<?php
/**
 * 统一 JSON 返回类
 * 用法：Response::success($data, $msg) / Response::error($msg, $code)
 */
class Response
{
    /**
     * 成功返回
     * @param mixed $data
     * @param string $msg
     */
    public static function success($data = null, $msg = '操作成功')
    {
        self::json(['code' => 0, 'msg' => $msg, 'data' => $data]);
    }

    /**
     * 失败返回
     * @param string $msg
     * @param int $code  非0错误码（401未登录/403无权限/400参数错误/1业务错误）
     */
    public static function error($msg = '操作失败', $code = 1)
    {
        self::json(['code' => $code, 'msg' => $msg]);
    }

    private static function json($payload)
    {
        header('Content-Type: application/json; charset=utf-8');
        echo json_encode($payload, JSON_UNESCAPED_UNICODE);
        exit;
    }
}