#!/usr/bin/env bash
set -Eeuo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
cd "$ROOT_DIR"

version="${1:-}"
release_date="${2:-$(date +%F)}"

if [[ -z "$version" ]]; then
  echo "usage: $0 <version-without-v> [YYYY-MM-DD]" >&2
  exit 1
fi

if ! [[ "$version" =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
  echo "version must look like 0.2.1" >&2
  exit 1
fi

if grep -q "## \[$version\]" CHANGELOG.md; then
  echo "version already exists in CHANGELOG.md" >&2
  exit 1
fi

python3 - <<PY
from pathlib import Path
p = Path("CHANGELOG.md")
text = p.read_text()
needle = "## [Unreleased]\n\n### Added\n- Platzhalter fuer neue Features\n\n### Changed\n- Platzhalter fuer geaenderte Betriebslogik\n\n### Fixed\n- Platzhalter fuer Bugfixes\n\n### Security\n- Platzhalter fuer sicherheitsrelevante Anpassungen\n"
if needle not in text:
    raise SystemExit("Unreleased template not found exactly; update CHANGELOG manually")
replacement = needle + f"\n## [{version}] - {release_date}\n\n### Added\n-\n\n### Changed\n-\n\n### Fixed\n-\n\n### Security\n-\n"
p.write_text(text.replace(needle, replacement, 1))
PY

echo "[OK] prepared CHANGELOG entry for $version on $release_date"
echo "[NEXT] fill the new release section, commit, then tag with: git tag -a v${version} -m 'v${version}'"