#!/bin/sh
echo Starting Restorecopy >&2
read -r args
read -r paths
echo "Arguments: $args" >&2
echo "Paths: $paths" >&2
if [ -f "$args" ] ; then
  echo "Performing restore from backup file $args" >&2
  TARGET="$args"
  echo "Copying $TARGET to STDOUT" >&2
  # shellcheck disable=SC2086
  /usr/lib/qubes/tar2qfile "$TARGET" $paths
else
  echo "Checking if arguments is matching a command" >&2
  COMMAND=$(echo "$args" | cut -d ' ' -f 1)
  if command -v "$COMMAND" >/dev/null; then
    tmpdir=$(mktemp -d)
    mkfifo "$tmpdir/backup-data"
    echo "Redirecting $args to STDOUT" >&2
    # Parsing args to handle quotes correctly
    # Dangerous method if args are uncontrolled
    eval "set -- $args"
    # Use named pipe to pass original stdin to tar2file
    "$@" > "$tmpdir/backup-data" < /dev/null &
    # shellcheck disable=SC2086
    /usr/lib/qubes/tar2qfile "$tmpdir/backup-data" $paths
    # Restoration may be terminated earlier because of selected files. This
    # will be seen as EPIPE to the retrieving process, which may cause retcode
    # other than 0 in some cases - which would be incorrectly treated as backup
    # restore error. So instead of that, use tar2qfile exit code (and have dom0
    # detect if anything wrong with actual data)
    retcode=$?
    wait $!
    rm "$tmpdir/backup-data"
    rmdir "$tmpdir"
    exit "$retcode"
  else
    echo "Invalid command $COMMAND" >&2
    exit 2
  fi
fi