<?php
/**
 * @package    awf
 * @copyright  Copyright (c)2014-2019 Nicholas K. Dionysopoulos / Akeeba Ltd
 * @license    GNU GPL version 3 or later
 */

/**
 * The Session package in Awf is based on the Session package in Aura for PHP. Please consult the LICENSE file in the
 * Awf\Session package for copyright and license information.
 */

namespace Awf\Session;

if (!defined('PHP_SESSION_NONE'))
{
	define('PHP_SESSION_NONE', 0);
}
if (!defined('PHP_SESSION_ACTIVE')) define('PHP_SESSION_ACTIVE', 1);

/**
 * A central control point for new session segments, PHP session management
 * values, and CSRF token checking.
 */
class Manager
{
	/**
	 *
	 * A session segment factory.
	 *
	 * @var SegmentFactory
	 *
	 */
	protected $segment_factory;

	/**
	 *
	 * The CSRF token for this session.
	 *
	 * @var CsrfToken
	 *
	 */
	protected $csrf_token;

	/**
	 *
	 * A CSRF token factory, for lazy-creating the CSRF token.
	 *
	 * @var CsrfTokenFactory
	 *
	 */
	protected $csrf_token_factory;

	/**
	 *
	 * Incoming cookies from the client, typically a copy of the $_COOKIE
	 * superglobal.
	 *
	 * @var array
	 *
	 */
	protected $cookies;

	/**
	 *
	 * Session cookie parameters.
	 *
	 * @var array
	 *
	 */
	protected $cookie_params = array();

	protected $segments = array();

	/**
	 *
	 * Constructor
	 *
	 * @param SegmentFactory $segment_factory A session segment factory.
	 *
	 * @param                CsrfTokenFactory A CSRF token factory.
	 *
	 * @param array          $cookies         An arry of cookies from the client, typically a
	 *                                        copy of $_COOKIE.
	 *
	 */
	public function __construct(
		SegmentFactory $segment_factory,
		CsrfTokenFactory $csrf_token_factory,
		array $cookies = array()
	)
	{
		$this->segment_factory = $segment_factory;
		$this->csrf_token_factory = $csrf_token_factory;
		$this->cookies = $cookies;
		$this->cookie_params = session_get_cookie_params();
	}

	/**
	 *
	 * Gets a new session segment instance by name. Segments with the same
	 * name will be different objects but will reference the same $_SESSION
	 * values, so it is possible to have two or more objects that share state.
	 * For good or bad, this a function of how $_SESSION works.
	 *
	 * @param string $name The name of the session segment, typically a
	 *                     fully-qualified class name.
	 *
	 * @return Segment
	 *
	 */
	public function newSegment($name)
	{
		if (!isset($this->segments[$name]))
		{
			$this->segments[$name] = $this->segment_factory->newInstance($this, $name);
		}

		return $this->segments[$name];
	}

	/**
	 *
	 * Tells us if a session is available to be reactivated, but not if it has
	 * started yet.
	 *
	 * @return bool
	 *
	 */
	public function isAvailable()
	{
		$name = $this->getName();

		return isset($this->cookies[$name]);
	}

	/**
	 *
	 * Tells us if a session has started.
	 *
	 * @return bool
	 *
	 */
	public function isStarted()
	{
		return $this->getStatus() == PHP_SESSION_ACTIVE;
	}

	/**
	 *
	 * Starts a new session, or resumes an existing one.
	 *
	 * @return bool
	 *
	 */
	public function start()
	{
		if (!$this->isStarted())
		{
			return @session_start();
		}
	}

	/**
	 *
	 * Clears all session variables across all segments.
	 *
	 * @return null
	 *
	 */
	public function clear()
	{
		$this->segments = array();

		@session_unset();
	}

	/**
	 *
	 * Writes session data from all segments and ends the session.
	 *
	 * @return null
	 *
	 */
	public function commit()
	{
		if (count($this->segments))
		{
			/** @var SegmentInterface $segment */
			foreach ($this->segments as $segment)
			{
				$segment->save();
			}
		}

		@session_write_close();
	}

	/**
	 *
	 * Destroys the session entirely.
	 *
	 * @return bool
	 *
	 */
	public function destroy()
	{
		if (!$this->isStarted())
		{
			$this->start();
		}

		$this->clear();

		$ret = @session_destroy();

		return $ret;
	}

	/**
	 *
	 * Returns the CSRF token, creating it if needed (and thereby starting a
	 * session).
	 *
	 * @return CsrfToken
	 *
	 */
	public function getCsrfToken()
	{
		if (!$this->csrf_token)
		{
			$this->csrf_token = $this->csrf_token_factory->newInstance($this);
		}

		return $this->csrf_token;
	}

	// =======================================================================
	//
	// support and admin methods
	//

	/**
	 *
	 * Sets the session cache expire time.
	 *
	 * @param int $expire The expiration time in seconds.
	 *
	 * @return int
	 *
	 * @see session_cache_expire()
	 *
	 */
	public function setCacheExpire($expire)
	{
		return session_cache_expire($expire);
	}

