<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2014 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
namespace Think\Db\Driver;
use Think\Db;
defined('THINK_PATH') or exit();
/**
 * Sqlsrv数据库驱动
 */
class Sqlsrv extends Db{
    protected $selectSql  =     'SELECT T1.* FROM (SELECT thinkphp.*, ROW_NUMBER() OVER (%ORDER%) AS ROW_NUMBER FROM (SELECT %DISTINCT% %FIELD% FROM %TABLE%%JOIN%%WHERE%%GROUP%%HAVING%) AS thinkphp) AS T1 %LIMIT%%COMMENT%';
    /**
     * 架构函数 读取数据库配置信息
     * @access public
     * @param array $config 数据库配置数组
     */
    public function __construct($config='') {
        if ( !function_exists('sqlsrv_connect') ) {
            E(L('_NOT_SUPPERT_').':sqlsrv');
        }
        if(!empty($config)) {
            $this->config	=	$config;
        }
    }

    /**
     * 连接数据库方法
     * @access public
     */
    public function connect($config='',$linkNum=0) {
        if ( !isset($this->linkID[$linkNum]) ) {
            if(empty($config))	$config  =  $this->config;
            $host = $config['hostname'].($config['hostport']?",{$config['hostport']}":'');
            $connectInfo  =  array('Database'=>$config['database'],'UID'=>$config['username'],'PWD'=>$config['password'],'CharacterSet' => C('DEFAULT_CHARSET'));
            $this->linkID[$linkNum] = sqlsrv_connect( $host, $connectInfo);
            if ( !$this->linkID[$linkNum] )  $this->error(false);
        }
        return $this->linkID[$linkNum];
    }

    /**
     * 释放查询结果
     * @access public
     */
    public function free() {
        sqlsrv_free_stmt($this->queryID);
        $this->queryID = null;
    }

    /**
     * 执行查询  返回数据集
     * @access public
     * @param string $str  sql指令
     * @param array $bind 参数绑定
     * @return mixed
     */
    public function query($str,$bind=array()) {
        $this->initConnect(false);
        if ( !$this->_linkID ) return false;
        //释放前次的查询结果
        if ( $this->queryID ) $this->free();
        N('db_query',1);
        // 记录开始执行时间
        G('queryStartTime');
        $str    =   str_replace(array_keys($bind),'?',$str);
        $bind   =   array_values($bind);
        $this->queryStr = $str;
        $this->queryID = sqlsrv_query($this->_linkID,$str,$bind, array( "Scrollable" => SQLSRV_CURSOR_KEYSET));
        $this->debug();
        if ( false === $this->queryID ) {
            $this->error();
            return false;
        } else {
            $this->numRows = sqlsrv_num_rows($this->queryID);
            return $this->getAll();
        }
    }

    /**
     * 执行语句
     * @access public
     * @param string $str  sql指令
     * @param array $bind 参数绑定
     * @return integer
     */
    public function execute($str,$bind=array()) {
        $this->initConnect(true);
        if ( !$this->_linkID ) return false;
        //释放前次的查询结果
        if ( $this->queryID ) $this->free();
        N('db_write',1);
        // 记录开始执行时间
        G('queryStartTime');
        $str    =   str_replace(array_keys($bind),'?',$str);
        $bind   =   array_values($bind);
        $this->queryStr = $str;
        $this->queryID=	sqlsrv_query($this->_linkID,$str,$bind);
        $this->debug();
        if ( false === $this->queryID ) {
            $this->error();
            return false;
        } else {
            $this->numRows = sqlsrv_rows_affected($this->queryID);
            $this->lastInsID = $this->mssql_insert_id();
            return $this->numRows;
        }
    }

    /**
     * 用于获取最后插入的ID
     * @access public
     * @return integer
     */
    public function mssql_insert_id() {
        $query  =   "SELECT @@IDENTITY as last_insert_id";
        $result =   sqlsrv_query($this->_linkID,$query);
        list($last_insert_id)   =   sqlsrv_fetch_array($result);
        sqlsrv_free_stmt($result);
        return $last_insert_id;
    }

    /**
     * 启动事务
     * @access public
     * @return void
     */
    public function startTrans() {
        $this->initConnect(true);
        if ( !$this->_linkID ) return false;
        //数据rollback 支持
        if ($this->transTimes == 0) {
            sqlsrv_begin_transaction($this->_linkID);
        }
        $this->transTimes++;
        return ;
    }

    /**
     * 用于非自动提交状态下面的查询提交
     * @access public
     * @return boolen
     */
    public function commit() {
        if ($this->transTimes > 0) {
            $result = sqlsrv_commit($this->_linkID);
            $this->transTimes = 0;
            if(!$result){
                $this->error();
                return false;
            }
        }
        return true;
    }

    /**
     * 事务回滚
     * @access public
     * @return boolen
     */
    public function rollback() {
        if ($this->transTimes > 0) {
            $result = sqlsrv_rollback($this->_linkID);
            $this->transTimes = 0;
            if(!$result){
                $this->error();
                return false;
            }
        }
        return true;
    }

