#!/bin/bash
 
  mirror_rootfs () {
    local boot; local dest; local rootfs; local opts
    [[ ! $(command -v rsync) ]] && { echo rsync must be installed to use this function; return 5; }
    opts=" --dry-run"
    [[ $1 == "--run" ]] && opts="" && shift
    [[ $1 == "-v" ]] && opts+=" -v" && shift
    [[ $1 == "-o" ]] && opts+=" $2" && shift

    dest=$(realpath -s $1)
    rootfs=$2

    [ ! -d "$dest" ] && echo destination $dest is not a directory && return 3
    [ ! -d "$rootfs/etc" ] && echo not root filesystem at $rootfs && return 3

    echo making mirror of root filesystem at ${rootfs:-/} to $dest/rootfs
    #TODO if destination is btrfs then make snapshot otherwise make directory
    sudo btrfs subvol create $dest/rootfs >/dev/null
    if sudo rsync -axHAWXS $opts --info=progress2 --numeric-ids --delete --delete-excluded --force --exclude-from="$(rootfs_excludes)" ${rootfs:-/} $dest/rootfs  ; then
        echo root parition mirror was made to $dest/rootfs
        boot=$rootfs/boot
        [[ ! $(mountpoint $boot) ]] && boot=$rootfs/boot/efi 
        [[ ! $(mountpoint $boot) ]] && echo neither $rootfs/boot nor $boot are mountpoints, no boot parition to mirror && return 2
        echo making mirror of boot $boot partition to $dest$boot
        sudo btrfs subvol create $dest$boot >/dev/null
        if sudo rsync -aHAWXS $opts --info=progress2 --numeric-ids --force --delete $boot/ $dest$boot; then
            echo boot partion is mirrored
        else 
            echo unable to sync a copy of $boot, aborted backup    
        fi
    else
        echo unable to sync a copy of root file system, backkup failed
    fi
}

  rclone () {
    local boot; local dest; local src; local opts
    [[ ! $(command -v rsync) ]] && { echo rsync must be installed to use this function; return 5; }
    opts=" --dry-run"
    [[ $1 == "--run" ]] && opts="" && shift
    [[ $1 == "-v" ]] && opts+=" -v" && shift
    [[ $1 == "-o" ]] && opts+=" $2" && shift

    src=$(realpath $1)
    dest=$(realpath $2)
    mkdir -p $dest >/dev/null
    echo making clone/mirror of $src to $dest 
    
    if [ "$(ls -A $dest)" ]; then
     echo WARNING: $dest is not empty but will be erased!, be sure before using --run
    # TODO RUN CONFIRM 
    #  if [[ $opt == *"--run"* ]]; then
    fi
    # if sudo rsync -axHAWXS $opts --info=progress2 --numeric-ids --delete --delete-excluded --force $src/ $dest/  ; then
    cmd="sudo rsync -axHAWXS $opts --info=progress2 --numeric-ids --delete --force $src/ $dest/" 
    echo "$cmd"
    if $cmd ; then
      echo mirror/clone was successful
    else
      echo unable to make the clone
    fi
}

rootfs_excludes () {

local list; local delete
[[ $1 == "-l" ]] && list=true && shift   
[[ $1 == "-r" ]] && delete=true && shift
[[ "$1" == "-"* ]] && >&2 echo bad option, aborting && return 1
rfse=${1:-/tmp/rootfs_excludes.lst}
touch $rfse
[[ $delete ]] && rm $rfse
cat <<EOF > $rfse
.[Tt]rash*
tmp/*
node_modules
[Cc]ache/*
logs/*
log/*
lost+found
EOF
if [[ $list ]];then
    cat $rfse; rm -f $rfse  
    else
    echo $rfse
fi
}

mountpoints () {
cat /proc/mounts | cut -d ' ' -f2 | sort
}