/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you 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 fr.pilato.demo.legacysearch.helper;

public class Strings {

    /**
     * Check that the given CharSequence is neither <code>null</code> nor of length 0.
     * Note: Will return <code>true</code> for a CharSequence that purely consists of whitespace.
     * <pre>
     * StringUtils.hasLength(null) = false
     * StringUtils.hasLength("") = false
     * StringUtils.hasLength(" ") = true
     * StringUtils.hasLength("Hello") = true
     * </pre>
     *
     * @param str the CharSequence to check (may be <code>null</code>)
     * @return <code>true</code> if the CharSequence is not null and has length
     * @see #hasText(String)
     */
    public static boolean hasLength(CharSequence str) {
        return (str != null && str.length() > 0);
    }


    /**
     * Check that the given CharSequence is either <code>null</code> or of length 0.
     * Note: Will return <code>false</code> for a CharSequence that purely consists of whitespace.
     * <pre>
     * StringUtils.isEmpty(null) = true
     * StringUtils.isEmpty("") = true
     * StringUtils.isEmpty(" ") = false
     * StringUtils.isEmpty("Hello") = false
     * </pre>
     *
     * @param str the CharSequence to check (may be <code>null</code>)
     * @return <code>true</code> if the CharSequence is either null or has a zero length
     */
    public static boolean isEmpty(CharSequence str) {
        return !hasLength(str);
    }


    /**
     * Check whether the given CharSequence has actual text.
     * More specifically, returns <code>true</code> if the string not <code>null</code>,
     * its length is greater than 0, and it contains at least one non-whitespace character.
     * <pre>
     * StringUtils.hasText(null) = false
     * StringUtils.hasText("") = false
     * StringUtils.hasText(" ") = false
     * StringUtils.hasText("12345") = true
     * StringUtils.hasText(" 12345 ") = true
     * </pre>
     *
     * @param str the CharSequence to check (may be <code>null</code>)
     * @return <code>true</code> if the CharSequence is not <code>null</code>,
     *         its length is greater than 0, and it does not contain whitespace only
     * @see Character#isWhitespace
     */
    public static boolean hasText(CharSequence str) {
        if (!hasLength(str)) {
            return false;
        }
        int strLen = str.length();
        for (int i = 0; i < strLen; i++) {
            if (!Character.isWhitespace(str.charAt(i))) {
                return true;
            }
        }
        return false;
    }

    /**
     * Check whether the given String has actual text.
     * More specifically, returns <code>true</code> if the string not <code>null</code>,
     * its length is greater than 0, and it contains at least one non-whitespace character.
     *
     * @param str the String to check (may be <code>null</code>)
     * @return <code>true</code> if the String is not <code>null</code>, its length is
     *         greater than 0, and it does not contain whitespace only
     * @see #hasText(CharSequence)
     */
    public static boolean hasText(String str) {
        return hasText((CharSequence) str);
    }
}
