#!/usr/bin/env bash
# ============================================================================
# MAX Timezone & TimeSync — 时区管理与 NTP 时间同步
# 原创脚本，支持一键设置上海/UTC/自定义时区、NTP多源优化配置、时间同步校准
#
# 风险等级: 🟡 修改配置 — 修改系统时区、NTP 服务与硬件时钟
# 用法: bash <(curl -fsSL https://dl.unvmax.com/linux/scripts/max-tools/max-timezone.sh)
# ============================================================================

set -e

R='\033[1;31m' G='\033[38;5;220m' Y='\033[1;33m' B='\033[38;5;220m'
C='\033[38;5;220m' M='\033[38;5;242m' W='\033[38;5;250m' N='\033[0m'
GR='\033[38;5;242m' BW='\033[38;5;255m' BG='\033[38;5;220m'

echo -e "${B}┌─────────────────────────────────────────────┐${N}"
echo -e "${B}│${N}  ${G}MAX 时区管理与 NTP 时间同步${N}  ${GR}(修改配置)${N}"
echo -e "${B}└─────────────────────────────────────────────┘${N}"
echo

# ── 检测当前时间与时区状态 ──
get_current_info() {
    CUR_TZ=""
    CUR_TIME=""
    CUR_UTC=""
    NTP_SYNC="未知"
    NTP_ACTIVE="未知"
    NTP_DAEMON="无"

    if command -v timedatectl &>/dev/null; then
        local td_out
        td_out=$(timedatectl 2>/dev/null || true)
        CUR_TZ=$(echo "$td_out" | grep -i "Time zone:" | sed -e 's/^[ \t]*Time zone:[ \t]*//' || echo "")
        CUR_TIME=$(echo "$td_out" | grep -i "Local time:" | sed -e 's/^[ \t]*Local time:[ \t]*//' || echo "")
        CUR_UTC=$(echo "$td_out" | grep -i "Universal time:" | sed -e 's/^[ \t]*Universal time:[ \t]*//' || echo "")
        NTP_SYNC=$(echo "$td_out" | grep -i "System clock synchronized:" | awk '{print $NF}' || echo "no")
        NTP_ACTIVE=$(echo "$td_out" | grep -i "NTP service:" | awk '{print $NF}' || echo "inactive")
    fi

    if [ -z "$CUR_TZ" ]; then
        if [ -f /etc/timezone ]; then
            CUR_TZ=$(cat /etc/timezone | tr -d ' \r\n')
        elif [ -h /etc/localtime ]; then
            CUR_TZ=$(readlink /etc/localtime | sed 's|.*/zoneinfo/||')
        else
            CUR_TZ=$(date +%Z 2>/dev/null || echo "未知")
        fi
    fi

    [ -z "$CUR_TIME" ] && CUR_TIME=$(date +"%Y-%m-%d %H:%M:%S %Z" 2>/dev/null || echo "未知")
    [ -z "$CUR_UTC" ] && CUR_UTC=$(date -u +"%Y-%m-%d %H:%M:%S UTC" 2>/dev/null || echo "未知")

    # 检测活跃守护进程
    if systemctl is-active --quiet systemd-timesyncd 2>/dev/null; then
        NTP_DAEMON="systemd-timesyncd"
    elif systemctl is-active --quiet chronyd 2>/dev/null || systemctl is-active --quiet chrony 2>/dev/null; then
        NTP_DAEMON="chrony"
    elif systemctl is-active --quiet ntpd 2>/dev/null || systemctl is-active --quiet ntp 2>/dev/null; then
        NTP_DAEMON="ntpd"
    fi
}

show_status_box() {
    get_current_info
    echo -e "  ${C}当前时区:${N}     ${BW}$CUR_TZ${N}"
    echo -e "  ${C}本地时间:${N}     ${W}$CUR_TIME${N}"
    echo -e "  ${C}UTC 时间:${N}     ${GR}$CUR_UTC${N}"
    
    local sync_color=$G
    [ "$NTP_SYNC" != "yes" ] && sync_color=$Y
    echo -e "  ${C}NTP 状态:${N}     ${sync_color}已同步: $NTP_SYNC${N}  ${GR}(服务: $NTP_ACTIVE / 守护: $NTP_DAEMON)${N}"
    echo
}

# ── 核心操作函数 ──

ensure_ntp_service() {
    echo -e "  ${GR}检查并激活时间同步服务...${N}"
    if command -v timedatectl &>/dev/null; then
        timedatectl set-ntp true 2>/dev/null || true
    fi

