#include <stdio.h>
#include <stdlib.h>
#include <mpi.h>
#include <string.h>
#include "distribution_methods/block_distribution.h"
#include "CommDist.h"

void prepare_redistribution(int qty, int myId, int numP, int numO, int is_children_group, int is_intercomm, char **recv, struct Counts *s_counts, struct Counts *r_counts);
void check_requests(struct Counts s_counts, struct Counts r_counts, MPI_Request **requests, size_t *request_qty);

void sync_point2point(char *send, char *recv, int is_intercomm, int myId, struct Counts s_counts, struct Counts r_counts, MPI_Comm comm);
void sync_rma(char *send, char *recv, struct Counts r_counts, int tamBl, MPI_Comm comm, int red_method);
void sync_rma_lock(char *recv, struct Counts r_counts, MPI_Win win);
void sync_rma_lockall(char *recv, struct Counts r_counts, MPI_Win win);


void async_point2point(char *send, char *recv, struct Counts s_counts, struct Counts r_counts, MPI_Comm comm, MPI_Request *requests);

void perform_manual_communication(char *send, char *recv, int myId, struct Counts s_counts, struct Counts r_counts);

/*
 * Reserva memoria para un vector de hasta "qty" elementos.
 * Los "qty" elementos se disitribuyen entre los "numP" procesos
 * que llaman a esta funcion.
 */
void malloc_comm_array(char **array, int qty, int myId, int numP) {
    struct Dist_data dist_data;

    get_block_dist(qty, myId, numP, &dist_data);
    if( (*array = calloc(dist_data.tamBl, sizeof(char))) == NULL) {
      printf("Memory Error (Malloc Arrays(%d))\n", dist_data.tamBl); 
      exit(1); 
    }

/*
        int i;
	for(i=0; i<dist_data.tamBl; i++) {
	  (*array)[i] = '!' + i + dist_data.ini;
	}
	
        printf("P%d Tam %d String: %s\n", myId, dist_data.tamBl, *array);
*/
}

//================================================================================
//================================================================================
//========================SYNCHRONOUS FUNCTIONS===================================
//================================================================================
//================================================================================

/*
 * Performs a communication to redistribute an array in a block distribution.
 * In the redistribution is differenciated parent group from the children and the values each group indicates can be
 * different.
 *
 * - send (IN):  Array with the data to send. This data can not be null for parents.
 * - recv (OUT): Array where data will be written. A NULL value is allowed if the process is not going to receive data.
 *               If the process receives data and is NULL, the behaviour is undefined.
 * - qty  (IN):  Sum of elements shared by all processes that will send data.
 * - myId (IN):  Rank of the MPI process in the local communicator. For the parents is not the rank obtained from "comm".
 * - numP (IN):  Size of the local group. If it is a children group, this parameter must correspond to using
 *               "MPI_Comm_size(comm)". For the parents is not always the size obtained from "comm".
 * - numO (IN):  Amount of processes in the remote group. For the parents is the target quantity of processes after the 
 *               resize, while for the children is the amount of parents.
 * - is_children_group (IN): Indicates wether this MPI rank is a children(TRUE) or a parent(FALSE).
 * - comm (IN):  Communicator to use to perform the redistribution.
 *
 * returns: An integer indicating if the operation has been completed(TRUE) or not(FALSE). //FIXME In this case is always true...
 */
int sync_communication(char *send, char **recv, int qty, int myId, int numP, int numO, int is_children_group, int red_method, MPI_Comm comm) {
    int is_intercomm, aux_comm_used = 0;
    struct Counts s_counts, r_counts;
    struct Dist_data dist_data;
    MPI_Comm aux_comm = MPI_COMM_NULL;

    /* PREPARE COMMUNICATION */
    MPI_Comm_test_inter(comm, &is_intercomm);
    prepare_redistribution(qty, myId, numP, numO, is_children_group, is_intercomm, recv, &s_counts, &r_counts);

    /* PERFORM COMMUNICATION */
    switch(red_method) {

      case MALL_RED_RMA_LOCKALL:
      case MALL_RED_RMA_LOCK:
        if(is_children_group) {
          get_block_dist(qty, myId, numP, &dist_data);
	} else {
          get_block_dist(qty, myId, numO, &dist_data);
	}
        if(is_intercomm) {
          MPI_Intercomm_merge(comm, is_children_group, &aux_comm);
	  aux_comm_used = 1;
	} else { aux_comm = comm; }
        sync_rma(send, *recv, r_counts, dist_data.tamBl, aux_comm, red_method);
	break;

      case MALL_RED_POINT:
        sync_point2point(send, *recv, is_intercomm, myId, s_counts, r_counts, comm);
	break;
      case MALL_RED_BASELINE:
      default:
        MPI_Alltoallv(send, s_counts.counts, s_counts.displs, MPI_CHAR, *recv, r_counts.counts, r_counts.displs, MPI_CHAR, comm);
	break;
    }

    if(aux_comm_used) {
      MPI_Comm_free(&aux_comm);
    } 
    freeCounts(&s_counts);
    freeCounts(&r_counts);
    return 1; //FIXME In this case is always true...
}

