<?php

/**
 * Vvveb
 *
 * Copyright (C) 2022  Ziadin Givan
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 */

/**
 * elFinder - file manager for web.
 * Session Wrapper Class.
 *
 * @package elfinder
 * @author  Naoki Sawada
 **/
class elFinderSession implements elFinderSessionInterface {
	/**
	 * A flag of session started.
	 *
	 * @var boolean
	 */
	protected $started = false;

	/**
	 * To fix PHP bug that duplicate Set-Cookie header to be sent.
	 *
	 * @var boolean
	 * @see        https://bugs.php.net/bug.php?id=75554
	 */
	protected $fixCookieRegist = false;

	/**
	 * Array of session keys of this instance.
	 *
	 * @var array
	 */
	protected $keys = [];

	/**
	 * Is enabled base64encode.
	 *
	 * @var boolean
	 */
	protected $base64encode = false;

	/**
	 * Default options array.
	 *
	 * @var array
	 */
	protected $opts = [
		'base64encode' => false,
		'keys'         => [
			'default'   => 'elFinderCaches',
			'netvolume' => 'elFinderNetVolumes',
		],
		'cookieParams' => [],
	];

	/**
	 * Constractor.
	 *
	 * @param array $opts The options
	 *
	 * @return self Instanse of this class
	 */
	public function __construct($opts) {
		$this->opts         = array_merge($this->opts, $opts);
		$this->base64encode = ! empty($this->opts['base64encode']);
		$this->keys         = $this->opts['keys'];

		if (function_exists('apache_get_version') || $this->opts['cookieParams']) {
			$this->fixCookieRegist = true;
		}
	}

	/**
	 * {@inheritdoc}
	 */
	public function get($key, $empty = null) {
		$closed = false;

		if (! $this->started) {
			$closed = true;
			$this->start();
		}

		$data = null;

		if ($this->started) {
			$session =&$this->getSessionRef($key);
			$data    = $session;

			if ($data && $this->base64encode) {
				$data = $this->decodeData($data);
			}
		}

		$checkFn = null;

		if (! is_null($empty)) {
			if (is_string($empty)) {
				$checkFn = 'is_string';
			} elseif (is_array($empty)) {
				$checkFn = 'is_array';
			} elseif (is_object($empty)) {
				$checkFn = 'is_object';
			} elseif (is_float($empty)) {
				$checkFn = 'is_float';
			} elseif (is_int($empty)) {
				$checkFn = 'is_int';
			}
		}

		if (is_null($data) || ($checkFn && ! $checkFn($data))) {
			$session = $data = $empty;
		}

		if ($closed) {
			$this->close();
		}

		return $data;
	}

	/**
	 * {@inheritdoc}
	 */
	public function start() {
		set_error_handler([$this, 'session_start_error'], E_NOTICE | E_WARNING);

		// apache2 SAPI has a bug of session cookie register
		// see https://bugs.php.net/bug.php?id=75554
		// see https://github.com/php/php-src/pull/3231
		if ($this->fixCookieRegist === true) {
			if ((int)ini_get('session.use_cookies') === 1) {
				if (ini_set('session.use_cookies', 0) === false) {
					$this->fixCookieRegist = false;
				}
			}
		}

		if (version_compare(PHP_VERSION, '5.4.0', '>=')) {
			if (session_status() !== PHP_SESSION_ACTIVE) {
				session_start();
			}
		} else {
			session_start();
		}
		$this->started = session_id() ? true : false;

		restore_error_handler();

		return $this;
	}

	/**
	 * Get variable reference of $_SESSION.
	 *
	 * @param string $key key of $_SESSION array
	 *
	 * @return mixed|null
	 */
	protected function &getSessionRef($key) {
		$session = null;

		if ($this->started) {
			list($cat, $name) = array_pad(explode('.', $key, 2), 2, null);

			if (is_null($name)) {
				if (! isset($this->keys[$cat])) {
					$name = $cat;
					$cat  = 'default';
				}
			}

