<?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 Closure;
use Fisharebest\Flysystem\Adapter\ChrootAdapter;
use Fisharebest\Webtrees\Contracts\UserInterface;
use Fisharebest\Webtrees\Functions\FunctionsExport;
use Fisharebest\Webtrees\Services\PendingChangesService;
use Illuminate\Database\Capsule\Manager as DB;
use Illuminate\Database\Query\Expression;
use Illuminate\Support\Collection;
use Illuminate\Support\Str;
use InvalidArgumentException;
use League\Flysystem\Filesystem;
use League\Flysystem\FilesystemInterface;
use Psr\Http\Message\StreamInterface;
use stdClass;

use function app;

/**
 * Provide an interface to the wt_gedcom table.
 */
class Tree
{
    private const RESN_PRIVACY = [
        'none'         => Auth::PRIV_PRIVATE,
        'privacy'      => Auth::PRIV_USER,
        'confidential' => Auth::PRIV_NONE,
        'hidden'       => Auth::PRIV_HIDE,
    ];

    /** @var int The tree's ID number */
    private $id;

    /** @var string The tree's name */
    private $name;

    /** @var string The tree's title */
    private $title;

    /** @var int[] Default access rules for facts in this tree */
    private $fact_privacy;

    /** @var int[] Default access rules for individuals in this tree */
    private $individual_privacy;

    /** @var integer[][] Default access rules for individual facts in this tree */
    private $individual_fact_privacy;

    /** @var string[] Cached copy of the wt_gedcom_setting table. */
    private $preferences = [];

    /** @var string[][] Cached copy of the wt_user_gedcom_setting table. */
    private $user_preferences = [];

    /**
     * Create a tree object.
     *
     * @param int    $id
     * @param string $name
     * @param string $title
     */
    public function __construct(int $id, string $name, string $title)
    {
        $this->id                      = $id;
        $this->name                    = $name;
        $this->title                   = $title;
        $this->fact_privacy            = [];
        $this->individual_privacy      = [];
        $this->individual_fact_privacy = [];

        // Load the privacy settings for this tree
        $rows = DB::table('default_resn')
            ->where('gedcom_id', '=', $this->id)
            ->get();

        foreach ($rows as $row) {
            // Convert GEDCOM privacy restriction to a webtrees access level.
            $row->resn = self::RESN_PRIVACY[$row->resn];

            if ($row->xref !== null) {
                if ($row->tag_type !== null) {
                    $this->individual_fact_privacy[$row->xref][$row->tag_type] = $row->resn;
                } else {
                    $this->individual_privacy[$row->xref] = $row->resn;
                }
            } else {
                $this->fact_privacy[$row->tag_type] = $row->resn;
            }
        }
    }

    /**
     * A closure which will create a record from a database row.
     *
     * @return Closure
     */
    public static function rowMapper(): Closure
    {
        return static function (stdClass $row): Tree {
            return new Tree((int) $row->tree_id, $row->tree_name, $row->tree_title);
        };
    }

    /**
     * Set the tree’s configuration settings.
     *
     * @param string $setting_name
     * @param string $setting_value
     *
     * @return $this
     */
    public function setPreference(string $setting_name, string $setting_value): Tree
    {
        if ($setting_value !== $this->getPreference($setting_name)) {
            DB::table('gedcom_setting')->updateOrInsert([
                'gedcom_id'    => $this->id,
                'setting_name' => $setting_name,
            ], [
                'setting_value' => $setting_value,
            ]);

            $this->preferences[$setting_name] = $setting_value;

            Log::addConfigurationLog('Tree preference "' . $setting_name . '" set to "' . $setting_value . '"', $this);
        }

        return $this;
    }

    /**
     * Get the tree’s configuration settings.
     *
     * @param string $setting_name
     * @param string $default
     *
     * @return string
     */
    public function getPreference(string $setting_name, string $default = ''): string
    {
        if ($this->preferences === []) {
            $this->preferences = DB::table('gedcom_setting')
                ->where('gedcom_id', '=', $this->id)
                ->pluck('setting_value', 'setting_name')
                ->all();
        }

        return $this->preferences[$setting_name] ?? $default;
    }

    /**
     * The name of this tree
     *
     * @return string
     */
    public function name(): string
    {
        return $this->name;
    }

    /**
     * The title of this tree
     *
     * @return string
     */
    public function title(): string
    {
        return $this->title;
    }

