#!/bin/bash

set -e

force=false

if [ "$REPO" = "" ]
then
  REPO="http://repo.typesafe.com/typesafe/ivy-releases/org.scala-tools.sbt/sbt-launch"
fi

usage() {
  echo "usage: $0 OPTIONS" >&2
  echo "Use $0 -? for usage help" >&2
  exit 1
}

find_latest() {
  echo "Finding latest version from $REPO ..."
  read version < <(wget -O - -q $REPO | sed -n "s,<a .*>\([0-9][0-9]*\)\.\([0-9][0-9]*\)\.\([0-9][0-9]*\)/</a.*,\1 \2 \3 \1.\2.\3,p" | sort -n -r -k 1 -k 2 -k 3| head -n 1 | cut -f 4 -d " ")

  if [ -z "$version" ]
  then
    echo "Unable to find the latest version." >&2
    exit 1
  fi

  url="$REPO/$version/sbt-launch.jar"
}

calculate_package_filename() {
  # TODO: Add arch to the filename (i386, amd64)
  repo=repository/debian
  mkdir -p $repo
  count=`find $repo -name sbt-$version-*.deb 2>/dev/null|wc -l`
  echo $count
  if [ $count != 0 ]
  then
    package_exist=1
  fi
  revision=$(($count + 1))
  package_filename=$repo/sbt-$version-$revision.deb
}

build_common() {
  rm -rf root

  mkdir -p root/usr/share/sbt-$version/
  mkdir -p root/usr/bin
  cat sbt.in | sed "s,@SBT_VERSION@,$version," > root/usr/bin/sbt-$version
  cat sbt+jrebel.in | sed "s,@SBT_VERSION@,$version," > root/usr/bin/sbt-$version+jrebel
  chmod +x root/usr/bin/*
  cp download/$version/sbt-launch.jar root/usr/share/sbt-$version/sbt-launch.jar
}

build_debian() {
  build_common

  mkdir -p root/DEBIAN
  sed \
    -e "s,@SBT_VERSION@,$version," \
    -e "s,@REVISION@,$revision," \
    debian/control.in > root/DEBIAN/control
  sed "s,@SBT_VERSION@,$version," debian/postinst.in > root/DEBIAN/postinst
  sed "s,@SBT_VERSION@,$version," debian/prerm.in > root/DEBIAN/prerm
  chmod a=rx root/DEBIAN/postinst root/DEBIAN/prerm

  echo > debian/fakeroot.save
  FAKEROOT="fakeroot -i debian/fakeroot.save -s debian/fakeroot.save"
  $FAKEROOT -- chown -R root:root root/
  $FAKEROOT -- chmod go=r `find root/usr -type f`
  $FAKEROOT -- chmod go=rx `find root/usr/bin -type f`
  $FAKEROOT -- dpkg-deb -b root $package_filename
  rm debian/fakeroot.save

  if [ "$update_repository" = 1 ]
  then
    (cd $repo && dpkg-scanpackages -m . /dev/null | tee Packages | gzip > Packages.gz )
  fi
}

while getopts "v:uF?" flag
do
  case "$flag" in
    v)
      version=$OPTARG
      ;;
    u)
      update_repository=1
      ;;
    F)
      force="true"
      ;;
    ?)
      less README
      exit 0
      ;;
  esac
done

if [ -z "$version" ]
then
  find_latest
  echo "The latest version is $version"
else
  url="$REPO/$version/sbt-launch.jar"
fi

calculate_package_filename

if [ "$package_exist" = 1 ]
then
  if [ $force = "false" ]
  then
    echo "The requested version ($version) already exist in the repository, add -F to force a re-build of the package" >&2
    exit 1
  else
    echo "WARNING: re-building package for version $version" >&2
  fi
fi

mkdir -p download

echo "Downloading version $version..."
if [ `wget -q -P download/$version -N $url; echo $?` != "0" ]
then
  echo "Could not download $url" >&2
  exit 1
fi

if [ ! -r download/$version/sbt-launch.jar ]
then
  echo "wget didn't place the downloaded file where expected: download/$version/sbt-launch.jar" >&2
  exit 1
fi

build_debian