#!/bin/sh
# usage:
#  $0 boot-ram                                             - use memory-only overlay
#  $0 boot-new          [dev name] [loop file] [megabytes] - create new luks-encrypted overlay
#  $0 boot-overwrite    [dev name] [loop file] [megabytes] - overwrite with new luks overlay
#  $0 boot-luks         [dev name] [loop file]             - boot existing luks-encrypted overlay
#  $0 boot-destroy-disk [dev-name]                         - install to a fresh hard disk

. btrfs-create.sh
. common.sh
exec 4>&1
debug_log

error()
{
  local sleep=3

  clear >&4
  echo "error -- ${*:-:(}" >&4
  echo "error -- ${*:-:(}" >/dev/tty1

  if [ $sleep -gt 0 ]; then
    echo "will try again in $sleep seconds..." >&4
    sleep $sleep
  fi
  bootmenu do_trigger no_panic
  exit
}

badopts=
fs=
while [ $# -ge 1 ]; do
  case $1 in
    --fs=*) fs="${1#--fs=}"; shift; continue ;;
    --*) echo "error: unknown option $1"; badopts=true; shift; continue ;;
  esac
  break
done
[ -z "$badopts" ] || error 'usage error'

[ $# -ge 2 -o "$1" = 'boot-ram' -o "$1" = boot-destroy-disk ] || error 'usage error'

remountrw()
{
  local fs="$1" dev="$2" loopfile="$3"
  if [ "$fs" = hfsplus ]; then
    mountpoint="/mnt/${dev##*/}"
    umount "$dev" || error
    fsck.hfsplus -q "$dev" || error
    mount -o force "$dev" "$mountpoint" || error
  else
    mount -o remount,rw "$dev" || error
  fi
}

hwclock_to_system()
{
  local fs="$1" UTC=UTC
  case "$fs" in ntfs|vfat) UTC=LOCAL ;; esac
  printf '0.0 0 0.0\n0\n%s' $UTC > /etc/adjtime
  hwclock --hctosys
}

clear >/dev/tty1
echo -n "Samizdat is attempting to load the root filesystem..." >/dev/tty1
chvt 1
case "$1" in
  boot-ram)
    read _ memtotal_kb _ < /proc/meminfo
    # This doesn't make sense to me, but setting rd_size _lower_ than total
    # memory seems to be what breaks things ('btrfs device add' hangs forever).
    # Somehow you can fill up the filesystem and there's still space for
    # programs and btrfs does not complain. I don't know what is going on here.

    # BTW, I verified with blockdev that the device size really is being
    # specified in KB here. I did not really believe it.
    modprobe brd rd_nr=1 rd_size=$memtotal_kb

    init_samizdat /dev/ram0 '' || {
        umount /root/cdrom
        umount /root/outerfs
        umount /root
        error
    }
    bootdone root-mounted
  ;;
  boot-destroy-disk)
    dev="$2"

    umount /plaintext || true
    partition_new_hard_drive_DESTROYING_EVERYTHING "$dev" || error

    mkfs.btrfs -f "$dev"2                                 || error
    mkdir /plaintext
    mount "$dev"2 /plaintext                              || error

    init_samizdat_blockdev "$dev"3 /plaintext/disk.key    || error
    init_samizdat /dev/mapper/samizdatcrypt ''            || error

    mark_partitions_as_complete "$dev"

    bootdone root-mounted
  ;;
  boot-native)
    dev="$2"
    umount /plaintext || true
    open_samizdat_blockdev "$dev"3 - || error
    open_samizdat                                      || error open_samizdat
    bootdone root-mounted
  ;;
  boot-overwrite|boot-new|boot-luks)
    dev="$2"
    loopfile="$3"
    megs="$4"

    [ "$1" != 'boot-new' -o ! -e "$loopfile" ] || error

    remountrw "$fs" "$dev" "$loopfile" || error

    hwclock_to_system "$fs"

    if [ "$1" = 'boot-overwrite' ]; then
      rm "$loopfile" "$loopfile"k
    fi

    if [ "$1" = 'boot-luks' ]; then
      open_samizdat_blockdev_from_loop "$loopfile" "$loopfile"k || error
      open_samizdat || error open_samizdat
      bootdone root-mounted
      exit
    fi

    start_meter "Allocating ${megs}MB in '$loopfile' on $dev..."

    if newdev=$(init_samizdat_lodev "$loopfile" "$megs") &&
        init_samizdat_blockdev "$newdev" "$loopfile"k &&
            init_samizdat /dev/mapper/samizdatcrypt "$loopfile"; then
      stop_meter done.
      bootdone root-mounted
    else
      stop_meter error!
      rm "$loopfile" "$loopfile"k
      dmsetup remove samizdatcrypt
      # TODO: more teardown
      error
    fi
  ;;
  *)
    error "Unimplemented boot command: $*"
  ;;
esac

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