#include <iostream>
#include <stdlib.h>
#include <mpi.h>
#include <time.h>

using std::cout;
using std::cin;

using namespace std;

int mpi_Gather(int* send_data, int send_count, MPI_Datatype send_datatype, int* recv_data, int recv_count, MPI_Datatype recv_datatype, int root, MPI_Comm communicator)
{
	int myid, numprocs;
	int* tmp = new int[send_count];
	MPI_Status status;
	MPI_Comm_rank(MPI_COMM_WORLD, &myid);
	MPI_Comm_size(MPI_COMM_WORLD, &numprocs);

	int index = 0;
	if (myid != root)
	{
		MPI_Send(send_data, send_count, MPI_INT, root, 99, MPI_COMM_WORLD);
	}
	else
	{
		for (int i = 0; i < send_count; i++)
		{
			recv_data[index] = send_data[i];
			index++;
		}
		for (int i = 1; i < numprocs; i++)
		{
			MPI_Recv(tmp, recv_count, MPI_INT, i, 99, MPI_COMM_WORLD, &status);
			for (int j = 0; j < send_count; j++)
			{
				recv_data[index] = *tmp;
				*(++tmp);
				index++;
			}
		}
	}
	return 0;
}

int main(int argc, char **argv) {
	int size, rank;
	int rcvData1;
	int rcvData2;
	int *global_array = NULL;
	MPI_Status status;


	MPI_Init(&argc, &argv);
	MPI_Comm_size(MPI_COMM_WORLD, &size);
	MPI_Comm_rank(MPI_COMM_WORLD, &rank);
	srand(time(NULL));

	int a = (size -1)/2;
	int b = a+1;
	int tableSize = a;

	//initialization of global_array in the memory of process 0
	if (rank == 0) {
		global_array = new int[tableSize];

		for (int i = 0; i < tableSize; i++) {
			global_array[i] = rand() % 100 + 1;
			int liczba = global_array[i];
			if (i == 0) {
				continue;
			}
			MPI_Send(&liczba, 1, MPI_INT, i, 99, MPI_COMM_WORLD);
		}
		rcvData1 = global_array[0];
		rcvData2 = global_array[0];
		cout << "Proces A" << rank + 1 << " otrzymal: " << rcvData1 << " oraz: " << rcvData2 << endl;
		/*for (int i = 0; i < tableSize; i++) {
			cout << global_array[i] << endl;
		}*/

		//MPI_Send(&rcvData1, 1, MPI_INT, tableSize + rank, 99, MPI_COMM_WORLD);
		//MPI_Send(&rcvData2, 1, MPI_INT, tableSize + rank + 1, 99, MPI_COMM_WORLD);
	}


	if (rank < a && rank != 0)
	{
		MPI_Recv(&rcvData1, 1, MPI_INT, 0, 99, MPI_COMM_WORLD, &status);
		rcvData2 = rcvData1;
		cout << "Proces A" << rank + 1<< " otrzymal: " << rcvData1 << " oraz: " << rcvData2 << endl;
		//MPI_Send(&rcvData1, 1, MPI_INT, tableSize + rank, 99, MPI_COMM_WORLD);
		//MPI_Send(&rcvData1, 1, MPI_INT, tableSize + rank + 1, 99, MPI_COMM_WORLD);
	}
	//Koniec inicjalizacji

