<?php

namespace loyalsoft;

// php + mysql fuction class
//error_reporting(E_ALL & ~ E_NOTICE);

/**
 * CDB工具类[APHP三大操作单元之一]
 * @author jgao
 */
class CDbUtil
{

    public $conn = 0;

    public function dbconn($dbhost, $dbport, $dbuser, $dbpw, $dbname)
    {
//        CLogUtil::output("数据库初始化: $dbhost,$dbport,$dbuser,$dbpw,$dbname");
//        DebugHelper::log2file($dbhost, $dbport, $dbname, $dbuser, $dbpw);
        $this->conn = mysqli_connect($dbhost, $dbuser, $dbpw, $dbname, $dbport, true);
        !$this->conn && $this->halt("Connect to MySQL failed");
        $serverinfo = mysqli_get_server_info($this->conn);
        if ($serverinfo > '4.1' && $GLOBALS['charset']) {
            mysqli_query($this->conn, "SET character_set_connection=" . $GLOBALS['charset'] . ",character_set_results=" . $GLOBALS['charset'] . ",character_set_client=binary");
        }
        if ($serverinfo > '5.0') {
            mysqli_query($this->conn, "SET sql_mode=''");
        }
        if ($dbname && !mysqli_select_db($this->conn, $dbname)) {
            $this->halt('Cannot use database');
        }
    }

    public function select_db($dbname)
    {
        if (!mysqli_select_db($this->conn, $dbname)) {
            $this->halt('Cannot use database');
        }
    }

    public function server_info()
    {
        return mysqli_get_server_info($this->conn);
    }

    public function insert_id()
    {
        $arr = $this->fetch_array('SELECT LAST_INSERT_ID() as id');
        return $arr["id"];
    }

    public function get_value($SQL, $offset = 0, $field = 0)
    {
        $rt = $this->fetch_result($SQL);
        if (isset($rt[$offset][$field])) {
            return $rt[$offset][$field];
        }
        return false;
    }

    /**
     * 执行查询
     * @param type $SQL
     * @param type $method
     * @param type $error
     * @return mixed
     */
    public function query($SQL, $method = null, $error = true)
    {
        $query = mysqli_query($this->conn, $SQL);
        !$query && $error && $this->halt('Query Error: ' . $SQL);
        return $query;
    }

    /**
     * 执行更新的时候加上事物逻辑
     * @param type $SQL
     * @return int errno
     */
    public function safeQuery($SQL)
    {
        mysql_query('start transaction');
        mysql_query('SET autocommit=0');
        $query = mysql_query($SQL, $this->conn);
        $err = mysql_errno();
        if ($err && !$query) {
            mysql_query('rollback');
        } else {
            mysql_query('commit');
        }
        mysql_query('SET autocommit=1');
        return $err;
    }

    /**
     * 将查询结果作为索引数组返回
     * @param string $SQL
     * @return array
     */
    public function fetch_row($SQL)
    {
        return $this->fetch_result($SQL, MYSQLI_NUM);
    }

    /**
     * 将查询结果作为关联数组返回
     * @param string $SQL
     * @return array
     */
    public function fetch_array($SQL)
    {
        return $this->fetch_result($SQL, MYSQLI_ASSOC);
    }

    /**
     * 从结果中取一行作为结果返回
     * @param string $SQL
     * @param int $result_type 1. 关联数组, 2. 索引数组, 3 both
     * @return type
     */
    public function fetch_result($SQL, $result_type = MYSQLI_BOTH)
    {
        $arr = array();
        $query = $this->query($SQL);
        $data = mysqli_fetch_array($query, $result_type);
        while ($data) {
            $arr[] = $data;
            $data = mysqli_fetch_array($query, $result_type);
        }
        $this->free_result();
        return $arr;
    }

    public function affected_rows()
    {
        return mysqli_affected_rows($this->conn);
    }

    /**
     * 调取结果集中行的数目
     * @param type $SQL
     * @return int
     */
    public function num_rows($SQL)
    {
        $query = $this->query($SQL);
        if (!is_bool($query)) {
            return mysqli_num_rows($query);
        }
        return 0;
    }

    public function num_fields($SQL)
    {
        $query = $this->query($SQL);
        return mysqli_num_fields($query);
    }

    public function escape_string($str)
    {
        return mysqli_real_escape_string($this->conn, $str);
    }

    public function free_result()
    {
        $void = func_get_args();
        foreach ($void as $query) {
            if (is_resource($query) && get_resource_type($query) === 'mysql result') {
                mysqli_free_result($query);
            }
        }
        unset($void);
    }

    public function close()
    {
        $this->free_result();
        return mysqli_close($this->conn);
    }

    public function halt($msg = null)
    {
        exit($msg . '<br /><br />' . mysqli_error($this->conn));
    }

}