    /**
     * The fact-level privacy for this tree.
     *
     * @return int[]
     */
    public function getFactPrivacy(): array
    {
        return $this->fact_privacy;
    }

    /**
     * The individual-level privacy for this tree.
     *
     * @return int[]
     */
    public function getIndividualPrivacy(): array
    {
        return $this->individual_privacy;
    }

    /**
     * The individual-fact-level privacy for this tree.
     *
     * @return int[][]
     */
    public function getIndividualFactPrivacy(): array
    {
        return $this->individual_fact_privacy;
    }

    /**
     * Set the tree’s user-configuration settings.
     *
     * @param UserInterface $user
     * @param string        $setting_name
     * @param string        $setting_value
     *
     * @return $this
     */
    public function setUserPreference(UserInterface $user, string $setting_name, string $setting_value): Tree
    {
        if ($this->getUserPreference($user, $setting_name) !== $setting_value) {
            // Update the database
            DB::table('user_gedcom_setting')->updateOrInsert([
                'gedcom_id'    => $this->id(),
                'user_id'      => $user->id(),
                'setting_name' => $setting_name,
            ], [
                'setting_value' => $setting_value,
            ]);

            // Update the cache
            $this->user_preferences[$user->id()][$setting_name] = $setting_value;
            // Audit log of changes
            Log::addConfigurationLog('Tree preference "' . $setting_name . '" set to "' . $setting_value . '" for user "' . $user->userName() . '"', $this);
        }

        return $this;
    }

    /**
     * Get the tree’s user-configuration settings.
     *
     * @param UserInterface $user
     * @param string        $setting_name
     * @param string        $default
     *
     * @return string
     */
    public function getUserPreference(UserInterface $user, string $setting_name, string $default = ''): string
    {
        // There are lots of settings, and we need to fetch lots of them on every page
        // so it is quicker to fetch them all in one go.
        if (!array_key_exists($user->id(), $this->user_preferences)) {
            $this->user_preferences[$user->id()] = DB::table('user_gedcom_setting')
                ->where('user_id', '=', $user->id())
                ->where('gedcom_id', '=', $this->id)
                ->pluck('setting_value', 'setting_name')
                ->all();
        }

        return $this->user_preferences[$user->id()][$setting_name] ?? $default;
    }

    /**
     * The ID of this tree
     *
     * @return int
     */
    public function id(): int
    {
        return $this->id;
    }

    /**
     * Can a user accept changes for this tree?
     *
     * @param UserInterface $user
     *
     * @return bool
     */
    public function canAcceptChanges(UserInterface $user): bool
    {
        return Auth::isModerator($this, $user);
    }

    /**
     * Are there any pending edits for this tree, than need reviewing by a moderator.
     *
     * @return bool
     */
    public function hasPendingEdit(): bool
    {
        return DB::table('change')
            ->where('gedcom_id', '=', $this->id)
            ->where('status', '=', 'pending')
            ->exists();
    }

    /**
     * Delete everything relating to a tree
     *
     * @return void
     */
    public function delete(): void
    {
        // If this is the default tree, then unset it
        if (Site::getPreference('DEFAULT_GEDCOM') === $this->name) {
            Site::setPreference('DEFAULT_GEDCOM', '');
        }

        $this->deleteGenealogyData(false);

        DB::table('block_setting')
            ->join('block', 'block.block_id', '=', 'block_setting.block_id')
            ->where('gedcom_id', '=', $this->id)
            ->delete();
        DB::table('block')->where('gedcom_id', '=', $this->id)->delete();
        DB::table('user_gedcom_setting')->where('gedcom_id', '=', $this->id)->delete();
        DB::table('gedcom_setting')->where('gedcom_id', '=', $this->id)->delete();
        DB::table('module_privacy')->where('gedcom_id', '=', $this->id)->delete();
        DB::table('hit_counter')->where('gedcom_id', '=', $this->id)->delete();
        DB::table('default_resn')->where('gedcom_id', '=', $this->id)->delete();
        DB::table('gedcom_chunk')->where('gedcom_id', '=', $this->id)->delete();
        DB::table('log')->where('gedcom_id', '=', $this->id)->delete();
        DB::table('gedcom')->where('gedcom_id', '=', $this->id)->delete();
    }

