#!/bin/bash
# =============================================================================
# setup-overlayroot.sh — RK3588 Edge 断电保护（方案一：overlayroot + /data 分区）
# -----------------------------------------------------------------------------
# 解决场景：SD 卡断电重启导致根文件系统损坏、无法启动。
#
# 原理：
#   1) 用 Ubuntu 官方 overlayroot 把根文件系统置于 tmpfs overlay 之上，
#      系统对根分区的一切写入进入内存，重启即丢，根分区永久只读，
#      断电不再损坏根文件系统。
#   2) 在 SD 卡剩余空间划分独立读写分区 /data（ext4），存放日志、
#      告警图片/视频、设备 ID 等需要持久化的数据，不受 overlay 影响。
#
# 用法（在设备上执行）:
#   sudo ./setup-overlayroot.sh install            一键启用（推荐）
#   sudo ./setup-overlayroot.sh install --yes      跳过确认（无人值守）
#   sudo ./setup-overlayroot.sh install --hls-ram  HLS 分片放内存(tmpfs)，
#                                                  减小 SD 写入（按需）
#   sudo ./setup-overlayroot.sh status             查看当前状态
#   sudo ./setup-overlayroot.sh verify             重启后验证是否生效
#   sudo ./setup-overlayroot.sh disable            临时禁用（维护模式，可写）
#   sudo ./setup-overlayroot.sh enable             重新启用（退出维护模式）
#
# 可选环境变量:
#   HLS_MODE=ram|data       HLS 分片存放位置（默认 data，--hls-ram 等价 ram）
#   JOURNAL_MODE=ram|data   系统 journal 日志（默认 ram）
#   SKIP_PARTITION=1        跳过分区创建（镜像已含 /data 分区时使用）
# =============================================================================
set -euo pipefail

# ---------------------------------------------------------------------------
# 颜色与输出
# ---------------------------------------------------------------------------
RED='\033[0;31m'; GREEN='\033[0;32m'; YELLOW='\033[1;33m'
BLUE='\033[0;34m'; CYAN='\033[0;36m'; NC='\033[0m'

info() { echo -e "${CYAN}[INFO]${NC} $*"; }
ok()   { echo -e "${GREEN}✓${NC} $*"; }
warn() { echo -e "${YELLOW}⚠${NC} $*"; }
die()  { echo -e "${RED}✗${NC} $*" >&2; exit 1; }

# ---------------------------------------------------------------------------
# 全局配置
# ---------------------------------------------------------------------------
DATA_MOUNT="/data"
DATA_LABEL="safesight-data"
DATA_SUBDIRS="hls logs alarms clips agent"
RUNTIME_ROOT="/var/lib/safesight-edge-server"
AGENT_LIB="/var/lib/safesight-edge-agent"
FSTAB="/etc/fstab"
OVERLAY_CONF="/etc/overlayroot.conf"
MARKER_BEGIN="# safesight-overlayroot (自动生成，勿手动修改)"
MARKER_END="# end safesight-overlayroot"

HLS_MODE="${HLS_MODE:-data}"          # data | ram
JOURNAL_MODE="${JOURNAL_MODE:-ram}"   # ram | data
SKIP_PARTITION="${SKIP_PARTITION:-0}"
ASSUME_YES=0

# ---------------------------------------------------------------------------
# 参数解析
# ---------------------------------------------------------------------------
CMD="${1:-install}"
shift || true
for arg in "$@"; do
    case "$arg" in
        --yes) ASSUME_YES=1 ;;
        --hls-ram) HLS_MODE=ram ;;
        --journal-data) JOURNAL_MODE=data ;;
        *) warn "未知参数: $arg" ;;
    esac
done

# ---------------------------------------------------------------------------
# 基础检查
# ---------------------------------------------------------------------------
require_root() {
    [ "$(id -u)" -eq 0 ] || die "请使用 sudo 运行此脚本"
}

detect_distro() {
    if [ -r /etc/os-release ]; then
        # shellcheck disable=SC1091
        . /etc/os-release
        case "${ID:-}" in
            ubuntu|debian) return 0 ;;
        esac
    fi
    warn "非 Ubuntu/Debian 系统，overlayroot 可能不可用，继续尝试..."
}

