<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006~2016 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
namespace think;

class Session {
	protected static $prefix = '';
	
	/**
	 * 设置或者获取session作用域（前缀）
	 * 
	 * @param string $prefix        	
	 * @return string|void
	 */
	public static function prefix($prefix = '') {
		if (empty ( $prefix ) && $prefix !== null) {
			return self::$prefix;
		} else {
			self::$prefix = $prefix;
		}
	}
	
	/**
	 * session初始化
	 * 
	 * @param array $config        	
	 * @return void
	 */
	public static function init($config = []) {
		if (isset ( $config ['use_trans_sid'] )) {
			ini_set ( 'session.use_trans_sid', $config ['use_trans_sid'] ? 1 : 0 );
		}
		
		// 启动session
		if (! empty ( $config ['auto_start'] ) && PHP_SESSION_ACTIVE != session_status ()) {
			ini_set ( 'session.auto_start', 0 );
			session_start ();
		}
		
		if (isset ( $config ['prefix'] )) {
			self::$prefix = $config ['prefix'];
		}
		if ($config ['var_session_id'] && isset ( $_REQUEST [$config ['var_session_id']] )) {
			session_id ( $_REQUEST [$config ['var_session_id']] );
		} elseif (isset ( $config ['id'] ) && ! empty ( $config ['id'] )) {
			session_id ( $config ['id'] );
		}
		if (isset ( $config ['name'] )) {
			session_name ( $config ['name'] );
		}
		if (isset ( $config ['path'] )) {
			session_save_path ( $config ['path'] );
		}
		if (isset ( $config ['domain'] )) {
			ini_set ( 'session.cookie_domain', $config ['domain'] );
		}
		if (isset ( $config ['expire'] )) {
			ini_set ( 'session.gc_maxlifetime', $config ['expire'] );
			ini_set ( 'session.cookie_lifetime', $config ['expire'] );
		}
		
		if (isset ( $config ['use_cookies'] )) {
			ini_set ( 'session.use_cookies', $config ['use_cookies'] ? 1 : 0 );
		}
		if (isset ( $config ['cache_limiter'] )) {
			session_cache_limiter ( $config ['cache_limiter'] );
		}
		if (isset ( $config ['cache_expire'] )) {
			session_cache_expire ( $config ['cache_expire'] );
		}
		if (! empty ( $config ['type'] )) {
			// 读取session驱动
			$class = (! empty ( $config ['namespace'] ) ? $config ['namespace'] : '\\think\\session\\driver\\') . ucwords ( $config ['type'] );
			
			// 检查驱动类
			if (! class_exists ( $class ) || ! session_set_save_handler ( new $class () )) {
				throw new \think\Exception ( 'error session handler', 11700 );
			}
		}
	}
	
	/**
	 * session设置
	 * 
	 * @param string $name
	 *        	session名称
	 * @param mixed $value
	 *        	session值
	 * @param string $prefix
	 *        	作用域（前缀）
	 * @return void
	 */
	public static function set($name, $value = '', $prefix = '') {
		$prefix = $prefix ? $prefix : self::$prefix;
		if (strpos ( $name, '.' )) {
			// 二维数组赋值
			list ( $name1, $name2 ) = explode ( '.', $name );
			if ($prefix) {
				$_SESSION [$prefix] [$name1] [$name2] = $value;
			} else {
				$_SESSION [$name1] [$name2] = $value;
			}
		} elseif ($prefix) {
			$_SESSION [$prefix] [$name] = $value;
		} else {
			$_SESSION [$name] = $value;
		}
	}
	
	/**
	 * session获取
	 * 
	 * @param string $name
	 *        	session名称
	 * @param string $prefix
	 *        	作用域（前缀）
	 * @return mixed
	 */
	public static function get($name = '', $prefix = '') {
		$prefix = $prefix ? $prefix : self::$prefix;
		if ('' == $name) {
			// 获取全部的session
			$value = $prefix ? $_SESSION [$prefix] : $_SESSION;
		} elseif ($prefix) {
			// 获取session
			if (strpos ( $name, '.' )) {
				list ( $name1, $name2 ) = explode ( '.', $name );
				$value = isset ( $_SESSION [$prefix] [$name1] [$name2] ) ? $_SESSION [$prefix] [$name1] [$name2] : null;
			} else {
				$value = isset ( $_SESSION [$prefix] [$name] ) ? $_SESSION [$prefix] [$name] : null;
			}
		} else {
			if (strpos ( $name, '.' )) {
				list ( $name1, $name2 ) = explode ( '.', $name );
				$value = isset ( $_SESSION [$name1] [$name2] ) ? $_SESSION [$name1] [$name2] : null;
			} else {
				$value = isset ( $_SESSION [$name] ) ? $_SESSION [$name] : null;
			}
		}
		return $value;
	}
	
	/**
	 * 删除session数据
	 * 
	 * @param string $name
	 *        	session名称
	 * @param string $prefix
	 *        	作用域（前缀）
	 * @return void
	 */
	public static function delete($name, $prefix = '') {
		$prefix = $prefix ? $prefix : self::$prefix;
		if (strpos ( $name, '.' )) {
			list ( $name1, $name2 ) = explode ( '.', $name );
			if ($prefix) {
				unset ( $_SESSION [$prefix] [$name1] [$name2] );
			} else {
				unset ( $_SESSION [$name1] [$name2] );
			}
		} else {
			if ($prefix) {
				unset ( $_SESSION [$prefix] [$name] );
			} else {
				unset ( $_SESSION [$name] );
			}
		}
	}
	
	/**
	 * 清空session数据
	 * 
	 * @param string $prefix
	 *        	作用域（前缀）
	 * @return void
	 */
	public static function clear($prefix = '') {
		$prefix = $prefix ? $prefix : self::$prefix;
		if ($prefix) {
			unset ( $_SESSION [$prefix] );
		} else {
			$_SESSION = [ ];
		}
	}
	
	/**
	 * 判断session数据
	 *
	 * @param string $name
	 *        	session名称
	 * @param string $prefix        	
	 *
	 * @return bool
	 * @internal param mixed $value session值
	 */
	public static function has($name, $prefix = '') {
		$prefix = $prefix ? $prefix : self::$prefix;
		if (strpos ( $name, '.' )) {
			// 支持数组
			list ( $name1, $name2 ) = explode ( '.', $name );
			return $prefix ? isset ( $_SESSION [$prefix] [$name1] [$name2] ) : isset ( $_SESSION [$name1] [$name2] );
		} else {
			return $prefix ? isset ( $_SESSION [$prefix] [$name] ) : isset ( $_SESSION [$name] );
		}
	}
	
	/**
	 * 暂停session
	 * 
	 * @return void
	 */
	public static function pause() {
		// 暂停session
		session_write_close ();
	}
	
	/**
	 * 启动session
	 * 
	 * @return void
	 */
	public static function start() {
		session_start ();
	}
	
	/**
	 * 销毁session
	 * 
	 * @return void
	 */
	public static function destroy() {
		$_SESSION = [ ];
		session_unset ();
		session_destroy ();
	}
	
	/**
	 * 重新生成session_id
	 * 
	 * @return void
	 */
	private static function regenerate() {
		session_regenerate_id ();
	}
}