#!/usr/bin/env bash
# reset environment variables that could interfere with normal usage
export GREP_OPTIONS=
# put all utility functions here

# make a temporary file
git_extra_mktemp() {
    mktemp -t "$(basename "$0")".XXXXXXX
}

git_extra_default_branch() {
    local default_branch
    default_branch=$(git config --get git-extras.default-branch)
    if [ -z "$default_branch" ]; then
        echo "master"
    else
        echo "$default_branch"
    fi
}
#
# check whether current directory is inside a git repository
#

is_git_repo() {
  git rev-parse --show-toplevel > /dev/null 2>&1
  result=$?
  if test $result != 0; then
    >&2 echo 'Not a git repo!'
    exit $result
  fi
}

is_git_repo

repo=$1
branch=$2
prefix=$3
flat=0

if test $prefix = "."; then
	prefix=$(mktemp -u 'git-merge-repo.XXXXXXX')
	flat=1
fi

git subtree add -P "$prefix" "$repo" "$branch" "${@:4}"

message=$(git log -1 --pretty=%B)

if test $flat -eq 1; then
	git stash -u
	mv -i $prefix/* ./
	git undo
	git add .
	git commit -am "$message"
	git stash apply
	rm -drf $prefix
fi