overlay_active() {
    grep -qs 'overlay' /proc/mounts
}

# ---------------------------------------------------------------------------
# 磁盘/分区检测
# ---------------------------------------------------------------------------
detect_root_disk() {
    ROOT_DEV="$(findmnt -no SOURCE / 2>/dev/null || true)"
    [ -n "${ROOT_DEV:-}" ] || die "无法定位根分区"
    case "$ROOT_DEV" in
        /dev/mmcblk*) ROOT_DISK="${ROOT_DEV%p*}"; ROOT_PART="${ROOT_DEV##*p}" ;;
        /dev/nvme*)   ROOT_DISK="${ROOT_DEV%p*}"; ROOT_PART="${ROOT_DEV##*p}" ;;
        /dev/sd*)     ROOT_DISK="${ROOT_DEV%[0-9]*}"; ROOT_PART="${ROOT_DEV##*[a-z]}" ;;
        *) die "无法识别的根设备: $ROOT_DEV（本脚本仅支持 SD 卡/eMMC/NVMe 直连分区）" ;;
    esac
    info "根分区: $ROOT_DEV  →  磁盘: $ROOT_DISK"
}

# /data 是否已存在（已挂载，或磁盘上有数据分区）
data_partition_exists() {
    # 已挂载
    if mountpoint -q "$DATA_MOUNT" 2>/dev/null; then
        DATA_PART="$(findmnt -no SOURCE "$DATA_MOUNT" 2>/dev/null || true)"
        return 0
    fi
    # 磁盘上已有标签 safesight-data 的分区（未挂载）
    for p in $(lsblk -ln -o NAME,TYPE "$ROOT_DISK" 2>/dev/null | awk '$2=="part"{print $1}'); do
        d="/dev/$p"
        if [ "$(blkid -s LABEL -o value "$d" 2>/dev/null)" = "$DATA_LABEL" ]; then
            DATA_PART="$d"
            return 0
        fi
    done
    return 1
}

find_free_space() {
    # 返回 "起始MiB 大小MiB"（取最后一个 >=2048MiB 的 Free Space），否则返回空
    LANG=C parted -s "$ROOT_DISK" unit MiB print free 2>/dev/null | \
        awk '$4=="Free" && $3>=2048 {start=$1; size=$3} END {if (size>=2048) print start, size}'
}

create_data_partition() {
    info "在 $ROOT_DISK 空闲空间中创建 /data 分区（$DATA_LABEL）..."
    FREE_INFO="$(find_free_space || true)"
    [ -n "$FREE_INFO" ] || die "未找到足够空闲空间（至少 2GiB）。请先扩容 SD 卡镜像或参考文档手动划分 /data 分区。"
    FREE_START="$(echo "$FREE_INFO" | awk '{print $1}' | tr -d 'MiB')"
    FREE_SIZE="$(echo "$FREE_INFO" | awk '{print $2}')"

    echo ""
    echo "即将执行:"
    echo "  在 $ROOT_DISK 偏移 ${FREE_START}MiB 处创建 ext4 分区（约 ${FREE_SIZE}）"
    echo "  分区标签: $DATA_LABEL"
    echo "  该分区将挂载到 $DATA_MOUNT，保存日志/告警/设备ID等持久数据"
    echo ""
    if [ "$ASSUME_YES" -ne 1 ]; then
        read -r -p "继续? [y/N]: " yn
        [ "${yn:-n}" = "y" ] || [ "${yn:-n}" = "Y" ] || die "已取消"
    fi

    # 分区表类型：gpt 用名称参数，msdos 用 primary
    TABLE_TYPE="$(parted -s "$ROOT_DISK" print 2>/dev/null | awk '/Partition Table/{print $3}')"
    if [ "$TABLE_TYPE" = "gpt" ]; then
        parted -s "$ROOT_DISK" mkpart "$DATA_LABEL" ext4 "${FREE_START}MiB" 100%
    else
        parted -s "$ROOT_DISK" mkpart primary ext4 "${FREE_START}MiB" 100%
    fi

    # 刷新分区表
    partprobe "$ROOT_DISK" 2>/dev/null || partx -u "$ROOT_DISK" 2>/dev/null || true
    udevadm settle 2>/dev/null || sleep 3

    # 新分区 = 磁盘上最后一个 part
    DATA_PART="$(lsblk -ln -o NAME,TYPE "$ROOT_DISK" | awk '$2=="part"{p=$1} END{print "/dev/"p}')"
    [ -n "${DATA_PART:-}" ] || die "分区创建失败"

    mkfs.ext4 -F -L "$DATA_LABEL" "$DATA_PART"
    ok "数据分区已创建: $DATA_PART (标签 $DATA_LABEL)"
}

