#!/bin/sh

GIT_CONFIG='.git/config'

OLD_REP=$1
NEW_REP=$2
WORKSPACE=$3

# show usage
if [ -z "$OLD_REP" -o -z "$NEW_REP" ]; then
  echo "git-svn-relocate OLD_REPOSITORY NEW_REPOSITORY [GIT_WORKSPACE]"
  exit 1
fi

# change woking directory
if [ $WORKSPACE ]; then
  cd $WORKSPACE
  if [ 0 -ne $? ]; then
    echo "invalid git workspace"
    exit 1
  fi
fi

# git config file is exists?
if [ ! -f $GIT_CONFIG ];then
  echo "not exists $GIT_CONFIG"
  exit 1
fi

# check old repository
grep $OLD_REP $GIT_CONFIG > /dev/null
if [ 0 -ne $? ]; then
  echo "url not found (invalid old repository)"
  exit 1
fi

# check current branch
RET=`git branch| grep master | grep '*'`
if [ -z "$RET" ]; then
  echo "not master branch"
  exit 1
fi

# check git index
RET=`git diff`
if [ "$RET" ]; then
  echo "dirty workspace..."
  exit 1
fi

# start relocation
echo "rewrite url $OLD_REP -> $NEW_REP"
sed -i -e "s|$OLD_REP|$NEW_REP|" $GIT_CONFIG

RET=`git svn fetch`
if [ 0 -ne $? -o -z "$RET" ]; then
  echo "revert url $NEW_REP -> $OLD_REP"
  sed -i -e "s|$NEW_REP|$OLD_REP|" $GIT_CONFIG
  if [ -z "$RET" ]; then
    echo "empty fetch from new repository."
  else
    echo "invalid repository?"
  fi
  exit 1
fi

echo "rewrite url $NEW_REP -> $OLD_REP"
sed -i -e "s|$NEW_REP|$OLD_REP|" $GIT_CONFIG
git svn rebase -l
echo "rewrite url $OLD_REP -> $NEW_REP"
sed -i -e "s|$OLD_REP|$NEW_REP|" $GIT_CONFIG

echo "repository relocation is completed"