// Producer:
// Retransfers sinusoidal signal sampled at a frequency of 2kHz
// Writes to the circular buffer:
//   Write sample into the free buffer position
//   Incremets the free position by one
//   After idx = size go to the beginning

// Consumers:
// 

#include <fcntl.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <unistd.h>
#include <time.h>

#define PI 3.14

// void generate_signal(double *signal, int n_samples) {
// 	static double signal[n_samples];
// 	double step = 2.*PI/(double)n_samples;
// 	for (int i = 0; i < n_samples; ++i) {
// 		signal[i] = sin(i*step);
// 	}
// }

struct CircBuffer {
    union {
        struct {
    	   int size;
    	   int rd_idx;
    	   int wr_idx;
        } info;
        char padding[1024];
    };
    int data[1024];
};

void producer(const char * memory_name, int fd) {
	printf("The producer has been called\n");
	double signal[] = {0, 0.7, 1, 0.7, 0};

    struct CircBuffer *buffer;


	buffer = mmap(NULL, 64, PROT_WRITE, MAP_SHARED, fd, 0);
    if (buffer == MAP_FAILED) {
        fprintf(stderr, "mmap: ");
        exit(EXIT_FAILURE);
    }

    

    
}

int main(int argc, char *argv[]) {
	int buffer_size = 64;
	const char *memory_name = "/dsp";
	int fd = shm_open(memory_name, O_CREAT | O_RDWR, 0777);
    if (fd < 0) {
        fprintf(stderr, "shm_open: ");
        exit(EXIT_FAILURE);
    }
    printf("Shred memory file descriptor: %d\n", fd);


	// double *signal;
	// generate_signal(signal, 100);

	struct CircBuffer *buffer;

    if (ftruncate(fd, sizeof(struct CircBuffer)) < 0) {
        fprintf(stderr, "ftruncate: \n");
        exit(EXIT_FAILURE);
    }

    pid_t pid;
    pid = fork();
        if (pid == -1) {
        perror("fork: ");
        exit(EXIT_FAILURE);
    }
    if (pid == 0) {
        buffer = (struct CircBuffer *)mmap(NULL, sizeof(buffer), PROT_READ, MAP_SHARED, fd, 0);
        if (buffer == MAP_FAILED) {
            fprintf(stderr, "mmap: ");
            exit(EXIT_FAILURE);
        }
        exit(EXIT_SUCCESS);
    } else {
    	producer(memory_name, fd);
    }


	return 0;
}