<?php

require_once $_SERVER["DOCUMENT_ROOT"] . "/config.php";
require_once $_SERVER["DOCUMENT_ROOT"] . "/Log.php";

interface DoExcute
{
//    参数处理
    function bind_param(mysqli_stmt $stmt, array $param = null);

//    执行结果处理
    function doResult(mysqli_stmt $stmt);
}


interface DoConn
{
//    连接关闭前处理
    function before_close(mysqli $conn);
}

class DbUtil
{

    private static function getConn()
    {
        try {
            $conn = new mysqli(db_config["servername"], db_config["username"], db_config["password"], db_config["dbname"]);
            if ($conn->connect_error) {
                error("数据库连接失败,请检查数据库配置" . "服务器:" . db_config["servername"] . ",用户名:" . db_config["username"] . ",密码:" . db_config["password"] . ",数据库：" . db_config["dbname"] . "是否正确");
                throw new Exception("数据库连接失败");
            } else {
                info("数据库连接成功");
            }
            return $conn;
        } catch (Exception $e) {
            error("数据库连接异常" . $e);
        }
    }

    private static function closeConn(mysqli $conn)
    {
        try {
            if ($conn->close()) {
                info("成功关闭数据库");
            } else {
                error("无法关闭数据库");
            }
        } catch (Exception $e) {
            error("关闭数据库连接出现异常：" . $e);
        }
    }

//    插入数据
    public static function modify($action, $sql, DoConn $do_conn = null, $types = null, ...$_)
    {

        try {// 创建连接
            $conn = self::getConn();
            if (!is_null($conn)) {
                $stmt = $conn->prepare($sql);//创建一个预定义的对象 ?占位
                if ($stmt instanceof mysqli_stmt) {
                    if (!is_null($types)) {

                        if (strlen($types) == count($_)) {
                            $stmt->bind_param($types, ...$_);//        参数绑定
                        } else {
                            throw new Exception("预处理sql" . $sql . ",参数绑定类型" . $types . "跟参数数量" . var_dump($_) . "不匹配");
                        }
                    }
                    $stmt->execute();//        执行sql
                    info($action . $stmt->affected_rows . "条数据");
                    $stmt->close();
                    info("执行sql.$sql.成功");
                    if (!is_null($do_conn)) {
                        $do_conn->before_close($conn);
                    }
                } else {
                    throw new Exception("预处理sql异常，无法处理sql" . $sql . ".");
                }
                self::closeConn($conn);//        关闭连接
            }
        } catch (Exception $e) {
            error($action . "数据异常" . $e);
        }
    }

//    插入数据
    public static function insert($sql, $db_conn = null, $types = null, ...$_)
    {
        self::modify("插入", $sql, $db_conn, $types, ...$_);
    }

//    更新数据
    public static function update($sql, $db_conn = null, $types = null, ...$_)
    {
        self::modify("更新", $sql, $db_conn, $types, ...$_);
    }

//    删除数据
    public static function delete($sql, $db_conn = null, $types = null, ...$_)
    {
        self::modify("删除", $sql, $db_conn, $types, ...$_);
    }


//查询数据
    public static function query($sql, DoExcute $doExcute, array $param = null)
    {
        try {// 创建连接
            $conn = self::getConn();
            if (!is_null($conn)) {
                $stmt = $conn->prepare($sql);//创建一个预定义的对象 ?占位
                if ($stmt instanceof mysqli_stmt) {
                    $doExcute->bind_param($stmt, $param);
                    $stmt->execute();//        执行sql
                    $doExcute->doResult($stmt);
                    info("执行sql.$sql.成功");
                    $stmt->close();
                } else {
                    throw new Exception("预处理sql异常，无法处理sql" . $sql . ".");
                }
            } else {
                throw new Exception("无法连接数据库");
            }
            //        关闭连接
            self::closeConn($conn);
        } catch (Exception $e) {
            error("查询数据异常" . $e);
            throw $e;
        }
    }
}