/*
 * Performs a series of blocking point2point communications to redistribute an array in a block distribution. 
 * It should be called after calculating how data should be redistributed.
 *
 * - send (IN):  Array with the data to send. This value can not be NULL for parents.
 * - recv (OUT): Array where data will be written. A NULL value is allowed if the process is not going to 
 *               receive data. If the process receives data and is NULL, the behaviour is undefined.
 * - is_intercomm (IN): Indicates wether the communicator is an intercommunicator (TRUE) or an
 *               intracommunicator (FALSE).
 * - myId (IN):  Rank of the MPI process in the local communicator. For the parents is not the rank obtained from "comm".
 * - s_counts (IN): Struct which describes how many elements will send this process to each children and 
 *               the displacements.
 * - r_counts (IN): Structure which describes how many elements will receive this process from each parent 
 *               and the displacements.
 * - comm (IN):  Communicator to use to perform the redistribution.
 *
 */
void sync_point2point(char *send, char *recv, int is_intercomm, int myId, struct Counts s_counts, struct Counts r_counts, MPI_Comm comm) {
    int i, init, end;

    init = s_counts.idI;
    end = s_counts.idE;
    if(!is_intercomm && (s_counts.idI == myId || s_counts.idE == myId + 1)) {
      perform_manual_communication(send, recv, myId, s_counts, r_counts);

      if(s_counts.idI == myId) init = s_counts.idI+1;
      else end = s_counts.idE-1;
    }

    for(i=init; i<end; i++) {
      MPI_Send(send+s_counts.displs[i], s_counts.counts[i], MPI_CHAR, i, 99, comm);
    }

    init = r_counts.idI;
    end = r_counts.idE;
    if(!is_intercomm) {
      if(r_counts.idI == myId) init = r_counts.idI+1;
      else if(r_counts.idE == myId + 1) end = r_counts.idE-1;
    }
    for(i=init; i<end; i++) {
      MPI_Recv(recv+r_counts.displs[i], r_counts.counts[i], MPI_CHAR, i, 99, comm, MPI_STATUS_IGNORE);
    }
}

/*
 * Performs synchronous MPI-RMA operations to redistribute an array in a block distribution. Is should be called after calculating
 * how data should be redistributed
 *
 * - send (IN):  Array with the data to send. This value can not be NULL for parents.
 * - recv (OUT): Array where data will be written. A NULL value is allowed if the process is not going to receive data.
 *               If the process receives data and is NULL, the behaviour is undefined.
 * - r_counts (IN): Structure which describes how many elements will receive this process from each parent and the
 *               displacements.
 * - tamBl (IN): How many elements are stored in the parameter "send".
 * - comm (IN):  Communicator to use to perform the redistribution. Must be an intracommunicator as MPI-RMA requirements.
 * - red_method (IN): Type of data redistribution to use. In this case indicates the RMA operation(Lock or LockAll).
 *
 */
void sync_rma(char *send, char *recv, struct Counts r_counts, int tamBl, MPI_Comm comm, int red_method) {
  int aux_array_used;
  MPI_Win win;

  aux_array_used = 0;
  if(send == NULL) {
    tamBl = 1;
    send = malloc(tamBl*sizeof(char)); //TODO Check if the value can be NULL at WIN_create
    aux_array_used = 1;
  }
  MPI_Win_create(send, (MPI_Aint)tamBl, sizeof(char), MPI_INFO_NULL, comm, &win);

  switch(red_method) {
    case MALL_RED_RMA_LOCKALL:
      sync_rma_lockall(recv, r_counts, win);
      break;
    case MALL_RED_RMA_LOCK:
      sync_rma_lock(recv, r_counts, win);
      break;
  }

  MPI_Win_free(&win);
  if(aux_array_used) { 
    free(send);
    send = NULL;
  }
}



