// 429 详情探针：打印 429 响应的全部头部 + 响应体，看清 CDN 到底怎么限的。
//
//	go run ./tools/probe429 -v <图片URL>
package main

import (
	"fmt"
	"io"
	"net/http"
	"os"
	"strings"
	"time"
)

func main() {
	if len(os.Args) < 2 {
		fmt.Fprintln(os.Stderr, "用法: go run ./tools/probe429 [-v] <图片URL>")
		os.Exit(1)
	}
	url := os.Args[len(os.Args)-1]
	verbose := false
	for _, a := range os.Args {
		if a == "-v" {
			verbose = true
		}
	}

	// 先探一张，看当前状态
	for round := 1; round <= 3; round++ {
		status, hdr, body, err := fullProbe(url, verbose)
		if err != nil {
			fmt.Printf("[第%d轮] 错误: %v\n", round, err)
			continue
		}
		fmt.Printf("[第%d轮] HTTP %d\n", round, status)
		if verbose || status == 429 {
			for _, k := range []string{
				"Retry-After", "X-RateLimit-Limit", "X-RateLimit-Remaining",
				"X-RateLimit-Reset", "X-Cache", "CF-RateLimited",
				"Server", "Content-Type", "X-Jetpack-Cache",
			} {
				if v := hdr.Get(k); v != "" {
					fmt.Printf("        %s: %s\n", k, v)
				}
			}
			if s := strings.TrimSpace(body); s != "" {
				fmt.Printf("        body: %.300s\n", s)
			}
		}
		if status == 200 {
			fmt.Println("        ✓ 这次成功了")
			break
		}
		if round < 3 {
			time.Sleep(3 * time.Second)
		}
	}
}

func fullProbe(url string, verbose bool) (int, http.Header, string, error) {
	tr := &http.Transport{ForceAttemptHTTP2: true}
	defer tr.CloseIdleConnections()
	client := &http.Client{Transport: tr, Timeout: 25 * time.Second}

	req, err := http.NewRequest(http.MethodGet, url, nil)
	if err != nil {
		return 0, nil, "", err
	}
	// 用我们客户端的头
	req.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36")
	req.Header.Set("Accept", "image/webp,image/*,*/*;q=0.8")
	req.Header.Set("Referer", "https://migmg.ssuu.uk/")

	resp, err := client.Do(req)
	if err != nil {
		return 0, nil, "", err
	}
	defer resp.Body.Close()
	b, _ := io.ReadAll(io.LimitReader(resp.Body, 4096))

	fmt.Printf("        Proto=%s  (2=HTTP/2, 1.1=HTTP/1.1)\n", resp.Proto)
	return resp.StatusCode, resp.Header, string(b), nil
}