<?php

/**
 * webtrees: online genealogy
 * Copyright (C) 2026 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 <https://www.gnu.org/licenses/>.
 */

declare(strict_types=1);

namespace Fisharebest\Webtrees\Services;

use Fisharebest\Webtrees\Auth;
use Fisharebest\Webtrees\DB;
use Fisharebest\Webtrees\Encodings\UTF16BE;
use Fisharebest\Webtrees\Encodings\UTF16LE;
use Fisharebest\Webtrees\Encodings\UTF8;
use Fisharebest\Webtrees\Encodings\Windows1252;
use Fisharebest\Webtrees\Factories\AbstractGedcomRecordFactory;
use Fisharebest\Webtrees\Gedcom;
use Fisharebest\Webtrees\GedcomFilters\GedcomEncodingFilter;
use Fisharebest\Webtrees\GedcomRecord;
use Fisharebest\Webtrees\Header;
use Fisharebest\Webtrees\Registry;
use Fisharebest\Webtrees\Site;
use Fisharebest\Webtrees\Tree;
use Fisharebest\Webtrees\Webtrees;
use Illuminate\Database\Query\Builder;
use Illuminate\Database\Query\Expression;
use Illuminate\Support\Collection;
use League\Flysystem\Filesystem;
use League\Flysystem\FilesystemOperator;
use Psr\Http\Message\ResponseFactoryInterface;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\StreamFactoryInterface;
use RuntimeException;
use ZipArchive;

use function addcslashes;
use function date;
use function explode;
use function fclose;
use function fopen;
use function fwrite;
use function is_string;
use function pathinfo;
use function preg_match_all;
use function rewind;
use function stream_filter_append;
use function stream_get_meta_data;
use function strlen;
use function strpos;
use function strtolower;
use function strtoupper;
use function tmpfile;

use const PATHINFO_EXTENSION;
use const PREG_SET_ORDER;
use const STREAM_FILTER_WRITE;

/**
 * Export data in GEDCOM format
 */
class GedcomExportService
{
    private const array ACCESS_LEVELS = [
        'gedadmin' => Auth::PRIV_NONE,
        'user'     => Auth::PRIV_USER,
        'visitor'  => Auth::PRIV_PRIVATE,
        'none'     => Auth::PRIV_HIDE,
    ];

    public function __construct(
        private readonly ResponseFactoryInterface $response_factory,
        private readonly StreamFactoryInterface $stream_factory,
    ) {
    }

    /**
     * @param Tree                                            $tree         Export data from this tree
     * @param bool                                            $sort_by_xref Write GEDCOM records in XREF order
     * @param string                                          $encoding     Convert from UTF-8 to other encoding
     * @param string                                          $privacy      Filter records by role
     * @param string                                          $line_endings CRLF or LF
     * @param string                                          $filename     Name of download file, without an extension
     * @param string                                          $format       One of: gedcom, zip, zipmedia, gedzip
     * @param Collection<int,string|object|GedcomRecord>|null $records
     */
    public function downloadResponse(
        Tree $tree,
        bool $sort_by_xref,
        string $encoding,
        string $privacy,
        string $line_endings,
        string $filename,
        string $format,
        Collection|null $records = null
    ): ResponseInterface {
        $access_level = self::ACCESS_LEVELS[$privacy];

        if ($format === 'gedcom') {
            $resource = $this->export($tree, $sort_by_xref, $encoding, $access_level, $line_endings, $records);
            $stream   = $this->stream_factory->createStreamFromResource($resource);

            return $this->response_factory->createResponse()
                ->withBody($stream)
                ->withHeader('content-type', 'text/x-gedcom; charset=' . UTF8::NAME)
                ->withHeader('content-disposition', 'attachment; filename="' . addcslashes($filename, '"') . '.ged"');
        }

