/*

 * 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.lang.ref.SoftReference;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import java.util.Set;

import com.sun.jdi.AbsentInformationException;

import com.sun.jdi.ClassLoaderReference;

import com.sun.jdi.ClassNotLoadedException;

import com.sun.jdi.ClassObjectReference;

import com.sun.jdi.Field;

import com.sun.jdi.InterfaceType;

import com.sun.jdi.InternalException;

import com.sun.jdi.Location;

import com.sun.jdi.Method;

import com.sun.jdi.ModuleReference;

import com.sun.jdi.ObjectReference;

import com.sun.jdi.ReferenceType;

import com.sun.jdi.Type;

import com.sun.jdi.Value;

import com.sun.jdi.VirtualMachine;

public abstract class ReferenceTypeImpl extends TypeImpl implements ReferenceType {

    protected long ref;

    private String signature = null;

    private String genericSignature = null;

    private boolean genericSignatureGotten = false;

    private String baseSourceName = null;

    private String baseSourceDir = null;

    private String baseSourcePath = null;

    protected int modifiers = -1;

    private SoftReference<List<Field>> fieldsRef = null;

    private SoftReference<List<Method>> methodsRef = null;

    private SoftReference<SDE> sdeRef = null;

    private boolean isClassLoaderCached = false;

    private ClassLoaderReference classLoader = null;

    private ClassObjectReference classObject = null;

    private ModuleReference module = null;

    private int status = 0;

    private boolean isPrepared = false;

    private boolean versionNumberGotten = false;

    private int majorVersion;

    private int minorVersion;

    private boolean constantPoolInfoGotten = false;

    private int constanPoolCount;

    private SoftReference<byte[]> constantPoolBytesRef = null;

    /* to mark a SourceFile request that returned a genuine JDWP.Error.ABSENT_INFORMATION */

    private static final String ABSENT_BASE_SOURCE_NAME = "**ABSENT_BASE_SOURCE_NAME**";

    /* to mark when no info available */

    static final SDE NO_SDE_INFO_MARK = new SDE();

    // bits set when initialization was attempted (succeeded or failed)

    private static final int INITIALIZED_OR_FAILED =

        JDWP.ClassStatus.INITIALIZED | JDWP.ClassStatus.ERROR;

    protected ReferenceTypeImpl(VirtualMachine aVm, long aRef) {

        super(aVm);

        ref = aRef;

        genericSignatureGotten = false;

    }

    void noticeRedefineClass() {

        //Invalidate information previously fetched and cached.

        //These will be refreshed later on demand.

        baseSourceName = null;

        baseSourcePath = null;

        modifiers = -1;

        fieldsRef = null;

        methodsRef = null;

        sdeRef = null;

        versionNumberGotten = false;

        constantPoolInfoGotten = false;

    }

    Method getMethodMirror(long ref) {

        if (ref == 0) {

            // obsolete method

            return new ObsoleteMethodImpl(vm, this);

        }

        // Fetch all methods for the class, check performance impact

        // Needs no synchronization now, since methods() returns

        // unmodifiable local data

        Iterator<Method> it = methods().iterator();

        while (it.hasNext()) {

            MethodImpl method = (MethodImpl)it.next();

            if (method.ref() == ref) {

                return method;

            }

        }

        throw new IllegalArgumentException("Invalid method id: " + ref);

    }

    Field getFieldMirror(long ref) {

        // Fetch all fields for the class, check performance impact

        // Needs no synchronization now, since fields() returns

        // unmodifiable local data

        Iterator<Field>it = fields().iterator();

        while (it.hasNext()) {

            FieldImpl field = (FieldImpl)it.next();

            if (field.ref() == ref) {

                return field;

            }

        }

        throw new IllegalArgumentException("Invalid field id: " + ref);

    }

    public boolean equals(Object obj) {

        if ((obj != null) && (obj instanceof ReferenceTypeImpl)) {

            ReferenceTypeImpl other = (ReferenceTypeImpl)obj;

            return (ref() == other.ref()) &&

                (vm.equals(other.virtualMachine()));

        } else {

            return false;

        }

    }

    public int hashCode() {

        return(int)ref();

    }

    public int compareTo(ReferenceType object) {

        /*

         * Note that it is critical that compareTo() == 0

         * implies that equals() == true. Otherwise, TreeSet

         * will collapse classes.

         *

         * (Classes of the same name loaded by different class loaders

         * or in different VMs must not return 0).

         */

        ReferenceTypeImpl other = (ReferenceTypeImpl)object;

        int comp = name().compareTo(other.name());

        if (comp == 0) {

            long rf1 = ref();

            long rf2 = other.ref();

            // optimize for typical case: refs equal and VMs equal

            if (rf1 == rf2) {

                // sequenceNumbers are always positive

                comp = vm.sequenceNumber -

                 ((VirtualMachineImpl)(other.virtualMachine())).sequenceNumber;

            } else {

                comp = (rf1 < rf2)? -1 : 1;

            }

        }

        return comp;

    }

    public String signature() {

        if (signature == null) {

            // Does not need synchronization, since worst-case

            // static info is fetched twice

            if (vm.canGet1_5LanguageFeatures()) {

                /*

                 * we might as well get both the signature and the

                 * generic signature.

