#!/bin/bash

# Debian 12 网络配置脚本
# 网络优化和配置

set -e

# 颜色定义
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

# 日志函数
log_info() {
    echo -e "${BLUE}[INFO]${NC} $1"
}

log_success() {
    echo -e "${GREEN}[SUCCESS]${NC} $1"
}

log_warning() {
    echo -e "${YELLOW}[WARNING]${NC} $1"
}

log_error() {
    echo -e "${RED}[ERROR]${NC} $1"
}

# 配置 DNS
configure_dns() {
    log_info "配置 DNS 服务器..."

    # 备份原始 resolv.conf
    cp /etc/resolv.conf /etc/resolv.conf.backup

    # 配置国内 DNS 服务器
    cat > /etc/resolv.conf << 'EOF'
# EM Script Library - DNS Configuration
nameserver 223.5.5.5        # AliDNS
nameserver 223.6.6.6        # AliDNS
nameserver 119.29.29.29     # DNSPod
nameserver 182.254.116.116  # DNSPod
nameserver 114.114.114.114  # 114DNS
nameserver 8.8.8.8          # Google DNS (fallback)
nameserver 1.1.1.1          # Cloudflare DNS (fallback)
EOF

    # 防止网络管理器覆盖 DNS 配置
    if [[ -f /etc/NetworkManager/NetworkManager.conf ]]; then
        sed -i '/\[main\]/a dns=none' /etc/NetworkManager/NetworkManager.conf
        systemctl restart NetworkManager
    fi

    log_success "DNS 配置完成"
}

# 测试 DNS 解析速度
test_dns_speed() {
    log_info "测试 DNS 解析速度..."

    local domains=("www.baidu.com" "www.qq.com" "www.taobao.com" "www.github.com")
    local dns_servers=(
        "223.5.5.5|AliDNS"
        "119.29.29.29|DNSPod"
        "114.114.114.114|114DNS"
        "8.8.8.8|Google"
        "1.1.1.1|Cloudflare"
    )

    echo "DNS 服务器性能测试:"
    echo "=========================================="

    for dns_server in "${dns_servers[@]}"; do
        local server=$(echo "$dns_server" | cut -d'|' -f1)
        local name=$(echo "$dns_server" | cut -d'|' -f2)

        local total_time=0
        local success_count=0

        for domain in "${domains[@]}"; do
            local start_time=$(date +%s%N)
            if nslookup "$domain" "$server" >/dev/null 2>&1; then
                local end_time=$(date +%s%N)
                local time_diff=$(( (end_time - start_time) / 1000000 ))
                total_time=$((total_time + time_diff))
                success_count=$((success_count + 1))
            fi
        done

        if [[ $success_count -gt 0 ]]; then
            local avg_time=$((total_time / success_count))
            printf "%-12s %-10s %dms (成功: %d/%d)\n" "$server" "$name" "$avg_time" "$success_count" "${#domains[@]}"
        else
            printf "%-12s %-10s 失败\n" "$server" "$name"
        fi
    done

    log_success "DNS 测试完成"
}

# 配置网络接口
configure_interfaces() {
    log_info "配置网络接口..."

    # 获取网络接口信息
    local interfaces=$(ip -o link show | awk -F': ' '{print $2}' | grep -v lo)

    for interface in $interfaces; do
        log_info "配置接口: $interface"

        # 创建网络接口配置
        cat > "/etc/network/interfaces.d/$interface" << EOF
# EM Script Library - Network Interface Configuration
auto $interface
iface $interface inet dhcp

# DNS 配置
dns-nameservers 223.5.5.5 223.6.6.6 119.29.29.29
dns-search local

# MTU 设置 (可选)
# mtu 1500
EOF
    done

    log_success "网络接口配置完成"
}

# 配置网络代理
configure_proxy() {
    local proxy_type="$1"
    local proxy_host="$2"
    local proxy_port="$3"

    if [[ -z "$proxy_host" || -z "$proxy_port" ]]; then
        log_error "请提供代理主机和端口"
        echo "用法: $0 proxy <类型> <主机> <端口>"
        echo "类型: http, https, socks5"
        return 1
    fi

    log_info "配置 $proxy_type 代理: $proxy_host:$proxy_port"

    case $proxy_type in
        http)
            export http_proxy="http://$proxy_host:$proxy_port"
            export https_proxy="http://$proxy_host:$proxy_port"
            ;;
        https)
            export http_proxy="https://$proxy_host:$proxy_port"
            export https_proxy="https://$proxy_host:$proxy_port"
            ;;
        socks5)
            export http_proxy="socks5://$proxy_host:$proxy_port"
            export https_proxy="socks5://$proxy_host:$proxy_port"
            ;;
        *)
            log_error "不支持的代理类型: $proxy_type"
            return 1
            ;;
    esac

