<?php
/**
 * SAE Mysql服务
 *
 * 支持主从分离
 *
 * @author Easychen <easychen@gmail.com>
 * @version $Id$
 * @package sae
 *
 */

/**
 * Sae Mysql Class
 *
 * <code>
 * <?php
 * $mysql = new SaeMysql();
 *
 * $sql = "SELECT * FROM `user` LIMIT 10";
 * $data = $mysql->getData( $sql );
 * $name = strip_tags( $_REQUEST['name'] );
 * $age = intval( $_REQUEST['age'] );
 * $sql = "INSERT  INTO `user` ( `name` , `age` , `regtime` ) VALUES ( '"  . $mysql->escape( $name ) . "' , '" . intval( $age ) . "' , NOW() ) ";
 * $mysql->runSql( $sql );
 * if( $mysql->errno() != 0 )
 * {
 *     die( "Error:" . $mysql->errmsg() );
 * }
 *
 * $mysql->closeDb();
 * ?>
 * </code>
 *
 * @package sae
 * @author EasyChen
 *
 */
class SaeMysql extends SaeObject
{

    /**
     * 构造函数
     *
     * @param bool $do_replication 是否支持主从分离，true:支持，false:不支持，默认为true
     * @return void
     * @author EasyChen
     */
    function __construct( $do_replication = true )
    {
        $this->port = 3307;
        $this->host = '.rdc.sae.sina.com.cn';

        $this->accesskey = SAE_ACCESSKEY;
        $this->secretkey = SAE_SECRETKEY;
        $this->appname =  'app_' . $_SERVER['HTTP_APPNAME'];

        //set default charset as utf8
        $this->charset = 'UTF8';

        $this->do_replication = $do_replication;
    }

    /**
     * 设置keys
     *
     * 当需要连接其他APP的数据库时使用
     *
     * @param string $akey AccessKey
     * @param string $skey SecretKey
     * @return void
     * @author EasyChen
     */
    public function setAuth( $akey , $skey )
    {
        $this->accesskey = $akey;
        $this->secretkey = $skey;
    }

    /**
     * 设置Mysql服务器端口
     *
     * 当需要连接其他APP的数据库时使用
     *
     * @param string $port
     * @return void
     * @author EasyChen
     */
    public function setPort( $port )
    {
        $this->port = 3307;
        $this->host = '.rdc.sae.sina.com.cn';

    }

    /**
     * 设置Appname
     *
     * 当需要连接其他APP的数据库时使用
     *
     * @param string $appname
     * @return void
     * @author EasyChen
     */
    public function setAppname( $appname )
    {
        $this->appname =  'app_' . $appname;
    }


    /**
     * 设置当前连接的字符集 , 必须在发起连接之前进行设置
     *
     * @param string $charset 字符集,如GBK,GB2312,UTF8
     * @return void
     */
    public function setCharset( $charset )
    {
        return $this->set_charset( $charset );
    }

    /**
     * 同setCharset,向前兼容
     *
     * @param string $charset
     * @return void
     * @ignore
     */
    public function set_charset( $charset )
    {
        $this->charset = $charset;
    }

    /**
     * 运行Sql语句,不返回结果集
     *
     * @param string $sql
     * @return mysqli_result|bool
     */
    public function runSql( $sql )
    {
        return $this->run_sql( $sql );
    }

    /**
     * 同runSql,向前兼容
     *
     * @param string $sql
     * @return bool
     * @author EasyChen
     * @ignore
     */
    public function run_sql( $sql )
    {
        $this->last_sql = $sql;
        $dblink = $this->db_write();
        if ($dblink === false) {
            return false;
        }
        $ret = mysqli_query( $dblink, $sql );
        $this->save_error( $dblink );
        return $ret;
    }

    /**
     * 运行Sql,以多维数组方式返回结果集
     *
     * @param string $sql
     * @return array 成功返回数组，失败时返回false
     * @author EasyChen
     */
    public function getData( $sql )
    {
        return $this->get_data( $sql );
    }

    /**
     * 同getData,向前兼容
     *
     * @ignore
     */
    public function get_data( $sql )
    {
        $this->last_sql = $sql;
        $data = Array();
        $i = 0;
        $dblink = $this->do_replication ? $this->db_read() : $this->db_write();
        if ($dblink === false) {
            return false;
        }
        $result = mysqli_query( $dblink , $sql );

        $this->save_error( $dblink );

        if (is_bool($result)) {
            return $result;
        } else {
            while( $Array = mysqli_fetch_array( $result, MYSQL_ASSOC ) )
            {
                $data[$i++] = $Array;
            }
        }

        mysqli_free_result($result);

        if( count( $data ) > 0 )
            return $data;
        else
            return NULL;
    }

