<?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\Driver;
use PDO;

/**
 * Sqlsrv数据库驱动
 */
class Sqlsrv extends Driver
{

    protected $selectSql = 'SELECT T1.* FROM (SELECT thinkphp.*, ROW_NUMBER() OVER (%ORDER%) AS ROW_NUMBER FROM (SELECT %DISTINCT% %FIELD% FROM %TABLE%%JOIN%%WHERE%%GROUP%%HAVING% %UNION%) AS thinkphp) AS T1 %LIMIT%%COMMENT%';
    // PDO连接参数
    protected $options = array(
        PDO::ATTR_CASE => PDO::CASE_LOWER,
        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
        PDO::ATTR_STRINGIFY_FETCHES => false,
        PDO::SQLSRV_ATTR_ENCODING => PDO::SQLSRV_ENCODING_UTF8
    );

    /**
     * 解析pdo连接的dsn信息
     * 
     * @access public
     * @param array $config
     *            连接信息
     * @return string
     */
    protected function parseDsn($config)
    {
        $dsn = 'sqlsrv:Database=' . $config['database'] . ';Server=' . $config['hostname'];
        if (! empty($config['hostport'])) {
            $dsn .= ',' . $config['hostport'];
        }
        
        return $dsn;
    }

    /**
     * 取得数据表的字段信息
     * 
     * @access public
     * @return array
     */
    public function getFields($tableName)
    {
        list ($tableName) = explode(' ', $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'");
        $info = array();
        if ($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' => false,
                    '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'];
        $this->parseBind(! empty($options['bind']) ? $options['bind'] : array());
        $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, ! empty($options['fetch_sql']) ? true : false);
    }

    /**
     * 删除记录
     * 
     * @access public
     * @param array $options
     *            表达式
     * @return false | integer
     */
    public function delete($options = array())
    {
        $this->model = $options['model'];
        $this->parseBind(! empty($options['bind']) ? $options['bind'] : array());
        $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, ! empty($options['fetch_sql']) ? true : false);
    }
}