    # 配置系统代理
    cat > /etc/environment << EOF
# EM Script Library - System Proxy Configuration
http_proxy=$http_proxy
https_proxy=$https_proxy
ftp_proxy=$http_proxy
no_proxy=localhost,127.0.0.1,::1,.local
EOF

    # 配置 apt 代理
    cat > /etc/apt/apt.conf.d/99proxy << EOF
# EM Script Library - APT Proxy Configuration
Acquire::http::Proxy "$http_proxy";
Acquire::https::Proxy "$https_proxy";
EOF

    # 配置 wget 代理
    cat > /root/.wgetrc << EOF
# EM Script Library - Wget Proxy Configuration
http_proxy=$http_proxy
https_proxy=$https_proxy
EOF

    # 配置 curl 代理
    cat > /root/.curlrc << EOF
# EM Script Library - Curl Proxy Configuration
proxy=$http_proxy
EOF

    log_success "代理配置完成"
}

# 移除代理配置
remove_proxy() {
    log_info "移除代理配置..."

    unset http_proxy https_proxy ftp_proxy no_proxy

    rm -f /etc/environment
    rm -f /etc/apt/apt.conf.d/99proxy
    rm -f /root/.wgetrc
    rm -f /root/.curlrc

    log_success "代理配置已移除"
}

# 测试网络连接
test_network() {
    log_info "测试网络连接..."

    local test_hosts=(
        "223.5.5.5|阿里DNS"
        "www.baidu.com|百度"
        "www.qq.com|腾讯"
        "www.github.com|GitHub"
        "registry.npmmirror.com|NPM镜像"
        "pypi.tuna.tsinghua.edu.cn|PyPI镜像"
    )

    echo "网络连接测试:"
    echo "=========================================="

    for host_info in "${test_hosts[@]}"; do
        local host=$(echo "$host_info" | cut -d'|' -f1)
        local name=$(echo "$host_info" | cut -d'|' -f2)

        if ping -c 3 -W 3 "$host" >/dev/null 2>&1; then
            local ping_time=$(ping -c 3 "$host" | tail -1 | awk '{print $4}' | cut -d'/' -f2)
            printf "%-30s ✓  %s ms\n" "$name ($host)" "$ping_time"
        else
            printf "%-30s ✗  连接失败\n" "$name ($host)"
        fi
    done

    log_success "网络测试完成"
}

# 配置 IPv6
configure_ipv6() {
    log_info "配置 IPv6 支持..."

    # 启用 IPv6
    sed -i 's/GRUB_CMDLINE_LINUX_DEFAULT="[^"]*/& ipv6.disable=0/' /etc/default/grub
    sed -i 's/GRUB_CMDLINE_LINUX="[^"]*/& ipv6.disable=0/' /etc/default/grub

    update-grub

    # 配置 sysctl IPv6 参数
    cat >> /etc/sysctl.d/99-custom.conf << 'EOF'

# IPv6 configuration
net.ipv6.conf.all.disable_ipv6 = 0
net.ipv6.conf.default.disable_ipv6 = 0
net.ipv6.conf.lo.disable_ipv6 = 0
EOF

    sysctl -p

    log_success "IPv6 配置完成，重启后生效"
}

# 显示网络信息
show_network_info() {
    log_info "网络配置信息:"

    echo "=== 网络接口 ==="
    ip addr show

    echo ""
    echo "=== 路由表 ==="
    ip route show

    echo ""
    echo "=== DNS 配置 ==="
    cat /etc/resolv.conf

    echo ""
    echo "=== 网络连接 ==="
    ss -tuln

    echo ""
    echo "=== 网络统计 ==="
    ip -s link
}

# 显示帮助信息
show_help() {
    cat << EOF
Debian 12 网络配置工具

用法: $0 [选项] [操作]

操作:
    dns            配置 DNS 服务器
    dns-test       测试 DNS 解析速度
    interfaces     配置网络接口
    proxy          配置网络代理
    remove-proxy   移除代理配置
    network-test   测试网络连接
    ipv6           配置 IPv6 支持
    info           显示网络信息

选项:
    -h, --help     显示此帮助信息

示例:
    $0 dns                 # 配置 DNS
    $0 proxy http 127.0.0.1 8080  # 配置 HTTP 代理
    $0 network-test        # 测试网络连接
    $0 info                # 显示网络信息

EOF
}

# 主函数
main() {
    local action="$1"

    case $action in
        dns)
            configure_dns
            ;;
        dns-test)
            test_dns_speed
            ;;
        interfaces)
            configure_interfaces
            ;;
        proxy)
            shift
            configure_proxy "$@"
            ;;
        remove-proxy)
            remove_proxy
            ;;
        network-test)
            test_network
            ;;
        ipv6)
            configure_ipv6
            ;;
        info)
            show_network_info
            ;;
        ""|-h|--help)
            show_help
            ;;
        *)
            log_error "未知操作: $action"
            show_help
            exit 1
            ;;
    esac

    log_success "网络配置完成！"
}

# 执行主函数
main "$@"