#!/usr/bin/env bash
# Usage: script/release
#
# - checks out the master branch
# - changes version in `bin/ruby-build` to current date
# - commits and tags the change
# - pushes master + tag to GitHub
# - opens pull request to update the Homebrew formula
#
# TODO: handle making multiple releases on the same date

set -e

echo "Running hub to see if configured correctly"
echo "This shows the latest release:"
hub release -L1

git fetch -q --tags origin master
git checkout -q master
git merge --ff-only @{upstream}

existing="$(git tag --points-at HEAD)"
if [ -n "$existing" ]; then
  echo "Aborting: HEAD is already tagged as '${existing}'" >&2
  exit 1
fi

binfile="bin/ruby-build"
new_version="$(date '+%Y%m%d')"
version_tag="v${new_version}"
previous_tag="$(git describe --tags HEAD --abbrev=0)"

if git diff --quiet "${previous_tag}..HEAD" -- bin share; then
  echo "Aborting: No features to release since '${previous_tag}'" >&2
  exit 1
fi

sed -i.bak -E "s!^(RUBY_BUILD_VERSION=).+!\\1\"${new_version}\"!" "$binfile"
rm -f "${binfile}.bak"

git commit -m "ruby-build ${new_version}" -- "$binfile"

notes_file="$(mktemp)"
{ echo "ruby-build $new_version"
  echo
  git log --no-merges --format='* %s%n%w(0,2,2)%+b' --reverse "${previous_tag}..HEAD^" -- bin share
} >"$notes_file"
trap "rm -f '$notes_file'" EXIT

git tag "$version_tag" -F "$notes_file" --edit
git push origin master "${version_tag}"

git tag --list "$version_tag" --format='%(contents:subject)%0a%0a%(contents:body)' | \
  hub release create -F- "$version_tag"