# ---------------------------------------------------------------------------
# fstab 写入（先于挂载执行）
# ---------------------------------------------------------------------------
write_fstab() {
    [ -n "${DATA_UUID:-}" ] || die "未获取到数据分区 UUID"
    local bak="$FSTAB.bak-$(date +%Y%m%d%H%M%S)"
    cp -a "$FSTAB" "$bak"
    info "fstab 已备份: $bak"

    # 移除旧的管理块（幂等）
    sed -i "/^${MARKER_BEGIN}/,/^${MARKER_END}/d" "$FSTAB"

    {
        echo "$MARKER_BEGIN"
        echo "# 独立读写数据分区（断电保护核心，rootfs 只读后唯一持久化区域）"
        echo "UUID=$DATA_UUID $DATA_MOUNT ext4 defaults,noatime,nofail,x-systemd.device-timeout=10s,commit=60 0 2"

        # safesight 运行数据 bind 到 /data（路径保持 /var/lib/... 不变，兼容现有部署）
        echo "# safesight 运行数据 → /data（日志/告警/视频/设备ID 断电不丢）"
        if [ "$HLS_MODE" = "ram" ]; then
            echo "# HLS 分片 → 内存 tmpfs（重启即丢，减小 SD 写入；容量按需调整）"
            echo "tmpfs $RUNTIME_ROOT/hls tmpfs defaults,noatime,size=512m,mode=755 0 0"
        else
            echo "$DATA_MOUNT/safesight/hls    $RUNTIME_ROOT/hls    none bind,nofail 0 0"
        fi
        echo "$DATA_MOUNT/safesight/logs   $RUNTIME_ROOT/logs   none bind,nofail 0 0"
        echo "$DATA_MOUNT/safesight/alarms $RUNTIME_ROOT/alarms none bind,nofail 0 0"
        echo "$DATA_MOUNT/safesight/clips  $RUNTIME_ROOT/clips  none bind,nofail 0 0"
        echo "$DATA_MOUNT/safesight/agent  $AGENT_LIB           none bind,nofail 0 0"

        if [ "$JOURNAL_MODE" = "data" ]; then
            echo "# 系统 journal → /data（断电不丢，便于事后排查）"
            echo "$DATA_MOUNT/safesight/journal /var/log/journal none bind,nofail 0 0"
        fi
        echo "$MARKER_END"
    } >> "$FSTAB"

    ok "fstab 已更新"
}

# ---------------------------------------------------------------------------
# /data 目录初始化 + 存量数据迁移 + 挂载
# ---------------------------------------------------------------------------
setup_data_dirs() {
    local sub
    for sub in $DATA_SUBDIRS; do
        mkdir -p "$DATA_MOUNT/safesight/$sub"
    done
    [ "$JOURNAL_MODE" = "data" ] && mkdir -p "$DATA_MOUNT/safesight/journal"

    # 迁移已有数据（bind 挂载前执行，避免覆盖）
    migrate_dir() {
        local src="$1" dst="$2" name="$3"
        # bind 已挂载时 src 与 dst 是同一目录，跳过
        [ "$(readlink -f "$src")" != "$(readlink -f "$dst")" ] || return 0
        if [ -d "$src" ] && [ -n "$(ls -A "$src" 2>/dev/null)" ]; then
            cp -a "$src"/. "$dst"/ && ok "已迁移 $name 存量数据 → $dst"
        fi
    }
    for sub in hls logs alarms clips; do
        migrate_dir "$RUNTIME_ROOT/$sub" "$DATA_MOUNT/safesight/$sub" "$sub"
    done
    migrate_dir "$AGENT_LIB" "$DATA_MOUNT/safesight/agent" "agent"

    # 确保 bind 目标目录存在
    for sub in hls logs alarms clips; do
        mkdir -p "$RUNTIME_ROOT/$sub"
    done
    mkdir -p "$AGENT_LIB"
    mkdir -p /var/log/journal
}

mount_all() {
    # 挂载 /data 与全部 bind（依赖上一步 fstab/目录已就绪）
    mount -a 2>/dev/null || true
    if ! mountpoint -q "$DATA_MOUNT" 2>/dev/null; then
        die "$DATA_MOUNT 挂载失败，请检查 /etc/fstab"
    fi
    ok "$DATA_MOUNT 已挂载 rw (UUID=$DATA_UUID)"
}

