#include "mat_mul.h"
//#include <algorithm>
#include <cstdlib>
#include <cstdio>
#include <pthread.h>

 #ifndef max
#define max(a,b)  (((a) > (b)) ? (a) : (b))
 #endif

 #ifndef min
 #define min(a,b)  (((a) < (b)) ? (a) : (b))
 #endif

static float *A, *B, *C;
static int M, N, K;
static int num_threads;

struct threadinfo
{
  int NumofThread;
  int idx;

};

int portion;



static void* mat_mul_thread(void *data) {
  // TODO: parallelize & optimize matrix multiplication
  threadinfo *thInfo=(threadinfo*)data;
  //printf("%s %d  %d %d created \n",__func__,__LINE__,thInfo->NumofThread,thInfo->idx);
  int totalthread=thInfo->NumofThread;
  int idx=thInfo->idx;
 

  int pid = thInfo->idx;

  int slice = M / num_threads;
  int start = pid * slice;
  int end = pid == num_threads - 1 ? M : (pid + 1) * slice;
  
  float Aik;
  int bs = 32;
  for (int kk = 0; kk < K; kk += bs) {
   // for (int jj = 0; jj < N; jj += bs) {
      for (int i = start; i < end; ++i) {
        for (int k = kk; k < min(kk + bs, K); ++k) {//blocking 
        //  for(int k=0; k<K;++k){
          Aik = A[i * K + k];
         // for (int j = jj; j < min(jj + bs, N); ++j) {//blocking
            for (int j = 0; j < N; ++j){
            C[i * N + j] += Aik * B[k * N + j];
          }
        }
      }
   // }
  }

  return NULL;
}

void mat_mul(float *_A, float *_B, float *_C, int _M, int _N, int _K, int _num_threads) {
  A = _A, B = _B, C = _C;
  M = _M, N = _N, K = _K;

  // TODO: create '_num_threads' pthreads
  num_threads = _num_threads;

  threadinfo *thInfo[81];//thread structure;
  for(int i=0;i<num_threads;i++)
  {
    thInfo[i]= (threadinfo *)malloc(sizeof(threadinfo));
    thInfo[i]->NumofThread = num_threads;

  }
  pthread_t thread[81];

  if(M % num_threads==0)
  {
      portion=M/num_threads;
  }
  else{
      portion=M/num_threads+1;
  }

  for(int i=0;i<num_threads;i++)
  {
    thInfo[i]->idx =i; 
    pthread_create(&thread[i], NULL, mat_mul_thread, (void *)thInfo[i]);
  }
  for(int i=0;i<num_threads;i++)
    pthread_join(thread[i], NULL);

  for(int i=0;i<num_threads;i++)
    free(thInfo[i]);
}