        // Create a new/empty .ZIP file
        $temp_zip_file  = stream_get_meta_data(tmpfile())['uri'];
        $zip_filesystem = new ZipArchive();
        $zip_filesystem->open($temp_zip_file, ZipArchive::CREATE | ZipArchive::OVERWRITE);

        if ($format === 'zipmedia') {
            $media_path = $tree->mediaFolder();
        } elseif ($format === 'gedzip') {
            $media_path = '';
        } else {
            // Don't add media
            $media_path = null;
        }

        $resource = $this->export($tree, $sort_by_xref, $encoding, $access_level, $line_endings, $records, $zip_filesystem, $media_path);

        if ($format === 'gedzip') {
            $zip_filesystem->addFromString('gedcom.ged', stream_get_contents($resource));
            $extension = '.gdz';
        } else {
            $zip_filesystem->addFromString($filename . '.ged', stream_get_contents($resource));
            $extension = '.zip';
        }

        fclose($resource);

        $zip_filesystem->close();

        $stream = $this->stream_factory->createStreamFromFile($temp_zip_file);

        return $this->response_factory->createResponse()
            ->withBody($stream)
            ->withHeader('content-type', 'application/zip')
            ->withHeader('content-disposition', 'attachment; filename="' . addcslashes($filename, '"') . $extension . '"');
    }

    /**
     * Write GEDCOM data to a stream.
     *
     * @param Tree                                            $tree           Export data from this tree
     * @param bool                                            $sort_by_xref   Write GEDCOM records in XREF order
     * @param string                                          $encoding       Convert from UTF-8 to other encoding
     * @param int                                             $access_level   Apply privacy filtering
     * @param string                                          $line_endings   CRLF or LF
     * @param Collection<int,string|object|GedcomRecord>|null $records        Just export these records
     * @param ZipArchive|FilesystemOperator|null              $zip_filesystem Write media files to this filesystem
     * @param string|null                                     $media_path     Location within the zip filesystem
     *
     * @return resource
     */
    public function export(
        Tree $tree,
        bool $sort_by_xref = false,
        string $encoding = UTF8::NAME,
        int $access_level = Auth::PRIV_HIDE,
        string $line_endings = 'CRLF',
        Collection|null $records = null,
        ZipArchive|FilesystemOperator|null $zip_filesystem = null,
        string|null $media_path = null
    ) {
        $stream = fopen('php://memory', 'wb+');

        if ($stream === false) {
            throw new RuntimeException('Failed to create temporary stream');
        }

        stream_filter_append($stream, GedcomEncodingFilter::class, STREAM_FILTER_WRITE, ['src_encoding' => UTF8::NAME, 'dst_encoding' => $encoding]);

        if ($records instanceof Collection) {
            // Export just these records - e.g. from clippings cart.
            $data = [
                new Collection([$this->createHeader($tree, $encoding, false, $access_level)]),
                $records,
                new Collection(['0 TRLR']),
            ];
        } elseif ($access_level === Auth::PRIV_HIDE) {
            // If we will be applying privacy filters, then we will need the GEDCOM record objects.
            $data = [
                new Collection([$this->createHeader($tree, $encoding, true, $access_level)]),
                $this->individualQuery($tree, $sort_by_xref)->cursor(),
                $this->familyQuery($tree, $sort_by_xref)->cursor(),
                $this->sourceQuery($tree, $sort_by_xref)->cursor(),
                $this->otherQuery($tree, $sort_by_xref)->cursor(),
                $this->mediaQuery($tree, $sort_by_xref)->cursor(),
                new Collection(['0 TRLR']),
            ];
        } else {
            // Disable the pending changes before creating GEDCOM records.
            Registry::cache()->array()->remember(AbstractGedcomRecordFactory::class . $tree->id(), static fn (): Collection => new Collection());

            $data = [
                new Collection([$this->createHeader($tree, $encoding, true, $access_level)]),
                $this->individualQuery($tree, $sort_by_xref)->get()->map(Registry::individualFactory()->mapper($tree)),
                $this->familyQuery($tree, $sort_by_xref)->get()->map(Registry::familyFactory()->mapper($tree)),
                $this->sourceQuery($tree, $sort_by_xref)->get()->map(Registry::sourceFactory()->mapper($tree)),
                $this->otherQuery($tree, $sort_by_xref)->get()->map(Registry::gedcomRecordFactory()->mapper($tree)),
                $this->mediaQuery($tree, $sort_by_xref)->get()->map(Registry::mediaFactory()->mapper($tree)),
                new Collection(['0 TRLR']),
            ];
        }