    /**
     * Delete all the genealogy data from a tree - in preparation for importing
     * new data. Optionally retain the media data, for when the user has been
     * editing their data offline using an application which deletes (or does not
     * support) media data.
     *
     * @param bool $keep_media
     *
     * @return void
     */
    public function deleteGenealogyData(bool $keep_media): void
    {
        DB::table('gedcom_chunk')->where('gedcom_id', '=', $this->id)->delete();
        DB::table('individuals')->where('i_file', '=', $this->id)->delete();
        DB::table('families')->where('f_file', '=', $this->id)->delete();
        DB::table('sources')->where('s_file', '=', $this->id)->delete();
        DB::table('other')->where('o_file', '=', $this->id)->delete();
        DB::table('places')->where('p_file', '=', $this->id)->delete();
        DB::table('placelinks')->where('pl_file', '=', $this->id)->delete();
        DB::table('name')->where('n_file', '=', $this->id)->delete();
        DB::table('dates')->where('d_file', '=', $this->id)->delete();
        DB::table('change')->where('gedcom_id', '=', $this->id)->delete();

        if ($keep_media) {
            DB::table('link')->where('l_file', '=', $this->id)
                ->where('l_type', '<>', 'OBJE')
                ->delete();
        } else {
            DB::table('link')->where('l_file', '=', $this->id)->delete();
            DB::table('media_file')->where('m_file', '=', $this->id)->delete();
            DB::table('media')->where('m_file', '=', $this->id)->delete();
        }
    }

    /**
     * Export the tree to a GEDCOM file
     *
     * @param resource $stream
     *
     * @return void
     */
    public function exportGedcom($stream): void
    {
        $buffer = FunctionsExport::reformatRecord(FunctionsExport::gedcomHeader($this, 'UTF-8'));

        $union_families = DB::table('families')
            ->where('f_file', '=', $this->id)
            ->select(['f_gedcom AS gedcom', 'f_id AS xref', new Expression('LENGTH(f_id) AS len'), new Expression('2 AS n')]);

        $union_sources = DB::table('sources')
            ->where('s_file', '=', $this->id)
            ->select(['s_gedcom AS gedcom', 's_id AS xref', new Expression('LENGTH(s_id) AS len'), new Expression('3 AS n')]);

        $union_other = DB::table('other')
            ->where('o_file', '=', $this->id)
            ->whereNotIn('o_type', ['HEAD', 'TRLR'])
            ->select(['o_gedcom AS gedcom', 'o_id AS xref', new Expression('LENGTH(o_id) AS len'), new Expression('4 AS n')]);

        $union_media = DB::table('media')
            ->where('m_file', '=', $this->id)
            ->select(['m_gedcom AS gedcom', 'm_id AS xref', new Expression('LENGTH(m_id) AS len'), new Expression('5 AS n')]);

        DB::table('individuals')
            ->where('i_file', '=', $this->id)
            ->select(['i_gedcom AS gedcom', 'i_id AS xref', new Expression('LENGTH(i_id) AS len'), new Expression('1 AS n')])
            ->union($union_families)
            ->union($union_sources)
            ->union($union_other)
            ->union($union_media)
            ->orderBy('n')
            ->orderBy('len')
            ->orderBy('xref')
            ->chunk(1000, static function (Collection $rows) use ($stream, &$buffer): void {
                foreach ($rows as $row) {
                    $buffer .= FunctionsExport::reformatRecord($row->gedcom);
                    if (strlen($buffer) > 65535) {
                        fwrite($stream, $buffer);
                        $buffer = '';
                    }
                }
            });

        fwrite($stream, $buffer . '0 TRLR' . Gedcom::EOL);
    }

    /**
     * Import data from a gedcom file into this tree.
     *
     * @param StreamInterface $stream   The GEDCOM file.
     * @param string          $filename The preferred filename, for export/download.
     *
     * @return void
     */
    public function importGedcomFile(StreamInterface $stream, string $filename): void
    {
        // Read the file in blocks of roughly 64K. Ensure that each block
        // contains complete gedcom records. This will ensure we don’t split
        // multi-byte characters, as well as simplifying the code to import
        // each block.

