#!/bin/sh

################################################################################
#
# This shell script will convert a project inside a Subversion
# repository that is managed by the SVA/SC utility into a Git
# repository.
#
# You will need to have the git-svn tool installed before you run this
# script.  I also highly recommend that you use a local Subversion
# repository, instead of a remote one.
#
################################################################################

args=`getopt A:t:b: $*`; e=$?; set -- $args
options="--no-metadata"
tags_subdir="rel"
branches_subdir="exp"

if [ $e != 0 ]; then
  echo "Usage: [options] svn-url project-name"
  echo " -A authors-file     Resolve commit authors, see git-svn(1)"
  echo " -t tags-subdir      The tags subdir to import (default: $tags_subdir)"
  echo " -b branches-subdir  The branches subdir to import (default: $branches_subdir)"
  exit 1
fi

while [ $# -ne 0 ]; do
  case "$1" in
    -A) options="-A $2 $options"; shift; shift;;
    -t) tags_subdir=$2; shift; shift;;
    -b) branches_subdir=$2; shift; shift;;
    --) shift; break;;
  esac
done

if [ $# -ne 2 ]; then
  echo "missing project name, or more than one project name given"
  exit 1
fi

# capture the URL and project name
svnurl=$1
project=$2

# if the output directory exists, we have a problem
if [ -r $project.git ]; then
  echo "error: output directory exists: $project.git"
  exit 1
fi

# make the URL a file:// if it's a local dir
if [ -d $svnurl ]; then
  svnurl=file://`pwd`/$svnurl
fi

# initial clone, but too shallow
echo "converting from svn to git"
git svn clone \
  --quiet \
  --trunk=trunk \
  --tags=tags/$tags_subdir \
  --branches=branches/$branches_subdir \
  $options $svnurl/$project $project.git || exit 1

# work inside the repo
cd $project.git || exit 1

# transform remote branches to local branches
for branch in `git branch -r|egrep -v '^ *tags'`; do
  echo "resolving remote branch: $branch"
  git checkout $branch
  git checkout -b $branch
done

# transform tags to real tags
for tag in `git branch -r|egrep '^ *tags'|egrep -v @`; do
  tag_name=`echo $tag|sed 's|tags/||'`
  git checkout $tag
  git tag -a -m "Tagging v$tag_name" v$tag_name
done

# rename the truck branch to master, since that's what it really is
git branch -M trunk master
git checkout master
git repack -a -d || exit 1
git prune-packed || exit 1

# create a bare clone, dropping the lame remote branches
cd .. || exit 1
git clone --bare $project.git $project.git.bare || exit 1
rm -rf $project.git || exit 1
mv $project.git.bare $project.git || exit 1

# done
echo "Bare repository in $project.git"