/*
 * Copyright (c) 2008, 2012, 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.classfile;

import java.util.Map;

import com.sun.tools.classfile.ConstantPool.CONSTANT_Class_info;
import com.sun.tools.classfile.ConstantPool.CONSTANT_Double_info;
import com.sun.tools.classfile.ConstantPool.CONSTANT_Fieldref_info;
import com.sun.tools.classfile.ConstantPool.CONSTANT_Float_info;
import com.sun.tools.classfile.ConstantPool.CONSTANT_Integer_info;
import com.sun.tools.classfile.ConstantPool.CONSTANT_InterfaceMethodref_info;
import com.sun.tools.classfile.ConstantPool.CONSTANT_InvokeDynamic_info;
import com.sun.tools.classfile.ConstantPool.CONSTANT_Long_info;
import com.sun.tools.classfile.ConstantPool.CONSTANT_MethodHandle_info;
import com.sun.tools.classfile.ConstantPool.CONSTANT_MethodType_info;
import com.sun.tools.classfile.ConstantPool.CONSTANT_Methodref_info;
import com.sun.tools.classfile.ConstantPool.CONSTANT_Module_info;
import com.sun.tools.classfile.ConstantPool.CONSTANT_NameAndType_info;
import com.sun.tools.classfile.ConstantPool.CONSTANT_Package_info;
import com.sun.tools.classfile.ConstantPool.CONSTANT_String_info;
import com.sun.tools.classfile.ConstantPool.CONSTANT_Utf8_info;
import com.sun.tools.classfile.ConstantPool.CPInfo;

Rewrites a class file using a map of translations.
 
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.
/**
 * Rewrites a class file using a map of translations.
 *
 *  <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 ClassTranslator
        implements ConstantPool.Visitor<ConstantPool.CPInfo,Map<Object,Object>> {
    
Create a new ClassFile from cf, such that for all entries k&nbsp;-\&gt;&nbsp;v in translations, each occurrence of k in cf will be replaced by v. in 
Params:
cf – the class file to be processed
translations – the set of translations to be applied
Returns:
a copy of  with the values in translations substituted/**
     * Create a new ClassFile from {@code cf}, such that for all entries
     * {@code k&nbsp;-\&gt;&nbsp;v} in {@code translations},
     * each occurrence of {@code k} in {@code cf} will be replaced by {@code v}.
     * in
     * @param cf the class file to be processed
     * @param translations the set of translations to be applied
     * @return a copy of {@code} with the values in {@code translations} substituted
     */
    public ClassFile translate(ClassFile cf, Map<Object,Object> translations) {
        ClassFile cf2 = (ClassFile) translations.get(cf);
        if (cf2 == null) {
            ConstantPool constant_pool2 = translate(cf.constant_pool, translations);
            Field[] fields2 = translate(cf.fields, cf.constant_pool, translations);
            Method[] methods2 = translateMethods(cf.methods, cf.constant_pool, translations);
            Attributes attributes2 = translateAttributes(cf.attributes, cf.constant_pool,
                    translations);

            if (constant_pool2 == cf.constant_pool &&
                    fields2 == cf.fields &&
                    methods2 == cf.methods &&
                    attributes2 == cf.attributes)
                cf2 = cf;
            else
                cf2 = new ClassFile(
                        cf.magic,
                        cf.minor_version,
                        cf.major_version,
                        constant_pool2,
                        cf.access_flags,
                        cf.this_class,
                        cf.super_class,
                        cf.interfaces,
                        fields2,
                        methods2,
                        attributes2);
            translations.put(cf, cf2);
        }
        return cf2;
    }