	//Początek algorytmu
	for (int i = 0; i < a * 2 ; i++) {
		if (rank < a) {
			if (rcvData1 < rcvData2) {
				MPI_Send(&rcvData1, 1, MPI_INT, tableSize + rank, 99, MPI_COMM_WORLD);
				MPI_Send(&rcvData2, 1, MPI_INT, tableSize + rank + 1, 99, MPI_COMM_WORLD);
				cout << "wysylam do procesu B" << rank << " oraz do B" << rank + 1 << endl;
			}
			else {
				MPI_Send(&rcvData1, 1, MPI_INT, tableSize + rank + 1, 99, MPI_COMM_WORLD);
				MPI_Send(&rcvData2, 1, MPI_INT, tableSize + rank, 99, MPI_COMM_WORLD);
				cout << "wysylam do procesu B" << rank << " oraz do B" << rank + 1 << endl;
			}
			MPI_Recv(&rcvData1, 1, MPI_INT, tableSize + rank, 99, MPI_COMM_WORLD, &status);
			MPI_Recv(&rcvData2, 1, MPI_INT, tableSize + rank + 1, 99, MPI_COMM_WORLD, &status);
			cout << "W iteracji Proces A" << rank +1 << " otrzymal: " << rcvData1 << " oraz: " << rcvData2 << endl;
		}
		if (rank >= a)
		{
			//pierwszy b
			if (rank == a)
			{
				MPI_Recv(&rcvData1, 1, MPI_INT, 0, 99, MPI_COMM_WORLD, &status);
				cout << "Proces B" << rank - a << " otrzymal: " << rcvData1 << endl;
				MPI_Send(&rcvData1, 1, MPI_INT, 0, 99, MPI_COMM_WORLD);

			}//ostatni b
			else if (rank == a + b -1)
			{
				MPI_Recv(&rcvData1, 1, MPI_INT, a - 1, 99, MPI_COMM_WORLD, &status);
				cout << "Proces B" << rank - a << " otrzymal: " << rcvData1 << endl;
				MPI_Send(&rcvData1, 1, MPI_INT, a - 1, 99, MPI_COMM_WORLD);
			}
			else
			{
				MPI_Recv(&rcvData1, 1, MPI_INT, rank - a - 1, 99, MPI_COMM_WORLD, &status);
				MPI_Recv(&rcvData2, 1, MPI_INT, rank - a, 99, MPI_COMM_WORLD, &status);
				cout << "Proces B" << rank - a<< " otrzymal: " << rcvData1 << " oraz: " << rcvData2 << endl;
				if (rcvData1 < rcvData2) {
					MPI_Send(&rcvData1, 1, MPI_INT, rank - a - 1, 99, MPI_COMM_WORLD);
					MPI_Send(&rcvData2, 1, MPI_INT, rank - a, 99, MPI_COMM_WORLD);
				}
				else {
					MPI_Send(&rcvData1, 1, MPI_INT, rank - a, 99, MPI_COMM_WORLD);
					MPI_Send(&rcvData2, 1, MPI_INT, rank - a - 1, 99, MPI_COMM_WORLD);
				}

			}

		}
	}
	if (rank < a && rank != 0) {
		MPI_Send(&rcvData1, 1, MPI_INT, 0, 99, MPI_COMM_WORLD);
	}
	if (rank == 0) {
		for (int i = 1; i < a; i++) {
			MPI_Recv(&global_array[i], 1, MPI_INT, i, 99, MPI_COMM_WORLD, &status);
		}
		global_array[0] = rcvData1;
		cout << "Posortowana tabela" << endl;
		for (int i = 0; i < tableSize; i++) {
			cout << global_array[i] << endl;
		}

	}

	//if (rank >= a)
	//{
	//	//pierwszy b
	//	if (rank == a)
	//	{
	//		//MPI_Recv(&rcvData1, 1, MPI_INT, 0, 99, MPI_COMM_WORLD, &status);
	//		//MPI_Send(&rcvData1, 1, MPI_INT, 0, 99, MPI_COMM_WORLD);

	//	}//ostatni b
	//	else if (rank == a + b - 1)
	//	{
	//		//MPI_Recv(&rcvData1, 1, MPI_INT, a + b - 1, 99, MPI_COMM_WORLD, &status);
	//		//MPI_Send(&rcvData1, 1, MPI_INT, a + b - 1, 99, MPI_COMM_WORLD);
	//	}
	//	else
	//	{
	//		//MPI_Recv(&rcvData2, 1, MPI_INT, rank - a, 99, MPI_COMM_WORLD, &status);
	//		//MPI_Recv(&rcvData1, 1, MPI_INT, rank - a - 1, 99, MPI_COMM_WORLD, &status);


	//	}

	//}
	//cout << "Koniec " << rank << endl;

	MPI_Finalize();
	return 0;
}