# ---------------------------------------------------------------------------
# journald 配置（控制系统日志内存占用 / 持久化）
# ---------------------------------------------------------------------------
setup_journald() {
    mkdir -p /etc/systemd/journald.conf.d
    if [ "$JOURNAL_MODE" = "data" ]; then
        cat > /etc/systemd/journald.conf.d/safesight.conf << 'EOF'
[Journal]
Storage=persistent
SystemMaxUse=256M
SystemMaxFile=32M
MaxRetentionSec=14d
SyncIntervalSec=1h
EOF
        ok "journald → /data（持久化，上限 256M / 保留14天）"
    else
        cat > /etc/systemd/journald.conf.d/safesight.conf << 'EOF'
[Journal]
Storage=volatile
RuntimeMaxUse=64M
EOF
        ok "journald → 内存（volatile，上限 64M，重启即丢）"
    fi
    systemctl restart systemd-journald 2>/dev/null || true
}

# ---------------------------------------------------------------------------
# overlayroot 安装与配置
# ---------------------------------------------------------------------------
install_overlayroot() {
    if ! dpkg -s overlayroot >/dev/null 2>&1; then
        info "安装 overlayroot ..."
        apt-get update -qq 2>/dev/null || warn "apt update 失败（设备可能离线），尝试直接安装..."
        apt-get install -y overlayroot || die "overlayroot 安装失败。若设备离线，请将 overlayroot 预装进母卡镜像（sudo apt install overlayroot）后重新打包。"
    else
        ok "overlayroot 已安装"
    fi

    # 备份旧配置
    if [ -f "$OVERLAY_CONF" ]; then
        cp -a "$OVERLAY_CONF" "$OVERLAY_CONF.bak-$(date +%Y%m%d%H%M%S)"
    fi

    cat > "$OVERLAY_CONF" << 'EOF'
# /etc/overlayroot.conf — 由 setup-overlayroot.sh 生成
# 启用后根文件系统只读，一切写入进入内存(tmpfs)，重启即丢，断电不损坏根分区。
# 维护模式: 运行 sudo /opt/safesight-edge-server/scripts/setup-overlayroot.sh disable
overlayroot="tmpfs"
overlayroot_tmpfs_size="50%"
overlayroot_quiet="n"
# /data 是独立分区（fstab 挂载，不经过 overlay），保持可写，无需排除。
# 若个别镜像出现其它分区被意外只读，可在此追加排除，例如:
# overlayroot_exclude_partitions="/var/lib/docker"
EOF
    ok "/etc/overlayroot.conf 已配置 (overlayroot=\"tmpfs\")"

    info "重建 initramfs ..."
    update-initramfs -u || die "update-initramfs 失败"

    if [ -d /boot/extlinux ]; then
        warn "检测到 extlinux 引导（U-Boot/香橙派）。overlayroot 由 initramfs 加载，无需改 extlinux.conf。"
    fi
    ok "initramfs 已更新"
}

# ---------------------------------------------------------------------------
# 命令实现
# ---------------------------------------------------------------------------
cmd_install() {
    require_root
    detect_distro
    detect_root_disk

    if overlay_active; then
        warn "当前系统已处于 overlayroot 保护模式。如需调整配置，请先运行: $0 disable"
    fi

    # 1) 数据分区
    if data_partition_exists; then
        ok "检测到数据分区: ${DATA_PART:-（/data 已挂载）}"
    else
        if [ "${SKIP_PARTITION:-0}" = "1" ]; then
            die "SKIP_PARTITION=1 但未检测到 $DATA_LABEL 分区，请确认镜像包含数据分区"
        fi
        create_data_partition
    fi
    DATA_UUID="$(blkid -s UUID -o value "$DATA_PART" 2>/dev/null || true)"
    [ -n "$DATA_UUID" ] || die "未获取到数据分区 UUID ($DATA_PART)"