/*
 * Performs a passive MPI-RMA data redistribution for a single array using the passive epochs Lock/Unlock.
 * - recv (OUT): Array where data will be written. A NULL value is allowed if the process is not going to receive data.
 *               If the process receives data and is NULL, the behaviour is undefined.
 * - r_counts (IN): Structure which describes how many elements will receive this process from each parent and the
 *               displacements.
 * - win (IN):   Window to use to perform the redistribution.
 *
 */
void sync_rma_lock(char *recv, struct Counts r_counts, MPI_Win win) {
  int i, target_displs;

  target_displs = r_counts.first_target_displs;
  for(i=r_counts.idI; i<r_counts.idE; i++) {
    MPI_Win_lock(MPI_LOCK_SHARED, i, MPI_MODE_NOCHECK, win);
    MPI_Get(recv+r_counts.displs[i], r_counts.counts[i], MPI_CHAR, i, target_displs, r_counts.counts[i], MPI_CHAR, win);
    MPI_Win_unlock(i, win);
    target_displs=0;
  }
}


/*
 * Performs a passive MPI-RMA data redistribution for a single array using the passive epochs Lockall/Unlockall.
 * - recv (OUT): Array where data will be written. A NULL value is allowed if the process is not going to receive data.
 *               If the process receives data and is NULL, the behaviour is undefined.
 * - r_counts (IN): Structure which describes how many elements will receive this process from each parent and the
 *               displacements.
 * - win (IN):   Window to use to perform the redistribution.
 *
 */
void sync_rma_lockall(char *recv, struct Counts r_counts, MPI_Win win) {
  int i, target_displs;

  target_displs = r_counts.first_target_displs;
  MPI_Win_lock_all(MPI_MODE_NOCHECK, win);
  for(i=r_counts.idI; i<r_counts.idE; i++) {
    MPI_Get(recv+r_counts.displs[i], r_counts.counts[i], MPI_CHAR, i, target_displs, r_counts.counts[i], MPI_CHAR, win);
    target_displs=0;
  }
  MPI_Win_unlock_all(win);
}

//================================================================================
//================================================================================
//========================ASYNCHRONOUS FUNCTIONS==================================
//================================================================================
//================================================================================

/*
 * //TODO Añadir estrategia IBARRIER
 * Performs a communication to redistribute an array in a block distribution with non-blocking MPI functions.
 * In the redistribution is differenciated parent group from the children and the values each group indicates can be
 * different.
 *
 * - send (IN):  Array with the data to send. This data can not be null for parents.
 * - recv (OUT): Array where data will be written. A NULL value is allowed if the process is not going to receive data.
 *               If the process receives data and is NULL, the behaviour is undefined.
 * - qty  (IN):  Sum of elements shared by all processes that will send data.
 * - myId (IN):  Rank of the MPI process in the local communicator. For the parents is not the rank obtained from "comm".
 * - numP (IN):  Size of the local group. If it is a children group, this parameter must correspond to using
 *               "MPI_Comm_size(comm)". For the parents is not always the size obtained from "comm".
 * - numO (IN):  Amount of processes in the remote group. For the parents is the target quantity of processes after the 
 *               resize, while for the children is the amount of parents.
 * - is_children_group (IN): Indicates wether this MPI rank is a children(TRUE) or a parent(FALSE).
 * - comm (IN):  Communicator to use to perform the redistribution.
 * - requests (OUT): Pointer to array of requests to be used to determine if the communication has ended. If the pointer 
 *               is null or not enough space has been reserved the pointer is allocated/reallocated.
 * - request_qty (OUT): Quantity of requests to be used. If a process sends and receives data, this value will be 
 *               modified to the expected value.
 *
 * returns: An integer indicating if the operation has been completed(TRUE) or not(FALSE). //FIXME In this case is always false...
 */
int async_communication(char *send, char **recv, int qty, int myId, int numP, int numO, int is_children_group, int red_method, int red_strategies, MPI_Comm comm, MPI_Request **requests, size_t *request_qty) {
    int is_intercomm, aux_comm_used = 0;
    struct Counts s_counts, r_counts;
    MPI_Comm aux_comm = MPI_COMM_NULL;

    /* PREPARE COMMUNICATION */
    MPI_Comm_test_inter(comm, &is_intercomm);
    prepare_redistribution(qty, myId, numP, numO, is_children_group, is_intercomm, recv, &s_counts, &r_counts);
    check_requests(s_counts, r_counts, requests, request_qty);

    /* PERFORM COMMUNICATION */
    switch(red_method) {

      case MALL_RED_RMA_LOCKALL:
      case MALL_RED_RMA_LOCK:
	return MALL_DENIED; //TODO Realizar versiones asíncronas
      case MALL_RED_POINT:
        async_point2point(send, *recv, s_counts, r_counts, comm, *requests);
	break;
      case MALL_RED_BASELINE:
      default:
        MPI_Ialltoallv(send, s_counts.counts, s_counts.displs, MPI_CHAR, *recv, r_counts.counts, r_counts.displs, MPI_CHAR, comm, &((*requests)[0]));
	break;
    }

