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

# Ensure upstream clone is synced before implementing OpenClaw code changes.
# Usage:
#   scripts/openclaw-upstream-preflight.sh
#   scripts/openclaw-upstream-preflight.sh fix/my-change

REPO="${OPENCLAW_UPSTREAM_REPO:-$HOME/.openclaw/workspace/external/openclaw-upstream}"
TARGET_BRANCH="${1:-}"

if [[ ! -d "$REPO/.git" ]]; then
  echo "error: upstream repo not found at $REPO" >&2
  echo "hint: git clone https://github.com/openclaw/openclaw $REPO" >&2
  exit 2
fi

cd "$REPO"

echo "[preflight] syncing upstream..."
git fetch --all --prune
git checkout main
git pull --rebase

if [[ -n "$(git status --porcelain)" ]]; then
  echo "error: working tree is not clean on main; resolve before branching" >&2
  git status --short
  exit 3
fi

if [[ -n "$TARGET_BRANCH" ]]; then
  if git show-ref --verify --quiet "refs/heads/$TARGET_BRANCH"; then
    echo "[preflight] switching to existing branch: $TARGET_BRANCH"
    git checkout "$TARGET_BRANCH"
    echo "[preflight] rebasing $TARGET_BRANCH onto origin/main"
    git rebase origin/main
  else
    echo "[preflight] creating branch: $TARGET_BRANCH"
    git checkout -b "$TARGET_BRANCH"
  fi
fi

MAIN_HEAD_LOCAL=$(git rev-parse --short main)
MAIN_HEAD_REMOTE=$(git rev-parse --short origin/main)
AB=$(git rev-list --left-right --count main...origin/main)
CUR=$(git rev-parse --abbrev-ref HEAD)

echo "[preflight] branch: $CUR"
echo "[preflight] main local:  $MAIN_HEAD_LOCAL"
echo "[preflight] main remote: $MAIN_HEAD_REMOTE"
echo "[preflight] main ahead/behind (local remote): $AB"
echo "[preflight] done"