usage() {
  echo "usage: git now grep [<base_branch>]"
}

cmd_default() {
  parse_args "$@"

  if [ -n "$BASE_BRANCH" ]; then
    WORKING_BRANCH=$(git_current_branch)
    COMMON_ANCESTOR_COMMIT=`git merge-base ${BASE_BRANCH} ${WORKING_BRANCH}`
    echo `git log ${COMMON_ANCESTOR_COMMIT}.. --pretty=oneline --grep="${PREFIX}"`
  else
    echo `git log --pretty=oneline --grep="${PREFIX}"`
  fi
}

parse_args() {
  # parse options
  FLAGS "$@" || exit $?
  eval set -- "${FLAGS_ARGV}"
  # read arguments into global variables
  BASE_BRANCH=$1
}

cmd_help() {
  usage
  exit 0
}