    /* POST REQUESTS CHECKS */
    if(is_children_group) {
      MPI_Waitall(*request_qty, *requests, MPI_STATUSES_IGNORE);
    }

    if(malleability_red_contains_strat(red_strategies, MALL_RED_IBARRIER, NULL)) { //FIXME Strategy not fully implemented
      MPI_Ibarrier(comm, &((*requests)[*request_qty-1]) ); //FIXME Not easy to read...
      if(is_children_group) {
        MPI_Wait(&((*requests)[*request_qty-1]), MPI_STATUSES_IGNORE); //FIXME Not easy to read...
      }
    }

    if(aux_comm_used) {
      MPI_Comm_free(&aux_comm);
    } 
    freeCounts(&s_counts);
    freeCounts(&r_counts);
    return 0; //FIXME In this case is always false...
}

/*
 * Performs a series of non-blocking point2point communications to redistribute an array in a block distribution. 
 * It should be called after calculating how data should be redistributed.
 *
 * - send (IN):  Array with the data to send. This value can not be NULL for parents.
 * - recv (OUT): Array where data will be written. A NULL value is allowed if the process is not going to 
 *               receive data. If the process receives data and is NULL, the behaviour is undefined.
 * - s_counts (IN): Struct which describes how many elements will send this process to each children and 
 *               the displacements.
 * - r_counts (IN): Structure which describes how many elements will receive this process from each parent 
 *               and the displacements.
 * - comm (IN):  Communicator to use to perform the redistribution.
 * - requests (OUT): Pointer to array of requests to be used to determine if the communication has ended.
 *
 */
void async_point2point(char *send, char *recv, struct Counts s_counts, struct Counts r_counts, MPI_Comm comm, MPI_Request *requests) {
    int i, j = 0;

    for(i=s_counts.idI; i<s_counts.idE; i++) {
      MPI_Isend(send+s_counts.displs[i], s_counts.counts[i], MPI_CHAR, i, 99, comm, &(requests[j]));
      j++;
    }

    for(i=r_counts.idI; i<r_counts.idE; i++) {
      MPI_Irecv(recv+r_counts.displs[i], r_counts.counts[i], MPI_CHAR, i, 99, comm, &(requests[j]));
      j++;
    }
}

/*
 * ========================================================================================
 * ========================================================================================
 * ================================DISTRIBUTION FUNCTIONS==================================
 * ========================================================================================
 * ========================================================================================
*/

/*
 * Performs a communication to redistribute an array in a block distribution. For each process calculates
 * how many elements sends/receives to other processes for the new group.
 *
 * - qty  (IN):  Sum of elements shared by all processes that will send data.
 * - myId (IN):  Rank of the MPI process in the local communicator. For the parents is not the rank obtained from "comm".
 * - numP (IN):  Size of the local group. If it is a children group, this parameter must correspond to using
 *               "MPI_Comm_size(comm)". For the parents is not always the size obtained from "comm".
 * - numO (IN):  Amount of processes in the remote group. For the parents is the target quantity of processes after the 
 *               resize, while for the children is the amount of parents.
 * - is_children_group (IN): Indicates wether this MPI rank is a children(TRUE) or a parent(FALSE).
 * - is_intercomm (IN): Indicates wether the used communicator is a intercomunicator(TRUE) or intracommunicator(FALSE).
 * - recv (OUT): Array where data will be written. A NULL value is allowed if the process is not going to receive data.
 *               process receives data and is NULL, the behaviour is undefined.
 * - s_counts (OUT): Struct where is indicated how many elements sends this process to processes in the new group.
 * - r_counts (OUT): Struct where is indicated how many elements receives this process from other processes in the previous group.
 *
 */
void prepare_redistribution(int qty, int myId, int numP, int numO, int is_children_group, int is_intercomm, char **recv, struct Counts *s_counts, struct Counts *r_counts) {
  int array_size, init_struct = 1;
  struct Dist_data dist_data;

  array_size = numO;
  if(!is_intercomm) {
    array_size = numP > numO ? numP : numO;
  }

