<?php

namespace app\common\middleware;

use think\facade\Cache;
use think\Response;

class RateLimitMiddleware
{
    // 频率限制配置（单位：秒）
    protected $rules = [
        'ip' => ['limit' => 20, 'window' => 60],    // 每IP每分钟10次
        'mobile' => ['limit' => 20, 'window' => 3600] // 每手机号每小时5次
    ];

    public function handle($request, \Closure $next)
    {
        $mobile = $request->param('mobile');
        $ip = $request->ip();

        // IP频率检查
        $ipKey = "rate:ip:{$ip}";
        if (!$this->checkRate($ipKey, $this->rules['ip'])) {
            return $this->tooManyRequests('IP请求过于频繁');
        }

        // 手机号频率检查
        $mobileKey = "rate:mobile:{$mobile}";
        if (!$this->checkRate($mobileKey, $this->rules['mobile'])) {
            return $this->tooManyRequests('该手机号请求过于频繁');
        }

        return $next($request);
    }

    protected function checkRate(string $key, array $rule): bool
    {
        $count = Cache::get($key, 0);

        if ($count >= $rule['limit']) {
            return false;
        }

        Cache::inc($key);
        if ($count === 0) {
            Cache::expire($key, $rule['window']);
        }

        return true;
    }

    protected function tooManyRequests(string $message): Response
    {
        return json([
            'code' => 429,
            'msg' => $message,
            'data' => null
        ])->code(429);
    }
}