#!/bin/bash
# =================================================================
# 🗑️ VPS Tailscale 智能卸载 - 身份保护版
# =================================================================

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m'

echo ""
echo -e "${RED}⚠️  [重要提示] 是否抹除这台服务器的身份信息?${NC}"
echo -e "${GREEN}选项 N (默认):${NC} 保留身份。重装后无需登录，IP 不变。"
echo -e "${RED}选项 Y (彻底抹除):${NC} 清除身份。下次安装视为新设备。"
echo -n "❓ 请选择 [y/N]: "
read yn < /dev/tty

case $yn in
    [Yy]* ) 
        UNINSTALL_CMD="purge"
        DELETE_DATA=true
        ;;
    * ) 
        UNINSTALL_CMD="remove"
        DELETE_DATA=false
        ;;
esac

echo -e "${YELLOW}>>> [1/4] 停止 Tailscale 服务...${NC}"
sudo systemctl stop tailscaled 2>/dev/null
sudo systemctl disable tailscaled 2>/dev/null
echo -e "${GREEN}✅ 已停止${NC}"

echo -e "${YELLOW}>>> [2/4] 清理网络转发规则...${NC}"
IFACE=$(ip route | grep default | awk '{print $5}' | head -n1)
sudo iptables -t nat -D POSTROUTING -o ${IFACE} -j MASQUERADE 2>/dev/null
sudo netfilter-persistent save > /dev/null 2>&1
echo -e "${GREEN}✅ 网络规则已恢复${NC}"

echo -e "${YELLOW}>>> [3/4] 执行程序卸载 (${UNINSTALL_CMD})...${NC}"
# 根据选择，要么温柔地 remove，要么狠心地 purge
sudo apt-get ${UNINSTALL_CMD} tailscale -y > /dev/null 2>&1
echo -e "${GREEN}✅ 程序清理完毕${NC}"

echo -e "${YELLOW}>>> [4/4] 身份数据处理...${NC}"
if [ "$DELETE_DATA" = true ]; then
    sudo rm -rf /var/lib/tailscale
    echo -e "${RED}🧨 身份数据已彻底烧毁。${NC}"
else
    echo -e "${GREEN}🛡️ 身份数据已成功锁定。下次重装将自动秒连！${NC}"
fi

echo ""
echo -e "${GREEN}🎉 卸载完成！系统已清空。${NC}"