  if(is_children_group) {
    if(is_intercomm) { 
      mallocCounts(s_counts, numO);
    } else { // Merge method needs an array equal to the number of processes
      mallocCounts(s_counts, array_size);
      mallocCounts(r_counts, array_size);
      init_struct = 0;
    }
    prepare_comm_alltoall(myId, numP, numO, qty, init_struct, r_counts);
    // Obtener distribución para este hijo
    get_block_dist(qty, myId, numP, &dist_data);
    *recv = malloc(dist_data.tamBl * sizeof(char));
//get_block_dist(qty, myId, numP, &dist_data);
//print_counts(dist_data, r_counts->counts, r_counts->displs, numO, 0, "Children C ");
  } else {
//get_block_dist(qty, myId, numP, &dist_data);

    if(is_intercomm) {
      mallocCounts(r_counts, numO);
      prepare_comm_alltoall(myId, numP, numO, qty, init_struct, s_counts);
    } else {
      mallocCounts(s_counts, array_size);
      mallocCounts(r_counts, array_size);
      init_struct = 0;

      prepare_comm_alltoall(myId, numP, numO, qty, init_struct, s_counts);
      if(myId < numO) {
        prepare_comm_alltoall(myId, numO, numP, qty, init_struct, r_counts);
        // Obtener distribución para este hijo
        get_block_dist(qty, myId, numO, &dist_data);
        *recv = malloc(dist_data.tamBl * sizeof(char));
      }

//print_counts(dist_data, r_counts->counts, r_counts->displs, array_size, 0, "Children P ");
    }
//print_counts(dist_data, s_counts->counts, s_counts->displs, numO, 0, "Parents ");
  }
}

/*
 * Ensures that the array of request of a process has an amount of elements equal to the amount of communication
 * functions the process will perform. In case the array is not initialized or does not have enough space it is
 * allocated/reallocated to the minimum amount of space needed.
 *
 * - s_counts (IN): Struct where is indicated how many elements sends this process to processes in the new group.
 * - r_counts (IN): Struct where is indicated how many elements receives this process from other processes in the previous group.
 * - requests (OUT): Pointer to array of requests to be used to determine if the communication has ended. If the pointer 
 *               is null or not enough space has been reserved the pointer is allocated/reallocated.
 * - request_qty (OUT): Quantity of requests to be used. If the value is smaller than the amount of communication
 *               functions to perform, it is modified to the minimum value.
 */
void check_requests(struct Counts s_counts, struct Counts r_counts, MPI_Request **requests, size_t *request_qty) {
  size_t i, sum;
  MPI_Request *aux;

  sum = (size_t) s_counts.idE - s_counts.idI;
  sum += (size_t) r_counts.idE - r_counts.idI;

  if (*requests != NULL && sum <= *request_qty) return; // Expected amount of requests

  // FIXME Si es la estrategia Ibarrier como se tiene en cuenta en el total??
  if (*requests == NULL) {
    *requests = (MPI_Request *) malloc(sum * sizeof(MPI_Request));
  } else { // Array exists, but is too small
    aux = (MPI_Request *) realloc(*requests, sum * sizeof(MPI_Request));
    *requests = aux;
  }

  if (*requests == NULL) {
    fprintf(stderr, "Fatal error - It was not possible to allocate/reallocate memory for the MPI_Requests before the redistribution\n");
    MPI_Abort(MPI_COMM_WORLD, 1);
  }

  for(i=0; i < sum; i++) {
    (*requests)[i] = MPI_REQUEST_NULL;
  }
  *request_qty = sum;
}


/*
 * Special case to perform a manual copy of data when a process has to send data to itself. Only used
 * when the MPI communication is not able to hand this situation. An example is when using point to point
 * communications and the process has to perform a Send and Recv to itself
 * - send (IN):  Array with the data to send. This value can not be NULL.
 * - recv (OUT): Array where data will be written. This value can not be NULL.
 * - myId (IN):  Rank of the MPI process in the local communicator. For the parents is not the rank obtained from "comm".
 * - s_counts (IN): Struct where is indicated how many elements sends this process to processes in the new group.
 * - r_counts (IN): Struct where is indicated how many elements receives this process from other processes in the previous group.
 */
void perform_manual_communication(char *send, char *recv, int myId, struct Counts s_counts, struct Counts r_counts) {
  int i;
  for(i=0; i<s_counts.counts[myId];i++) {
    recv[i+r_counts.displs[myId]] = send[i+s_counts.displs[myId]];
  }
}

/*
 * Función para obtener si entre las estrategias elegidas, se utiliza
 * la estrategia pasada como segundo argumento.
 *
 * Devuelve en "result" 1(Verdadero) si utiliza la estrategia, 0(Falso) en caso
 * contrario.
 */
int malleability_red_contains_strat(int comm_strategies, int strategy, int *result) {
  int value = comm_strategies % strategy ? 0 : 1;
  if(result != NULL) *result = value;
  return value;
}