    # 2) fstab + 目录 + 挂载（fstab 先写，再按新 fstab 挂载）
    write_fstab
    setup_data_dirs
    mount_all

    # 3) journald
    setup_journald

    # 4) overlayroot
    install_overlayroot

    echo ""
    echo -e "${GREEN}════════════════════════════════════════════════════════════════${NC}"
    echo -e "${GREEN}  配置完成！重启后根文件系统将进入只读保护模式${NC}"
    echo -e "${GREEN}════════════════════════════════════════════════════════════════${NC}"
    echo ""
    echo "下一步:"
    echo "  sudo reboot                      # 重启生效"
    echo ""
    echo "重启后验证:"
    echo "  sudo /opt/safesight-edge-server/scripts/setup-overlayroot.sh verify"
    echo ""
    echo "数据分区（断电不丢）:"
    echo "  $DATA_MOUNT/safesight/{logs,alarms,clips,agent}"
    echo "  $DATA_MOUNT/safesight/hls        # HLS 分片 (${HLS_MODE})"
    echo ""
    echo "日常维护（装软件/改系统配置，需临时可写）:"
    echo "  sudo /opt/safesight-edge-server/scripts/setup-overlayroot.sh disable"
    echo "  sudo reboot    # 进入可写维护模式"
    echo "  sudo /opt/safesight-edge-server/scripts/setup-overlayroot.sh enable"
    echo "  sudo reboot    # 恢复只读保护"
    echo ""
    echo "注意：overlayroot 启用后，apt 安装、系统配置修改都会在重启后丢失，"
    echo "      必须进入维护模式操作！"
}

cmd_status() {
    require_root
    echo -e "${BLUE}══════════ overlayroot 状态 ══════════${NC}"

    if overlay_active; then
        echo -e "  根文件系统: ${GREEN}● 保护模式（overlay, 只读+tmpfs）${NC}"
        mount | grep ' / ' | sed 's/^/    /'
        echo -e "    上层(tmpfs)容量: $(df -h / | awk 'NR==2{print $2}')  已用: $(df -h / | awk 'NR==2{print $3}')"
    else
        echo -e "  根文件系统: ${YELLOW}○ 可写模式（overlay 未启用）${NC}"
    fi

    echo ""
    if mountpoint -q "$DATA_MOUNT" 2>/dev/null; then
        echo -e "  $DATA_MOUNT: ${GREEN}已挂载 rw${NC}  $(findmnt -no SOURCE,FSTYPE "$DATA_MOUNT")"
        echo "    磁盘占用: $(df -h "$DATA_MOUNT" | awk 'NR==2{print "总"$2" 已用"$3" 可用"$4}')"
    else
        echo -e "  $DATA_MOUNT: ${RED}未挂载${NC}"
    fi

    echo ""
    echo "  bind 挂载:"
    for b in logs alarms clips hls agent; do
        m="$RUNTIME_ROOT/$b"
        [ "$b" = "agent" ] && m="$AGENT_LIB"
        if mountpoint -q "$m" 2>/dev/null; then
            echo -e "    ${GREEN}✓${NC} $m → $(findmnt -no SOURCE "$m")"
        else
            echo -e "    ${RED}✗${NC} $m 未挂载"
        fi
    done

    echo ""
    if [ -f "$OVERLAY_CONF" ]; then
        echo "  /etc/overlayroot.conf:"
        grep -E '^overlayroot' "$OVERLAY_CONF" | sed 's/^/    /'
    else
        echo -e "  /etc/overlayroot.conf: ${RED}不存在${NC}"
    fi

    if [ -f /etc/systemd/journald.conf.d/safesight.conf ]; then
        echo ""
        echo "  journald: $(grep -E '^\s*(Storage|RuntimeMaxUse|SystemMaxUse)=' /etc/systemd/journald.conf.d/safesight.conf | tr '\n' ' ')"
    fi

    echo ""
    if [ -f "$AGENT_LIB/device_id" ]; then
        echo "  设备 ID: $(cat "$AGENT_LIB/device_id")（持久化于 /data）"
    else
        echo -e "  设备 ID: ${YELLOW}尚未生成${NC}"
    fi
}

cmd_verify() {
    require_root
    echo -e "${BLUE}══════════ 断电保护验证 ══════════${NC}"
    FAIL=0

    if overlay_active; then
        ok "overlay 已启用，根分区写入受保护"
    else
        warn "overlay 未启用（仍处于可写模式）"
        FAIL=1
    fi

