/*

 * Copyright (c) 2001, 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.java.util.jar.pack;

import com.sun.java.util.jar.pack.ConstantPool.Entry;

import com.sun.java.util.jar.pack.ConstantPool.Index;

import com.sun.java.util.jar.pack.ConstantPool.NumberEntry;

import com.sun.java.util.jar.pack.ConstantPool.MethodHandleEntry;

import com.sun.java.util.jar.pack.ConstantPool.BootstrapMethodEntry;

import com.sun.java.util.jar.pack.Package.Class;

import com.sun.java.util.jar.pack.Package.InnerClass;

import java.io.BufferedOutputStream;

import java.io.ByteArrayOutputStream;

import java.io.DataOutputStream;

import java.io.IOException;

import java.io.OutputStream;

import java.util.List;

import static com.sun.java.util.jar.pack.Constants.*;

/**

 * Writer for a class file that is incorporated into a package.

 * @author John Rose

 */

class ClassWriter {

    int verbose;

    Package pkg;

    Class cls;

    DataOutputStream out;

    Index cpIndex;

    Index bsmIndex;

    ClassWriter(Class cls, OutputStream out) throws IOException {

        this.pkg = cls.getPackage();

        this.cls = cls;

        this.verbose = pkg.verbose;

        this.out = new DataOutputStream(new BufferedOutputStream(out));

        this.cpIndex = ConstantPool.makeIndex(cls.toString(), cls.getCPMap());

        this.cpIndex.flattenSigs = true;

        if (cls.hasBootstrapMethods()) {

            this.bsmIndex = ConstantPool.makeIndex(cpIndex.debugName+".BootstrapMethods",

                                                   cls.getBootstrapMethodMap());

        }

        if (verbose > 1)

            Utils.log.fine("local CP="+(verbose > 2 ? cpIndex.dumpString() : cpIndex.toString()));

    }

    private void writeShort(int x) throws IOException {

        out.writeShort(x);

    }

    private void writeInt(int x) throws IOException {

        out.writeInt(x);

    }

    /** Write a 2-byte int representing a CP entry, using the local cpIndex. */

    private void writeRef(Entry e) throws IOException {

        writeRef(e, cpIndex);

    }

    /** Write a 2-byte int representing a CP entry, using the given cpIndex. */

    private void writeRef(Entry e, Index cpIndex) throws IOException {

        int i = (e == null) ? 0 : cpIndex.indexOf(e);

        writeShort(i);

    }

    void write() throws IOException {

        boolean ok = false;

        try {

            if (verbose > 1)  Utils.log.fine("...writing "+cls);

            writeMagicNumbers();

            writeConstantPool();

            writeHeader();

            writeMembers(false);  // fields

            writeMembers(true);   // methods

            writeAttributes(ATTR_CONTEXT_CLASS, cls);

            /* Closing here will cause all the underlying

               streams to close, Causing the jar stream

               to close prematurely, instead we just flush.

               out.close();

             */

            out.flush();

            ok = true;

        } finally {

            if (!ok) {

                Utils.log.warning("Error on output of "+cls);

            }

        }

    }

    void writeMagicNumbers() throws IOException {

        writeInt(cls.magic);

        writeShort(cls.version.minor);

        writeShort(cls.version.major);

    }

    void writeConstantPool() throws IOException {

        Entry[] cpMap = cls.cpMap;

        writeShort(cpMap.length);

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

            Entry e = cpMap[i];

            assert((e == null) == (i == 0 || cpMap[i-1] != null && cpMap[i-1].isDoubleWord()));

            if (e == null)  continue;

            byte tag = e.getTag();

            if (verbose > 2)  Utils.log.fine("   CP["+i+"] = "+e);

            out.write(tag);

            switch (tag) {

                case CONSTANT_Signature:

                    throw new AssertionError("CP should have Signatures remapped to Utf8");

                case CONSTANT_Utf8:

                    out.writeUTF(e.stringValue());

                    break;

                case CONSTANT_Integer:

                    out.writeInt(((NumberEntry)e).numberValue().intValue());

                    break;

                case CONSTANT_Float:

                    float fval = ((NumberEntry)e).numberValue().floatValue();

                    out.writeInt(Float.floatToRawIntBits(fval));

                    break;

                case CONSTANT_Long:

                    out.writeLong(((NumberEntry)e).numberValue().longValue());

                    break;

                case CONSTANT_Double:

                    double dval = ((NumberEntry)e).numberValue().doubleValue();

                    out.writeLong(Double.doubleToRawLongBits(dval));

                    break;

                case CONSTANT_Class:

                case CONSTANT_String:

                case CONSTANT_MethodType:

                    writeRef(e.getRef(0));

                    break;

                case CONSTANT_MethodHandle:

                    MethodHandleEntry mhe = (MethodHandleEntry) e;

                    out.writeByte(mhe.refKind);

                    writeRef(mhe.getRef(0));

                    break;

                case CONSTANT_Fieldref:

                case CONSTANT_Methodref:

                case CONSTANT_InterfaceMethodref:

                case CONSTANT_NameandType:

                    writeRef(e.getRef(0));

                    writeRef(e.getRef(1));

                    break;

                case CONSTANT_InvokeDynamic:

                    writeRef(e.getRef(0), bsmIndex);

                    writeRef(e.getRef(1));

                    break;

                case CONSTANT_BootstrapMethod:

                    throw new AssertionError("CP should have BootstrapMethods moved to side-table");

                default:

                    throw new IOException("Bad constant pool tag "+tag);

