using System;
using System.IO;
using System.Runtime.InteropServices;
using System.Diagnostics;
using System.Text;
using Cloo;
using OpenTK;
using OpenTK.Compute.CL10;
using System.Collections.Generic;

namespace AsyncReadTest
{
    [StructLayout(LayoutKind.Sequential, Pack = 8)]
    struct TestStruct
    {
        public int testInt;
        public float testFloat;        
    }

    class AsyncReadTest
    {
        public void Run()
        {
            #region Create Context
            StreamReader sourceReader = File.OpenText("Kernel.cl");
            string testKernel = sourceReader.ReadToEnd();
            sourceReader.Close();

            ComputeContextPropertyList cpl = new ComputeContextPropertyList(ComputePlatform.Platforms[0]);
            ComputeContext context = new ComputeContext(ComputeDeviceTypes.Default, cpl, null, IntPtr.Zero);
            ComputeProgram program = new ComputeProgram(context, new string[] { testKernel });

            try
            {
                program.Build(null, null, null, IntPtr.Zero);
            }
            catch (ComputeException)
            {
            }
            finally
            {
                string errorMessages = program.GetBuildLog(context.Devices[0]);
                StreamWriter errorSW = new StreamWriter("BuildLog.txt");
                errorSW.Write(errorMessages);
                errorSW.Close();
                Console.WriteLine(errorMessages);
            }
            ComputeKernel kernel = program.CreateKernel("KernelTest");
            ComputeCommandQueue queue = new ComputeCommandQueue(context, context.Devices[0], ComputeCommandQueueFlags.None);

            ComputeEventList events = new ComputeEventList();
            
            #endregion

            List<IntPtr> hMemList = new List<IntPtr>();

            TestStruct inputStruct = new TestStruct();
            inputStruct.testInt = 12345;
            inputStruct.testFloat = 1.2345f;

            TestStruct outputStruct = new TestStruct();
            outputStruct.testInt = -1;
            outputStruct.testFloat = -1;
            GCHandle outputStructPtr = GCHandle.Alloc(outputStruct, GCHandleType.Pinned);

            ClooHelpers.SetKernelArg<TestStruct>(ref inputStruct, ref context, ref hMemList, ref kernel, 
                MemFlags.MemReadOnly | MemFlags.MemCopyHostPtr, 0);

            ClooHelpers.SetKernelArg<TestStruct>(ref outputStruct, ref context, ref hMemList, ref kernel,
                 MemFlags.MemReadWrite | MemFlags.MemCopyHostPtr, 1);

            Console.WriteLine("---Async Read Demo---");
            Console.WriteLine("Executing.....");
            
            queue.Execute(kernel, null, new long[] { 1 }, null, null);
            queue.Finish();

            // True for blocking, false for an async read
            outputStruct.testInt = -1;
            outputStruct.testFloat = -1; 
            ClooHelpers.ReadKernelArg<TestStruct>(ref outputStruct, ref queue, hMemList[1], true, outputStructPtr);
            queue.Finish();           

            // Should output 12345 and 1.2345 if the read was successful
            Console.WriteLine("Blocking Output:");
            Console.WriteLine("testInt: " + outputStruct.testInt);
            Console.WriteLine("testFloat: " + outputStruct.testFloat);
            Console.WriteLine();

            // True for blocking, false for an async read  
            outputStruct.testInt = -1;
            outputStruct.testFloat = -1;
            //ClooHelpers.ReadKernelArg<TestStruct>(ref outputStruct, ref queue, hMemList[1], false, outputStructPtr);
            unsafe
            {
                CL.EnqueueReadBuffer( queue.Handle, hMemList[1], false, new IntPtr( 0 ),
                       new IntPtr( Marshal.SizeOf( outputStruct ) ),
                       new IntPtr( &outputStruct ),
                       //ref outputStruct,
                       0, ( IntPtr* )null, ( IntPtr* )null );
            }
            queue.Finish();

            // Should output 12345 and 1.2345 if the read was successful
            Console.WriteLine("Async Output:");
            Console.WriteLine("testInt: " + outputStruct.testInt);
            Console.WriteLine("testFloat: " + outputStruct.testFloat);
            Console.WriteLine();

            // Cleanup
            for (int i = 0; i < hMemList.Count; i++)
            {
                CL.ReleaseMemObject(hMemList[i]);
            }

            outputStructPtr.Free();
        }
    }
}