#include <unittest/unittest.h>
#include <thrust/inner_product.h>
#include <thrust/execution_policy.h>


template<typename ExecutionPolicy, typename Iterator1, typename Iterator2, typename T, typename Iterator3>
__global__
void inner_product_kernel(ExecutionPolicy exec, Iterator1 first1, Iterator1 last1, Iterator2 first2, T init, Iterator3 result)
{
  *result = thrust::inner_product(exec, first1, last1, first2, init);
}


template<typename ExecutionPolicy>
void TestInnerProductDevice(ExecutionPolicy exec)
{
  size_t n = 1000;

  thrust::host_vector<int> h_v1 = unittest::random_integers<int>(n);
  thrust::host_vector<int> h_v2 = unittest::random_integers<int>(n);
  
  thrust::device_vector<int> d_v1 = h_v1;
  thrust::device_vector<int> d_v2 = h_v2;
  
  thrust::device_vector<int> result(1);
  
  int init = 13;
  
  int expected = thrust::inner_product(h_v1.begin(), h_v1.end(), h_v2.begin(), init);

  inner_product_kernel<<<1,1>>>(exec, d_v1.begin(), d_v1.end(), d_v2.begin(), init, result.begin());
  {
    cudaError_t const err = cudaDeviceSynchronize();
    ASSERT_EQUAL(cudaSuccess, err);
  }
  
  ASSERT_EQUAL(expected, result[0]);
}


void TestInnerProductDeviceSeq()
{
  TestInnerProductDevice(thrust::seq);
};
DECLARE_UNITTEST(TestInnerProductDeviceSeq);


void TestInnerProductDeviceDevice()
{
  TestInnerProductDevice(thrust::device);
};
DECLARE_UNITTEST(TestInnerProductDeviceDevice);


void TestInnerProductCudaStreams()
{
  thrust::device_vector<int> v1(3);
  thrust::device_vector<int> v2(3);
  v1[0] =  1; v1[1] = -2; v1[2] =  3;
  v2[0] = -4; v2[1] =  5; v2[2] =  6;

  cudaStream_t s;
  cudaStreamCreate(&s);
  
  int init = 3;
  int result = thrust::inner_product(thrust::cuda::par.on(s), v1.begin(), v1.end(), v2.begin(), init);
  ASSERT_EQUAL(result, 7);

  cudaStreamDestroy(s);
}
DECLARE_UNITTEST(TestInnerProductCudaStreams);