/*
 ** Copyright 2011, The Android Open Source Project
 **
 ** Licensed under the Apache License, Version 2.0 (the "License");
 ** you may not use this file except in compliance with the License.
 ** You may obtain a copy of the License at
 **
 **     http://www.apache.org/licenses/LICENSE-2.0
 **
 ** Unless required by applicable law or agreed to in writing, software
 ** distributed under the License is distributed on an "AS IS" BASIS,
 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 ** See the License for the specific language governing permissions and
 ** limitations under the License.
 */

package com.android.glesv2debugger;

import com.google.protobuf.ByteString;

import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.PaletteData;

import java.nio.ByteBuffer;

public class MessageProcessor {
    static void showError(final String message) {
        // need to call SWT from UI thread
        MessageDialog.openError(null, "MessageProcessor", message);
    }

    static byte[] RLEDecode(final byte[] data) {
        byte dataSize = data[0];
        int a = data[1] & 0xff, b = data[2] & 0xff, c = data[3] & 0xff, d = data[4] & 0xff;
        int count = (d << 24) | (c << 16) | (b << 8) | a;
        byte[] buffer = new byte[count * dataSize];
        int write = 0;
        int i = 5;
        for (i = 5; i < data.length;) {
            byte flag = data[i];
            int repeat = (flag & 0x7f) + 1;
            assert 0 < repeat && repeat < 129;
            i++;
            if (0x80 == (flag & 0x80)) {
                for (int j = 0; j < repeat; j++)
                    for (int k = 0; k < dataSize; k++)
                        buffer[write++] = data[i + k];
                i += dataSize;
            } else // literal runs
            {
                for (int j = 0; j < repeat; j++)
                    for (int k = 0; k < dataSize; k++)
                        buffer[write++] = data[i++];
            }
        }
        assert write == count * dataSize;
        assert i == data.length;
        return buffer;
    }

    public static ImageData ReceiveImage(int width, int height, int format,
            int type, byte[] data) {
        assert width > 0 && height > 0;
        int bpp = 0;
        int redMask = 0, blueMask = 0, greenMask = 0;
        switch (GLEnum.valueOf(type)) {
            case GL_UNSIGNED_SHORT_5_6_5:
            case GL_UNSIGNED_SHORT_4_4_4_4:
            case GL_UNSIGNED_SHORT_5_5_5_1:
                format = type;
                break;
            case GL_UNSIGNED_BYTE:
                break;
            default:
                showError("unsupported texture type " + type);
        }

        switch (GLEnum.valueOf(format)) {
            case GL_ALPHA:
            case GL_LUMINANCE:
                redMask = blueMask = greenMask = 0xff;
                bpp = 8;
                break;
            case GL_LUMINANCE_ALPHA:
                blueMask = 0xff;
                redMask = 0xff00;
                bpp = 16;
                break;
            case GL_RGB:
                blueMask = 0xff;
                greenMask = 0xff00;
                redMask = 0xff0000;
                bpp = 24;
                break;
            case GL_RGBA:
                blueMask = 0xff00;
                greenMask = 0xff0000;
                redMask = 0xff000000;
                bpp = 32;
                break;
            case GL_UNSIGNED_SHORT_5_6_5:
                blueMask = ((1 << 5) - 1) << 0;
                greenMask = ((1 << 6) - 1) << 5;
                redMask = ((1 << 5) - 1) << 11;
                bpp = 16;
                break;
            case GL_UNSIGNED_SHORT_4_4_4_4:
                blueMask = ((1 << 4) - 1) << 4;
                greenMask = ((1 << 4) - 1) << 8;
                redMask = ((1 << 4) - 1) << 12;
                bpp = 16;
                break;
            case GL_UNSIGNED_SHORT_5_5_5_1:
                blueMask = ((1 << 5) - 1) << 1;
                greenMask = ((1 << 5) - 1) << 6;
                redMask = ((1 << 5) - 1) << 11;
                bpp = 16;
                break;
            default:
                showError("unsupported texture format: " + format);
                return null;
        }
        // data = RLEDecode(data);
        PaletteData palette = new PaletteData(redMask, greenMask, blueMask);
        return new ImageData(width, height, bpp, palette, 1, data);
    }

    static public float[] ReceiveData(final GLEnum type, final ByteString data) {
        final ByteBuffer buffer = data.asReadOnlyByteBuffer();
        if (type == GLEnum.GL_FLOAT) {
            float[] elements = new float[buffer.remaining() / 4];
            for (int i = 0; i < elements.length; i++)
                elements[i] = buffer.getFloat();
            return elements;
        } else if (type == GLEnum.GL_UNSIGNED_SHORT) {
            float[] elements = new float[buffer.remaining() / 2];
            for (int i = 0; i < elements.length; i++)
                elements[i] = buffer.getShort() & 0xffff;
            return elements;
        } else if (type == GLEnum.GL_UNSIGNED_BYTE) {
            float[] elements = new float[buffer.remaining() / 4];
            for (int i = 0; i < elements.length; i++)
                elements[i] = buffer.get() & 0xff;
            return elements;
        } else
            assert false;
        return null;
    }
}