#!/bin/bash
# Copyright (C) 2020-Ω Miquel Sabaté Solà <mikisabate@gmail.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

set -e

# Nuke the given branch, both locally and remotely.

# Give me one argument.
if [ "$#" -ne 1 ]; then
    echo "usage: git nuke <branch>"
    exit 1
fi

upstream="origin"
if [ -n "$1" ]; then
    upstream="$1"
fi
default=$(git rev-parse --abbrev-ref "$upstream"/HEAD | cut -c8-)

# The `default` branch should not be removed.
if [ "$1" = "$default" ]; then
    echo "You are not allowed to delete the default branch."
    exit 1
fi

full_name="$(git symbolic-ref HEAD 2>/dev/null)" || (
    echo "Detached branch, bailing..."
    exit 1
)
name="$(basename "$full_name")"

# If we are nuking the current branch, move to `master` first.
if [ "$1" = "$name" ]; then
    echo "Nuking the current branch, moving to 'master' first..."
    git checkout --force master
fi

# Nuke it!
git push origin :"$full_name"
git branch --delete --force "$name"