#!/usr/bin/env bash
#
# Author: Dmitry Razumov <asmeron@ublinux.com>
# Copyright (c) 2021-2025 UBLinux <support@ublinux.com>
#

ENABLED=yes
[[ ${ENABLED} == "yes" ]] || exit 0

PATH_BOOT="/memory/layer-base/0"
PATH_KERNEL="/usr/lib/modules"

copy_newkernel_to_boot(){
# Найти все файлы ядра и initramfs. Еслии новее по дате модификации в системе, то заменить загрузочные
    mountpoint --quiet "${PATH_BOOT}" || return 0
    find ${PATH_KERNEL} -maxdepth 2 \( -name "vmlinuz-*.*.*-*" -o -name "ublinux-*.*.*-*" -o -name "addon-*.*.*-*" \) -print | while read FIND_FILE; do
        local DTIME_FIND_FILE=$(stat -c'%Y' $(readlink -e ${FIND_FILE} 2>/dev/null))
        [[ -e ${PATH_BOOT}/${FIND_FILE##*/} ]] && local DTIME_BOOT_FILE=$(stat -c'%Y' ${PATH_BOOT}/${FIND_FILE##*/} 2>/dev/null) || local DTIME_BOOT_FILE=0
        [[ ${DTIME_FIND_FILE} =~ ^[0-9]+$ && ${DTIME_BOOT_FILE} =~ ^[0-9]+$ ]] && [[ ${DTIME_FIND_FILE} -gt ${DTIME_BOOT_FILE} ]] \
        && cp -aL "${FIND_FILE}" "${PATH_BOOT}/" && chown root:root "${PATH_BOOT}/${FIND_FILE##*/}" && chmod 400 "${PATH_BOOT}/${FIND_FILE##*/}"
    done
}

remove_oldkernel_from_boot(){
# Найти все файлы ядра "vmlinuz-*.*.*-*" и initramfs "ublinux-*.*.*-*" в ${PATH_BOOT}/boot и которые отсутствуют в /usr/modules/*/ удалить
    mountpoint --quiet "${PATH_BOOT}" || return 0
    find ${PATH_BOOT} -maxdepth 1 -name "vmlinuz-*.*.*-*" -exec bash -c "find ${PATH_KERNEL} -maxdepth 2 -name \${1##*/} -exec false \{\} + && rm -f \$1" bash {} \;
    find ${PATH_BOOT} -maxdepth 1 -name "ublinux-*.*.*-*" -exec bash -c "find ${PATH_KERNEL} -maxdepth 2 -name \${1##*/} -exec false \{\} + && rm -f \$1" bash {} \;
}

exec_prepare_menu_kernel(){
# Сформировать меню выбора версии ядра
    mountpoint --quiet "${PATH_BOOT}" || return 0
    FILE_BOOTMENU_KERNEL="/memory/data/from/0/boot/grub/ublinux/grub_settings_kernel.cfg"
    local DATA_BOOTMENU_KERNEL=
    for VMLINUZ_FILES in ${PATH_BOOT}/vmlinuz-*; do
        [[ -f "${VMLINUZ_FILES}" ]] || continue
        [[ ${VMLINUZ_FILES} =~ .*\/vmlinuz\-([0-9]+\.[0-9]+\.[a-z0-9_]+\-[0-9]+)$ ]]
        VMLINUZ_VER=${BASH_REMATCH[1]}
        if [[ -n ${VMLINUZ_VER} && -f ${PATH_BOOT}/ublinux-${VMLINUZ_VER} ]]; then
            VMLINUZ_FILE="\${PATH_DISTR_BOOT}/vmlinuz-\${VMLINUZ_VER}"
            UBLINUX_FILE="\${PATH_DISTR_BOOT}/ublinux-\${VMLINUZ_VER}"
            [[ -f ${PATH_BOOT}/addon-${VMLINUZ_VER} ]] && ADDON_FILE="\${PATH_DISTR_BOOT}/addon-\${VMLINUZ_VER}" || ADDON_FILE=""
            DATA_BOOTMENU_KERNEL+=\
"    menuentry \$\"Change the kernel version\"\": ${VMLINUZ_VER}\" --unrestricted {
        VMLINUZ_VER=\"${VMLINUZ_VER}\"
        VMLINUZ_FILE=\"${VMLINUZ_FILE}\"
        UBLINUX_FILE=\"${UBLINUX_FILE}\"
        ADDON_FILE=\"${ADDON_FILE}\"
        export VMLINUZ_VER
        export VMLINUZ_FILE
        export UBLINUX_FILE
        export ADDON_FILE
        configfile \${PATH_DISTR_GRUB}/grub_main.cfg
    }
"
        fi
    done
    if [[ -n ${DATA_BOOTMENU_KERNEL} ]]; then
	DATA_BOOTMENU_KERNEL+=\
"    if [ -f \${PATH_DISTR_GRUB}/grub_main.cfg ]; then
        menuentry \$\"Return\" --unrestricted {
            configfile \${PATH_DISTR_GRUB}/grub_main.cfg
        }
    fi"
	[[ -f ${FILE_BOOTMENU_KERNEL} ]] && [[ "$(< ${FILE_BOOTMENU_KERNEL})" == "${DATA_BOOTMENU_KERNEL}" ]] || echo "${DATA_BOOTMENU_KERNEL}" > "${FILE_BOOTMENU_KERNEL}"
    else
        [[ -f ${FILE_BOOTMENU_KERNEL} ]] && rm -f ${FILE_BOOTMENU_KERNEL}
    fi
}

    copy_newkernel_to_boot
    remove_oldkernel_from_boot
    exec_prepare_menu_kernel