    # 如果没有可用的 NTP 守护进程，尝试安装并启动 systemd-timesyncd 或 chrony
    if ! systemctl is-active --quiet systemd-timesyncd 2>/dev/null && \
       ! systemctl is-active --quiet chronyd 2>/dev/null && \
       ! systemctl is-active --quiet chrony 2>/dev/null && \
       ! systemctl is-active --quiet ntp 2>/dev/null; then
        
        if command -v apt-get &>/dev/null; then
            echo -e "  ${Y}安装 systemd-timesyncd...${N}"
            apt-get update -qq 2>/dev/null || true
            apt-get install -y -qq systemd-timesyncd 2>/dev/null || apt-get install -y -qq chrony 2>/dev/null || true
        elif command -v yum &>/dev/null; then
            echo -e "  ${Y}安装 chrony...${N}"
            yum install -y chrony 2>/dev/null || true
        elif command -v dnf &>/dev/null; then
            dnf install -y chrony 2>/dev/null || true
        fi
    fi

    if systemctl list-unit-files systemd-timesyncd.service &>/dev/null; then
        systemctl enable --now systemd-timesyncd 2>/dev/null || true
    elif systemctl list-unit-files chronyd.service &>/dev/null; then
        systemctl enable --now chronyd 2>/dev/null || true
    elif systemctl list-unit-files chrony.service &>/dev/null; then
        systemctl enable --now chrony 2>/dev/null || true
    fi
}

apply_timezone() {
    local target_tz="$1"
    local tz_desc="$2"

    if [ ! -f "/usr/share/zoneinfo/$target_tz" ]; then
        echo -e "  ${R}✘ 时区文件不存在: /usr/share/zoneinfo/$target_tz${N}"
        return 1
    fi

    echo -e "  ${Y}正在设置时区为: ${BW}$target_tz${Y} (${tz_desc})...${N}"
    
    if command -v timedatectl &>/dev/null; then
        timedatectl set-timezone "$target_tz" 2>/dev/null || {
            ln -sf "/usr/share/zoneinfo/$target_tz" /etc/localtime
            echo "$target_tz" > /etc/timezone 2>/dev/null || true
        }
    else
        ln -sf "/usr/share/zoneinfo/$target_tz" /etc/localtime
        echo "$target_tz" > /etc/timezone 2>/dev/null || true
    fi

    echo -e "  ${G}✔ 时区设置成功: $target_tz${N}"
}

trigger_sync() {
    echo -e "  ${Y}正在执行 NTP 时间强制同步...${N}"
    ensure_ntp_service

    # 如果是 timesyncd，重启服务触发即时校准
    if systemctl is-active --quiet systemd-timesyncd 2>/dev/null; then
        systemctl restart systemd-timesyncd 2>/dev/null || true
    fi

    # 如果是 chrony，触发立即步进同步
    if command -v chronyc &>/dev/null; then
        chronyc makestep 2>/dev/null || chronyc -a 'burst 4/4' 2>/dev/null || true
    fi

    # 如果有时钟同步命令
    if command -v ntpdate &>/dev/null; then
        ntpdate -u ntp.aliyun.com 2>/dev/null || true
    fi

    # 同步至硬件 RTC 时钟
    if command -v hwclock &>/dev/null; then
        hwclock --systohc 2>/dev/null || true
    fi

    sleep 1
    echo -e "  ${G}✔ 时间同步命令已执行完毕${N}"
}

optimize_ntp_conf() {
    echo -e "  ${Y}正在配置高可用 NTP 上游服务器...${N}"
    
    # 优质 NTP 池：阿里云、腾讯云、国家授时中心、Cloudflare、Google、公共池
    local ntp_servers="ntp.aliyun.com ntp.tencent.com ntp.ntsc.ac.cn cn.pool.ntp.org time.cloudflare.com"
    local fallback_servers="time.google.com time.apple.com pool.ntp.org"

    # 1. 尝试配置 systemd-timesyncd
    if [ -d /etc/systemd ]; then
        mkdir -p /etc/systemd/timesyncd.conf.d 2>/dev/null || true
        cat <<EOF > /etc/systemd/timesyncd.conf.d/max-timesync.conf
[Time]
NTP=$ntp_servers
FallbackNTP=$fallback_servers
RootDistanceMaxSec=5
PollIntervalMinSec=32
PollIntervalMaxSec=2048
EOF
        echo -e "  ${G}✔ 已写入 /etc/systemd/timesyncd.conf.d/max-timesync.conf${N}"
    fi

    # 2. 如果存在 chrony，同步配置
    if [ -f /etc/chrony/chrony.conf ] || [ -f /etc/chrony.conf ]; then
        local cconf="/etc/chrony/chrony.conf"
        [ ! -f "$cconf" ] && cconf="/etc/chrony.conf"
        
        if ! grep -q "ntp.aliyun.com" "$cconf" 2>/dev/null; then
            cat <<EOF >> "$cconf"

# MAX NTP Servers
server ntp.aliyun.com iburst minpoll 4 maxpoll 10
server ntp.tencent.com iburst minpoll 4 maxpoll 10
server ntp.ntsc.ac.cn iburst minpoll 4 maxpoll 10
server time.cloudflare.com iburst minpoll 4 maxpoll 10
EOF
            echo -e "  ${G}✔ 已追加优质 NTP 源至 $cconf${N}"
        fi
    fi

    trigger_sync
}

show_detailed_diag() {
    echo -e "\n  ${M}── timedatectl 详细状态 ──${N}"
    if command -v timedatectl &>/dev/null; then
        timedatectl status 2>/dev/null || true
        echo
        if timedatectl timesync-status &>/dev/null; then
            echo -e "  ${M}── NTP 同步链路追踪 ──${N}"
            timedatectl timesync-status 2>/dev/null || true
        fi
    else
        date -R 2>/dev/null || true
    fi

    if command -v chronyc &>/dev/null; then
        echo -e "\n  ${M}── Chrony 源与偏差 ──${N}"
        chronyc sources -v 2>/dev/null || true
    fi
}

