Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle 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.

//

// Moodle 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 Moodle.  If not, see <http://www.gnu.org/licenses/>.

namespace mod_data\local\importer;

use coding_exception;

use core_php_time_limit;

use file_packer;

/**

 * Importer class for importing data and - if needed - files as well from a zip archive.

 *

 * @package    mod_data

 * @copyright  2023 ISB Bayern

 * @author     Philipp Memmel

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

abstract class entries_importer {

    /** @var string The import file path of the file which data should be imported from. */

    protected string $importfilepath;

    /** @var string The original name of the import file name including extension of the file which data should be imported from. */

    protected string $importfilename;

    /** @var string $importfiletype The file type of the import file. */

    protected string $importfiletype;

    /** @var file_packer Zip file packer to extract files from a zip archive. */

    private file_packer $packer;

    /** @var bool Tracks state if zip archive has been extracted already. */

    private bool $zipfileextracted;

    /** @var string Temporary directory where zip archive is being extracted to. */

    private string $extracteddir;

    /**

     * Creates an entries_importer object.

     *

     * This object can be used to import data from data files (like csv) and zip archives both including a data file and files to be

     * stored in the course module context.

     *

     * @param string $importfilepath the complete path of the import file including filename

     * @param string $importfilename the import file name as uploaded by the user

     * @throws coding_exception if a wrong file type is being used

     */

    public function __construct(string $importfilepath, string $importfilename) {

        $this->importfilepath = $importfilepath;

        $this->importfilename = $importfilename;

        $this->importfiletype = pathinfo($importfilename, PATHINFO_EXTENSION);

        $this->zipfileextracted = false;

        if ($this->importfiletype !== $this->get_import_data_file_extension() && $this->importfiletype !== 'zip') {

            throw new coding_exception('Only "zip" or "' . $this->get_import_data_file_extension() . '" files are '

                . 'allowed.');

        }

    }

    /**

     * Return the file extension of the import data file which is being used, for example 'csv' for a csv entries_importer.

     *

     * @return string the file extension of the export data file

     */

    abstract public function get_import_data_file_extension(): string;

    /**

     * Returns the file content of the data file.

     *

     * Returns the content of the file directly if the entries_importer's file is a data file itself.

     *  If the entries_importer's file is a zip archive, the content of the first found data file in the

     *  zip archive's root will be returned.

     *

     * @return false|string the data file content as string; false, if file cannot be found/read

     */

    public function get_data_file_content(): false|string {

        if ($this->importfiletype !== 'zip') {

            // We have no zip archive, so the file itself must be the data file.

            return file_get_contents($this->importfilepath);

        }

        // So we have a zip archive and need to find the right data file in the root of the zip archive.

        $this->extract_zip();

        $datafilenames = array_filter($this->packer->list_files($this->importfilepath),

            fn($file) => pathinfo($file->pathname, PATHINFO_EXTENSION) === $this->get_import_data_file_extension()

                && !str_contains($file->pathname, '/'));

        if (empty($datafilenames) || count($datafilenames) > 1) {

            return false;

        }

        return file_get_contents($this->extracteddir . reset($datafilenames)->pathname);

    }

    /**

     * Returns the file content from a file which has been stored in the zip archive.

     *

     * @param string $filename

     * @param string $zipsubdir

     * @return false|string the file content as string, false if the file could not be found/read

     */

    public function get_file_content_from_zip(string $filename, string $zipsubdir = 'files/'): false|string {

        if (empty($filename)) {

            // Nothing to return.

            return false;

        }

        // Just to be sure extract if not extracted yet.

        $this->extract_zip();

        if (!str_ends_with($zipsubdir, '/')) {

            $zipsubdir .= '/';

        }

        $filepathinextractedzip = $this->extracteddir . $zipsubdir . $filename;

        return file_exists($filepathinextractedzip) ? file_get_contents($filepathinextractedzip) : false;

    }

    /**

     * Extracts (if not already done and if we have a zip file to deal with) the zip file to a temporary directory.

     *

     * @return void

     */

    private function extract_zip(): void {

        if ($this->zipfileextracted || $this->importfiletype !== 'zip') {

            return;

        }

        $this->packer = get_file_packer();

        core_php_time_limit::raise(180);

        $this->extracteddir = make_request_directory();

        if (!str_ends_with($this->extracteddir, '/')) {

            $this->extracteddir .= '/';

        }

        $this->packer->extract_to_pathname($this->importfilepath, $this->extracteddir);

        $this->zipfileextracted = true;

    }

}