if [ -d "$HOME/.claude/skills/lang" ]; then
  INSTALL_DIR="$HOME/.claude/skills"
  echo "Install location: $INSTALL_DIR"
else
  echo "ERROR: langskill not found in ~/.claude/skills/"
  echo "请先安装：npx skills add YiXinHui/langskill --all -y"
  exit 1
fi

OLD_VERSION=$(cat "$HOME/.claude/skills/lang-upgrade/../../VERSION" 2>/dev/null || echo "unknown")
echo "Current version: $OLD_VERSION"

REMOTE_VERSION=$(curl -sL https://raw.githubusercontent.com/YiXinHui/langskill/main/VERSION || echo "")
if [ -z "$REMOTE_VERSION" ]; then
  echo "ERROR: Cannot fetch remote version"
  exit 1
fi
echo "Remote version: $REMOTE_VERSION"

BACKUP_DIR="$HOME/.claude/skills/.langskill-backup-$(date +%Y%m%d-%H%M%S)"
mkdir -p "$BACKUP_DIR"
cp -r "$HOME/.claude/skills"/lang* "$BACKUP_DIR/" 2>/dev/null || true
echo "Backup created: $BACKUP_DIR"

TMP_DIR=$(mktemp -d)
git clone --depth 1 https://github.com/YiXinHui/langskill.git "$TMP_DIR/langskill"
if [ $? -ne 0 ]; then
  echo "ERROR: Failed to clone repository"
  exit 1
fi
echo "Downloaded to: $TMP_DIR/langskill"

rm -rf "$HOME/.claude/skills"/lang*
cp -r "$TMP_DIR/langskill/skills"/lang* "$HOME/.claude/skills/"
rm -rf "$TMP_DIR"
echo "Upgrade completed"

if [ $? -ne 0 ]; then
  echo "ERROR: Upgrade failed, restoring from backup..."
  rm -rf "$HOME/.claude/skills"/lang*
  cp -r "$BACKUP_DIR"/* "$HOME/.claude/skills/"
  echo "Restored from backup"
  exit 1
fi

langskill v{REMOTE_VERSION} — 从 v{OLD_VERSION} 升级成功！

更新内容：
- [从 README 提取的更新要点]

升级完成！

echo "Backup location: $BACKUP_DIR"
echo "Keep backup? (will be auto-deleted in 7 days if not used)"