/*-
 Author: Brian Tiffin
 Dedicated to the public domain

 Date started: January 2017
 Modified: 2017-01-08/06:16-0500

 Tectonics:
     gcc -o unilist.so -shared -fpic unilist.c
     unicon -s unilist.icn -x
+*/

/* unilist.c, trials with C functions and Unicon lists */
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include "icall.h"

/* access src/runtime/rstruct.r low level put */
void c_put(descriptor *, descriptor *);

/* some characters for random strings */
#define ALPHABET "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
#define ALPHASIZE (sizeof(ALPHABET) - 1)

/* replace all character positions with a random element from ALPHABET */
char *
randomize(char *str)
{
    int i;
    unsigned int rnd;
    static unsigned int seed;
    char *p = str;

    if (seed == 0) {
        seed = ((unsigned) time(NULL)<<8) ^ (unsigned)clock();
    }
    srand(seed++);
    while (*p) {
        rnd = rand() % ALPHASIZE;
        *p++ = (ALPHABET)[rnd];
    }
    return str;
}


/*
  Build out a heterogeneous list
*/
int
unilist(int argc, descriptor argv[])
{
    char *str;
    int len;
    int size;
    int limit;

    double dbl;

    descriptor listReturn;
    descriptor stringReturn;
    descriptor fileReturn;
    descriptor realReturn;

    /*
      Cheating, need list to work with
      todo: create your own list ya lazy git
    */
    ArgList(1);

    /* set a limit on randomized string lengths */
    ArgInteger(2);
    limit = IntegerVal(argv[2]);
    
    /* make a randomized string, 0 to limit, don't care about bias */
    size = 0;
    while (size < 1) {
        size = ((float)rand()) / RAND_MAX * limit+1;
    }

    str = malloc(size);
    if (!str) exit(1);
    memset(str, ' ', size);
    str[size-1] = '\0';
    len = size;
    randomize(str);

    /* add string to end of list */
    Protect(StringAddr(stringReturn) = alcstr(str, len), Error(306));
    StringLen(stringReturn) = len;
    c_put(&argv[1], &stringReturn);
    free(str);

    /* random real from [0, size], ignoring bias */
    dbl = ((double)rand() / (double)(RAND_MAX)) * (size-1);
    realReturn.dword = D_Real;
#if defined(DescriptorDouble)
    realReturn.vword.realval = dbl;
#else
    Protect(realReturn = alcreal(dbl), Error(307));
    realReturn.vword.bptr = (union block *)realReturn;
#endif
    /* add real to end of list */
    c_put(&argv[1], &realReturn);

    /* return string size */    
    RetInteger(size-1);
}