#!/usr/bin/env bash
# Prepare a release IN THE WORKING TREE only — no commit, no tag. Regenerates CHANGELOG.md
# ([Unreleased] -> the target version) and writes the VERSION file. The commit/tag/push is
# the caller's job, so this is shared by:
#   - scripts/release.sh          (local: prepare -> commit -> tag)
#   - the release-PR CI step      (prepare -> commit onto chore/release -> force-push)
#
# Usage: ./scripts/prepare-release.sh [X.Y.Z]
#   No arg  -> next version is computed from conventional commits since the last tag via
#              `git-cliff --bumped-version` (SemVer 0.x rules: feat/fix -> patch,
#              breaking -> minor). A leading `v` is tolerated on an explicit arg.
#
# Prints the resolved version (no leading `v`) to stdout. All diagnostics go to stderr, so
# callers can capture the version with `ver="$(scripts/prepare-release.sh)"`.
set -euo pipefail

command -v git-cliff >/dev/null || { echo "error: git-cliff not installed (brew install git-cliff)" >&2; exit 1; }

ver="${1:-}"
if [ -z "$ver" ]; then
  # git-cliff prints the bumped version (e.g. v0.3.4) to stdout; warnings go to stderr.
  ver="$(git-cliff --bumped-version)"
fi
ver="${ver#v}"
tag="v${ver}"

# [Unreleased] -> [<ver>] in the changelog, and bump the VERSION file (the publish trigger).
git-cliff --tag "$tag" -o CHANGELOG.md >&2
printf '%s\n' "$ver" > VERSION

echo "$ver"