# ── 交互菜单 ──
show_status_box

echo -e "  ${M}请选择操作:${N}"
echo -e "    ${C}1${N}) ${G}设为中国上海时区 (Asia/Shanghai, CST+8) + 立即校准时间${N}  ${GR}(推荐)${N}"
echo -e "    ${C}2${N}) ${G}仅立即同步网络时间 (NTP 校准)${N}  ${GR}(保持当前时区)${N}"
echo -e "    ${C}3${N}) ${W}设为标准 UTC 时区 (Etc/UTC, +0000) + 立即校准时间${N}"
echo -e "    ${C}4${N}) ${W}选择其他常用时区 / 自定义时区${N}"
echo -e "    ${C}5${N}) ${W}优化配置高可用 NTP 上游源${N}  ${GR}(阿里/腾讯/国家授时/Cloudflare)${N}"
echo -e "    ${C}6${N}) ${W}查看详细时钟与 NTP 诊断信息${N}  ${GR}(只读)${N}"
echo -e "    ${C}0${N}) 返回主菜单  ${GR}(q 同样可用)${N}"
echo

read -r -p "$(echo -e "  ${C}选择 (1-6/0): ${N}")" choice || choice=0

case "$choice" in
    1)
        echo
        apply_timezone "Asia/Shanghai" "中国标准时间 CST+8"
        optimize_ntp_conf
        ;;
    2)
        echo
        trigger_sync
        ;;
    3)
        echo
        apply_timezone "Etc/UTC" "世界协调时间 UTC+0"
        trigger_sync
        ;;
    4)
        echo
        echo -e "  ${M}常用时区列表:${N}"
        echo -e "    ${C}1${N}) 香港  Asia/Hong_Kong    (UTC+8)"
        echo -e "    ${C}2${N}) 东京  Asia/Tokyo        (UTC+9)"
        echo -e "    ${C}3${N}) 新加坡 Asia/Singapore    (UTC+8)"
        echo -e "    ${C}4${N}) 伦敦  Europe/London     (UTC+0/+1)"
        echo -e "    ${C}5${N}) 美西  America/Los_Angeles (UTC-8/-7)"
        echo -e "    ${C}6${N}) 美东  America/New_York    (UTC-5/-4)"
        echo -e "    ${C}7${N}) 手动输入时区名称 (如 Europe/Berlin)"
        echo -e "    ${C}0${N}) 取消返回"
        echo
        read -r -p "$(echo -e "  ${C}选择 (1-7/0): ${N}")" sub_choice
        case "$sub_choice" in
            1) apply_timezone "Asia/Hong_Kong" "香港时间"; trigger_sync ;;
            2) apply_timezone "Asia/Tokyo" "东京时间"; trigger_sync ;;
            3) apply_timezone "Asia/Singapore" "新加坡时间"; trigger_sync ;;
            4) apply_timezone "Europe/London" "伦敦时间"; trigger_sync ;;
            5) apply_timezone "America/Los_Angeles" "美西时间"; trigger_sync ;;
            6) apply_timezone "America/New_York" "美东时间"; trigger_sync ;;
            7)
                read -r -p "$(echo -e "  ${C}请输入时区全称 (如 Asia/Shanghai 或 Europe/Berlin): ${N}")" custom_tz
                custom_tz=$(echo "$custom_tz" | tr -d ' ')
                if [ -n "$custom_tz" ]; then
                    apply_timezone "$custom_tz" "自定义" && trigger_sync
                else
                    echo -e "  ${R}时区名称不能为空${N}"
                fi
                ;;
            0|q|Q) echo -e "  ${GR}已取消${N}" ;;
            *) echo -e "  ${R}无效选择${N}" ;;
        esac
        ;;
    5)
        echo
        optimize_ntp_conf
        ;;
    6)
        show_detailed_diag
        ;;
    0|q|Q)
        echo -e "  ${GR}返回主菜单${N}"
        exit 0
        ;;
    *)
        echo -e "  ${R}无效选择${N}"
        exit 1
        ;;
esac

echo
echo -e "  ${M}最新状态验证:${N}"
get_current_info
echo -e "  ${G}✔${N} ${C}时区:${N} ${BW}$CUR_TZ${N}"
echo -e "  ${G}✔${N} ${C}时间:${N} ${W}$CUR_TIME${N}"
echo -e "  ${G}✔${N} ${C}NTP:${N}  ${W}$NTP_SYNC (服务: $NTP_ACTIVE / $NTP_DAEMON)${N}"

echo
echo -e "${GR}👉 更多工具: max-sysinfo.sh | 服务巡检: max-service-check.sh${N}"
echo -e "${GR}👉 一键执行: bash <(curl -fsSL https://dl.unvmax.com/linux/scripts/max-tools/max-timezone.sh)${N}"