    ConstantPool translate(ConstantPool cp, Map<Object,Object> translations) {
        ConstantPool cp2 = (ConstantPool) translations.get(cp);
        if (cp2 == null) {
            ConstantPool.CPInfo[] pool2 = new ConstantPool.CPInfo[cp.size()];
            boolean eq = true;
            for (int i = 0; i < cp.size(); ) {
                ConstantPool.CPInfo cpInfo;
                try {
                    cpInfo = cp.get(i);
                } catch (ConstantPool.InvalidIndex e) {
                    throw new IllegalStateException(e);
                }
                ConstantPool.CPInfo cpInfo2 = translate(cpInfo, translations);
                eq &= (cpInfo == cpInfo2);
                pool2[i] = cpInfo2;
                if (cpInfo.getTag() != cpInfo2.getTag())
                    throw new IllegalStateException();
                i += cpInfo.size();
            }

            if (eq)
                cp2 = cp;
            else
                cp2 = new ConstantPool(pool2);

            translations.put(cp, cp2);
        }
        return cp2;
    }

    ConstantPool.CPInfo translate(ConstantPool.CPInfo cpInfo, Map<Object,Object> translations) {
        ConstantPool.CPInfo cpInfo2 = (ConstantPool.CPInfo) translations.get(cpInfo);
        if (cpInfo2 == null) {
            cpInfo2 = cpInfo.accept(this, translations);
            translations.put(cpInfo, cpInfo2);
        }
        return cpInfo2;
    }

    Field[] translate(Field[] fields, ConstantPool constant_pool, Map<Object,Object> translations) {
        Field[] fields2 = (Field[]) translations.get(fields);
        if (fields2 == null) {
            fields2 = new Field[fields.length];
            for (int i = 0; i < fields.length; i++)
                fields2[i] = translate(fields[i], constant_pool, translations);
            if (equal(fields, fields2))
                fields2 = fields;
            translations.put(fields, fields2);
        }
        return fields2;
    }

    Field translate(Field field, ConstantPool constant_pool, Map<Object,Object> translations) {
        Field field2 = (Field) translations.get(field);
        if (field2 == null) {
            Attributes attributes2 = translateAttributes(field.attributes, constant_pool,
                    translations);

            if (attributes2 == field.attributes)
                field2 = field;
            else
                field2 = new Field(
                        field.access_flags,
                        field.name_index,
                        field.descriptor,
                        attributes2);
            translations.put(field, field2);
        }
        return field2;
    }

    Method[] translateMethods(Method[] methods, ConstantPool constant_pool, Map<Object,Object> translations) {
        Method[] methods2 = (Method[]) translations.get(methods);
        if (methods2 == null) {
            methods2 = new Method[methods.length];
            for (int i = 0; i < methods.length; i++)
                methods2[i] = translate(methods[i], constant_pool, translations);
            if (equal(methods, methods2))
                methods2 = methods;
            translations.put(methods, methods2);
        }
        return methods2;
    }

    Method translate(Method method, ConstantPool constant_pool, Map<Object,Object> translations) {
        Method method2 = (Method) translations.get(method);
        if (method2 == null) {
            Attributes attributes2 = translateAttributes(method.attributes, constant_pool,
                    translations);

            if (attributes2 == method.attributes)
                method2 = method;
            else
                method2 = new Method(
                        method.access_flags,
                        method.name_index,
                        method.descriptor,
                        attributes2);
            translations.put(method, method2);
        }
        return method2;
    }

    Attributes translateAttributes(Attributes attributes,
            ConstantPool constant_pool, Map<Object,Object> translations) {
        Attributes attributes2 = (Attributes) translations.get(attributes);
        if (attributes2 == null) {
            Attribute[] attrArray2 = new Attribute[attributes.size()];
            ConstantPool constant_pool2 = translate(constant_pool, translations);
            boolean attrsEqual = true;
            for (int i = 0; i < attributes.size(); i++) {
                Attribute attr = attributes.get(i);
                Attribute attr2 = translate(attr, translations);
                if (attr2 != attr)
                    attrsEqual = false;
                attrArray2[i] = attr2;
            }
            if ((constant_pool2 == constant_pool) && attrsEqual)
                attributes2 = attributes;
            else
                attributes2 = new Attributes(constant_pool2, attrArray2);
            translations.put(attributes, attributes2);
        }
        return attributes2;
    }

