#include "convolution.h"
#include "util.h"
#include <mpi.h>
#include <stdio.h>


static float *input, *output, *filter;
static int N, C, H, W;
static int K, R, S;
static int OH, OW;
static int pad;
static int dilation;
static int stride;
static int mpi_rank, mpi_world_size;

void convolution(
    float *_input, float *_output, float *_filter, 
    int _N, int _C, int _H, int _W,
    int _K, int _R, int _S,
    int _pad, int _dilation, int _stride) {
  input = _input;
  output = _output;
  filter = _filter;

  int num_threads = 200;

  OH = (H + 2 * pad - dilation * (R - 1) - 1) / stride + 1;
  OW = (W + 2 * pad - dilation * (S - 1) - 1) / stride + 1;

  if (mpi_rank != 0) {
    alloc_tensor(&input, N, C, H, W);
    alloc_tensor(&output, N, K, OH, OW);
    alloc_tensor(&filter, K, C, R, S);
  }

  int ns[mpi_world_size], ne[mpi_world_size];
  for (int i = 0; i < mpi_world_size; i++) {
    ns[i] = N / mpi_world_size * i;
    ne[i] = N / mpi_world_size * (i + 1);
  }
  ne[mpi_world_size - 1] = N;

  if (mpi_world_size > 1) {
    if (mpi_rank == 0) {
      for (int i = 1; i < mpi_world_size; i++) {
        MPI_Send(input + ns[i] * C * H * W, (ne[i] - ns[i]) * C * H * W, MPI_FLOAT, i, 0,
            MPI_COMM_WORLD);
        MPI_Send(filter, K * C * R * S, MPI_FLOAT, i, 0, MPI_COMM_WORLD);
      }
    } else {
      MPI_Recv(input + ns[mpi_rank] * C * H * W, (ne[mpi_rank] - ns[mpi_rank]) * C * H * W, MPI_FLOAT,
          0, 0, MPI_COMM_WORLD, nullptr);
      MPI_Recv(filter, K * C * R * S, MPI_FLOAT, 0, 0, MPI_COMM_WORLD, nullptr);
    }
  }

  
#pragma omp parallel for num_threads(num_threads) collapse (3) schedule(auto)
  for (int n = ns[mpi_rank]; n < ne[mpi_rank]; ++n) {
    for (int k = 0; k < K; ++k) {
      for (int oh = 0; oh < OH; ++oh) {
        for (int ow = 0; ow < OW; ++ow) {
          float o = 0.f;
          for (int c = 0; c < C; ++c) {
            for (int r = 0; r < R; ++r) {
              for (int s = 0; s < S; ++s) {
                int h = oh * stride - pad + r * dilation;
                int w = ow * stride - pad + s * dilation;
                if (h < 0 || h >= H || w < 0 || w >= W) continue;
                float i = input[n * C * H * W + c * H * W + h * W + w];
                float f = filter[k * C * R * S + c * R * S + r * S + s];
                o += i * f;
              }
            }
          }
          output[n * K * OH * OW + k * OH * OW + oh * OW + ow] = o;
        }
      }
    }
  }
  
  if (mpi_world_size > 1) {
    if (mpi_rank == 0) {
      for (int i = 1; i < mpi_world_size; i++) {
        MPI_Recv(output + ns[i] * K * OH * OW, (ne[i] - ns[i]) * K * OH * OW, MPI_FLOAT, i, 0,
            MPI_COMM_WORLD, nullptr);
      }
    } else {
      MPI_Send(output + ns[mpi_rank] * K * OH * OW, (ne[mpi_rank] - ns[mpi_rank]) * K * OH * OW, MPI_FLOAT, 0, 0, MPI_COMM_WORLD);
    }
  }
}

void convolution_init(
    int _N, int _C, int _H, int _W,
    int _K, int _R, int _S,
    int _pad, int _dilation, int _stride) {
  N = _N; C = _C; H = _H; W = _W;
  K = _K; R = _R; S = _S;
  pad = _pad;
  dilation = _dilation;
  stride = _stride;

  MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank);
  MPI_Comm_size(MPI_COMM_WORLD, &mpi_world_size);
/*
  OH = (H + 2 * pad - dilation * (R - 1) - 1) / stride + 1;
  OW = (W + 2 * pad - dilation * (S - 1) - 1) / stride + 1;

  if (mpi_rank != 0) {
    alloc_tensor(&input, N, C, H, W);
    alloc_tensor(&output, N, K, OH, OW);
    alloc_tensor(&filter, K, C, R, S);
  }
*/
}

void convolution_final(
    int _N, int _C, int _H, int _W,
    int _K, int _R, int _S,
    int _pad, int _dilation, int _stride) {
}