/*
 * Copyright (c) 1998, 2017, 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.jdi;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

import com.sun.jdi.ClassLoaderReference;
import com.sun.jdi.ClassNotLoadedException;
import com.sun.jdi.ReferenceType;
import com.sun.jdi.Type;
import com.sun.jdi.VirtualMachine;

public class ClassLoaderReferenceImpl extends ObjectReferenceImpl
                                      implements ClassLoaderReference
{
    // This is cached only while the VM is suspended
    private static class Cache extends ObjectReferenceImpl.Cache {
        List<ReferenceType> visibleClasses = null;
    }

    protected ObjectReferenceImpl.Cache newCache() {
        return new Cache();
    }

    ClassLoaderReferenceImpl(VirtualMachine aVm, long ref) {
        super(aVm, ref);
        vm.state().addListener(this);
    }

    protected String description() {
        return "ClassLoaderReference " + uniqueID();
    }

    public List<ReferenceType> definedClasses() {
        ArrayList<ReferenceType> definedClasses = new ArrayList<>();
        for (ReferenceType type :  vm.allClasses()) {
            if (type.isPrepared() &&
                equals(type.classLoader())) {
                definedClasses.add(type);
            }
        }
        return definedClasses;
    }

    public List<ReferenceType> visibleClasses() {
        List<ReferenceType> classes = null;
        try {
            Cache local = (Cache)getCache();

            if (local != null) {
                classes = local.visibleClasses;
            }
            if (classes == null) {
                JDWP.ClassLoaderReference.VisibleClasses.ClassInfo[]
                  jdwpClasses = JDWP.ClassLoaderReference.VisibleClasses.
                                            process(vm, this).classes;
                classes = new ArrayList<>(jdwpClasses.length);
                for (int i = 0; i < jdwpClasses.length; ++i) {
                    classes.add(vm.referenceType(jdwpClasses[i].typeID,
                                                 jdwpClasses[i].refTypeTag));
                }
                classes = Collections.unmodifiableList(classes);
                if (local != null) {
                    local.visibleClasses = classes;
                    if ((vm.traceFlags & VirtualMachine.TRACE_OBJREFS) != 0) {
                        vm.printTrace(description() +
                           " temporarily caching visible classes (count = " +
                                      classes.size() + ")");
                    }
                }
            }
        } catch (JDWPException exc) {
            throw exc.toJDIException();
        }
        return classes;
    }

    Type findType(String signature) throws ClassNotLoadedException {
        List<ReferenceType> types = visibleClasses();
        Iterator<ReferenceType> iter = types.iterator();
        while (iter.hasNext()) {
            ReferenceType type = iter.next();
            if (type.signature().equals(signature)) {
                return type;
            }
        }
        JNITypeParser parser = new JNITypeParser(signature);
        throw new ClassNotLoadedException(parser.typeName(),
                                         "Class " + parser.typeName() + " not loaded");
    }

    byte typeValueKey() {
        return JDWP.Tag.CLASS_LOADER;
    }
}