#!/usr/bin/env bash
# This script cleans up local Git branches which have been merged into
# the main branch.  I use it to clean up the branch view in GitUp
# (my Git GUI of choice), so I'm not distracted by lots of old branches.
#
# It's based on the commands from this Stack Overflow post:
# https://stackoverflow.com/a/6127884/1558022

set -o errexit
set -o nounset

GIT_ROOT=$(git rev-parse --absolute-git-dir)

if [[ -f "$GIT_ROOT/refs/remotes/origin/HEAD" ]]
then
  PRIMARY_BRANCH=$(cat "$GIT_ROOT/refs/remotes/origin/HEAD" \
    | tr '/' ' ' \
    | awk '{print $5}')
elif [[ -f "$GIT_ROOT/refs/remotes/origin/live" ]]
then
  PRIMARY_BRANCH="live"
else
  PRIMARY_BRANCH="main"
fi

CURRENT_BRANCH=$(git branch --show-current)

if [[ "$PRIMARY_BRANCH" = "$CURRENT_BRANCH" ]]
then
  print_info "-> Current branch is $CURRENT_BRANCH, which is primary"
else
  print_info "-> Primary branch is $PRIMARY_BRANCH"
  print_info "-> Current branch is $CURRENT_BRANCH"
fi

for branch in $(git branch --merged "$PRIMARY_BRANCH" | grep -v '*')
do
  if [[ "$branch" == "$PRIMARY_BRANCH" ]]
  then
    continue
  fi

  if [[ "$branch" == "$CURRENT_BRANCH" ]]
  then
    continue
  fi

  git branch --delete "$branch"
done