			if (isset($this->keys[$cat])) {
				$cat = $this->keys[$cat];
			} else {
				$name = $cat . '.' . $name;
				$cat  = $this->keys['default'];
			}

			if (is_null($name)) {
				if (! isset($_SESSION[$cat])) {
					$_SESSION[$cat] = null;
				}
				$session =&$_SESSION[$cat];
			} else {
				if (! isset($_SESSION[$cat]) || ! is_array($_SESSION[$cat])) {
					$_SESSION[$cat] = [];
				}

				if (! isset($_SESSION[$cat][$name])) {
					$_SESSION[$cat][$name] = null;
				}
				$session =&$_SESSION[$cat][$name];
			}
		}

		return $session;
	}

	/**
	 * base64 decode of session val.
	 *
	 * @param $data
	 *
	 * @return bool|mixed|string|null
	 */
	protected function decodeData($data) {
		if ($this->base64encode) {
			if (is_string($data)) {
				if (($data = base64_decode($data)) !== false) {
					$data = unserialize($data);
				} else {
					$data = null;
				}
			} else {
				$data = null;
			}
		}

		return $data;
	}

	/**
	 * {@inheritdoc}
	 */
	public function close() {
		if ($this->started) {
			if ($this->fixCookieRegist === true) {
				// regist cookie only once for apache2 SAPI
				$cParm = session_get_cookie_params();

				if ($this->opts['cookieParams'] && is_array($this->opts['cookieParams'])) {
					$cParm = array_merge($cParm, $this->opts['cookieParams']);
				}

				if (version_compare(PHP_VERSION, '7.3', '<')) {
					setcookie(session_name(), session_id(), 0, $cParm['path'] . (! empty($cParm['SameSite']) ? '; SameSite=' . $cParm['SameSite'] : ''), $cParm['domain'], $cParm['secure'], $cParm['httponly']);
				} else {
					$allows = ['expires' => true, 'path' => true, 'domain' => true, 'secure' => true, 'httponly' => true, 'samesite' => true];

					foreach (array_keys($cParm) as $_k) {
						if (! isset($allows[$_k])) {
							unset($cParm[$_k]);
						}
					}
					setcookie(session_name(), session_id(), $cParm);
				}
				$this->fixCookieRegist = false;
			}
			session_write_close();
		}
		$this->started = false;

		return $this;
	}

	/**
	 * {@inheritdoc}
	 */
	public function set($key, $data) {
		$closed = false;

		if (! $this->started) {
			$closed = true;
			$this->start();
		}
		$session =&$this->getSessionRef($key);

		if ($this->base64encode) {
			$data = $this->encodeData($data);
		}
		$session = $data;

		if ($closed) {
			$this->close();
		}

		return $this;
	}

	/**
	 * base64 encode for session val.
	 *
	 * @param $data
	 *
	 * @return string
	 */
	protected function encodeData($data) {
		if ($this->base64encode) {
			$data = base64_encode(serialize($data));
		}

		return $data;
	}

	/**
	 * {@inheritdoc}
	 */
	public function remove($key) {
		$closed = false;

		if (! $this->started) {
			$closed = true;
			$this->start();
		}

		list($cat, $name) = array_pad(explode('.', $key, 2), 2, null);

		if (is_null($name)) {
			if (! isset($this->keys[$cat])) {
				$name = $cat;
				$cat  = 'default';
			}
		}

		if (isset($this->keys[$cat])) {
			$cat = $this->keys[$cat];
		} else {
			$name = $cat . '.' . $name;
			$cat  = $this->keys['default'];
		}

		if (is_null($name)) {
			unset($_SESSION[$cat]);
		} else {
			if (isset($_SESSION[$cat]) && is_array($_SESSION[$cat])) {
				unset($_SESSION[$cat][$name]);
			}
		}

		if ($closed) {
			$this->close();
		}

		return $this;
	}

	/**
	 * sessioin error handler (Only for suppression of error at session start).
	 *
	 * @param $errno
	 * @param $errstr
	 */
	protected function session_start_error($errno, $errstr) {
	}
}
