/*
 * Copyright 2013-2021 the original author or 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
 *
 *      https://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 org.springframework.cloud.sleuth.internal;

import org.springframework.util.StringUtils;

/**
 * Utility class that provides the name in hyphen based notation.
 *
 * @author Adrian Cole
 * @since 1.0.2
 */
public final class SpanNameUtil {

	static final int MAX_NAME_LENGTH = 50;

	private SpanNameUtil() {

	}

	public static String shorten(String name) {
		if (StringUtils.isEmpty(name)) {
			return name;
		}
		int maxLength = Math.min(name.length(), MAX_NAME_LENGTH);
		return name.substring(0, maxLength);
	}

	public static String toLowerHyphen(String name) {
		StringBuilder result = new StringBuilder();
		for (int i = 0; i < name.length(); i++) {
			char c = name.charAt(i);
			if (Character.isUpperCase(c)) {
				if (i != 0) {
					result.append('-');
				}
				result.append(Character.toLowerCase(c));
			}
			else {
				result.append(c);
			}
		}
		return SpanNameUtil.shorten(result.toString());
	}

}
