package com.mbien.opencl;

import java.nio.Buffer;
import com.mbien.opencl.CLMemory.Mem;
import com.sun.gluegen.runtime.PointerBuffer;
import com.sun.opengl.impl.GLContextImpl;
import com.sun.opengl.impl.macosx.cgl.MacOSXCGLContext;
import com.sun.opengl.impl.windows.wgl.WindowsWGLContext;
import com.sun.opengl.impl.x11.glx.X11GLXContext;
import javax.media.nativewindow.DefaultGraphicsConfiguration;
import javax.media.opengl.GLContext;

import static com.mbien.opencl.CLGLI.*;

/**
 * OpenCL Context supporting interoperablity between JOGL and JOCL.
 * @author Michael Bien
 */
public final class CLGLContext extends CLContext {

    final long glID;

    private CLGLContext(long clContextID, long glContextID) {
        super(clContextID);
        this.glID = glContextID;
    }

    /**
     * Creates a shared context on all available devices (CL_DEVICE_TYPE_ALL).
     */
    public static final CLGLContext create(GLContext glContext) {
        return create(glContext, (CLPlatform)null, CLDevice.Type.ALL);
    }

    /**
     * Creates a shared context on the specified platform on all available devices (CL_DEVICE_TYPE_ALL).
     */
    public static CLGLContext create(GLContext glContext, CLPlatform platform) {
        return create(glContext, platform, CLDevice.Type.ALL);
    }

    public static CLGLContext create(GLContext glContext, CLDevice.Type... deviceTypes) {
        return create(glContext, null, deviceTypes);
    }

    /**
     * Creates a shared context on the specified devices.
     * The platform to be used is implementation dependent.
     */
    public static final CLGLContext create(GLContext glContext, CLDevice... devices) {
        return create(glContext, null, devices);
    }

    /**
     * Creates a shared context on the specified platform and with the specified
     * device types.
     */
    private static final CLGLContext create(GLContext glContext, CLPlatform platform, CLDevice.Type... deviceTypes) {

        long[] glID = new long[1];
        PointerBuffer properties = setupContextProperties(glContext, platform, glID);
        long clID = createContextFromType(properties, toDeviceBitmap(deviceTypes));

        return new CLGLContext(clID, glID[0]);

    }

    /**
     * Creates a shared context on the specified platform and with the specified
     * devices.
     */
    private static final CLGLContext create(GLContext glContext, CLPlatform platform, CLDevice... devices) {

        long[] glID = new long[1];
        PointerBuffer properties = setupContextProperties(glContext, platform, glID);
        long clID = createContext(properties, devices);

        return new CLGLContext(clID, glID[0]);
    }


    private static final PointerBuffer setupContextProperties(GLContext glContext, CLPlatform platform, long[] glID) {

        if(platform == null) {
            platform = CLPlatform.getDefault();
        }

        if(platform == null) {
            throw new RuntimeException("no OpenCL installation found");
        }

        GLContextImpl ctxImpl = (GLContextImpl)glContext;

        DefaultGraphicsConfiguration config = (DefaultGraphicsConfiguration)ctxImpl.getDrawableImpl()
             .getNativeWindow().getGraphicsConfiguration().getNativeGraphicsConfiguration();

        PointerBuffer properties = null;
        if(glContext instanceof X11GLXContext) {
            properties = PointerBuffer.allocateDirect(7);
            long handle = config.getScreen().getDevice().getHandle();
            glID[0] = ((X11GLXContext)glContext).getContext();
            properties.put(CL_GL_CONTEXT_KHR).put(glID[0])
                      .put(CL_GLX_DISPLAY_KHR).put(handle)
                      .put(CL_CONTEXT_PLATFORM).put(platform.ID);
        }else if(glContext instanceof WindowsWGLContext) {
            // TODO test on windows
            //WIN32
            //cl_context_properties props[] = {
            //         CL_GL_CONTEXT_KHR, (cl_context_properties)0,
            //         CL_WGL_HDC_KHR, (cl_context_properties)0,
            //         CL_CONTEXT_PLATFORM, (cl_context_properties)cpPlatform, 0};
            properties = PointerBuffer.allocateDirect(7);
            long handle = config.getScreen().getDevice().getHandle();
            glID[0] = ((WindowsWGLContext)glContext).getHGLRC();
            properties.put(CL_GL_CONTEXT_KHR).put(glID[0])
                      .put(CL_WGL_HDC_KHR).put(handle)
                      .put(CL_CONTEXT_PLATFORM).put(platform.ID);
        }else if(glContext instanceof MacOSXCGLContext) {
            // TODO test on mac
            //MACOSX
            //cl_context_properties props[] = {
            //         CL_CGL_SHAREGROUP_KHR, (cl_context_properties)0,
            //         CL_CONTEXT_PLATFORM, (cl_context_properties)cpPlatform, 0};
            properties = PointerBuffer.allocateDirect(5);
            glID[0] = ((MacOSXCGLContext)glContext).getCGLContext();
            properties.put(CL_CGL_SHAREGROUP_KHR).put(glID[0])
                      .put(CL_CONTEXT_PLATFORM).put(platform.ID);
        }else{
            throw new RuntimeException("unsupported GLContext: "+glContext);
        }

        return properties.put(0).rewind(); // 0 terminated array
    }


    public final <B extends Buffer> CLGLBuffer<B> createFromGLBuffer(B directBuffer, int glBuffer, Mem... flags) {
        return createFromGLBuffer(directBuffer, glBuffer, Mem.flagsToInt(flags));
    }

    public final <B extends Buffer> CLGLBuffer<B> createFromGLBuffer(B directBuffer, int glBuffer, int flags) {
        CLGLBuffer<B> buffer = CLGLBuffer.create(this, directBuffer, flags, glBuffer);
        memoryObjects.add(buffer);
        return buffer;
    }

}