        $media_filesystem = $tree->mediaFilesystem();

        foreach ($data as $rows) {
            foreach ($rows as $datum) {
                if (is_string($datum)) {
                    $gedcom = $datum;
                } elseif ($datum instanceof GedcomRecord) {
                    $gedcom = $datum->privatizeGedcom($access_level);

                    if ($gedcom === '') {
                        continue;
                    }
                } else {
                    $gedcom =
                        $datum->i_gedcom ??
                        $datum->f_gedcom ??
                        $datum->s_gedcom ??
                        $datum->m_gedcom ??
                        $datum->o_gedcom;
                }

                if ($media_path !== null && preg_match('/^0 @' . Gedcom::REGEX_XREF . '@ OBJE/', $gedcom) === 1) {
                    preg_match_all('/\n1 FILE (.+)/', $gedcom, $matches, PREG_SET_ORDER);

                    foreach ($matches as $match) {
                        $media_file = $match[1];

                        if ($media_filesystem->fileExists($media_file)) {
                            if ($zip_filesystem instanceof Filesystem) {
                                $zip_filesystem->writeStream($media_path . $media_file, $media_filesystem->readStream($media_file));
                            }

                            if ($zip_filesystem instanceof ZipArchive) {
                                $tmpfile = tempnam(sys_get_temp_dir(), 'wt-zip-');
                                $src = $media_filesystem->readStream($media_file);
                                $dst = fopen($tmpfile, 'wb+');
                                stream_copy_to_stream($src, $dst);

                                $zip_filesystem->addFile($tmpfile, $media_path . $media_file);
                                // Media files are (almost always) already compressed.  Don't recompress them.
                                $zip_filesystem->setCompressionName($media_path . $media_file, ZipArchive::CM_STORE);

                                fclose($src);
                                fclose($dst);
                            }
                        }
                    }
                }

                $gedcom = $this->wrapLongLines($gedcom, Gedcom::LINE_LENGTH) . "\n";

                if ($line_endings === 'CRLF') {
                    $gedcom = strtr($gedcom, ["\n" => "\r\n"]);
                }

                $bytes_written = fwrite($stream, $gedcom);

                if ($bytes_written !== strlen($gedcom)) {
                    throw new RuntimeException('Unable to write to stream.  Perhaps the disk is full?');
                }
            }
        }

        if (rewind($stream) === false) {
            throw new RuntimeException('Cannot rewind temporary stream');
        }

        return $stream;
    }

    public function createHeader(Tree $tree, string $encoding, bool $include_sub, int $access_level): string
    {
        // Force a ".ged" suffix
        $filename = $tree->name();

        if (strtolower(pathinfo($filename, PATHINFO_EXTENSION)) !== 'ged') {
            $filename .= '.ged';
        }

        $gedcom_encodings = [
            UTF16BE::NAME     => 'UNICODE',
            UTF16LE::NAME     => 'UNICODE',
            Windows1252::NAME => 'ANSI',
        ];

        $encoding = $gedcom_encodings[$encoding] ?? $encoding;

        // Build a new header record
        $gedcom = '0 HEAD';
        $gedcom .= "\n1 SOUR " . Webtrees::NAME;
        $gedcom .= "\n2 NAME " . Webtrees::NAME;
        $gedcom .= "\n2 VERS " . Webtrees::VERSION;
        $gedcom .= "\n1 DEST DISKETTE";
        $gedcom .= "\n1 DATE " . strtoupper(date('d M Y'));
        $gedcom .= "\n2 TIME " . date('H:i:s');
        $gedcom .= "\n1 GEDC\n2 VERS 5.5.1\n2 FORM LINEAGE-LINKED";
        $gedcom .= "\n1 CHAR " . $encoding;
        $gedcom .= "\n1 FILE " . $filename;

