/*
 * Copyright (C) 1999-2017 David Schweinsberg.
 *
 * 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 com.steadystate.css.util;

import java.util.List;

public final class LangUtils {
    public static final int HASH_SEED = 17;
    public static final int HASH_OFFSET = 37;

    private LangUtils() {
    }

    public static int hashCode(final int seed, final int hashcode) {
        return seed * HASH_OFFSET + hashcode;
    }

    public static int hashCode(final int seed, final boolean b) {
        return hashCode(seed, b ? 1 : 0);
    }

    public static int hashCode(final int seed, final Object obj) {
        return hashCode(seed, obj != null ? obj.hashCode() : 0);
    }

    public static String join(final List<String> values, String separator) {
        if (values == null) {
            return null;
        }
        if (separator == null) {
            separator = "";
        }

        boolean isFirst = true;
        final StringBuilder result = new StringBuilder();
        for (String part : values) {
            if (part != null && part.length() > 0) {
                if (isFirst) {
                    isFirst = false;
                }
                else {
                    result.append(separator);
                }
                result.append(part);
            }
        }
        return result.toString();
    }

    public static boolean equals(final Object obj1, final Object obj2) {
        return obj1 == null ? obj2 == null : obj1.equals(obj2);
    }
}