<?php

namespace app\middleware;

use app\controller\MetricsController;
use support\Request;
use Webman\Http\Response;

/**
 * 指标收集中间件
 * 自动记录HTTP请求指标
 */
class MetricsMiddleware
{
    /**
     * 请求开始时间
     */
    protected $startTime;

    /**
     * 处理请求
     *
     * @param Request $request
     * @param callable $handler
     * @return Response
     */
    public function process(Request $request, callable $handler): Response
    {
        // 记录请求开始时间
        $this->startTime = microtime(true);
        
        // 处理请求
        $response = $handler($request);
        
        // 计算请求处理时间
        $duration = microtime(true) - $this->startTime;
        
        // 记录指标
        $this->recordMetrics($request, $response, $duration);
        
        return $response;
    }

    /**
     * 记录指标
     *
     * @param Request $request
     * @param Response $response
     * @param float $duration
     */
    protected function recordMetrics(Request $request, Response $response, float $duration): void
    {
        try {
            $method = $request->method();
            $path = $request->path();
            $status = $response->getStatusCode();
            
            // 获取响应大小
            $responseSize = strlen($response->rawBody());
            
            // 记录HTTP请求指标
            MetricsController::recordHttpRequest($method, $path, $status, $duration, $responseSize);
            
            // 记录请求处理时间
            MetricsController::setGauge('webman_http_request_duration_seconds', $duration, [
                'method' => $method,
                'path' => $path,
                'status' => (string)$status
            ]);
            
        } catch (\Exception $e) {
            // 记录指标失败不应影响正常请求
            error_log('Metrics recording failed: ' . $e->getMessage());
        }
    }
}