// Copyright 2026 The TCell Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package widthutil

import (
	"os"
	"strings"

	"github.com/clipperhouse/displaywidth"
)

// Options returns the display-width options derived from the user's
// environment. We preserve the historical RUNEWIDTH_EASTASIAN toggle.
func Options() displaywidth.Options {
	if rw := strings.ToLower(os.Getenv("RUNEWIDTH_EASTASIAN")); rw == "1" || rw == "true" || rw == "yes" {
		return displaywidth.Options{EastAsianWidth: true}
	}
	return displaywidth.Options{}
}
