#!/bin/bash
# 深挖 api.cloudflare.com 为什么连不上 —— 下载登录证书必须走它。
set -u

echo "===== 1. DNS：分别看 A 和 AAAA ====="
for tool in "dig +short A" "dig +short AAAA" "nslookup -type=A"; do
    echo "  --- $tool ---"
    timeout 8 $tool api.cloudflare.com 2>/dev/null | head -6 | sed 's/^/    /'
done
echo
echo "  系统解析器（getent）："
getent ahostsv4 api.cloudflare.com | head -3 | sed 's/^/    v4: /'
getent ahostsv6 api.cloudflare.com | head -3 | sed 's/^/    v6: /'

echo
echo "===== 2. 强制 IPv4 详细过程 ====="
timeout 15 curl -4 -v -o /dev/null https://api.cloudflare.com/client/v4/user 2>&1 \
    | grep -E 'Trying|Connected|error|refused|timed|SSL|HTTP/' | head -10 | sed 's/^/  /'

echo
echo "===== 3. 换一个 Cloudflare 域名对比 ====="
for host in api.cloudflare.com www.cloudflare.com cloudflare.com dash.cloudflare.com; do
    OUT=$(timeout 10 curl -4 -s -o /dev/null -w '%{http_code} %{time_total}s' "https://$host" 2>/dev/null)
    printf "  %-26s %s\n" "$host" "${OUT:-超时}"
done

echo
echo "===== 4. 用指定 IP 直连（绕过 DNS）====="
# api.cloudflare.com 的 IPv4 通常是 104.16.x.x / 104.17.x.x
for ip in 104.16.132.229 104.16.133.229 104.17.0.1; do
    OUT=$(timeout 10 curl -4 -s -o /dev/null -w '%{http_code} %{time_total}s' \
          --resolve "api.cloudflare.com:443:$ip" \
          https://api.cloudflare.com/client/v4/user 2>/dev/null)
    printf "  经 %-16s -> %s\n" "$ip" "${OUT:-超时}"
done

echo
echo "===== 5. 走 Tunnel 那条路（它一直通）====="
OUT=$(timeout 10 curl -4 -s -o /dev/null -w '%{http_code} %{time_total}s' \
      https://region1.v2.argotunnel.com 2>/dev/null)
echo "  region1.v2.argotunnel.com -> ${OUT:-超时}"

echo
echo "===== 6. 结论 ====="
CODE=$(timeout 10 curl -4 -s -o /dev/null -w '%{http_code}' https://api.cloudflare.com/client/v4/user 2>/dev/null)
if [ "$CODE" = "200" ]; then
    echo "  api.cloudflare.com 通 —— 证书应该能下下来"
else
    echo "  api.cloudflare.com 不通（HTTP ${CODE:-000}）"
    echo "  这就是 cloudflared 报 Failed to fetch resource 的原因。"
    echo
    echo "  绕过办法：授权后让浏览器下载 cert.pem，"
    echo "  再手动放到 /root/.cloudflared/cert.pem"
fi