#include "kernel_Point_retract.h"
#include "memops.cuh"
#include <cooperative_groups.h>
#include <cooperative_groups/details/partitioning.h>
#include <cooperative_groups/memcpy_async.h>
#include <cooperative_groups/reduce.h>
#include <cuda_runtime.h>

namespace cg = cooperative_groups;

namespace caspar {

__global__ void __launch_bounds__(1024, 1)
    PointRetractKernel(double* Point,
                       unsigned int Point_num_alloc,
                       double* delta,
                       unsigned int delta_num_alloc,
                       double* out_Point_retracted,
                       unsigned int out_Point_retracted_num_alloc,
                       size_t problem_size) {
  const int global_thread_idx = blockIdx.x * blockDim.x + threadIdx.x;

  double r0, r1, r2, r3;

  if (global_thread_idx < problem_size) {
    ReadIdx2<1024, double, double, double2>(
        Point, 0 * Point_num_alloc, global_thread_idx, r0, r1);
    ReadIdx2<1024, double, double, double2>(
        delta, 0 * delta_num_alloc, global_thread_idx, r2, r3);
    r2 = r0 + r2;
    r3 = r1 + r3;
    WriteIdx2<1024, double, double, double2>(out_Point_retracted,
                                             0 * out_Point_retracted_num_alloc,
                                             global_thread_idx,
                                             r2,
                                             r3);
    ReadIdx1<1024, double, double, double>(
        Point, 2 * Point_num_alloc, global_thread_idx, r3);
    ReadIdx1<1024, double, double, double>(
        delta, 2 * delta_num_alloc, global_thread_idx, r2);
    r2 = r3 + r2;
    WriteIdx1<1024, double, double, double>(out_Point_retracted,
                                            2 * out_Point_retracted_num_alloc,
                                            global_thread_idx,
                                            r2);
  };
}

void PointRetract(double* Point,
                  unsigned int Point_num_alloc,
                  double* delta,
                  unsigned int delta_num_alloc,
                  double* out_Point_retracted,
                  unsigned int out_Point_retracted_num_alloc,
                  size_t problem_size) {
  if (problem_size == 0) {
    return;
  }

  const int n_blocks = (problem_size + 1024 - 1) / 1024;
  PointRetractKernel<<<n_blocks, 1024>>>(Point,
                                         Point_num_alloc,
                                         delta,
                                         delta_num_alloc,
                                         out_Point_retracted,
                                         out_Point_retracted_num_alloc,
                                         problem_size);
}

}  // namespace caspar