        $file_data = '';

        $this->deleteGenealogyData((bool) $this->getPreference('keep_media'));
        $this->setPreference('gedcom_filename', $filename);
        $this->setPreference('imported', '0');

        while (!$stream->eof()) {
            $file_data .= $stream->read(65536);
            // There is no strrpos() function that searches for substrings :-(
            for ($pos = strlen($file_data) - 1; $pos > 0; --$pos) {
                if ($file_data[$pos] === '0' && ($file_data[$pos - 1] === "\n" || $file_data[$pos - 1] === "\r")) {
                    // We’ve found the last record boundary in this chunk of data
                    break;
                }
            }
            if ($pos) {
                DB::table('gedcom_chunk')->insert([
                    'gedcom_id'  => $this->id,
                    'chunk_data' => substr($file_data, 0, $pos),
                ]);

                $file_data = substr($file_data, $pos);
            }
        }
        DB::table('gedcom_chunk')->insert([
            'gedcom_id'  => $this->id,
            'chunk_data' => $file_data,
        ]);

        $stream->close();
    }

    /**
     * Create a new record from GEDCOM data.
     *
     * @param string $gedcom
     *
     * @return GedcomRecord|Individual|Family|Note|Source|Repository|Media
     * @throws InvalidArgumentException
     */
    public function createRecord(string $gedcom): GedcomRecord
    {
        if (!Str::startsWith($gedcom, '0 @@ ')) {
            throw new InvalidArgumentException('GedcomRecord::createRecord(' . $gedcom . ') does not begin 0 @@');
        }

        $xref   = $this->getNewXref();
        $gedcom = '0 @' . $xref . '@ ' . Str::after($gedcom, '0 @@ ');

        // Create a change record
        $gedcom .= "\n1 CHAN\n2 DATE " . date('d M Y') . "\n3 TIME " . date('H:i:s') . "\n2 _WT_USER " . Auth::user()->userName();

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

        // Accept this pending change
        if (Auth::user()->getPreference(User::PREF_AUTO_ACCEPT_EDITS)) {
            $record = new GedcomRecord($xref, $gedcom, null, $this);
            
            app(PendingChangesService::class)->acceptRecord($record);

            return $record;
        }

        return GedcomRecord::getInstance($xref, $this, $gedcom);
    }

    /**
     * Generate a new XREF, unique across all family trees
     *
     * @return string
     */
    public function getNewXref(): string
    {
        // Lock the row, so that only one new XREF may be generated at a time.
        DB::table('site_setting')
            ->where('setting_name', '=', 'next_xref')
            ->lockForUpdate()
            ->get();

        $prefix = 'X';

        $increment = 1.0;
        do {
            $num = (int) Site::getPreference('next_xref') + (int) $increment;

            // This exponential increment allows us to scan over large blocks of
            // existing data in a reasonable time.
            $increment *= 1.01;

            $xref = $prefix . $num;

            // Records may already exist with this sequence number.
            $already_used =
                DB::table('individuals')->where('i_id', '=', $xref)->exists() ||
                DB::table('families')->where('f_id', '=', $xref)->exists() ||
                DB::table('sources')->where('s_id', '=', $xref)->exists() ||
                DB::table('media')->where('m_id', '=', $xref)->exists() ||
                DB::table('other')->where('o_id', '=', $xref)->exists() ||
                DB::table('change')->where('xref', '=', $xref)->exists();
        } while ($already_used);

        Site::setPreference('next_xref', (string) $num);

        return $xref;
    }

    /**
     * Create a new family from GEDCOM data.
     *
     * @param string $gedcom
     *
     * @return Family
     * @throws InvalidArgumentException
     */
    public function createFamily(string $gedcom): GedcomRecord
    {
        if (!Str::startsWith($gedcom, '0 @@ FAM')) {
            throw new InvalidArgumentException('GedcomRecord::createFamily(' . $gedcom . ') does not begin 0 @@ FAM');
        }

        $xref   = $this->getNewXref();
        $gedcom = '0 @' . $xref . '@ FAM' . Str::after($gedcom, '0 @@ FAM');

        // Create a change record
        $gedcom .= "\n1 CHAN\n2 DATE " . date('d M Y') . "\n3 TIME " . date('H:i:s') . "\n2 _WT_USER " . Auth::user()->userName();

