#include <stdio.h>
#include <math.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>

#define FIFO "my_fifo"

void policz(FILE*output, float a, float b, float c)
{
    if(a!=0)//kwadratowe
    {
        fprintf(output, "%.2fx^2 + %.2fx + %.2f = 0 - ",a,b,c);
        float delta = b*b-4*a*c;

        if(delta<0)
            fprintf(output, "Brak rozwiazan(rzeczywistych)");
        else if(delta == 0)
            fprintf(output, "x1 = x2 = %.2f", -b/(2*a) );
        else
        {
            delta = sqrtf(delta);
            fprintf(output, "x1 = %.2f x2 = %.2f", (-b-delta)/(2*a), (-b+delta)/(2*a));
        }
    }
    else if(b!=0)//liniowe
    {
        fprintf(output, "%.2fx + %.2f = 0 - ",b,c);
        fprintf(output,"x = %f", -c/b);
    }
    else
    {
        fprintf(output, "%.2f = 0 - ",c);
        if(c==0)
            fprintf(output,"x nalezy do R");
        else
            fprintf(output,"Brak rozwiazan");
    }

    fprintf(output, "\n");

}


void PP1(FILE*input, int ilosc)
{
    FILE*fp;
    for(int i = 0;i<ilosc;i++)
    {
        fp = fopen(FIFO, "w");
        float a,b,c;
        fscanf(input, "%f %f %f", &a, &b, &c);
        printf("%f %f %f out from PP1\n", a,b,c);
        fflush(stdout);
        fprintf(fp, "%f %f %f", a,b,c);
        fclose(fp);

        sleep(1);
    }
}


void PP2(FILE*output, int ilosc)
{
    sleep(1);
    FILE*fp;
    for(int i = 0;i<ilosc;i++)
    {
        fp = fopen(FIFO, "r");
        float a,b,c;
        fscanf(fp, "%f %f %f", &a,&b,&c);
        printf("%f %f %f in PP2\n", a,b,c);
        policz(output, a,b,c);
        fclose(fp);
	}
}

int main(int argc, char *argv[])
{
    if(argc!=2)
    {
        printf("Zla ilosc argumentow!\n");
        return 1;
    }
    FILE*input = fopen(argv[1], "r+");
    if(input == NULL) {
        printf("Blad przy odczytywaniu pliku!\n");
        return 2;
    }
    else if(access ( argv[1], F_OK ) == -1)
    {
        printf("Brak dostepu!\n");
        return 3;
    }
    FILE* output = fopen("out.txt", "w+");
    if(output == NULL) {
        printf("Blad przy otwieraniu pliku do zapisu!\n");
        return 4;
    }

    umask(0);
    mkfifo(FIFO, 0666); //0 z przodu oznacza notacje ósemkowa


    int ilosc;
    fscanf(input, "%d", &ilosc);

    if(fork())
    {
        PP1(input, ilosc);
    }
    else
    {
        PP2(output, ilosc);
    }



    return 0;
}