/*
 * Copyright (c) 1997, 2022 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0, which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package com.sun.tools.xjc.model;

import java.util.Set;
import java.util.Map;
import java.util.HashMap;
import java.util.HashSet;

import com.sun.tools.xjc.api.ClassNameAllocator;

/**
 * {@link ClassNameAllocator} filter that performs automatic name conflict resolution.
 * 
 * @author Kohsuke Kawaguchi
 */
public class AutoClassNameAllocator implements ClassNameAllocator {
    private final ClassNameAllocator core;

    private final Map<String,Set<String>> names = new HashMap<>();

    public AutoClassNameAllocator(ClassNameAllocator core) {
        this.core = core;
    }

    @Override
    public String assignClassName(String packageName, String className) {
        className = determineName(packageName, className);
        if(core!=null)
            className = core.assignClassName(packageName,className);
        return className;
    }

    private String determineName(String packageName, String className) {
        Set<String> s = names.computeIfAbsent(packageName, k -> new HashSet<>());

        if(s.add(className))
            return className;

        for(int i=2;true;i++) {
            if(s.add(className+i))
                return className+i;
        }
    }
}