#!/bin/bash
# SSH反向隧道设置脚本

echo "=== SSH反向隧道设置脚本 ==="

# 1. 检查SSH客户端是否安装
echo "1. 检查SSH客户端..."
if command -v ssh &> /dev/null; then
    echo "✓ SSH客户端已安装: $(which ssh)"
    ssh -V
else
    echo "✗ SSH客户端未安装，开始安装..."
    
    # 检测Linux发行版
    if [ -f /etc/redhat-release ]; then
        # CentOS/RHEL
        echo "检测到 CentOS/RHEL 系统"
        sudo yum install -y openssh-clients openssh-server
    elif [ -f /etc/debian_version ]; then
        # Debian/Ubuntu
        echo "检测到 Debian/Ubuntu 系统"
        sudo apt-get update
        sudo apt-get install -y openssh-client openssh-server
    elif [ -f /etc/arch-release ]; then
        # Arch Linux
        echo "检测到 Arch Linux 系统"
        sudo pacman -S --noconfirm openssh
    else
        echo "无法自动检测系统类型，请手动安装 openssh-client"
        exit 1
    fi
    
    # 验证安装
    if command -v ssh &> /dev/null; then
        echo "✓ SSH客户端安装成功"
        ssh -V
    else
        echo "✗ SSH客户端安装失败，请手动安装"
        exit 1
    fi
fi

echo ""
echo "2. 检查SSH服务是否运行..."
if systemctl is-active --quiet sshd || systemctl is-active --quiet ssh; then
    echo "✓ SSH服务正在运行"
else
    echo "⚠ SSH服务未运行，启动SSH服务..."
    sudo systemctl start sshd 2>/dev/null || sudo systemctl start ssh
    sudo systemctl enable sshd 2>/dev/null || sudo systemctl enable ssh
fi

echo ""
echo "3. 生成SSH密钥（如果不存在）..."
if [ ! -f ~/.ssh/id_rsa ]; then
    echo "生成SSH密钥..."
    ssh-keygen -t rsa -b 2048 -f ~/.ssh/id_rsa -N ""
    echo "✓ SSH密钥已生成"
else
    echo "✓ SSH密钥已存在"
fi

echo ""
echo "4. 配置SSH密钥免密登录（可选）..."
read -p "是否配置免密登录到阿里云服务器？(y/n): " setup_key
if [ "$setup_key" = "y" ] || [ "$setup_key" = "Y" ]; then
    read -p "请输入阿里云服务器IP: " server_ip
    read -p "请输入阿里云服务器用户名（默认root）: " server_user
    server_user=${server_user:-root}
    
    echo "复制SSH公钥到阿里云服务器..."
    ssh-copy-id -p 22 ${server_user}@${server_ip}
    
    if [ $? -eq 0 ]; then
        echo "✓ 免密登录配置成功"
    else
        echo "⚠ 免密登录配置失败，请手动配置或使用密码登录"
    fi
fi

echo ""
echo "5. 测试SSH连接..."
read -p "请输入阿里云服务器IP（用于测试连接）: " test_ip
read -p "请输入用户名（默认root）: " test_user
test_user=${test_user:-root}

echo "测试连接到 ${test_user}@${test_ip}..."
ssh -o ConnectTimeout=5 -p 22 ${test_user}@${test_ip} "echo '连接成功！'"

if [ $? -eq 0 ]; then
    echo "✓ SSH连接测试成功"
else
    echo "✗ SSH连接测试失败，请检查："
    echo "  - 网络连接是否正常"
    echo "  - 阿里云服务器防火墙是否开放22端口"
    echo "  - 用户名和密码是否正确"
fi

echo ""
echo "=== 设置完成 ==="
echo ""
echo "使用方法："
echo "  手动连接: ssh -fN -R 2222:localhost:22 root@123.56.98.4 -p 22"
echo ""
echo "  或者使用自动重连脚本（见下方）"