                 */

                genericSignature();

            } else {

                try {

                    signature = JDWP.ReferenceType.Signature.

                        process(vm, this).signature;

                } catch (JDWPException exc) {

                    throw exc.toJDIException();

                }

            }

        }

        return signature;

    }

    public String genericSignature() {

        // This gets both the signature and the generic signature

        if (vm.canGet1_5LanguageFeatures() && !genericSignatureGotten) {

            // Does not need synchronization, since worst-case

            // static info is fetched twice

            JDWP.ReferenceType.SignatureWithGeneric result;

            try {

                result = JDWP.ReferenceType.SignatureWithGeneric.

                    process(vm, this);

            } catch (JDWPException exc) {

                throw exc.toJDIException();

            }

            signature = result.signature;

            setGenericSignature(result.genericSignature);

        }

        return genericSignature;

    }

    public ClassLoaderReference classLoader() {

        if (!isClassLoaderCached) {

            // Does not need synchronization, since worst-case

            // static info is fetched twice

            try {

                classLoader = JDWP.ReferenceType.ClassLoader.

                    process(vm, this).classLoader;

                isClassLoaderCached = true;

            } catch (JDWPException exc) {

                throw exc.toJDIException();

            }

        }

        return classLoader;

    }

    public ModuleReference module() {

        if (module != null) {

            return module;

        }

        // Does not need synchronization, since worst-case

        // static info is fetched twice

        try {

            ModuleReferenceImpl m = JDWP.ReferenceType.Module.

                process(vm, this).module;

            module = vm.getModule(m.ref());

        } catch (JDWPException exc) {

            throw exc.toJDIException();

        }

        return module;

    }

    public boolean isPublic() {

        if (modifiers == -1)

            getModifiers();

        return((modifiers & VMModifiers.PUBLIC) > 0);

    }

    public boolean isProtected() {

        if (modifiers == -1)

            getModifiers();

        return((modifiers & VMModifiers.PROTECTED) > 0);

    }

    public boolean isPrivate() {

        if (modifiers == -1)

            getModifiers();

        return((modifiers & VMModifiers.PRIVATE) > 0);

    }

    public boolean isPackagePrivate() {

        return !isPublic() && !isPrivate() && !isProtected();

    }

    public boolean isAbstract() {

        if (modifiers == -1)

            getModifiers();

        return((modifiers & VMModifiers.ABSTRACT) > 0);

    }

    public boolean isFinal() {

        if (modifiers == -1)

            getModifiers();

        return((modifiers & VMModifiers.FINAL) > 0);

    }

    public boolean isStatic() {

        if (modifiers == -1)

            getModifiers();

        return((modifiers & VMModifiers.STATIC) > 0);

    }

    public boolean isPrepared() {

        // This ref type may have been prepared before we were getting

        // events, so get it once.  After that,

        // this status flag is updated through the ClassPrepareEvent,

        // there is no need for the expense of a JDWP query.

        if (status == 0) {

            updateStatus();

        }

        return isPrepared;

    }

    public boolean isVerified() {

        // Once true, it never resets, so we don't need to update

        if ((status & JDWP.ClassStatus.VERIFIED) == 0) {

            updateStatus();

        }

        return (status & JDWP.ClassStatus.VERIFIED) != 0;

    }

    public boolean isInitialized() {

        // Once initialization succeeds or fails, it never resets,

        // so we don't need to update

        if ((status & INITIALIZED_OR_FAILED) == 0) {

            updateStatus();

        }

        return (status & JDWP.ClassStatus.INITIALIZED) != 0;

    }

    public boolean failedToInitialize() {

        // Once initialization succeeds or fails, it never resets,

        // so we don't need to update

        if ((status & INITIALIZED_OR_FAILED) == 0) {

            updateStatus();

        }

        return (status & JDWP.ClassStatus.ERROR) != 0;

    }

    public List<Field> fields() {

        List<Field> fields = (fieldsRef == null) ? null : fieldsRef.get();

        if (fields == null) {

            if (vm.canGet1_5LanguageFeatures()) {

                JDWP.ReferenceType.FieldsWithGeneric.FieldInfo[] jdwpFields;

                try {

                    jdwpFields = JDWP.ReferenceType.FieldsWithGeneric.

                        process(vm, this).declared;

                } catch (JDWPException exc) {

                    throw exc.toJDIException();

                }

                fields = new ArrayList<>(jdwpFields.length);

                for (int i=0; i<jdwpFields.length; i++) {

                    JDWP.ReferenceType.FieldsWithGeneric.FieldInfo fi

                        = jdwpFields[i];

                    Field field = new FieldImpl(vm, this, fi.fieldID,

                                                fi.name, fi.signature,

                                                fi.genericSignature,

                                                fi.modBits);

                    fields.add(field);

                }

            } else {

                JDWP.ReferenceType.Fields.FieldInfo[] jdwpFields;

                try {

                    jdwpFields = JDWP.ReferenceType.Fields.

