<?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\Http\Controllers;

use Fisharebest\Webtrees\Database;
use Fisharebest\Webtrees\Functions\FunctionsImport;
use Fisharebest\Webtrees\Gedcom;
use Fisharebest\Webtrees\I18N;
use Fisharebest\Webtrees\Services\TimeoutService;
use Fisharebest\Webtrees\Tree;
use Illuminate\Database\Capsule\Manager as DB;
use Illuminate\Support\Str;
use PDOException;
use Symfony\Component\HttpFoundation\Response;

/**
 * Controller for the processing GEDCOM files.
 */
class GedcomFileController extends AbstractBaseController
{
    /** @var string */
    protected $layout = 'layouts/ajax';

    /**
     * Import the next chunk of a GEDCOM file.
     *
     * @param TimeoutService $timeout_service
     * @param Tree           $tree
     *
     * @return Response
     */
    public function import(TimeoutService $timeout_service, Tree $tree): Response
    {
        // Only allow one process to import each gedcom at a time
        DB::table('gedcom_chunk')
            ->where('gedcom_id', '=', $tree->id())
            ->lockForUpdate()
            ->get();

        // What is the current import status?
        $import_offset = (int) DB::table('gedcom_chunk')
            ->where('gedcom_id', '=', $tree->id())
            ->where('imported', '=', '1')
            ->sum(DB::raw("LENGTH(chunk_data)"));

        $import_total = (int) DB::table('gedcom_chunk')
            ->where('gedcom_id', '=', $tree->id())
            ->sum(DB::raw("LENGTH(chunk_data)"));

        // Finished?
        if ($import_offset === $import_total) {
            $tree->setPreference('imported', '1');

            $html = view('admin/import-complete');

            return new Response($html);
        }

        // Calculate progress so far
        $progress = $import_offset / $import_total;

        $first_time = ($import_offset === 0);

        // Run for a short period of time. This keeps the resource requirements low.
        do {
            $data = DB::table('gedcom_chunk')
                ->where('gedcom_id', '=', $tree->id())
                ->where('imported', '=', '0')
                ->orderby('gedcom_chunk_id')
                ->select(['gedcom_chunk_id', 'chunk_data'])
                ->first();

            // If we are loading the first (header) record, make sure the encoding is UTF-8.
            if ($first_time) {
                // Remove any byte-order-mark
                if (Str::startsWith($data->chunk_data, Gedcom::UTF8_BOM)) {
                    $data->chunk_data = Str::after($data->chunk_data, Gedcom::UTF8_BOM);
                    // Put it back in the database, so we can do character conversion
                    DB::table('gedcom_chunk')
                        ->where('gedcom_chunk_id', '=', $data->gedcom_chunk_id)
                        ->update(['chunk_data' => $data->chunk_data]);
                }

                if (!Str::startsWith($data->chunk_data, '0 HEAD')) {
                    return $this->viewResponse('admin/import-fail', [
                        'error' => I18N::translate('Invalid GEDCOM file - no header record found.'),
                    ]);
                }

                // What character set is this? Need to convert it to UTF8
                if (preg_match('/[\r\n][ \t]*1 CHAR(?:ACTER)? (.+)/', $data->chunk_data, $match)) {
                    $charset = trim(strtoupper($match[1]));
                } else {
                    $charset = 'ASCII';
                }
                // MySQL supports a wide range of collation conversions. These are ones that
                // have been encountered "in the wild".
                switch ($charset) {
                    case 'ASCII':
                        DB::table('gedcom_chunk')
                            ->where('gedcom_id', '=', $tree->id())
                            ->update(['chunk_data' => DB::raw('CONVERT(CONVERT(chunk_data USING ascii) USING utf8)')]);
                        break;
                    case 'IBMPC':   // IBMPC, IBM WINDOWS and MS-DOS could be anything. Mostly it means CP850.
                    case 'IBM WINDOWS':
                    case 'MS-DOS':
                    case 'CP437':
                    case 'CP850':
                        // CP850 has extra letters with diacritics to replace box-drawing chars in CP437.
                        DB::table('gedcom_chunk')
                            ->where('gedcom_id', '=', $tree->id())
                            ->update(['chunk_data' => DB::raw('CONVERT(CONVERT(chunk_data USING cp850) USING utf8)')]);
                        break;
                    case 'ANSI': // ANSI could be anything. Most applications seem to treat it as latin1.
                    case 'WINDOWS':
                    case 'CP1252':
                    case 'ISO8859-1':
                    case 'ISO-8859-1':
                    case 'LATIN1':
                    case 'LATIN-1':
                        // Convert from ISO-8859-1 (western european) to UTF8.
                        DB::table('gedcom_chunk')
                            ->where('gedcom_id', '=', $tree->id())
                            ->update(['chunk_data' => DB::raw('CONVERT(CONVERT(chunk_data USING latin1) USING utf8)')]);
                        break;
                    case 'CP1250':
                    case 'ISO8859-2':
                    case 'ISO-8859-2':
                    case 'LATIN2':
                    case 'LATIN-2':
                        // Convert from ISO-8859-2 (eastern european) to UTF8.
                        DB::table('gedcom_chunk')
                            ->where('gedcom_id', '=', $tree->id())
                            ->update(['chunk_data' => DB::raw('CONVERT(CONVERT(chunk_data USING latin2) USING utf8)')]);
                        break;
                    case 'MACINTOSH':
                        // Convert from MAC Roman to UTF8.
                        DB::table('gedcom_chunk')
                            ->where('gedcom_id', '=', $tree->id())
                            ->update(['chunk_data' => DB::raw('CONVERT(CONVERT(chunk_data USING macroman) USING utf8)')]);
                        break;
                    case 'UTF8':
                    case 'UTF-8':
                        // Already UTF-8 so nothing to do!
                        break;
                    case 'ANSEL':
                    default:
                        return $this->viewResponse('admin/import-fail', [
                            'error' => I18N::translate('Error: converting GEDCOM files from %s encoding to UTF-8 encoding not currently supported.', $charset),
                        ]);
                }
                $first_time = false;

                // Re-fetch the data, now that we have performed character set conversion.
                $data = DB::table('gedcom_chunk')
                    ->where('gedcom_chunk_id', '=', $data->gedcom_chunk_id)
                    ->select(['gedcom_chunk_id', 'chunk_data'])
                    ->first();
            }

            if (!$data) {
                break;
            }

            $data->chunk_data = str_replace("\r", "\n", $data->chunk_data);

            try {
                // Import all the records in this chunk of data
                foreach (preg_split('/\n+(?=0)/', $data->chunk_data) as $rec) {
                    FunctionsImport::importRecord($rec, $tree, false);
                }
                // Mark the chunk as imported
                DB::table('gedcom_chunk')
                    ->where('gedcom_chunk_id', '=', $data->gedcom_chunk_id)
                    ->update(['imported' => 1]);
            } catch (PDOException $ex) {
                return $this->viewResponse('admin/import-fail', [
                    'error' => $ex->getMessage(),
                ]);
            }
        } while (!$timeout_service->isTimeLimitUp());

        return $this->viewResponse('admin/import-progress', [
            'progress' => $progress,
        ]);
    }
}
