#!/bin/bash

PATH=/sbin:$PATH # mount.dragfs

self=`basename "$0"`

if (($# < 2)) || [[ "$1" = '-h' ]] || [[ "$1" = '--help' ]]; then
 cat << END
This program merges several dragon isotope libraries into one.
Usage: $self result library1 ...
END
 exit
fi

result="$1"
if ! [[ -e "$1" ]]; then
 echo "$2"
 cp "$2" "$1" || exit $?
 shift
fi
shift

workdir=`mktemp -t $self.XXXXXX` &&
rm "$workdir" &&
mkdir "$workdir" || exit $?

clean() {
 [[ -e "$workdir/2" ]] && fusermount -u "$workdir/2" 2> /dev/null
 [[ -e "$workdir/1" ]] && fusermount -u "$workdir/1"
 rm -r "$workdir"
}

trap clean exit

mkdir "$workdir/1" &&
mkdir "$workdir/2" &&
mount.dragfs "$result" "$workdir/1" || exit $?

while (($# > 0)); do
 echo "$1"
 mount.dragfs "$1" "$workdir/2" || {
  echo "$self: unable to mount $1" >&2
  exit $?
 }
 cmp "$workdir/1/energy.real" "$workdir/2/energy.real" || {
  echo "$self: energy grid is different in $1" >&2
  exit 1
 }
 for f in "$workdir/2"/*; do
  [[ "$f" =~ (energy\.real|signature|version)$ ]] && continue
  cp -r "$f" "$workdir/1" || exit $?
 done
 fusermount -u "$workdir/2"
 shift
done