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

REMOTE="${REMOTE:-origin}"
BRANCH="${BRANCH:-main}"
ALLOW_DIRTY=0
VERSION=""
MSG=""

usage(){
  echo "Usage: $0 <X.Y.Z> [-m \"release notes\"] [-b branch] [--allow-dirty]"
  exit 1
}

# Args
[[ $# -ge 1 ]] || usage
VERSION="$1"; shift || true
[[ "$VERSION" =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]] || { echo "[x] Ungültige Version: $VERSION (erwarte SemVer X.Y.Z)"; exit 1; }

while [[ $# -gt 0 ]]; do
  case "$1" in
    -m) MSG="$2"; shift 2 ;;
    -b) BRANCH="$2"; shift 2 ;;
    --allow-dirty) ALLOW_DIRTY=1; shift ;;
    *) usage ;;
  esac
done

git rev-parse --git-dir >/dev/null 2>&1 || { echo "[x] kein Git-Repo"; exit 1; }

# Clean tree?
if [[ $ALLOW_DIRTY -eq 0 ]]; then
  if ! git diff --quiet || ! git diff --cached --quiet; then
    echo "[x] Arbeitsbaum nicht sauber. Committe oder nutze --allow-dirty."
    exit 1
  fi
fi

# Aktuellen Stand holen
git fetch --quiet "$REMOTE" --tags
# Branch check-out/sync
git checkout -q "$BRANCH"
git pull --ff-only "$REMOTE" "$BRANCH"

TAG="v${VERSION}"
if git rev-parse -q --verify "refs/tags/${TAG}" >/dev/null; then
  echo "[x] Tag ${TAG} existiert bereits."
  exit 1
fi

LAST_TAG="$(git describe --tags --abbrev=0 2>/dev/null || true)"
if [[ -n "$LAST_TAG" ]]; then
  CHANGELOG="$(git log --pretty=format:'- %s (%h)' "${LAST_TAG}..HEAD" || true)"
else
  CHANGELOG="$(git log --pretty=format:'- %s (%h)' || true)"
fi
[[ -n "$CHANGELOG" ]] || CHANGELOG="- initial release content"

# VERSION bumpen
echo -n "$VERSION" > VERSION
git add VERSION
git commit -m "chore(release): v${VERSION}"

# Tag-Message bauen
if [[ -z "$MSG" ]]; then
read -r -d '' MSG <<EOF || true
MailWolt v${VERSION}

Changes since ${LAST_TAG:-repo start}:
${CHANGELOG}
EOF
fi

git tag -a "$TAG" -m "$MSG"

# Push commit + tag
git push "$REMOTE" "$BRANCH"
git push "$REMOTE" "$TAG"

echo "[✓] Release ${TAG} erstellt & gepusht."