#!/bin/bash
# 强制隧道走 IPv4 + HTTP2。
#
# 根因：这条 4G 线路**分配了 IPv6 地址但实际不通**。
# Cloudflare 边缘默认优先 IPv6（日志里是 2606:4700:a8::10），
# 于是每次建隧道都在等一个永远连不上的地址 -> context deadline exceeded。
#
# 修法：
#   --edge-ip-version 4   只走 IPv4
#   --protocol http2      用 TCP 而不是 QUIC（有些 4G 会拦 UDP）
set -u

RELAY_DIR=/root/lanremote-relay

echo "===== 确认 IPv4 / IPv6 ====="
timeout 6 curl -4 -s -o /dev/null -w '  IPv4 -> %{http_code}\n' https://www.cloudflare.com || echo '  IPv4 不通'
timeout 6 curl -6 -s -o /dev/null -w '  IPv6 -> %{http_code}\n' https://www.cloudflare.com || echo '  IPv6 不通（这就是根因）'

echo
echo "===== 更新 systemd 服务，加 IPv4 参数 ====="
systemctl stop lanremote-tunnel 2>/dev/null || true
pkill -f 'cloudflared tunnel' 2>/dev/null || true
sleep 2

cat > /etc/systemd/system/lanremote-tunnel.service <<'UNIT'
[Unit]
Description=LanRemote Cloudflare 隧道
After=network-online.target lanremote-relay.service
Wants=network-online.target
Requires=lanremote-relay.service

[Service]
Type=simple
# 这条 4G 线路的 IPv6 有地址但不通，必须强制 IPv4；
# 同时用 http2 而不是 QUIC，避开某些 4G 对 UDP 的拦截。
ExecStart=/usr/local/bin/cloudflared tunnel --no-autoupdate \
    --edge-ip-version 4 --protocol http2 \
    --url http://127.0.0.1:8080
Restart=always
RestartSec=5
MemoryMax=128M
StandardOutput=append:/root/lanremote-relay/tunnel.log
StandardError=append:/root/lanremote-relay/tunnel.log

[Install]
WantedBy=multi-user.target
UNIT

systemctl daemon-reload
systemctl enable lanremote-tunnel >/dev/null 2>&1
rm -f "$RELAY_DIR/tunnel.log"
systemctl start lanremote-tunnel
echo "  服务已更新并启动"

echo
echo "===== 等公网地址（最多 100 秒）====="
URL=""
for i in $(seq 1 50); do
    sleep 2
    URL=$(grep -oE 'https://[a-z0-9]+(-[a-z0-9]+)+\.trycloudflare\.com' \
          "$RELAY_DIR/tunnel.log" 2>/dev/null | tail -1)
    if [ -n "$URL" ]; then
        echo "  第 $((i*2)) 秒拿到: $URL"
        break
    fi
done

if [ -z "$URL" ]; then
    echo "  还是没拿到，日志尾部："
    tail -12 "$RELAY_DIR/tunnel.log"
    exit 1
fi

echo "$URL" > "$RELAY_DIR/public_url.txt"

echo
echo "===== 公网可达性 ====="
for i in 1 2 3 4 5; do
    if curl -s --max-time 20 "$URL/v1/health" | grep -q '"ok"'; then
        echo "  第 $i 次: 通了"
        break
    fi
    echo "  第 $i 次: 还没通"
    sleep 4
done

echo
echo "===== 走的是 IPv4 吗 ====="
curl -s --max-time 15 -o /dev/null -w '  连接对端 IP: %{remote_ip}\n' "$URL/v1/health"

echo
echo "===== 服务状态 ====="
systemctl is-active lanremote-relay lanremote-tunnel
echo
free -m | head -2
echo
echo "PUBLIC_URL=$URL"