#!/bin/bash
#
# 07.12.2020 disable pikaur
#
# Snapshot + System Update
# ---------------------------
# Snapshot - Rollback - Btrfs
# ---------------------------

BTRFS=/usr/bin/btrfs
CP=/usr/bin/cp
ECHO=/usr/bin/echo
GREP=/usr/bin/grep
MKDIR=/usr/bin/mkdir
MOUNT=/usr/bin/mount
MV=/usr/bin/mv
#PIKAUR=/usr/bin/pikaur
PACMAN=/usr/bin/pacman
REFLECTOR=/usr/bin/reflector
SED=/usr/bin/sed
SUDO=/usr/bin/sudo
CHECKUPDATES=/usr/bin/checkupdates
MAXSAVESNAPSHOTS=23
SNAPSHOTHISTORYFOLDER="/.snapshots/STABLE-Snapshot-History"

# ---------------------------
#      Snapshot System
# ---------------------------
[ -d ${SNAPSHOTHISTORYFOLDER} ] || $SUDO $MKDIR -p ${SNAPSHOTHISTORYFOLDER}
if $CHECKUPDATES ; then
# if true ; then
bootstate=`$MOUNT | $GREP "on / type btrfs" | $GREP "subvol=/@snapshots/TESTING"`
if [ -z "$bootstate" ]
    then
        $ECHO ""
        $ECHO $bootstate
        $ECHO ""
        $ECHO "System ist nicht mit TESTING hochgefahren !"
        $ECHO "ENDE !"
        sleep 2
        exit 1
    else
    # -------- make new OLDSTABLE --------
        $SUDO $BTRFS subvolume delete /.snapshots/OLDSTABLE
        $SUDO $MV /.snapshots/STABLE /.snapshots/OLDSTABLE
        $SUDO $SED -i 's/STABLE/OLDSTABLE/g' /.snapshots/OLDSTABLE/etc/fstab
        $SUDO $CP /boot/vmlinuz-linux-stable /boot/vmlinuz-linux-oldstable
        $SUDO $CP /boot/initramfs-linux-stable.img /boot/initramfs-linux-oldstable.img
        # $SUDO $CP /boot/vmlinuz-linux-lts-stable /boot/vmlinuz-linux-lts-oldstable
        # $SUDO $CP /boot/initramfs-linux-lts-stable.img /boot/initramfs-linux-lts-oldstable.img

        # --------- make new STABLE ----------
        $SUDO $BTRFS subvolume snapshot / /.snapshots/STABLE
        $SUDO $SED -i 's/TESTING/STABLE/g' /.snapshots/STABLE/etc/fstab
        $SUDO $CP /boot/vmlinuz-linux /boot/vmlinuz-linux-stable
        $SUDO $CP /boot/initramfs-linux.img /boot/initramfs-linux-stable.img
        # $SUDO $CP /boot/vmlinuz-linux-lts /boot/vmlinuz-linux-lts-stable
        # $SUDO $CP /boot/initramfs-linux-lts.img /boot/initramfs-linux-lts-stable.img

        # --------- backup TESTING and Kernels ----------
        TIMESTAMP=`date +%Y-%m-%d-%H%M`
        $SUDO $BTRFS subvolume snapshot / ${SNAPSHOTHISTORYFOLDER}/${TIMESTAMP}_STABLE
        $SUDO cp /boot/vmlinuz-linux ${SNAPSHOTHISTORYFOLDER}/${TIMESTAMP}_vmlinuz-linux
        $SUDO cp /boot/initramfs-linux.img ${SNAPSHOTHISTORYFOLDER}/${TIMESTAMP}_initramfs-linux.img

        # ---------------------------
        #      Update System
        # ---------------------------
        $SUDO $REFLECTOR -f 8 -p https -i ".de/" --sort rate --save /etc/pacman.d/mirrorlist
        $SUDO $PACMAN -Syu
        #$PIKAUR -Syu # aktualisiert AUR gleich mit :-)

        # --------------------------------------------
        #    delete old saved Snapshots and Kernels
        # --------------------------------------------
        typeset -i FILECOUNT
        FILECOUNT=0
        for file in `ls -r ${SNAPSHOTHISTORYFOLDER} | grep _STABLE` ; do
            FILECOUNT=$FILECOUNT+1
            [ $FILECOUNT -le $MAXSAVESNAPSHOTS ] && continue
            kernelfilename=`echo ${file} | cut -c-15`
            $SUDO $BTRFS subvolume delete ${SNAPSHOTHISTORYFOLDER}/${file}
        #   echo  "deleting snapshot ${SNAPSHOTHISTORYFOLDER}/${file}"
            [ -f "${SNAPSHOTHISTORYFOLDER}/${kernelfilename}_vmlinuz-linux" ] && $SUDO rm ${SNAPSHOTHISTORYFOLDER}/${kernelfilename}_vmlinuz-linux
            echo "delete file ${SNAPSHOTHISTORYFOLDER}/${kernelfilename}_vmlinuz-linux"
            [ -f "${SNAPSHOTHISTORYFOLDER}/${kernelfilename}_initramfs-linux.img" ] && $SUDO rm ${SNAPSHOTHISTORYFOLDER}/${kernelfilename}_initramfs-linux.img
            echo "delete file ${SNAPSHOTHISTORYFOLDER}/${kernelfilename}_initramfs-linux.img"
        done

        # --------------------------------------------
        #    Balance Filesystem
        # --------------------------------------------
        $SUDO $BTRFS balance start -dusage=5 /btrfs
fi
else
    echo "Keine Updates vorhanden - ENDE !"
    sleep 2
fi
        # -------------------------------------------------------------------------------------
        #    disable automatic-search for grub - only 00_header 40_custom 41_custom are needed
        # -------------------------------------------------------------------------------------
        for file in `ls /etc/grub.d/ | grep -v ^4 | grep -v README | grep -v ^00 | grep -v disabled$` ; do
            $SUDO chmod 644 /etc/grub.d/$file
            $SUDO mv /etc/grub.d/$file /etc/grub.d/"$file"_disabled
        done