/*

 * 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.apple.jobjc;

import java.nio.ByteOrder;

import com.apple.jobjc.Coder.PrimitivePointerCoder;

public final class NativeArgumentBuffer{

    private static final ThreadLocal<NativeArgumentBuffer> threadLocal = new ThreadLocal<NativeArgumentBuffer>();

    static NativeArgumentBuffer getThreadLocalBuffer(final JObjCRuntime runtime) {

        runtime.assertOK();

        final NativeArgumentBuffer alreadyCreated = threadLocal.get();

        if (alreadyCreated != null) return alreadyCreated;

        final NativeArgumentBuffer newThreadLocalState = new NativeArgumentBuffer(runtime);

        threadLocal.set(newThreadLocalState);

        return newThreadLocalState;

    }

    final JObjCRuntime runtime;

    final NativeBuffer buffer;

    long argPtrsPtr;

    long argValuesPtr;

    final long retValPtr;

    private static final int MAX_ARGS = 512;

    private static final int BUF_SIZE = MAX_ARGS * 8 * 2;

    private static final int ARG_VALS_OFFSET = BUF_SIZE/2;

    private NativeArgumentBuffer(final JObjCRuntime runtime) {

        runtime.assertOK();

        this.runtime = runtime;

        this.buffer = new NativeBuffer(BUF_SIZE);

        this.buffer.buffer.order(ByteOrder.nativeOrder());

        reset();

        this.retValPtr = buffer.bufferPtr;

    }

    // Call before each new call

    public void reset() {

        argPtrsPtr = buffer.bufferPtr;

        argValuesPtr = buffer.bufferPtr + ARG_VALS_OFFSET;

        assert buffer.ptrInBounds(argValuesPtr);

    }

    // Push a pointer to a block of memory

    public void doPutArgPtr(long ptr) {

        assert buffer.ptrInBounds(argPtrsPtr);

        PrimitivePointerCoder.INST.push(runtime, argPtrsPtr, ptr);

        argPtrsPtr += JObjCRuntime.PTR_LEN;

    }

    // Call this after having written a value of size `sizeof` to `argValuesPtr`.

    public void didPutArgValue(int sizeof) {

        assert buffer.ptrInBounds(argValuesPtr);

        doPutArgPtr(argValuesPtr);

        argValuesPtr += sizeof;

    }

    @Override public String toString() {

        final StringBuilder builder = new StringBuilder();

        final long bptr = buffer.bufferPtr;

        for(long i = bptr; i < bptr + ARG_VALS_OFFSET; i += JObjCRuntime.PTR_LEN){

            if(argPtrsPtr == i)

                builder.append("*");

            builder.append(PrimitivePointerCoder.INST.popPtr(JObjCRuntime.inst(), i));

            builder.append(" ");

        }

        builder.append("\n");

        for(long i = bptr + ARG_VALS_OFFSET; i < bptr + BUF_SIZE; i += JObjCRuntime.PTR_LEN){

            if(argValuesPtr == i)

                builder.append("*");

            builder.append(PrimitivePointerCoder.INST.popPtr(JObjCRuntime.inst(), i));

            builder.append(" ");

        }

        return builder.toString();

    }

}