date()->isOK()) {
                $dates[] = $event->date();
            }
        }

        return $dates;
    }

    /**
     * Get all the places for a particular type of event
     *
     * @param string[] $events
     *
     * @return Place[]
     */
    public function getAllEventPlaces(array $events): array
    {
        $places = [];
        foreach ($this->facts($events) as $event) {
            if (preg_match_all('/\n(?:2 PLAC|3 (?:ROMN|FONE|_HEB)) +(.+)/', $event->gedcom(), $ged_places)) {
                foreach ($ged_places[1] as $ged_place) {
                    $places[] = new Place($ged_place, $this->tree);
                }
            }
        }

        return $places;
    }

    /**
     * Get the first (i.e. prefered) Fact for the given fact type
     *
     * @param string $tag
     *
     * @return Fact|null
     */
    public function getFirstFact(string $tag)
    {
        foreach ($this->facts() as $fact) {
            if ($fact->getTag() === $tag) {
                return $fact;
            }
        }

        return null;
    }

    /**
     * The facts and events for this record.
     *
     * @param string[] $filter
     * @param bool     $sort
     * @param int|null $access_level
     * @param bool     $override Include private records, to allow us to implement $SHOW_PRIVATE_RELATIONSHIPS and $SHOW_LIVING_NAMES.
     *
     * @return Fact[]
     */
    public function facts(array $filter = [], bool $sort = false, int $access_level = null, bool $override = false): array
    {
        if ($access_level === null) {
            $access_level = Auth::accessLevel($this->tree);
        }

        $facts = [];
        if ($this->canShow($access_level) || $override) {
            foreach ($this->facts as $fact) {
                if (($filter === [] || in_array($fact->getTag(), $filter)) && $fact->canShow($access_level)) {
                    $facts[] = $fact;
                }
            }
        }

        if ($sort) {
            Functions::sortFacts($facts);
        }

        return $facts;
    }

    /**
     * Get the last-change timestamp for this record, either as a formatted string
     * (for display) or as a unix timestamp (for sorting)
     *
     * @param bool $sorting
     *
     * @return string|int
     */
    public function lastChangeTimestamp(bool $sorting = false)
    {
        $chan = $this->getFirstFact('CHAN');

        if ($chan) {
            // The record does have a CHAN event
            $d = $chan->date()->minimumDate();
            if (preg_match('/\n3 TIME (\d\d):(\d\d):(\d\d)/', $chan->gedcom(), $match)) {
                $t = mktime((int) $match[1], (int) $match[2], (int) $match[3], (int) $d->format('%n'), (int) $d->format('%j'), (int) $d->format('%Y'));
            } elseif (preg_match('/\n3 TIME (\d\d):(\d\d)/', $chan->gedcom(), $match)) {
                $t = mktime((int) $match[1], (int) $match[2], 0, (int) $d->format('%n'), (int) $d->format('%j'), (int) $d->format('%Y'));
            } else {
                $t = mktime(0, 0, 0, (int) $d->format('%n'), (int) $d->format('%j'), (int) $d->format('%Y'));
            }
            if ($sorting) {
                return $t;
            }

            return strip_tags(FunctionsDate::formatTimestamp($t));
        }

        // The record does not have a CHAN event
        if ($sorting) {
            return '0';
        }

        return '';
    }

    /**
     * Get the last-change user for this record
     *
     * @return string
     */
    public function lastChangeUser()
    {
        $chan = $this->getFirstFact('CHAN');

        if ($chan === null) {
            return I18N::translate('Unknown');
        }

        $chan_user = $chan->attribute('_WT_USER');
        if ($chan_user === '') {
            return I18N::translate('Unknown');
        }

        return $chan_user;
    }

    /**
     * Add a new fact to this record
     *
     * @param string $gedcom
     * @param bool   $update_chan
     *
     * @return void
     */
    public function createFact(string $gedcom, bool $update_chan)
    {
        $this->updateFact('', $gedcom, $update_chan);
    }

    /**
     * Delete a fact from this record
     *
     * @param string $fact_id
     * @param bool   $update_chan
     *
     * @return void
     */
    public function deleteFact(string $fact_id, bool $update_chan)
    {
        $this->updateFact($fact_id, '', $update_chan);
    }

    /**
     * Replace a fact with a new gedcom data.
     *
     * @param string $fact_id
     * @param string $gedcom
     * @param bool   $update_chan
     *
     * @return void
     * @throws Exception
     */
    public function updateFact(string $fact_id, string $gedcom, bool $update_chan)
    {
        // MSDOS line endings will break things in horrible ways
        $gedcom = preg_replace('/[\r\n]+/', "\n", $gedcom);
        $gedcom = trim($gedcom);

        if ($this->pending === '') {
            throw new Exception('Cannot edit a deleted record');
        }
        if ($gedcom !== '' && !preg_match('/^1 ' . Gedcom::REGEX_TAG . '/', $gedcom)) {
            throw new Exception('Invalid GEDCOM data passed to GedcomRecord::updateFact(' . $gedcom . ')');
        }

        if ($this->pending) {
            $old_gedcom = $this->pending;
        } else {
            $old_gedcom = $this->gedcom;
        }

        // First line of record may contain data - e.g. NOTE records.
        [$new_gedcom] = explode("\n", $old_gedcom, 2);

