#!/usr/bin/env bash
# This script updates the version of the release in the release file
# Usage: ./update_release_version.sh <new_version>

set -eo pipefail

if [ "$#" -ne 1 ]; then
  echo "Usage: $0 <new_version>"
  exit 1
fi

new_version="$1"
release_minor=$(echo "${new_version}" | cut -d. -f1-2)
index_file=content/en/docs/"${release_minor}"/_index.md
git_remote="${GIT_REMOTE:-origin}"
branch="release-${release_minor}-update-latest-release-to-${new_version}"
current_branch=$(git symbolic-ref HEAD --short)

if [ -z "${GITHUB_ACTIONS}" ]; then
  git_author="$(git config user.name)"
  git_email="$(git config user.email)"
else
  # Refer to https://github.com/orgs/community/discussions/26560#discussioncomment-3252340
  git_author="github-actions[bot]"
  git_email="41898282+github-actions[bot]@users.noreply.github.com"
fi

# Check for prerequisites to run the script.
if ! which gh >/dev/null; then
  echo "gh needs to be installed for this script to work"
  exit 1
fi
if ! gh auth status >/dev/null; then
  echo "gh needs to be authenticated for this script to work"
  exit 1
fi
if ! grep git_version_tag "${index_file}" | grep -v -e "${new_version}\$" >/dev/null; then
  echo "nothing to do; file ${index_file} is already up to date with ${new_version}"
  exit 0
fi
if git ls-remote --exit-code "${git_remote}" --heads refs/heads/"${branch}" >/dev/null; then
  echo "nothing to do; branch ${branch} already exists"
  exit 0
fi

# Switch to a new branch.
git checkout -b "${branch}"
trap 'git checkout "${current_branch}"' EXIT

# Update the release version in the release file.
sed -i 's/git_version_tag:\sv\([0-9]\+\.\)\{2\}[0-9]\+/git_version_tag: '"${new_version}"'/' "${index_file}"

# Commit the changes, push and create a PR.
git add "${index_file}"
git -c user.name="${git_author}" -c user.email="${git_email}" commit --file=- <<EOL
[${release_minor}] Update installation version to latest tag (${new_version})

cc. @etcd-io/maintainers-website

Signed-off-by: ${git_author} <${git_email}>
EOL
git push "${git_remote}" "${branch}"

if [ -n "${CREATE_PULL_REQUEST}" ]; then
  gh pr create --fill --body "Automated update for ${release_minor}: ${new_version}"
fi