	/**
	 *
	 * Gets the session cache expire time.
	 *
	 * @return int The cache expiration time in seconds.
	 *
	 * @see session_cache_expire()
	 *
	 */
	public function getCacheExpire()
	{
		return session_cache_expire();
	}

	/**
	 *
	 * Sets the session cache limiter value.
	 *
	 * @param string $limiter The limiter value.
	 *
	 * @return string
	 *
	 * @see session_cache_limiter()
	 *
	 */
	public function setCacheLimiter($limiter)
	{
		return session_cache_limiter($limiter);
	}

	/**
	 *
	 * Gets the session cache limiter value.
	 *
	 * @return string The limiter value.
	 *
	 * @see session_cache_limiter()
	 *
	 */
	public function getCacheLimiter()
	{
		return session_cache_limiter();
	}

	/**
	 *
	 * Sets the session cookie params.  Param array keys are:
	 *
	 * - `lifetime` : Lifetime of the session cookie, defined in seconds.
	 *
	 * - `path` : Path on the domain where the cookie will work.
	 *   Use a single slash ('/') for all paths on the domain.
	 *
	 * - `domain` : Cookie domain, for example 'www.php.net'.
	 *   To make cookies visible on all subdomains then the domain must be
	 *   prefixed with a dot like '.php.net'.
	 *
	 * - `secure` : If TRUE cookie will only be sent over secure connections.
	 *
	 * - `httponly` : If set to TRUE then PHP will attempt to send the httponly
	 *   flag when setting the session cookie.
	 *
	 * @param array $params The array of session cookie param keys and values.
	 *
	 * @return void
	 *
	 * @see session_set_cookie_params()
	 *
	 */
	public function setCookieParams(array $params)
	{
		$this->cookie_params = array_merge($this->cookie_params, $params);
		@session_set_cookie_params(
			$this->cookie_params['lifetime'],
			$this->cookie_params['path'],
			$this->cookie_params['domain'],
			$this->cookie_params['secure'],
			$this->cookie_params['httponly']
		);
	}

	/**
	 *
	 * Gets the session cookie params.
	 *
	 * @return array
	 *
	 */
	public function getCookieParams()
	{
		return $this->cookie_params;
	}

	/**
	 *
	 * Gets the current session id.
	 *
	 * @return string
	 *
	 */
	public function getId()
	{
		return session_id();
	}

	/**
	 *
	 * Regenerates and replaces the current session id; also regenerates the
	 * CSRF token value if one exists.
	 *
	 * @return bool True is regeneration worked, false if not.
	 *
	 */
	public function regenerateId()
	{
		$result = session_regenerate_id(true);

		if ($result && $this->csrf_token)
		{
			$this->csrf_token->regenerateValue();
		}

		return $result;
	}

	/**
	 *
	 * Sets the current session name.
	 *
	 * @param string $name The session name to use.
	 *
	 * @return string
	 *
	 * @see session_name()
	 *
	 */
	public function setName($name)
	{
		return session_name($name);
	}

	/**
	 *
	 * Returns the current session name.
	 *
	 * @return string
	 *
	 */
	public function getName()
	{
		return session_name();
	}

	/**
	 *
	 * Sets the session save path.
	 *
	 * @param string $path The new save path.
	 *
	 * @return string
	 *
	 * @see session_save_path()
	 *
	 */
	public function setSavePath($path)
	{
		// Workaround for some servers where the call to session_save_path() is ignored (yeah, there ARE broken servers out there...)
		$usedIniSet = false;

		if (function_exists('ini_set'))
		{
			$usedIniSet = true;
			ini_set('session.save_path', $path);
		}

		if (function_exists('session_save_path'))
		{
			// session_save_path exists, return its output
			return session_save_path($path);
		}
		elseif ($usedIniSet)
		{
			// session_save_path does not exist, but we used ini_set, i.e. we're using $path
			return $path;
		}
		else
		{
			// session_save_path does not exist and we could not use ini_set, all bets are off...
			return $this->getSavePath();
		}
	}

	/**
	 *
	 * Gets the session save path.
	 *
	 * @return string
	 *
	 * @see session_save_path()
	 *
	 */
	public function getSavePath()
	{
		$sessionPath = '';

		if (function_exists('session_save_path'))
		{
			$sessionPath = session_save_path();
		}
		elseif (function_exists('ini_get'))
		{
			$sessionPath = ini_get('session.save_path');
		}

		if (empty($sessionPath) && function_exists('sys_get_temp_dir'))
		{
			$sessionPath = sys_get_temp_dir();
		}

		return $sessionPath;
	}

	/**
	 *
	 * Returns the current session status:
	 *
	 * - `PHP_SESSION_DISABLED` if sessions are disabled.
	 * - `PHP_SESSION_NONE` if sessions are enabled, but none exists.
	 * - `PHP_SESSION_ACTIVE` if sessions are enabled, and one exists.
	 *
	 * @return int
	 *
	 * @see session_status()
	 *
	 */
	public function getStatus()
	{
		if (function_exists('session_status'))
		{
			return session_status();
		}

		$sid = session_id();

		if (empty($sid))
		{
			return PHP_SESSION_NONE;
		}
		else
		{
			return PHP_SESSION_ACTIVE;
		}
	}
}