    # /data 可写测试
    if mountpoint -q "$DATA_MOUNT"; then
        TEST_FILE="$DATA_MOUNT/.write_test_$(date +%s)"
        if echo ok > "$TEST_FILE" 2>/dev/null && rm -f "$TEST_FILE"; then
            ok "$DATA_MOUNT 可读写"
        else
            warn "$DATA_MOUNT 不可写！"
            FAIL=1
        fi
    else
        warn "$DATA_MOUNT 未挂载"
        FAIL=1
    fi

    # bind 挂载
    for b in logs alarms clips agent; do
        m="$RUNTIME_ROOT/$b"
        [ "$b" = "agent" ] && m="$AGENT_LIB"
        if mountpoint -q "$m" 2>/dev/null; then
            ok "$m → $(findmnt -no SOURCE "$m")"
        else
            warn "$m 未挂载（若为首次启用，服务运行后会自动创建）"
        fi
    done

    # 根分区是否真的只读（写测试）
    ROTEST="/.write_test_root_$$"
    if touch "$ROTEST" 2>/dev/null; then
        rm -f "$ROTEST"
        warn "警告: 根分区仍可写！请检查 overlayroot 配置"
        FAIL=1
    else
        ok "根分区只读"
    fi

    # 服务状态
    for s in safesight-edge-server safesight-edge-agent; do
        if systemctl is-active --quiet "$s" 2>/dev/null; then
            ok "$s 运行中"
        else
            warn "$s 未运行"
        fi
    done

    echo ""
    if [ "$FAIL" -eq 0 ]; then
        echo -e "${GREEN}✓ 断电保护配置正常，可放心断电${NC}"
    else
        echo -e "${YELLOW}存在未通过项，请按上方提示处理${NC}"
    fi
    exit "$FAIL"
}

# 切换 overlayroot 开关（disable=可写维护 / enable=恢复保护）
toggle_overlay() {
    local mode="$1"
    require_root
    [ -f "$OVERLAY_CONF" ] || cp /dev/null "$OVERLAY_CONF"
    cp -a "$OVERLAY_CONF" "$OVERLAY_CONF.bak-$(date +%Y%m%d%H%M%S)"

    if [ "$mode" = "disable" ]; then
        sed -i 's/^overlayroot=.*/overlayroot=""/' "$OVERLAY_CONF"
        # 若文件里没有可识别的行则追加
        grep -q '^overlayroot=' "$OVERLAY_CONF" || echo 'overlayroot=""' >> "$OVERLAY_CONF"
        echo ""
        echo -e "${YELLOW}overlayroot 已设为空（可写模式）。重启后根分区恢复可写，用于安装软件/修改配置。${NC}"
    else
        sed -i 's/^overlayroot=.*/overlayroot="tmpfs"/' "$OVERLAY_CONF"
        grep -q '^overlayroot=' "$OVERLAY_CONF" || echo 'overlayroot="tmpfs"' >> "$OVERLAY_CONF"
        echo ""
        echo -e "${GREEN}overlayroot 已重新启用（保护模式）。重启后根分区只读。${NC}"
    fi

    info "重建 initramfs ..."
    update-initramfs -u
    echo ""
    echo "请执行: sudo reboot"
}

# ---------------------------------------------------------------------------
# 主入口
# ---------------------------------------------------------------------------
case "$CMD" in
    install) cmd_install ;;
    status)  cmd_status ;;
    verify)  cmd_verify ;;
    disable) toggle_overlay disable ;;
    enable)  toggle_overlay enable ;;
    *)
        echo "RK3588 Edge 断电保护脚本（overlayroot + /data）"
        echo ""
        echo "用法: sudo $(basename "$0") [命令] [选项]"
        echo ""
        echo "命令:"
        echo "  install   一键启用断电保护（创建/挂载 /data + 启用 overlayroot）"
        echo "  status    查看当前保护状态"
        echo "  verify    重启后验证保护是否生效"
        echo "  disable   临时禁用（维护模式：装软件/改系统配置）"
        echo "  enable    重新启用（恢复保护）"
        echo ""
        echo "选项:"
        echo "  --yes          跳过确认"
        echo "  --hls-ram      HLS 分片放内存（减小 SD 写入，重启即丢）"
        echo "  --journal-data 系统日志持久化到 /data（默认内存）"
        echo ""
        echo "示例:"
        echo "  sudo $(basename "$0") install"
        echo "  sudo $(basename "$0") install --hls-ram"
        echo "  sudo $(basename "$0") status"
        ;;
esac