<?php
/**
 * Provides the file class, an interface to the file table in the database
 *
 * @author Camil Staps
 *
 * BusinessAdmin: administrative software for small companies
 * Copyright (C) 2015 Camil Staps (ViviSoft)
 *
 * 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/>.
 */

/**
 * An interface to the file table in the database
 */
class File extends Model {
	/** {@inheritDoc} */
	public static
		$table = 'file',
		$fillable_columns = ['filename', 'secret_key'];

	/**
	 * {@inheritDoc} 
	 * @param PDO $pdo {@inheritDoc}
	 * @param mixed[] $values {@inheritDoc}
	 */
	public static function create($pdo, $values) {
		$filename = $values[0];

		// Check for file existence
		if (file_exists(Constants::files_folder . $filename)) {
			throw new Exception("$filename already exists.");
		}

		// Try to create the file
		if (file_put_contents(Constants::files_folder . $filename, '') === false) {
			throw new Exception("$filename could not be created. Check the permissions.");
		}

		if (count($values) < count(static::$fillable_columns)) {
			$values[] = self::getRandomSecretKey();
		}

		return parent::create($pdo, $values);
	}

	/**
	 * A random max-63-char string that can be used as secret_key
	 *
	 * @return string                       The random string
	 */
	public static function getRandomSecretKey() {
		return preg_replace('/[^\w]+/', '',
			base64_encode(openssl_random_pseudo_bytes(45)));
	}

	/**
	 * Get the full internal path to the file
	 *
	 * @see file::getFilenameURI    To get the full external path to the file
	 *
	 * @return string               The path
	 */
	public function getFilenamePath() {
		return Constants::files_folder . $this->filename;
	}

	/**
	 * Get the full external path to the file
	 *
	 * @see file::getFilenamePath   To get the full internal path to the file
	 *
	 * @return string               The URI
	 */
	public function getFilenameURI() {
		return Constants::url_external . 'file/get?name=' . $this->filename . '&key=' . $this->secret_key;
	}

	//------------------------------------------------------------------------------
	// Other functions
	//------------------------------------------------------------------------------

	/**
	 * Move this file to the trash and delete all records for it
	 *
	 * Physically, this moves the file to a trash folder
	 * Then, the file will be removed from the file table in the database
	 * Any appendices linking to this file with fileId will have fileId NULL
	 * Any offers linking to this file with invoice_fileId will have invoice_fileId NULL
	 *
	 * @throws PDOException         If there's something wrong with the database
	 *
	 * @return bool                 True on success, false on failure
	 */
	public function delete() {
		// Try to move the file to trash
		$newname = pathinfo($this->filename, PATHINFO_FILENAME) . '--' . date('Y-m-d.H.i.s.') . pathinfo($this->filename, PATHINFO_EXTENSION);
		$newdir = pathinfo($this->getFilenamePath(), PATHINFO_DIRNAME) . '/' . Constants::files_folder_trash . '/';
		if (!file_exists($newdir)) {
			if (!mkdir($newdir)) {
				return false;
			}
		}
		if (!(@rename($this->getFilenamePath(), $newdir . $newname))) {
			return false;
		}

		// Remove offers linked by invoice_fileId
		$this->pdo->query("UPDATE `".Constants::db_prefix."offer` SET `invoice_fileId`=NULL WHERE `invoice_fileId`={$this->id}");

		return parent::delete();
	}
}