branchdel() {
  # branchdel — remove a branch worktree (optional branch arg)
  local branch_arg
  branch_arg="$1"
  local wt_path
  wt_path=$(pwd)
  local common_dir repo_dir
  if ! common_dir=$(git rev-parse --git-common-dir 2>/dev/null); then
    echo "Not inside a git repository." >&2
    return 1
  fi
  if [ "${common_dir#/}" = "$common_dir" ]; then
    common_dir="$(pwd)/$common_dir"
  fi
  repo_dir="${common_dir%%/.git*}"
  if [ -z "$repo_dir" ]; then
    echo "Unable to determine repository root." >&2
    return 1
  fi

  # determine current branch in this worktree
  local current default_branch branch target_wt
  current=$(git rev-parse --abbrev-ref HEAD 2>/dev/null) || { echo "Not inside a git repository." >&2; return 1; }

  default_branch=$(getdefault)

  # choose branch: provided arg or current
  if [ -z "$branch_arg" ]; then
    branch="$current"
  else
    branch="$branch_arg"
  fi
  # normalize branch name if refs/heads/ was provided
  branch="${branch#refs/heads/}"

  # don't remove default
  if [ "$branch" = "$default_branch" ] || [ "$branch" = "default" ]; then
    echo "Refusing to remove default branch worktree ($default_branch)." >&2
    return 1
  fi

  # find the worktree path for the requested branch
  target_wt=$(git -C "$repo_dir" worktree list --porcelain 2>/dev/null | awk -v b="refs/heads/$branch" '
    $1=="worktree" { w=$2 }
    $1=="branch" && $2==b { print w; exit }
  ')

  # if not found in worktree list, check main worktree branch
  if [ -z "$target_wt" ]; then
    local main_branch
    main_branch=$(git -C "$repo_dir" rev-parse --abbrev-ref HEAD 2>/dev/null || true)
    if [ "$main_branch" = "$branch" ]; then
      target_wt="$repo_dir"
    fi
  fi

  if [ -z "$target_wt" ]; then
    echo "No worktree found for branch '$branch'." >&2
    return 1
  fi

  if [ "$target_wt" = "$repo_dir" ]; then
    echo "Branch '$branch' is the main worktree at '$repo_dir'. Will not delete main worktree." >&2
    return 1
  fi

  # if we're currently in that branch/worktree, switch to default and cd to repo root first
  if [ "$current" = "$branch" ]; then
    echo "Currently on branch '$branch' in '$wt_path'. Switching to default branch '$default_branch' in main worktree..."
    if declare -f branch >/dev/null 2>&1; then
      branch default || { echo "Failed to switch to default branch" >&2; return 1; }
    else
      git -C "$repo_dir" checkout "$default_branch" || { echo "Failed to checkout default branch" >&2; return 1; }
    fi
    cd "$repo_dir" || { echo "Failed to change directory to repo root: $repo_dir" >&2; return 1; }
  fi

  echo "Removing worktree at: $target_wt"
  if git -C "$repo_dir" worktree remove "$target_wt" 2>/dev/null; then
    rm -rf -- "$target_wt" 2>/dev/null || true
    echo "Removed worktree: $target_wt"
    return 0
  fi
  # try with --force as a fallback
  if git -C "$repo_dir" worktree remove --force "$target_wt" 2>/dev/null; then
    rm -rf -- "$target_wt" 2>/dev/null || true
    echo "Removed worktree (forced): $target_wt"
    return 0
  fi

  echo "Failed to remove worktree: $target_wt" >&2
  return 1
}