#!/bin/bash
# 脚本文件名：setup_chrony_param.sh
# 修订版本：1.2 (兼容性增强版)
# 日期：2025/11/13
# 作者：Jack.liu
# 电子邮件：lqf@xlsys.cn
# 网址：www.xlsys.cn
# 支持：RHEL/CentOS/Fedora、Debian/Ubuntu、CTyunOS（包括 CentOS 7）

set -e  # 遇错即停

ALIYUN_PUBLIC_NTP_SERVERS=(
    "ntp1.aliyun.com"
    "ntp2.aliyun.com"
    "ntp3.aliyun.com"
    "ntp4.aliyun.com"
)

ALIYUN_PRIVATE_NTP_SERVERS=(
    "222.22.120.52"
    "134.144.144.81"
    "132.155.166.82"
    "136.153.11.220"
    "132.108.11.220"
    # 请根据实际环境修改内网 NTP 服务器
)

# 全局变量
CHRONY_CONF=""
CHRONY_SERVICE=""
PKG_MANAGER=""

detect_os() {
    if [ -f /etc/os-release ]; then
        . /etc/os-release
        OS_ID="${ID,,}"
    else
        echo "错误: 无法读取 /etc/os-release，无法识别系统。"
        exit 1
    fi

    case "$OS_ID" in
        *centos*|*rhel*|*rocky*|*almalinux*|*ctyunos*)
            CHRONY_CONF="/etc/chrony.conf"
            CHRONY_SERVICE="chronyd"
            PKG_MANAGER="yum"
            ;;
        *debian*|*ubuntu*)
            CHRONY_CONF="/etc/chrony/chrony.conf"
            CHRONY_SERVICE="chrony"
            PKG_MANAGER="apt"
            ;;
        *)
            echo "错误: 不支持的操作系统: $OS_ID"
            exit 1
            ;;
    esac
}

set_timezone_to_cst() {
    local CURRENT_TIMEZONE

    # 尝试使用新式命令（systemd >= 230）
    if timedatectl show --property=Timezone --value &>/dev/null; then
        CURRENT_TIMEZONE=$(timedatectl show --property=Timezone --value)
    else
        # 回退到解析文本（兼容 CentOS 7 等）
        CURRENT_TIMEZONE=$(timedatectl status 2>/dev/null | grep 'Time zone' | awk '{print $3}')
    fi

    if [[ "$CURRENT_TIMEZONE" != "Asia/Shanghai" ]]; then
        echo "当前时区不是 CST，正在设置为 Asia/Shanghai..."
        sudo timedatectl set-timezone Asia/Shanghai
        echo "时区已设置为 CST (Asia/Shanghai)。"
    else
        echo "时区已经是 CST (Asia/Shanghai)，无需更改。"
    fi
}

check_chrony_installed() {
    command -v chronyc >/dev/null 2>&1
}

install_chrony() {
    echo "正在安装 chrony..."
    if [[ "$PKG_MANAGER" == "yum" ]]; then
        sudo yum install -y chrony
    elif [[ "$PKG_MANAGER" == "apt" ]]; then
        sudo apt-get update
        sudo apt-get install -y chrony
    fi
}

stop_ntpd() {
    echo "正在停止并禁用 ntpd/ntp 服务..."
    for svc in ntpd ntp; do
        if systemctl list-units --full --all | grep -q "^${svc}\."; then
            if systemctl is-active --quiet "$svc" 2>/dev/null; then
                sudo systemctl stop "$svc"
            fi
            sudo systemctl disable "$svc" --now 2>/dev/null || true
        fi
    done
    echo "ntpd/ntp 服务已处理。"
}

backup_chrony_conf() {
    if [[ ! -f "$CHRONY_CONF" ]]; then
        echo "警告: $CHRONY_CONF 不存在，跳过备份。"
        return 0
    fi
    local backup_file="${CHRONY_CONF}.bak.$(date +%F_%H%M%S)"
    echo "正在备份配置文件到 $backup_file..."
    sudo cp "$CHRONY_CONF" "$backup_file"
}

configure_chrony_servers() {
    local servers=("$@")
    echo "清空现有 server 配置并添加新服务器..."
    sudo sed -i '/^server /d' "$CHRONY_CONF"
    for s in "${servers[@]}"; do
        echo "server $s iburst" | sudo tee -a "$CHRONY_CONF" >/dev/null
    done
}

start_chronyd() {
    echo "启动并启用 $CHRONY_SERVICE 服务..."
    sudo systemctl enable --now "$CHRONY_SERVICE"
}

restart_and_sync_chronyd() {
    echo "重启 $CHRONY_SERVICE 服务..."
    sudo systemctl restart "$CHRONY_SERVICE"
    echo "强制时间同步..."
    sudo chronyc -a makestep
}

display_ntp_status() {
    echo -e "\n===================================="
    echo "NTP 源状态："
    chronyc sources -v
    echo "------------------------------------"
    echo "同步状态："
    chronyc tracking
    echo "------------------------------------"
    echo "系统时间与时区："
    timedatectl status | grep -E 'Local time|Time zone'
    echo -e "====================================\n"
}

select_ntp_servers() {
    case "$1" in
        public)
            configure_chrony_servers "${ALIYUN_PUBLIC_NTP_SERVERS[@]}"
            ;;
        private)
            configure_chrony_servers "${ALIYUN_PRIVATE_NTP_SERVERS[@]}"
            ;;
        *)
            echo -e "\n\033[1;31m错误: 无效选项。\033[0m\n"
            display_usage
            exit 1
            ;;
    esac
}

display_usage() {
    echo -e "\n\033[1;34m用法: $0 {public|private}\033[0m"
    echo "  public - 使用阿里云公网 NTP 服务器"
    echo "  private - 使用内网 NTP 服务器"
}

main() {
    detect_os
    set_timezone_to_cst

    if ! check_chrony_installed; then
        install_chrony
    fi

    stop_ntpd
    backup_chrony_conf
    select_ntp_servers "$1"
    start_chronyd
    restart_and_sync_chronyd
    display_ntp_status

    echo -e "\n\033[1;32m✅ chrony 配置完成！\033[0m\n"
}

if [[ $# -ne 1 ]]; then
    display_usage
    exit 1
else
    main "$1"
fi