#!/bin/bash
# 查为什么轻负载 OK、密集请求就 502/530。
#
# 现象：
#   每 2 秒打一次健康检查 -> 15/15 全通
#   e2e 测试（密集请求 + 长轮询 + 256KB）-> 全 502/530
#
# 502 = Cloudflare 到不了源站；530 = 源站 DNS 错误。
# 但源站就是本机 127.0.0.1:8080 —— 那说明 cloudflared 自己的连接掉了。
set -u

RELAY_DIR=/root/lanremote-relay
URL=https://relay.xxmxxs.top

echo "===== 1. 隧道当前状态 ====="
echo "  服务: $(systemctl is-active lanremote-tunnel)"
echo "  已注册连接: $(grep -c 'Registered tunnel connection' $RELAY_DIR/tunnel.log 2>/dev/null || echo 0)"
echo "  连接断开: $(grep -c 'Connection terminated' $RELAY_DIR/tunnel.log 2>/dev/null || echo 0)"
echo "  quic 错误: $(grep -c 'Failed to dial a quic' $RELAY_DIR/tunnel.log 2>/dev/null || echo 0)"
echo
echo "  日志最近 6 行："
tail -6 "$RELAY_DIR/tunnel.log" 2>/dev/null | sed 's/^/    /'

echo
echo "===== 2. 轻负载（每 2 秒一次，10 次）====="
OK=0
for i in $(seq 1 10); do
    C=$(timeout 20 curl -4 -s -o /dev/null -w '%{http_code}' -H 'User-Agent: LanRemote/1.4.0' "$URL/v1/health" 2>/dev/null)
    [ "$C" = "200" ] && OK=$((OK+1))
    printf "    %2d: %s\n" "$i" "${C:-超时}"
    sleep 2
done
echo "  轻负载 $OK/10"

echo
echo "===== 3. 密集负载（不间隔，20 次）====="
DOK=0
for i in $(seq 1 20); do
    C=$(timeout 20 curl -4 -s -o /dev/null -w '%{http_code}' -H 'User-Agent: LanRemote/1.4.0' "$URL/v1/health" 2>/dev/null)
    [ "$C" = "200" ] && DOK=$((DOK+1))
    printf "    %2d: %s\n" "$i" "${C:-超时}"
done
echo "  密集负载 $DOK/20"

echo
echo "===== 4. 大包（256KB 上传）====="
head -c 262144 /dev/zero | tr '\0' 'A' > /tmp/big.bin
C=$(timeout 60 curl -4 -s -o /dev/null -w '%{http_code}' \
    -H 'User-Agent: LanRemote/1.4.0' \
    -X POST --data-binary @/tmp/big.bin "$URL/v1/admin/devices" 2>/dev/null)
echo "  256KB POST: HTTP ${C:-超时}"
rm -f /tmp/big.bin

echo
echo "===== 5. 大包之后隧道还活着吗 ====="
echo "  已注册连接: $(grep -c 'Registered tunnel connection' $RELAY_DIR/tunnel.log 2>/dev/null || echo 0)"
echo "  连接断开: $(grep -c 'Connection terminated' $RELAY_DIR/tunnel.log 2>/dev/null || echo 0)"
echo
echo "  日志最近 8 行："
tail -8 "$RELAY_DIR/tunnel.log" 2>/dev/null | sed 's/^/    /'

echo
echo "===== 6. 源站（本地）在同一时刻的表现 ====="
LOK=0
for i in $(seq 1 20); do
    C=$(timeout 8 curl -s -o /dev/null -w '%{http_code}' http://127.0.0.1:8080/v1/health)
    [ "$C" = "200" ] && LOK=$((LOK+1))
done
echo "  本地源站 $LOK/20"

echo
echo "===== 7. 结论 ====="
echo "  轻负载 $OK/10   密集 $DOK/20   本地 $LOK/20"
if [ "$LOK" -ge 19 ] && [ "$DOK" -lt 10 ]; then
    echo "  -> 源站没问题，是**隧道在密集请求下扛不住**"
    echo "     这条 4G 线路的带宽/丢包撑不住高并发。"
    echo "     客户端本身的失败重试就是关键（被控端/手表都有）。"
elif [ "$LOK" -lt 15 ]; then
    echo "  -> 源站也有问题，去看 relay.log"
fi