    /**
     * 运行Sql,以数组方式返回结果集第一条记录
     *
     * @param string $sql
     * @return array 成功返回数组，失败时返回false
     * @author EasyChen
     */
    public function getLine( $sql )
    {
        return $this->get_line( $sql );
    }

    /**
     * 同getLine,向前兼容
     *
     * @param string $sql
     * @return array
     * @author EasyChen
     * @ignore
     */
    public function get_line( $sql )
    {
        $data = $this->get_data( $sql );
        if ($data) {
            return @reset($data);
        } else {
            return false;
        }
    }

    /**
     * 运行Sql,返回结果集第一条记录的第一个字段值
     *
     * @param string $sql
     * @return mixxed 成功时返回一个值，失败时返回false
     * @author EasyChen
     */
    public function getVar( $sql )
    {
        return $this->get_var( $sql );
    }

    /**
     * 同getVar,向前兼容
     *
     * @param string $sql
     * @return array
     * @author EasyChen
     * @ignore
     */
    public function get_var( $sql )
    {
        $data = $this->get_line( $sql );
        if ($data) {
            return $data[ @reset(@array_keys( $data )) ];
        } else {
            return false;
        }
    }

    /**
     * 同mysqli_affected_rows函数
     *
     * @return int 成功返回行数,失败时返回-1
     * @author Elmer Zhang
     */
    public function affectedRows()
    {
        $result = isset($this->db_write) ? mysqli_affected_rows( $this->db_write ) : -1;
        return $result;
    }

    /**
     * 同mysqli_insert_id函数
     *
     * @return int 成功返回last_id,失败时返回false
     * @author EasyChen
     */
    public function lastId()
    {
        return $this->last_id();
    }

    /**
     * 同lastId,向前兼容
     *
     * @return int
     * @author EasyChen
     * @ignore
     */
    public function last_id()
    {
        $result = mysqli_insert_id( $this->db_write( false ) );
        return $result;
    }

    /**
     * 关闭数据库连接
     *
     * @return bool
     * @author EasyChen
     */
    public function closeDb()
    {
        return $this->close_db();
    }

    /**
     * 同closeDb,向前兼容
     *
     * @return bool
     * @author EasyChen
     * @ignore
     */
    public function close_db()
    {
        if( isset( $this->db_read ) )
            @mysqli_close( $this->db_read );

        if( isset( $this->db_write ) )
            @mysqli_close( $this->db_write );

    }

    /**
     *  同mysqli_real_escape_string
     *
     * @param string $str
     * @return string
     * @author EasyChen
     */
    public function escape( $str )
    {
        if( isset($this->db_read) ) {
            $db = $this->db_read;
        } elseif( isset($this->db_write) ) {
            $db = $this->db_write;
        } else {
            $db = $this->db_read();
        }

        return mysqli_real_escape_string( $db , $str );
    }

    /**
     * 返回错误码
     *
     *
     * @return int
     * @author EasyChen
     */
    public function errno()
    {
        return     $this->errno;
    }

    /**
     * 返回错误信息
     *
     * @return string
     * @author EasyChen
     */
    public function error()
    {
        return $this->error;
    }

    /**
     * 返回错误信息,error的别名
     *
     * @return string
     * @author EasyChen
     */
    public function errmsg()
    {
        return $this->error();
    }

    /**
     * @ignore
     */
    private function connect( $is_master = true )
    {
        if ($this->port == 0) {
            $this->error = 13048;
            $this->errno = 'Not Initialized';
            return false;
        }
        if( $is_master ) $host = 'w' . $this->host;
        else $host = 'r' . $this->host;

        $db = mysqli_init();
        mysqli_options($db, MYSQLI_OPT_CONNECT_TIMEOUT, 5);

        if( !mysqli_real_connect( $db, $host , $this->accesskey , $this->secretkey , $this->appname , $this->port ) )
        {
            $this->error = mysqli_connect_error();
            $this->errno = mysqli_connect_errno();
            return false;
        }

        mysqli_set_charset( $db, $this->charset);

        return $db;
    }

    /**
     * @ignore
     */
    private function db_read()
    {
        if( isset( $this->db_read ) && mysqli_ping( $this->db_read ) )
        {
            return $this->db_read;
        }
        else
        {
            if( !$this->do_replication ) return $this->db_write();
            else
            {
                $this->db_read = $this->connect( false );
                return $this->db_read;
            }
        }
    }

    /**
     * @ignore
     */
    private function db_write( $reconnect = true )
    {
        if( isset( $this->db_write ) && ( $reconnect == false || mysqli_ping( $this->db_write ) ) )
        {
            return $this->db_write;
        }
        else
        {
            $this->db_write = $this->connect( true );
            return $this->db_write;
        }
    }

    /**
     * @ignore
     */
    private function save_error($dblink)
    {
        $this->error = mysqli_error($dblink);
        $this->errno = mysqli_errno($dblink);
    }

    private $error;
    private $errno;
    private $last_sql;


}