/*

 * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package java.beans;

import java.util.HashMap;

import java.util.IdentityHashMap;

import java.util.Map;

import static java.util.Locale.ENGLISH;

/**

 * A utility class which generates unique names for object instances.

 * The name will be a concatenation of the unqualified class name

 * and an instance number.

 * <p>

 * For example, if the first object instance javax.swing.JButton

 * is passed into <code>instanceName</code> then the returned

 * string identifier will be "JButton0".

 *

 * @author Philip Milne

 */

class NameGenerator {

    private Map<Object, String> valueToName;

    private Map<String, Integer> nameToCount;

    public NameGenerator() {

        valueToName = new IdentityHashMap<>();

        nameToCount = new HashMap<>();

    }

    /**

     * Clears the name cache. Should be called to near the end of

     * the encoding cycle.

     */

    public void clear() {

        valueToName.clear();

        nameToCount.clear();

    }

    /**

     * Returns the root name of the class.

     */

    @SuppressWarnings("rawtypes")

    public static String unqualifiedClassName(Class type) {

        if (type.isArray()) {

            return unqualifiedClassName(type.getComponentType())+"Array";

        }

        String name = type.getName();

        return name.substring(name.lastIndexOf('.')+1);

    }

    /**

     * Returns a String which capitalizes the first letter of the string.

     */

    public static String capitalize(String name) {

        if (name == null || name.length() == 0) {

            return name;

        }

        return name.substring(0, 1).toUpperCase(ENGLISH) + name.substring(1);

    }

    /**

     * Returns a unique string which identifies the object instance.

     * Invocations are cached so that if an object has been previously

     * passed into this method then the same identifier is returned.

     *

     * @param instance object used to generate string

     * @return a unique string representing the object

     */

    public String instanceName(Object instance) {

        if (instance == null) {

            return "null";

        }

        if (instance instanceof Class) {

            return unqualifiedClassName((Class)instance);

        }

        else {

            String result = valueToName.get(instance);

            if (result != null) {

                return result;

            }

            Class<?> type = instance.getClass();

            String className = unqualifiedClassName(type);

            Integer size = nameToCount.get(className);

            int instanceNumber = (size == null) ? 0 : (size).intValue() + 1;

            nameToCount.put(className, new Integer(instanceNumber));

            result = className + instanceNumber;

            valueToName.put(instance, result);

            return result;

        }

    }

}