            }

        }

    }

    void writeHeader() throws IOException {

        writeShort(cls.flags);

        writeRef(cls.thisClass);

        writeRef(cls.superClass);

        writeShort(cls.interfaces.length);

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

            writeRef(cls.interfaces[i]);

        }

    }

    void writeMembers(boolean doMethods) throws IOException {

        List<? extends Class.Member> mems;

        if (!doMethods)

            mems = cls.getFields();

        else

            mems = cls.getMethods();

        writeShort(mems.size());

        for (Class.Member m : mems) {

            writeMember(m, doMethods);

        }

    }

    void writeMember(Class.Member m, boolean doMethod) throws IOException {

        if (verbose > 2)  Utils.log.fine("writeMember "+m);

        writeShort(m.flags);

        writeRef(m.getDescriptor().nameRef);

        writeRef(m.getDescriptor().typeRef);

        writeAttributes(!doMethod ? ATTR_CONTEXT_FIELD : ATTR_CONTEXT_METHOD,

                        m);

    }

    private void reorderBSMandICS(Attribute.Holder h) {

        Attribute bsmAttr = h.getAttribute(Package.attrBootstrapMethodsEmpty);

        if (bsmAttr == null) return;

        Attribute icsAttr = h.getAttribute(Package.attrInnerClassesEmpty);

        if (icsAttr == null) return;

        int bsmidx = h.attributes.indexOf(bsmAttr);

        int icsidx = h.attributes.indexOf(icsAttr);

        if (bsmidx > icsidx) {

            h.attributes.remove(bsmAttr);

            h.attributes.add(icsidx, bsmAttr);

        }

        return;

    }

    // handy buffer for collecting attrs

    ByteArrayOutputStream buf    = new ByteArrayOutputStream();

    DataOutputStream      bufOut = new DataOutputStream(buf);

    void writeAttributes(int ctype, Attribute.Holder h) throws IOException {

        if (h.attributes == null) {

            writeShort(0);  // attribute size

            return;

        }

        // there may be cases if an InnerClass attribute is explicit, then the

        // ordering could be wrong, fix the ordering before we write it out.

        if (h instanceof Package.Class)

            reorderBSMandICS(h);

        writeShort(h.attributes.size());

        for (Attribute a : h.attributes) {

            a.finishRefs(cpIndex);

            writeRef(a.getNameRef());

            if (a.layout() == Package.attrCodeEmpty ||

                a.layout() == Package.attrBootstrapMethodsEmpty ||

                a.layout() == Package.attrInnerClassesEmpty) {

                // These are hardwired.

                DataOutputStream savedOut = out;

                assert(out != bufOut);

                buf.reset();

                out = bufOut;

                if ("Code".equals(a.name())) {

                    Class.Method m = (Class.Method) h;

                    writeCode(m.code);

                } else if ("BootstrapMethods".equals(a.name())) {

                    assert(h == cls);

                    writeBootstrapMethods(cls);

                } else if ("InnerClasses".equals(a.name())) {

                    assert(h == cls);

                    writeInnerClasses(cls);

                } else {

                    throw new AssertionError();

                }

                out = savedOut;

                if (verbose > 2)

                    Utils.log.fine("Attribute "+a.name()+" ["+buf.size()+"]");

                writeInt(buf.size());

                buf.writeTo(out);

            } else {

                if (verbose > 2)

                    Utils.log.fine("Attribute "+a.name()+" ["+a.size()+"]");

                writeInt(a.size());

                out.write(a.bytes());

            }

        }

    }

    void writeCode(Code code) throws IOException {

        code.finishRefs(cpIndex);

        writeShort(code.max_stack);

        writeShort(code.max_locals);

        writeInt(code.bytes.length);

        out.write(code.bytes);

        int nh = code.getHandlerCount();

        writeShort(nh);

        for (int i = 0; i < nh; i++) {

             writeShort(code.handler_start[i]);

             writeShort(code.handler_end[i]);

             writeShort(code.handler_catch[i]);

             writeRef(code.handler_class[i]);

        }

        writeAttributes(ATTR_CONTEXT_CODE, code);

    }

    void writeBootstrapMethods(Class cls) throws IOException {

        List<BootstrapMethodEntry> bsms = cls.getBootstrapMethods();

        writeShort(bsms.size());

        for (BootstrapMethodEntry e : bsms) {

            writeRef(e.bsmRef);

            writeShort(e.argRefs.length);

            for (Entry argRef : e.argRefs) {

                writeRef(argRef);

            }

        }

    }

    void writeInnerClasses(Class cls) throws IOException {

        List<InnerClass> ics = cls.getInnerClasses();

        writeShort(ics.size());

        for (InnerClass ic : ics) {

            writeRef(ic.thisClass);

            writeRef(ic.outerClass);

            writeRef(ic.name);

            writeShort(ic.flags);

        }

    }

}