/*
 * Copyright (c) 2019, 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 com.sun.tools.javac.code;

import com.sun.source.util.ParameterNameProvider;
import com.sun.tools.javac.code.Symbol.ParamSymbol;
import com.sun.tools.javac.util.Context;
import com.sun.tools.javac.util.Name;
import com.sun.tools.javac.util.Names;

A Context class, that can return additional useful information for Symbols, currently parameter names. It does so by calling user-supplied ParameterNameProvider. 
This is NOT part of any supported API.
If you write code that depends on this, you do so at your own risk.
This code and its internal interfaces are subject to change or
deletion without notice.
/**
 * A Context class, that can return additional useful information for Symbols, currently
 * parameter names. It does so by calling user-supplied {@link ParameterNameProvider}.
 *
 * <p><b>This is NOT part of any supported API.
 * If you write code that depends on this, you do so at your own risk.
 * This code and its internal interfaces are subject to change or
 * deletion without notice.</b>
 */
public class MissingInfoHandler {
    protected static final Context.Key<MissingInfoHandler> missingInfoHandlerWrapperKey = new Context.Key<>();

    public static MissingInfoHandler instance(Context context) {
        MissingInfoHandler instance = context.get(missingInfoHandlerWrapperKey);
        if (instance == null)
            instance = new MissingInfoHandler(context);
        return instance;
    }

    private final Names names;
    private ParameterNameProvider parameterNameProvider;

    protected MissingInfoHandler(Context context) {
        context.put(missingInfoHandlerWrapperKey, this);
        names = Names.instance(context);
    }

    public Name getParameterName(ParamSymbol parameter) {
        if (parameterNameProvider != null) {
            CharSequence name = parameterNameProvider.getParameterName(parameter);
            if (name != null) {
                return names.fromString(name.toString());
            }
        }

        return null;
    }

    public void setDelegate(ParameterNameProvider delegate) {
        this.parameterNameProvider = delegate;
    }
}