#!/usr/bin/env bash
# Based on https://gist.github.com/gnarf/5406589 and https://gist.github.com/jhnns/d654d9d6da6d3b749986

if test "$1" = "clean"; then
  git for-each-ref refs/heads/pr/* --format='%(refname)' | while read ref; do
    git branch -D ${ref#refs/heads/}
  done
  exit 0
elif [[ $1 =~ ^(https?://[^/]+/(.+))/pull/([0-9]+).*$ ]]; then
  remote=${BASH_REMATCH[1]}.git
  id=${BASH_REMATCH[3]}
  branch=pr/$id
else
  test -z $1 && echo "pr number required." 1>&2 && exit 1
  remote=${2:-origin}
  id=$1
  branch=pr/$id
fi
git fetch -fu $remote refs/pull/$id/head:$branch && \
git checkout $branch && \
git config --local --replace branch.\"$branch\".merge refs/pull/$id/head && \
git config --local --replace branch.\"$branch\".remote $remote;