#include <stdio.h>
#include <mpi.h>
#include <math.h>
#define PRECISION 0.0000001
#define RANGESIZE 0.1
#define DATA 0
#define RESULT 1
#define FINISH 2
#define PI 3.14159265359
//#define DEBUG
struct moja
{
	double range1;
	double range2;
	int dlakogo;
	int czyProcessed;
}kolejka[100];
int countKolejki = 0;

void wlozNaKolejke(double wartosc, double wartosc2, int proc)
{
	kolejka[countKolejki].czyProcessed = 0;
	kolejka[countKolejki].range1 = wartosc;
	kolejka[countKolejki].range2 = wartosc2;
	kolejka[countKolejki].dlakogo = proc;
	countKolejki++;
}

int getYourElement(int rank)
{
	for (int i = 0; i < countKolejki + 1; i++)
	{
		if (kolejka[i].czyProcessed == 0 && kolejka[i].dlakogo == rank)
		{
			kolejka[i].czyProcessed = 1;
			return i;
		}
	}
	return -1;
}

double f(double x) {
	return sin(x);
}


double SimpleIntegration(double a, double b) {
	double i;
	double sum = 0;
	int liczbaOdebranych = 0;
	for (i = a; i < b; i += PRECISION)
		sum += f(i)*PRECISION;
	return sum;
}
int main(int argc, char **argv) {
	int myrank, proccount;
	double a = 1, b = 10*PI;
	double range[2];
	double result = 0, resulttemp;
	int sentcount = 0;
	int receivedcount = 0;
	int i;
	MPI_Status status;
	MPI_Request r;
	// Initialize MPI
	MPI_Init(&argc, &argv);
	// find out my rank
	MPI_Comm_rank(MPI_COMM_WORLD, &myrank);
	// find out the number of processes in MPI_COMM_WORLD
	MPI_Comm_size(MPI_COMM_WORLD, &proccount);
	if (proccount < 2) {
		printf("Run with at least 2 processes");
		MPI_Finalize();
		return -1;
	}
	if (((b - a) / RANGESIZE) < 2 * (proccount - 1)) {
		printf("More subranges needed");
		MPI_Finalize();
		return -1;
	}
	// now the master will distribute the data and slave processes will perform computations

	if (myrank == 0) {
		range[0] = a;

		//moje

		i = 0;
		do
		{
			i++;
			if (i == proccount)
			{
				i = 1;
			}
			range[1] = range[0] + RANGESIZE;
			MPI_Send(&range, 2, MPI_DOUBLE, i, DATA, MPI_COMM_WORLD);
		//	printf("Wyslalem range %f,%f do nr: %d\n", range[0], range[1], i);
			wlozNaKolejke(range[0], range[1], i);
			sentcount++;
			range[0] = range[1];
		} while (range[1]+ RANGESIZE < b);
		range[0] = range[1];
		range[1] = b;
		MPI_Send(&range, 2, MPI_DOUBLE, i, DATA, MPI_COMM_WORLD);
		while (sentcount != receivedcount) {
			MPI_Recv(&resulttemp, 1, MPI_DOUBLE, MPI_ANY_SOURCE, RESULT, MPI_COMM_WORLD, &status);
			receivedcount++;
			printf("\nMaster dostal wynik %f from process %d", resulttemp, status.MPI_SOURCE);
			result += resulttemp;
		}

		// shut down the slaves
		for (i = 1; i < proccount; i++) {
			MPI_Send(NULL, 0, MPI_DOUBLE, i, FINISH, MPI_COMM_WORLD);
		}
		// now display the result
		printf("\n\n\n\n\n\n\nHi, I am process 0, the result is %f\n", result);

	}
	else
	{
		double lastEndRange;
		double range3[3];
		int flag = 0;
		do {
			MPI_Iprobe(0, MPI_ANY_TAG, MPI_COMM_WORLD, &flag, &status);
			MPI_Irecv(range3, 2, MPI_DOUBLE, 0, DATA, MPI_COMM_WORLD, &r);
			if (lastEndRange != range3[1])
			{
			//	printf("Slave %d received subrange %f %f\n", myrank, range3[0], range3[1]);
				if(range3[0] !=0 && range3[1] != 0)
					wlozNaKolejke(range3[0], range3[1], myrank);

				//licz dziwko
				int indeks = getYourElement(myrank);
				if (indeks != -1)
				{
					resulttemp = SimpleIntegration(kolejka[i].range1, kolejka[i].range2);
					printf("Slave %d sending result %f %f", myrank, range3[0], range3[1]);
					lastEndRange = range3[1];
					MPI_Isend(&resulttemp, 1, MPI_DOUBLE, 0, RESULT, MPI_COMM_WORLD, &r);
				}
			}

			/*	for (int i = 0; i<countKolejki; i++)
				{
					if (kolejka[i].dlakogo == myrank)
					{
						printf("Otrzymalem zadanie dla %d\n", myrank);
					}
				}*/
		} while (status.MPI_TAG != FINISH);
		/*

		do {
			MPI_Iprobe(0, MPI_ANY_TAG, MPI_COMM_WORLD, &flag, &status);
			if (status.MPI_TAG == DATA)
			{
				MPI_Irecv(range, 2, MPI_DOUBLE, 0, DATA, MPI_COMM_WORLD, &status);
				printf("Otrzymalem range %f,%f w nr: %d\n", range[0], range[1], myrank);

				//wloz na kolejke
				//oblicz nastepny element ktory nie jest processed

				//odeslij

			//	resulttemp = SimpleIntegration(range[0], range[1]);
			}
		}
		while (status.MPI_TAG != FINISH);
		*/
	}
	MPI_Finalize();
	return 0;
}