#!/bin/bash

# ========================================
# DHCP & DNS 管理器 - Linux 安装脚本（修复版）
# ========================================

set -e

INSTALL_DIR="/opt/dhcp-dns-manager"
SERVICE_NAME="dhcp-dns-manager"

echo "========================================"
echo "  DHCP & DNS 管理器 - Linux 安装脚本"
echo "========================================"
echo ""

# 检查是否以 root 运行
if [ "$EUID" -ne 0 ]; then 
    echo "❌ 请使用 sudo 运行此脚本"
    echo "   sudo ./install.sh"
    exit 1
fi

# 检测系统
if [ -f /etc/debian_version ]; then
    OS="debian"
    echo "✓ 检测到 Debian/Ubuntu 系统"
elif [ -f /etc/redhat-release ]; then
    OS="redhat"
    echo "✓ 检测到 RHEL/CentOS 系统"
else
    OS="unknown"
    echo "⚠ 未识别的 Linux 发行版，尝试通用安装"
fi

# 安装依赖
echo ""
echo "📦 安装依赖..."

if [ "$OS" = "debian" ]; then
    apt update
    apt install -y curl wget git build-essential
elif [ "$OS" = "redhat" ]; then
    yum install -y curl wget git gcc make
fi

# 检查 Go 环境
if ! command -v go &> /dev/null; then
    echo ""
    echo "📦 安装 Go 环境..."
    GO_VERSION="1.21.0"
    wget -q https://go.dev/dl/go${GO_VERSION}.linux-amd64.tar.gz
    tar -C /usr/local -xzf go${GO_VERSION}.linux-amd64.tar.gz
    rm go${GO_VERSION}.linux-amd64.tar.gz
    echo 'export PATH=$PATH:/usr/local/go/bin' >> /etc/profile
    export PATH=$PATH:/usr/local/go/bin
    echo "✓ Go 已安装"
else
    echo "✓ Go 环境已存在: $(go version)"
fi

# 创建安装目录
echo ""
echo "📁 创建安装目录..."
mkdir -p $INSTALL_DIR

# 复制文件
echo ""
echo "📋 复制项目文件..."
cp -r ./* $INSTALL_DIR/

# 编译程序
echo ""
echo "🔨 编译程序..."
cd $INSTALL_DIR

# 整理并下载依赖
echo "整理依赖..."
go mod tidy

# 下载依赖
echo "下载 Go 依赖..."
go mod download

# 编译
echo "编译程序..."
CGO_ENABLED=1 go build -o dhcp-dns-manager ./cmd

# 创建数据目录
mkdir -p $INSTALL_DIR/data
chown -R root:root $INSTALL_DIR

# 创建 systemd 服务
echo ""
echo "⚙️  创建 systemd 服务..."
cat > /etc/systemd/system/$SERVICE_NAME.service << EOF
[Unit]
Description=DHCP & DNS Manager Service
After=network.target
Documentation=https://github.com/your-repo/dhcp-dns-manager

[Service]
Type=simple
User=root
WorkingDirectory=$INSTALL_DIR
ExecStart=$INSTALL_DIR/dhcp-dns-manager -config $INSTALL_DIR/configs/config.json
Restart=always
RestartSec=5
StandardOutput=journal
StandardError=journal
SyslogIdentifier=dhcp-dns-manager

# 安全设置
NoNewPrivileges=false
ProtectSystem=false
ProtectHome=false

[Install]
WantedBy=multi-user.target
EOF

# 重载 systemd
systemctl daemon-reload

# 配置防火墙
echo ""
echo "🔥 配置防火墙..."

if command -v ufw &> /dev/null; then
    echo "配置 UFW 防火墙..."
    ufw allow 53/udp comment "DNS"
    ufw allow 67/udp comment "DHCP"
    ufw allow 8080/tcp comment "Web UI"
elif command -v firewall-cmd &> /dev/null; then
    echo "配置 Firewalld..."
    firewall-cmd --permanent --add-port=53/udp
    firewall-cmd --permanent --add-port=67/udp
    firewall-cmd --permanent --add-port=8080/tcp
    firewall-cmd --reload
else
    echo "⚠  未检测到防火墙工具，请手动配置"
fi

# 启动服务
echo ""
echo "🚀 启动服务..."
systemctl enable $SERVICE_NAME
systemctl start $SERVICE_NAME

# 检查状态
sleep 2
echo ""
echo "========================================"
echo "  ✅ 安装完成！"
echo "========================================"
echo ""
echo "服务状态：$(systemctl is-active $SERVICE_NAME)"
echo ""
echo "📱 Web 界面：http://$(hostname -I | awk '{print $1}'):8080"
echo "👤 默认账号：admin / admin"
echo ""
echo "常用命令："
echo "  查看状态：systemctl status $SERVICE_NAME"
echo "  查看日志：journalctl -u $SERVICE_NAME -f"
echo "  重启服务：systemctl restart $SERVICE_NAME"
echo "  停止服务：systemctl stop $SERVICE_NAME"
echo ""
echo "⚠️  首次使用请修改默认密码！"
echo ""