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

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

git_extra_default_branch() {
    local extras_default_branch init_default_branch
    extras_default_branch=$(git config --get git-extras.default-branch)
    init_default_branch=$(git config --get init.defaultBranch)
    if [ -n "$extras_default_branch" ]; then
        echo "$extras_default_branch"
    elif [ -n "$init_default_branch" ]; then
        echo "$init_default_branch"
    else
        echo "main"
    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

set -e -o pipefail

coauthor=$1
email=$2

test -z "$coauthor" && echo "co-author required." 1>&2 && exit 1
test -z "$email" && echo "co-author email required." 1>&2 && exit 1

old_message="$(git log --format=%B -n1)"
if [[ "$old_message" == *"Co-authored-by:"* ]]; then
  git commit --amend -m "$old_message
Co-authored-by: $coauthor <$email>"
else
  git commit --amend -m "$old_message" -m "Co-authored-by: $coauthor <$email>"
fi
