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

#include <linux/random.h>
#include "xoroshiro128_plus.h"


int devrandom_getbytes(uint64_t dest[], size_t size)
{
    FILE *fp;
    int i=0;

    fp=fopen("/dev/urandom","r");

    if (fp==NULL)
	    return 1;

    while(i < size){
	    sprintf((void *) dest,"%s%02x",(void *) dest,fgetc(fp));
	    i++;
    }

    fclose(fp) ; 

    // invert the 2nd seed value to avoid similar reads from
    // urandom.
    dest[1] = 1 - dest[1] ;
    return 0 ;
}


void main() {
	// Simple test program for the xoroshiro128+ RNG

	// Define a seed.
	uint64_t seed[XOROSHIRO128_PLUS_SEED_LENGTH] ;


	uint64_t jump_seed[XOROSHIRO128_PLUS_SEED_LENGTH] ;

	// Use /dev/random on Linux to get some random bytes as a starting seed.
	if (devrandom_getbytes((void*)seed, sizeof(seed)) > 0) {
		printf("Error using /dev/urandom, using fixed seed.\n") ;
		seed[0] = 839482348329484L ;
		seed[1] = 585904385021312L ;
	}

	const int NUM = 10 ;
	// Print out a few 64-bit ints.
	printf("Some 64-bit ints: \n") ;
	for (int i = 0 ; i < NUM ; i++) {	
		printf("%lu\n",next(seed)) ;
	}
	// And now some doubles.
  	printf("\n Some doubles: \n") ;
	for (int i = 0 ; i < NUM ; i++) {	
		printf("%f\n",next_double(seed)) ;
	}
	// And finally some floats.
  	printf("\n Some floats: \n") ;
	for (int i = 0 ; i < NUM ; i++) {	
		printf("%f\n",next_float(seed)) ;
	}

	// Now jump
	jump(seed,jump_seed);

	// And printout a few more ...
	printf("Seed and jump seed output\n") ;
	for (int i = 0 ; i < NUM ; i++) {	
		printf("%lu  :   %lu\n",next(seed),next(jump_seed)) ;
	}

}