#!/bin/sh

if [ "$#" -eq 0 ] ; then
  echo "Usage: $0 <gem> [gem2 gem3 ...]"
  exit 1
fi
GEMS="$*"

if ! gem list --local | grep -q gem2rpm ; then
  echo "You need to install gem2rpm; run 'gem install gem2rpm'"
  exit 1
fi
   

tmp=$(mktemp -d)
RPM_TOPDIR="$tmp"
export RPM_TOPDIR
pushd $tmp
mkdir -p SOURCES SPECS BUILD SRPMS RPMS
for gem in $GEMS; do 
  (cd SOURCES; gem fetch $gem) 2>&1 | grep '^ERROR: ' && exit 1
  set -e

  spec="SPECS/rubygem-$gem.spec"
  gem2rpm SOURCES/$gem*.gem > $spec

  # concatonate line continuations for easier substituting.
  sed -i -ne '/\\$/N; /\\$/! { s/\\\n//g; p; }' $spec

  # Hacks to handle CentOS gem builds go here.
  case $gem in
    mysql)
      sed -i -e 's@^gem install.*@& -- --with-mysql-lib=/usr/lib64/mysql --with-mysql-include=/usr/include/mysql@' $spec
    ;;
    stompserver)
      sed -i -e 's@^URL: .*@URL: http://stompserver.rubyforge.org/@' $spec
    ;;
  esac

  rpmbuild -ba $spec --buildroot $PWD/BUILD-$gem --define "_topdir $tmp" $spec
done
popd
find $tmp -name '*.rpm' -print0 | xargs -0 -n1 sh -c 'cp -v $1 .' -
rm -r "$tmp"