                        process(vm, this).declared;

                } catch (JDWPException exc) {

                    throw exc.toJDIException();

                }

                fields = new ArrayList<>(jdwpFields.length);

                for (int i=0; i<jdwpFields.length; i++) {

                    JDWP.ReferenceType.Fields.FieldInfo fi = jdwpFields[i];

                    Field field = new FieldImpl(vm, this, fi.fieldID,

                                            fi.name, fi.signature,

                                            null,

                                            fi.modBits);

                    fields.add(field);

                }

            }

            fields = Collections.unmodifiableList(fields);

            fieldsRef = new SoftReference<List<Field>>(fields);

        }

        return fields;

    }

    abstract List<? extends ReferenceType> inheritedTypes();

    void addVisibleFields(List<Field> visibleList, Map<String, Field> visibleTable, List<String> ambiguousNames) {

        for (Field field : visibleFields()) {

            String name = field.name();

            if (!ambiguousNames.contains(name)) {

                Field duplicate = visibleTable.get(name);

                if (duplicate == null) {

                    visibleList.add(field);

                    visibleTable.put(name, field);

                } else if (!field.equals(duplicate)) {

                    ambiguousNames.add(name);

                    visibleTable.remove(name);

                    visibleList.remove(duplicate);

                } else {

                    // identical field from two branches; do nothing

                }

            }

        }

    }

    public List<Field> visibleFields() {

        /*

         * Maintain two different collections of visible fields. The

         * list maintains a reasonable order for return. The

         * hash map provides an efficient way to lookup visible fields

         * by name, important for finding hidden or ambiguous fields.

         */

        List<Field> visibleList = new ArrayList<>();

        Map<String, Field>  visibleTable = new HashMap<String, Field>();

        /* Track fields removed from above collection due to ambiguity */

        List<String> ambiguousNames = new ArrayList<String>();

        /* Add inherited, visible fields */

        List<? extends ReferenceType> types = inheritedTypes();

        Iterator<? extends ReferenceType> iter = types.iterator();

        while (iter.hasNext()) {

            /*

             * TO DO: Be defensive and check for cyclic interface inheritance

             */

            ReferenceTypeImpl type = (ReferenceTypeImpl)iter.next();

            type.addVisibleFields(visibleList, visibleTable, ambiguousNames);

        }

        /*

         * Insert fields from this type, removing any inherited fields they

         * hide.

         */

        List<Field> retList = new ArrayList<>(fields());

        for (Field field : retList) {

            Field hidden = visibleTable.get(field.name());

            if (hidden != null) {

                visibleList.remove(hidden);

            }

        }

        retList.addAll(visibleList);

        return retList;

    }

    void addAllFields(List<Field> fieldList, Set<ReferenceType> typeSet) {

        /* Continue the recursion only if this type is new */

        if (!typeSet.contains(this)) {

            typeSet.add(this);

            /* Add local fields */

            fieldList.addAll(fields());

            /* Add inherited fields */

            List<? extends ReferenceType> types = inheritedTypes();

            Iterator<? extends ReferenceType> iter = types.iterator();

            while (iter.hasNext()) {

                ReferenceTypeImpl type = (ReferenceTypeImpl)iter.next();

                type.addAllFields(fieldList, typeSet);

            }

        }

    }

    public List<Field> allFields() {

        List<Field> fieldList = new ArrayList<>();

        Set<ReferenceType> typeSet = new HashSet<ReferenceType>();

        addAllFields(fieldList, typeSet);

        return fieldList;

    }

    public Field fieldByName(String fieldName) {

        List<Field> searchList = visibleFields();

        for (int i = 0; i < searchList.size(); i++) {

            Field f = searchList.get(i);

            if (f.name().equals(fieldName)) {

                return f;

            }

        }

        //throw new NoSuchFieldException("Field '" + fieldName + "' not found in " + name());

        return null;

    }

    public List<Method> methods() {

        List<Method> methods = (methodsRef == null) ? null : methodsRef.get();

        if (methods == null) {

            if (!vm.canGet1_5LanguageFeatures()) {

                methods = methods1_4();

            } else {

                JDWP.ReferenceType.MethodsWithGeneric.MethodInfo[] declared;

                try {

                    declared = JDWP.ReferenceType.MethodsWithGeneric.

                        process(vm, this).declared;

                } catch (JDWPException exc) {

                    throw exc.toJDIException();

                }

                methods = new ArrayList<>(declared.length);

                for (int i = 0; i < declared.length; i++) {

                    JDWP.ReferenceType.MethodsWithGeneric.MethodInfo

                        mi = declared[i];

                    Method method = MethodImpl.createMethodImpl(vm, this,

                                                         mi.methodID,

                                                         mi.name, mi.signature,

                                                         mi.genericSignature,

                                                         mi.modBits);

                    methods.add(method);

                }

            }

            methods = Collections.unmodifiableList(methods);

            methodsRef = new SoftReference<List<Method>>(methods);

        }

        return methods;

    }

    private List<Method> methods1_4() {

        List<Method> methods;

        JDWP.ReferenceType.Methods.MethodInfo[] declared;

        try {