    Attribute translate(Attribute attribute, Map<Object,Object> translations) {
        Attribute attribute2 = (Attribute) translations.get(attribute);
        if (attribute2 == null) {
            attribute2 = attribute; // don't support translation within attributes yet
                                    // (what about Code attribute)
            translations.put(attribute, attribute2);
        }
        return attribute2;
    }

    private static <T> boolean equal(T[] a1, T[] a2) {
        if (a1 == null || a2 == null)
            return (a1 == a2);
        if (a1.length != a2.length)
            return false;
        for (int i = 0; i < a1.length; i++) {
            if (a1[i] != a2[i])
                return false;
        }
        return true;
    }

    @Override
    public CPInfo visitClass(CONSTANT_Class_info info, Map<Object, Object> translations) {
        CONSTANT_Class_info info2 = (CONSTANT_Class_info) translations.get(info);
        if (info2 == null) {
            ConstantPool cp2 = translate(info.cp, translations);
            if (cp2 == info.cp)
                info2 = info;
            else
                info2 = new CONSTANT_Class_info(cp2, info.name_index);
            translations.put(info, info2);
        }
        return info;
    }

    @Override
    public CPInfo visitDouble(CONSTANT_Double_info info, Map<Object, Object> translations) {
        CONSTANT_Double_info info2 = (CONSTANT_Double_info) translations.get(info);
        if (info2 == null) {
            info2 = info;
            translations.put(info, info2);
        }
        return info;
    }

    @Override
    public CPInfo visitFieldref(CONSTANT_Fieldref_info info, Map<Object, Object> translations) {
        CONSTANT_Fieldref_info info2 = (CONSTANT_Fieldref_info) translations.get(info);
        if (info2 == null) {
            ConstantPool cp2 = translate(info.cp, translations);
            if (cp2 == info.cp)
                info2 = info;
            else
                info2 = new CONSTANT_Fieldref_info(cp2, info.class_index, info.name_and_type_index);
            translations.put(info, info2);
        }
        return info;
    }

    @Override
    public CPInfo visitFloat(CONSTANT_Float_info info, Map<Object, Object> translations) {
        CONSTANT_Float_info info2 = (CONSTANT_Float_info) translations.get(info);
        if (info2 == null) {
            info2 = info;
            translations.put(info, info2);
        }
        return info;
    }

    @Override
    public CPInfo visitInteger(CONSTANT_Integer_info info, Map<Object, Object> translations) {
        CONSTANT_Integer_info info2 = (CONSTANT_Integer_info) translations.get(info);
        if (info2 == null) {
            info2 = info;
            translations.put(info, info2);
        }
        return info;
    }

    @Override
    public CPInfo visitInterfaceMethodref(CONSTANT_InterfaceMethodref_info info, Map<Object, Object> translations) {
        CONSTANT_InterfaceMethodref_info info2 = (CONSTANT_InterfaceMethodref_info) translations.get(info);
        if (info2 == null) {
            ConstantPool cp2 = translate(info.cp, translations);
            if (cp2 == info.cp)
                info2 = info;
            else
                info2 = new CONSTANT_InterfaceMethodref_info(cp2, info.class_index, info.name_and_type_index);
            translations.put(info, info2);
        }
        return info;
    }

    @Override
    public CPInfo visitInvokeDynamic(CONSTANT_InvokeDynamic_info info, Map<Object, Object> translations) {
        CONSTANT_InvokeDynamic_info info2 = (CONSTANT_InvokeDynamic_info) translations.get(info);
        if (info2 == null) {
            ConstantPool cp2 = translate(info.cp, translations);
            if (cp2 == info.cp) {
                info2 = info;
            } else {
                info2 = new CONSTANT_InvokeDynamic_info(cp2, info.bootstrap_method_attr_index, info.name_and_type_index);
            }
            translations.put(info, info2);
        }
        return info;
    }

    @Override
    public CPInfo visitLong(CONSTANT_Long_info info, Map<Object, Object> translations) {
        CONSTANT_Long_info info2 = (CONSTANT_Long_info) translations.get(info);
        if (info2 == null) {
            info2 = info;
            translations.put(info, info2);
        }
        return info;
    }