        // Preserve some values from the original header
        $header = Registry::headerFactory()->make('HEAD', $tree) ?? Registry::headerFactory()->new('HEAD', '0 HEAD', null, $tree);

        // There should always be a header record.
        if ($header instanceof Header) {
            foreach ($header->facts(['COPR', 'LANG', 'PLAC', 'NOTE'], false, $access_level) as $fact) {
                $gedcom .= "\n" . $fact->gedcom();
            }

            if ($include_sub) {
                foreach ($header->facts(['SUBM', 'SUBN'], false, $access_level) as $fact) {
                    $gedcom .= "\n" . $fact->gedcom();
                }
            }
        }

        return $gedcom;
    }

    public function wrapLongLines(string $gedcom, int $max_line_length): string
    {
        $lines = [];

        foreach (explode("\n", $gedcom) as $line) {
            // Split long lines
            // The total length of a GEDCOM line, including level number, cross-reference number,
            // tag, value, delimiters, and terminator, must not exceed 255 (wide) characters.
            if (mb_strlen($line) > $max_line_length) {
                [$level, $tag] = explode(' ', $line, 3);
                if ($tag !== 'CONT') {
                    $level++;
                }
                do {
                    // Split after $pos chars
                    $pos = $max_line_length;
                    // Split on a non-space (standard gedcom behavior)
                    while (mb_substr($line, $pos - 1, 1) === ' ') {
                        --$pos;
                    }
                    if ($pos === strpos($line, ' ', 3)) {
                        // No non-spaces in the data! Can’t split it :-(
                        break;
                    }
                    $lines[] = mb_substr($line, 0, $pos);
                    $line    = $level . ' CONC ' . mb_substr($line, $pos);
                } while (mb_strlen($line) > $max_line_length);
            }
            $lines[] = $line;
        }

        return implode("\n", $lines);
    }

    private function familyQuery(Tree $tree, bool $sort_by_xref): Builder
    {
        $query = DB::table('families')
            ->where('f_file', '=', $tree->id())
            ->select(['f_gedcom', 'f_id']);

        if ($sort_by_xref) {
            $query
                ->orderBy(new Expression('LENGTH(f_id)'))
                ->orderBy('f_id');
        }

        return $query;
    }

    private function individualQuery(Tree $tree, bool $sort_by_xref): Builder
    {
        $query = DB::table('individuals')
            ->where('i_file', '=', $tree->id())
            ->select(['i_gedcom', 'i_id']);

        if ($sort_by_xref) {
            $query
                ->orderBy(new Expression('LENGTH(i_id)'))
                ->orderBy('i_id');
        }

        return $query;
    }

    private function sourceQuery(Tree $tree, bool $sort_by_xref): Builder
    {
        $query = DB::table('sources')
            ->where('s_file', '=', $tree->id())
            ->select(['s_gedcom', 's_id']);

        if ($sort_by_xref) {
            $query
                ->orderBy(new Expression('LENGTH(s_id)'))
                ->orderBy('s_id');
        }

        return $query;
    }

    private function mediaQuery(Tree $tree, bool $sort_by_xref): Builder
    {
        $query = DB::table('media')
            ->where('m_file', '=', $tree->id())
            ->select(['m_gedcom', 'm_id']);

        if ($sort_by_xref) {
            $query
                ->orderBy(new Expression('LENGTH(m_id)'))
                ->orderBy('m_id');
        }

        return $query;
    }

    private function otherQuery(Tree $tree, bool $sort_by_xref): Builder
    {
        $query = DB::table('other')
            ->where('o_file', '=', $tree->id())
            ->whereNotIn('o_type', [Header::RECORD_TYPE, 'TRLR'])
            ->select(['o_gedcom', 'o_id']);

        if ($sort_by_xref) {
            $query
                ->orderBy('o_type')
                ->orderBy(new Expression('LENGTH(o_id)'))
                ->orderBy('o_id');
        }

        return $query;
    }
}
