#include <CL/cl.hpp>

#include <cstring>
#include <iostream>

int main( int argc, char** argv )
{
    cl_int err = CL_SUCCESS;
    
    std::vector<cl::Platform> platforms;
    cl::Platform::get( &platforms );
    cl_context_properties properties[] = { CL_CONTEXT_PLATFORM, (cl_context_properties)(platforms[0])(), 0};
    cl::Context context(CL_DEVICE_TYPE_GPU, properties);
    std::vector<cl::Device> devices = context.getInfo<CL_CONTEXT_DEVICES>();

    const char * helloStr  = "__kernel void hello(void){}";
    cl::Program::Sources source(1, std::make_pair( helloStr, strlen(helloStr) ) );
    cl::Program program_ = cl::Program(context, source);
    err = program_.build(devices);
    if( err == CL_BUILD_SUCCESS ){
        std::cout<<"Build successfull"<<std::endl;
    }else{
        std::cout<<"Build failed ("<<err<<")"<<std::endl;
        return err;
    }
    
    cl::CommandQueue queue(context, devices[0], 0, &err);
    cl::Kernel kernel(program_, "hello", &err);
    
    cl::Event kernelExecutedEvent;
    err = queue.enqueueNDRangeKernel(
        kernel, 
        cl::NullRange, 
        cl::NDRange(1),
        cl::NDRange(1),
        NULL,
        &kernelExecutedEvent);
    kernelExecutedEvent.wait();
    
    if( err == CL_SUCCESS ){
        std::cout<<"Kernel executed"<<std::endl;
    }else{
        std::cout<<"Kernel execution failed with err "<<err<<std::endl;
        return err;
    }

    return 0;
}