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

        // Accept this pending change
        if (Auth::user()->getPreference(User::PREF_AUTO_ACCEPT_EDITS) === '1') {
            $record = new Family($xref, $gedcom, null, $this);

            app(PendingChangesService::class)->acceptRecord($record);

            return $record;
        }

        return new Family($xref, '', $gedcom, $this);
    }

    /**
     * Create a new individual from GEDCOM data.
     *
     * @param string $gedcom
     *
     * @return Individual
     * @throws InvalidArgumentException
     */
    public function createIndividual(string $gedcom): GedcomRecord
    {
        if (!Str::startsWith($gedcom, '0 @@ INDI')) {
            throw new InvalidArgumentException('GedcomRecord::createIndividual(' . $gedcom . ') does not begin 0 @@ INDI');
        }

        $xref   = $this->getNewXref();
        $gedcom = '0 @' . $xref . '@ INDI' . Str::after($gedcom, '0 @@ INDI');

        // Create a change record
        $gedcom .= "\n1 CHAN\n2 DATE " . date('d M Y') . "\n3 TIME " . date('H:i:s') . "\n2 _WT_USER " . Auth::user()->userName();

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

        // Accept this pending change
        if (Auth::user()->getPreference(User::PREF_AUTO_ACCEPT_EDITS) === '1') {
            $record = new Individual($xref, $gedcom, null, $this);

            app(PendingChangesService::class)->acceptRecord($record);

            return $record;
        }

        return new Individual($xref, '', $gedcom, $this);
    }

    /**
     * Create a new media object from GEDCOM data.
     *
     * @param string $gedcom
     *
     * @return Media
     * @throws InvalidArgumentException
     */
    public function createMediaObject(string $gedcom): Media
    {
        if (!Str::startsWith($gedcom, '0 @@ OBJE')) {
            throw new InvalidArgumentException('GedcomRecord::createIndividual(' . $gedcom . ') does not begin 0 @@ OBJE');
        }

        $xref   = $this->getNewXref();
        $gedcom = '0 @' . $xref . '@ OBJE' . Str::after($gedcom, '0 @@ OBJE');

        // Create a change record
        $gedcom .= "\n1 CHAN\n2 DATE " . date('d M Y') . "\n3 TIME " . date('H:i:s') . "\n2 _WT_USER " . Auth::user()->userName();

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

        // Accept this pending change
        if (Auth::user()->getPreference(User::PREF_AUTO_ACCEPT_EDITS) === '1') {
            $record = new Media($xref, $gedcom, null, $this);

            app(PendingChangesService::class)->acceptRecord($record);

            return $record;
        }

        return new Media($xref, '', $gedcom, $this);
    }

    /**
     * What is the most significant individual in this tree.
     *
     * @param UserInterface $user
     * @param string        $xref
     *
     * @return Individual
     */
    public function significantIndividual(UserInterface $user, $xref = ''): Individual
    {
        if ($xref === '') {
            $individual = null;
        } else {
            $individual = Individual::getInstance($xref, $this);

            if ($individual === null) {
                $family = Family::getInstance($xref, $this);

                if ($family instanceof Family) {
                    $individual = $family->spouses()->first() ?? $family->children()->first();
                }
            }
        }

        if ($this->getUserPreference($user, User::PREF_TREE_DEFAULT_XREF) !== '') {
            $individual = Individual::getInstance($this->getUserPreference($user, User::PREF_TREE_DEFAULT_XREF), $this);
        }

        if ($individual === null && $this->getUserPreference($user, User::PREF_TREE_ACCOUNT_XREF) !== '') {
            $individual = Individual::getInstance($this->getUserPreference($user, User::PREF_TREE_ACCOUNT_XREF), $this);
        }

        if ($individual === null && $this->getPreference('PEDIGREE_ROOT_ID') !== '') {
            $individual = Individual::getInstance($this->getPreference('PEDIGREE_ROOT_ID'), $this);
        }
        if ($individual === null) {
            $xref = (string) DB::table('individuals')
                ->where('i_file', '=', $this->id())
                ->min('i_id');

            $individual = Individual::getInstance($xref, $this);
        }
        if ($individual === null) {
            // always return a record
            $individual = new Individual('I', '0 @I@ INDI', null, $this);
        }

        return $individual;
    }

    /**
     * Where do we store our media files.
     *
     * @param FilesystemInterface $data_filesystem
     *
     * @return FilesystemInterface
     */
    public function mediaFilesystem(FilesystemInterface $data_filesystem): FilesystemInterface
    {
        $media_dir = $this->getPreference('MEDIA_DIRECTORY', 'media/');
        $adapter   = new ChrootAdapter($data_filesystem, $media_dir);

        return new Filesystem($adapter);
    }
}