    /**
     * 获得所有的查询数据
     * @access private
     * @return array
     */
    private function getAll() {
        //返回数据集
        $result = array();
        if($this->numRows >0) {
            while($row = sqlsrv_fetch_array($this->queryID,SQLSRV_FETCH_ASSOC))
                $result[]   =   $row;
        }
        return $result;
    }

    /**
     * 取得数据表的字段信息
     * @access public
     * @return array
     */
    public function getFields($tableName) {
        $result = $this->query("
            SELECT column_name,data_type,column_default,is_nullable
            FROM   information_schema.tables AS t
            JOIN   information_schema.columns AS c
            ON     t.table_catalog = c.table_catalog
            AND    t.table_schema  = c.table_schema
            AND    t.table_name    = c.table_name
            WHERE  t.table_name = '{$tableName}'");
        $pk = $this->query("SELECT * FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE WHERE TABLE_NAME='{$tableName}'");
        $info = array();
        if($result) {
            foreach ($result as $key => $val) {
                $info[$val['column_name']] = array(
                    'name'    => $val['column_name'],
                    'type'    => $val['data_type'],
                    'notnull' => (bool) ($val['is_nullable'] === ''), // not null is empty, null is yes
                    'default' => $val['column_default'],
                    'primary' => $val['column_name'] == $pk[0]['COLUMN_NAME'],
                    'autoinc' => false,
                );
            }
        }
        return $info;
    }

    /**
     * 取得数据表的字段信息
     * @access public
     * @return array
     */
    public function getTables($dbName='') {
        $result   =  $this->query("SELECT TABLE_NAME
            FROM INFORMATION_SCHEMA.TABLES
            WHERE TABLE_TYPE = 'BASE TABLE'
            ");
        $info   =   array();
        foreach ($result as $key => $val) {
            $info[$key] = current($val);
        }
        return $info;
    }

	/**
     * order分析
     * @access protected
     * @param mixed $order
     * @return string
     */
    protected function parseOrder($order) {
        return !empty($order)?  ' ORDER BY '.$order:' ORDER BY rand()';
    }

    /**
     * 字段名分析
     * @access protected
     * @param string $key
     * @return string
     */
    protected function parseKey(&$key) {
        $key   =  trim($key);
        if(!is_numeric($key) && !preg_match('/[,\'\"\*\(\)\[.\s]/',$key)) {
           $key = '['.$key.']';
        }
        return $key;   
    }
    
    /**
     * limit
     * @access public
     * @param mixed $limit
     * @return string
     */
    public function parseLimit($limit) {
		if(empty($limit)) return '';
        $limit	=	explode(',',$limit);
        if(count($limit)>1)
            $limitStr	=	'(T1.ROW_NUMBER BETWEEN '.$limit[0].' + 1 AND '.$limit[0].' + '.$limit[1].')';
		else
            $limitStr = '(T1.ROW_NUMBER BETWEEN 1 AND '.$limit[0].")";
        return 'WHERE '.$limitStr;
    }

    /**
     * 更新记录
     * @access public
     * @param mixed $data 数据
     * @param array $options 表达式
     * @return false | integer
     */
    public function update($data,$options) {
        $this->model  =   $options['model'];
        $sql   = 'UPDATE '
            .$this->parseTable($options['table'])
            .$this->parseSet($data)
            .$this->parseWhere(!empty($options['where'])?$options['where']:'')
            .$this->parseLock(isset($options['lock'])?$options['lock']:false)
            .$this->parseComment(!empty($options['comment'])?$options['comment']:'');
        return $this->execute($sql,$this->parseBind(!empty($options['bind'])?$options['bind']:array()));
    }

    /**
     * 删除记录
     * @access public
     * @param array $options 表达式
     * @return false | integer
     */
    public function delete($options=array()) {
        $this->model  =   $options['model'];
        $sql   = 'DELETE FROM '
            .$this->parseTable($options['table'])
            .$this->parseWhere(!empty($options['where'])?$options['where']:'')
            .$this->parseLock(isset($options['lock'])?$options['lock']:false)
            .$this->parseComment(!empty($options['comment'])?$options['comment']:'');
        return $this->execute($sql,$this->parseBind(!empty($options['bind'])?$options['bind']:array()));
    }

    /**
     * 关闭数据库
     * @access public
     */
    public function close() {
        if ($this->_linkID){
            sqlsrv_close($this->_linkID);
        }
        $this->_linkID = null;
    }

    /**
     * 数据库错误信息
     * 并显示当前的SQL语句
     * @access public
     * @return string
     */
    public function error($result = true) {
        $errors = sqlsrv_errors();
        $this->error    =   '';
        foreach( $errors as $error ) {
            $this->error .= $error['code'].':'.$error['message'];
        }
        if('' != $this->queryStr){
            $this->error .= "\n [ SQL语句 ] : ".$this->queryStr;
        }
        $result? trace($this->error,'','ERR'):E($this->error);
        return $this->error;
    }
}