#!/bin/bash
# 受控 A/B：隧道协议和连接数，哪个在"稳 + 快"上更好。
#
# 背景：
#   实测隧道大多稳（12/12），但每个请求稳定吃 ~1100ms 回源延迟。
#   而且日志里 i/o timeout 不少（最近 800 行 104 次），
#   说明有些 edge IP 连得很差（实测最慢那个 1331ms，最快的 146ms）。
#
#   假定：连接数多一些，撞上"慢 IP"的窗口就小一些。
#   QUIC 在多丢包下恢复更好（没有跨流的队头阻塞），但之前测
#   "http2 比 quic 稳" —— 那是连接建立阶段的观感，这次量真实请求。
#
# 组合：
#   http2 + 4   （当前配置，基线）
#   http2 + 6
#   quic  + 4
#   quic  + 6
#
# 每个组合：重启隧道 -> 等连接建齐 -> 打 20 次 -> 记录
#   成功率 / 中位耗时 / P90 / 连接数
set -u

URL=https://relay.xxmxxs.top/v1/health
UA='LanRemote/1.8.0'
SVC=/etc/systemd/system/lanremote-tunnel.service
BACKUP=/root/lanremote-tunnel.service.bak.$(date +%s)
cp -a "$SVC" "$BACKUP"

echo "  备份: $BACKUP"
echo "  原参数:"
grep -A3 'ExecStart' "$SVC" | grep -E 'protocol|ha-connections|edge-ip' | sed 's/^/    /'
echo

run_combo() {
    local proto="$1" conns="$2" label="$3"

    echo "════════ $label ════════"
    # 改参数
    if grep -q '\-\-protocol' "$SVC"; then
        sed -i "s/--protocol [a-z0-9]*/--protocol $proto/" "$SVC"
    else
        sed -i "s|\(ExecStart=.*cloudflared tunnel\)|\1 --protocol $proto|" "$SVC"
    fi
    if grep -q '\-\-ha-connections' "$SVC"; then
        sed -i "s/--ha-connections [0-9]*/--ha-connections $conns/" "$SVC"
    else
        sed -i "s|\(ExecStart=.*cloudflared tunnel\)|\1 --ha-connections $conns|" "$SVC"
    fi
    grep -oE '\-\-protocol [a-z0-9]+|--ha-connections [0-9]+' "$SVC" | tr '\n' ' ' | sed 's/^/  参数: /'
    echo

    systemctl daemon-reload
    systemctl restart lanremote-tunnel

    # 等连接建齐
    built=0
    for i in $(seq 1 24); do
        sleep 5
        n=$(curl -s --max-time 4 http://127.0.0.1:20241/metrics 2>/dev/null \
            | grep '^cloudflared_tunnel_ha_connections' | awk '{print $2}')
        if [ "${n:-0}" -ge "$conns" ]; then built="$n"; break; fi
    done
    echo "  连接建齐: ${built:-0}/$conns（等了 ${i}0 秒）"

    # 预热几次，跳过建连阶段的冷启动
    for i in 1 2 3; do curl -s -o /dev/null --max-time 20 -H "User-Agent: $UA" "$URL"; sleep 1; done

    # 正式测
    ok=0; times=()
    for i in $(seq 1 20); do
        out=$(curl -s -o /dev/null -w '%{http_code} %{time_total}' --max-time 30 -H "User-Agent: $UA" "$URL")
        code=$(echo "$out" | awk '{print $1}')
        ms=$(echo "$out" | awk '{printf "%d", $2*1000}')
        times+=("$ms")
        [ "$code" = "200" ] && ok=$((ok+1))
        sleep 1
    done

    stats=$(printf '%s\n' "${times[@]}" | sort -n | awk '{a[NR]=$1} END {
        p90 = a[int(NR*0.9)+1];
        printf "最小 %d  中位 %d  P90 %d  最大 %d", a[1], a[int(NR/2)+1], p90, a[NR]}')
    echo "  == 结果: $ok/20 成功   $stats ms"
    echo

    # 存下来给最后比较
    echo "$label|$ok|$stats" >> /tmp/ab_result.txt
}

rm -f /tmp/ab_result.txt

run_combo http2 4 "A. http2 + 4（基线，当前配置）"
run_combo http2 6 "B. http2 + 6"
run_combo quic  4 "C. quic + 4"
run_combo quic  6 "D. quic + 6"

echo "════════ 汇总 ════════"
cat /tmp/ab_result.txt | sed 's/^/  /'

echo
echo "════════ 回滚到基线（http2 + 4），等后面按结果再定 ════════"
cp -a "$BACKUP" "$SVC"
systemctl daemon-reload
systemctl restart lanremote-tunnel
sleep 20
echo "  已回滚。当前参数:"
grep -oE '\-\-protocol [a-z0-9]+|--ha-connections [0-9]+' "$SVC" | sed 's/^/    /'
echo "  连接数: $(curl -s --max-time 5 http://127.0.0.1:20241/metrics 2>/dev/null | grep '^cloudflared_tunnel_ha_connections' | awk '{print $2}')"