        // Replacing (or deleting) an existing fact
        foreach ($this->facts([], false, Auth::PRIV_HIDE) as $fact) {
            if (!$fact->isPendingDeletion()) {
                if ($fact->id() === $fact_id) {
                    if ($gedcom !== '') {
                        $new_gedcom .= "\n" . $gedcom;
                    }
                    $fact_id = 'NOT A VALID FACT ID'; // Only replace/delete one copy of a duplicate fact
                } elseif ($fact->getTag() != 'CHAN' || !$update_chan) {
                    $new_gedcom .= "\n" . $fact->gedcom();
                }
            }
        }
        if ($update_chan) {
            $new_gedcom .= "\n1 CHAN\n2 DATE " . strtoupper(date('d M Y')) . "\n3 TIME " . date('H:i:s') . "\n2 _WT_USER " . Auth::user()->getUserName();
        }

        // Adding a new fact
        if ($fact_id === '') {
            $new_gedcom .= "\n" . $gedcom;
        }

        if ($new_gedcom != $old_gedcom) {
            // Save the changes
            DB::table('change')->insert([
                'gedcom_id'  => $this->tree->id(),
                'xref'       => $this->xref,
                'old_gedcom' => $old_gedcom,
                'new_gedcom' => $new_gedcom,
                'user_id'    => Auth::id(),
            ]);

            $this->pending = $new_gedcom;

            if (Auth::user()->getPreference('auto_accept')) {
                FunctionsImport::acceptAllChanges($this->xref, $this->tree);
                $this->gedcom  = $new_gedcom;
                $this->pending = null;
            }
        }
        $this->parseFacts();
    }

    /**
     * Update this record
     *
     * @param string $gedcom
     * @param bool   $update_chan
     *
     * @return void
     */
    public function updateRecord(string $gedcom, bool $update_chan)
    {
        // MSDOS line endings will break things in horrible ways
        $gedcom = preg_replace('/[\r\n]+/', "\n", $gedcom);
        $gedcom = trim($gedcom);

        // Update the CHAN record
        if ($update_chan) {
            $gedcom = preg_replace('/\n1 CHAN(\n[2-9].*)*/', '', $gedcom);
            $gedcom .= "\n1 CHAN\n2 DATE " . date('d M Y') . "\n3 TIME " . date('H:i:s') . "\n2 _WT_USER " . Auth::user()->getUserName();
        }

        // Create a pending change
        DB::table('change')->insert([
            'gedcom_id'  => $this->tree->id(),
            'xref'       => $this->xref,
            'old_gedcom' => $this->gedcom(),
            'new_gedcom' => $gedcom,
            'user_id'    => Auth::id(),
        ]);

        // Clear the cache
        $this->pending = $gedcom;

        // Accept this pending change
        if (Auth::user()->getPreference('auto_accept')) {
            FunctionsImport::acceptAllChanges($this->xref, $this->tree);
            $this->gedcom  = $gedcom;
            $this->pending = null;
        }

        $this->parseFacts();

        Log::addEditLog('Update: ' . static::RECORD_TYPE . ' ' . $this->xref, $this->tree);
    }

    /**
     * Delete this record
     *
     * @return void
     */
    public function deleteRecord()
    {
        // Create a pending change
        if (!$this->isPendingDeletion()) {
            DB::table('change')->insert([
                'gedcom_id'  => $this->tree->id(),
                'xref'       => $this->xref,
                'old_gedcom' => $this->gedcom(),
                'new_gedcom' => '',
                'user_id'    => Auth::id(),
            ]);
        }

        // Auto-accept this pending change
        if (Auth::user()->getPreference('auto_accept')) {
            FunctionsImport::acceptAllChanges($this->xref, $this->tree);
        }

        // Clear the cache
        self::$gedcom_record_cache  = [];
        self::$pending_record_cache = [];

        Log::addEditLog('Delete: ' . static::RECORD_TYPE . ' ' . $this->xref, $this->tree);
    }

    /**
     * Remove all links from this record to $xref
     *
     * @param string $xref
     * @param bool   $update_chan
     *
     * @return void
     */
    public function removeLinks(string $xref, bool $update_chan)
    {
        $value = '@' . $xref . '@';

        foreach ($this->facts() as $fact) {
            if ($fact->value() === $value) {
                $this->deleteFact($fact->id(), $update_chan);
            } elseif (preg_match_all('/\n(\d) ' . Gedcom::REGEX_TAG . ' ' . $value . '/', $fact->gedcom(), $matches, PREG_SET_ORDER)) {
                $gedcom = $fact->gedcom();
                foreach ($matches as $match) {
                    $next_level  = $match[1] + 1;
                    $next_levels = '[' . $next_level . '-9]';
                    $gedcom      = preg_replace('/' . $match[0] . '(\n' . $next_levels . '.*)*/', '', $gedcom);
                }
                $this->updateFact($fact->id(), $gedcom, $update_chan);
            }
        }
    }

    /**
     * Fetch XREFs of all records linked to a record - when deleting an object, we must
     * also delete all links to it.
     *
     * @return GedcomRecord[]
     */
    public function linkingRecords(): array
    {
        $union = DB::table('change')
            ->where('gedcom_id', '=', $this->tree()->id())
            ->where('new_gedcom', 'LIKE', '%@' . $this->xref() . '@%')
            ->where('new_gedcom', 'NOT LIKE', '0 @' . $this->xref() . '@%')
            ->select(['xref']);

        $xrefs = DB::table('link')
            ->where('l_file', '=', $this->tree()->id())
            ->where('l_to', '=', $this->xref())
            ->select('l_from')
            ->union($union)
            ->pluck('l_from');

        return $xrefs->map(function (string $xref): GedcomRecord {
            return GedcomRecord::getInstance($xref, $this->tree);
        })->all();
    }
}