/*

 * Copyright (c) 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.

 *

 * 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 jdk.experimental.bytecode;

import java.util.function.Consumer;

/**

 * Base class builder. The base of higher level class builders.

 *

 * @param <S> the type of symbol representation

 * @param <T> the type of type descriptors representation

 * @param <C> the type of this builder

 */

public class ClassBuilder<S, T, C extends ClassBuilder<S, T, C>>

        extends DeclBuilder<S, T, byte[], C> {

    /**

     * The helper to use to manipulate type descriptors.

     */

    protected TypeHelper<S, T> typeHelper;

    /**

     * The symbol for the class being built.

     */

    protected S thisClass;

    /**

     * The super-interfaces of the class being built..

     */

    protected GrowableByteBuffer interfaces = new GrowableByteBuffer();

    /**

     * The fields of the class being built.

     */

    protected GrowableByteBuffer fields = new GrowableByteBuffer();

    /**

     * The methods of the class being built.

     */

    protected GrowableByteBuffer methods = new GrowableByteBuffer();

    int majorVersion;

    int minorVersion;

    int flags;

    int superclass;

    int nmethods, nfields, ninterfaces;

    /**

     * Create a class builder.

     *

     * @param poolHelper the helper to build the constant pool

     * @param typeHelper the helper to use to manipulate type descriptors

     */

    public ClassBuilder(BytePoolHelper<S, T> poolHelper, TypeHelper<S, T> typeHelper) {

        super(poolHelper, typeHelper);

        this.typeHelper = typeHelper;

    }

    /**

     * Set the minor class file version.

     *

     * @param minorVersion the minor version number

     * @return this builder, for chained calls

     */

    public C withMinorVersion(int minorVersion) {

        this.minorVersion = minorVersion;

        return thisBuilder();

    }

    /**

     * Set the major class file version.

     *

     * @param majorVersion the major version number

     * @return this builder, for chained calls

     */

    public C withMajorVersion(int majorVersion) {

        this.majorVersion = majorVersion;

        return thisBuilder();

    }

    /**

     * Set the class symbol

     *

     * @param thisClass the class symbol

     * @return this builder, for chained calls

     */

    public C withThisClass(S thisClass) {

        this.thisClass = thisClass;

        return thisBuilder();

    }

    /**

     * Set the class access flags

     *

     * @param flags an array of {@code Flag}

     * @return this builder, for chained calls

     */

    @Override

    public C withFlags(Flag... flags) {

        for (Flag f : flags) {

            this.flags |= f.flag;

        }

        return thisBuilder();

    }

    /**

     * Set the superclass

     *

     * @param sup the superclass symbol

     * @return this builder, for chained calls

     */

    public C withSuperclass(S sup) {

        this.superclass = poolHelper.putClass(sup);

        return thisBuilder();

    }

    /**

     * Add a super interface.

     *

     * @param sup an interface symbol

     * @return this builder, for chained calls

     */

    public C withSuperinterface(S sup) {

        this.interfaces.writeChar(poolHelper.putClass(sup));

        ninterfaces++;

        return thisBuilder();

    }

    /**

     * Add a field.

     *

     * @param name the name of the field

     * @param type the type descriptor of the field

     * @return this builder, for chained calls

     */

    public final C withField(CharSequence name, T type) {

        return withField(name, type, FB -> {

        });

    }

    /**

     * Add a field.

     *

     * @param name the name of the field

     * @param type the type descriptor of the field

     * @param fieldConfig access to the {@code FieldBuilder} to allow clients to

     * adjust flags, annotations and bytecode attributes on the field declaration

     * @return this builder, for chained calls

     */

    public C withField(CharSequence name, T type, Consumer<? super FieldBuilder<S, T, byte[]>> fieldConfig) {

        FieldBuilder<S, T, byte[]> F = new FieldBuilder<>(name, type, poolHelper, typeHelper);

        fieldConfig.accept(F);

        F.build(fields);

        nfields++;

        return thisBuilder();

    }

    /**

     * Add a method

     *

     * @param name the name of the method

     * @param type the type descriptor of the method

     * @return this builder, for chained calls

     */

    public final C withMethod(CharSequence name, T type) {

        return withMethod(name, type, MB -> {

        });

    }

    /**

     * Add a method

     *

     * @param name the name of the method

     * @param type the type descriptor of the method

     * @param methodConfig access to the {@code MethodBuilder} to allow clients to

     * adjust flags, annotations and bytecode attributes on the method declaration

     * @return this builder, for chained calls

     */

    public C withMethod(CharSequence name, T type, Consumer<? super MethodBuilder<S, T, byte[]>> methodConfig) {

        MethodBuilder<S, T, byte[]> M = new MethodBuilder<>(thisClass, name, type, poolHelper, typeHelper);

        methodConfig.accept(M);

        M.build(methods);

        nmethods++;

        return thisBuilder();

    }

    /**

     * Build the constant pool into a byte array.

     *

     * @return a representation of this constant pool as a byte array

     */

    @SuppressWarnings("unchecked")

    public byte[] build() {

        ((BytePoolHelper<S, T>)poolHelper).addAttributes(this);

        addAnnotations();

        int thisClassIdx = poolHelper.putClass(thisClass);

        byte[] poolBytes = poolHelper.entries();

        GrowableByteBuffer buf = new GrowableByteBuffer();

        buf.writeInt(0xCAFEBABE);

        buf.writeChar(minorVersion);

        buf.writeChar(majorVersion);

        buf.writeChar(poolHelper.size() + 1);

        buf.writeBytes(poolBytes);

        buf.writeChar(flags);

        buf.writeChar(thisClassIdx);

        buf.writeChar(superclass);

        buf.writeChar(ninterfaces);

        if (ninterfaces > 0) {

            buf.writeBytes(interfaces);

        }

        buf.writeChar(nfields);

        buf.writeBytes(fields);

        buf.writeChar(nmethods);

        buf.writeBytes(methods);

        buf.writeChar(nattrs);

        buf.writeBytes(attributes);

        return buf.bytes();

    }

}