    @Override
    public CPInfo visitMethodref(CONSTANT_Methodref_info info, Map<Object, Object> translations) {
        CONSTANT_Methodref_info info2 = (CONSTANT_Methodref_info) translations.get(info);
        if (info2 == null) {
            ConstantPool cp2 = translate(info.cp, translations);
            if (cp2 == info.cp)
                info2 = info;
            else
                info2 = new CONSTANT_Methodref_info(cp2, info.class_index, info.name_and_type_index);
            translations.put(info, info2);
        }
        return info;
    }

    @Override
    public CPInfo visitMethodHandle(CONSTANT_MethodHandle_info info, Map<Object, Object> translations) {
        CONSTANT_MethodHandle_info info2 = (CONSTANT_MethodHandle_info) translations.get(info);
        if (info2 == null) {
            ConstantPool cp2 = translate(info.cp, translations);
            if (cp2 == info.cp) {
                info2 = info;
            } else {
                info2 = new CONSTANT_MethodHandle_info(cp2, info.reference_kind, info.reference_index);
            }
            translations.put(info, info2);
        }
        return info;
    }

    @Override
    public CPInfo visitMethodType(CONSTANT_MethodType_info info, Map<Object, Object> translations) {
        CONSTANT_MethodType_info info2 = (CONSTANT_MethodType_info) translations.get(info);
        if (info2 == null) {
            ConstantPool cp2 = translate(info.cp, translations);
            if (cp2 == info.cp) {
                info2 = info;
            } else {
                info2 = new CONSTANT_MethodType_info(cp2, info.descriptor_index);
            }
            translations.put(info, info2);
        }
        return info;
    }

    @Override
    public CPInfo visitModule(CONSTANT_Module_info info, Map<Object, Object> translations) {
        CONSTANT_Module_info info2 = (CONSTANT_Module_info) translations.get(info);
        if (info2 == null) {
            ConstantPool cp2 = translate(info.cp, translations);
            if (cp2 == info.cp)
                info2 = info;
            else
                info2 = new CONSTANT_Module_info(cp2, info.name_index);
            translations.put(info, info2);
        }
        return info;
    }

    @Override
    public CPInfo visitNameAndType(CONSTANT_NameAndType_info info, Map<Object, Object> translations) {
        CONSTANT_NameAndType_info info2 = (CONSTANT_NameAndType_info) translations.get(info);
        if (info2 == null) {
            ConstantPool cp2 = translate(info.cp, translations);
            if (cp2 == info.cp)
                info2 = info;
            else
                info2 = new CONSTANT_NameAndType_info(cp2, info.name_index, info.type_index);
            translations.put(info, info2);
        }
        return info;
    }

    @Override
    public CPInfo visitPackage(CONSTANT_Package_info info, Map<Object, Object> translations) {
        CONSTANT_Package_info info2 = (CONSTANT_Package_info) translations.get(info);
        if (info2 == null) {
            ConstantPool cp2 = translate(info.cp, translations);
            if (cp2 == info.cp)
                info2 = info;
            else
                info2 = new CONSTANT_Package_info(cp2, info.name_index);
            translations.put(info, info2);
        }
        return info;
    }

    @Override
    public CPInfo visitString(CONSTANT_String_info info, Map<Object, Object> translations) {
        CONSTANT_String_info info2 = (CONSTANT_String_info) translations.get(info);
        if (info2 == null) {
            ConstantPool cp2 = translate(info.cp, translations);
            if (cp2 == info.cp)
                info2 = info;
            else
                info2 = new CONSTANT_String_info(cp2, info.string_index);
            translations.put(info, info2);
        }
        return info;
    }

    @Override
    public CPInfo visitUtf8(CONSTANT_Utf8_info info, Map<Object, Object> translations) {
        CONSTANT_Utf8_info info2 = (CONSTANT_Utf8_info) translations.get(info);
        if (info2 == null) {
            info2 = info;
            translations.put(info, info2);
        }
        return info;
    }

}