/**
 * A Little program to print the contents of an array
 * But this version has been expanded to be anything but
 * little.  All of the expansions are in pursuit of genericness
 * of the the printing
 * 
 * @author gtowell
 * Created: April 16, 2021
 * Modified: April 21, 2021
 * **/

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#ifndef NULL
#define NULL (void *)0
#endif

/**
 * Print the contents of the structure into a string that is passed into 
 * the function. This avoids awkward problems with free and malloc
 * @param item -- the thing to be printed
 * @param printInto -- the string to be modified 
 * **/
void pprinter4(void * item, char* printInto) {
    char *citem = (char *)item;
    sprintf(printInto, "[%c]", *citem);
}

/**
 * print array of structs using the pprinter4
  * @param base -- a pointer to the start of the array -- or at
 * least the start of the portion of the array to be printed
 * @param nmemb -- the number of item in the array (or at least 
 * the number of items to be printed)
 * @param size -- the number of bytes of the items in the array
 * @param f - function pointer to a function of type pprinter4 
* **/
void parray4(void * base, size_t nmemb, size_t size, void(*f)(void*, char*)) {
    char aa[100];
    for (int i = 0; i < nmemb; i++)
    {
        f(base, aa);
        printf("%s ", aa);
        base += size;
    }
    printf("\n");
}

/**
 * print structure into a string and return the string
 * @param -- the struct to be printed
 * @return -- a string rep of the struct 
* **/
char * pprinter3(void * item) {
    char *citem = (char *)item;
    char *rtn = malloc(6 * sizeof(char));
    sprintf(rtn, "<%c>", *citem);
    return rtn;
}

/**
 * print array of structs using the pprinter3
  * @param base -- a pointer to the start of the array -- or at
 * least the start of the portion of the array to be printed
 * @param nmemb -- the number of item in the array (or at least 
 * the number of items to be printed)
 * @param size -- the number of bytes of the items in the array
 * @param f - function pointer to a function of type pprinter3 
* **/
void parray3(void * base, size_t nmemb, size_t size, char*(*f)(void *)) {
    for (int i = 0; i < nmemb; i++) {
        char *tmp = f(base);
        printf("%s ", tmp);
        base += size;
        free(tmp);
    }
    printf("\n");
}


/**
 * A ridiculously complex way to print an array, but almost
 * generic and, even better, it follows qsort
 * @param base -- a pointer to the start of the array -- or at
 * least the start of the portion of the array to be printed
 * @param nmemb -- the number of item in the array (or at least 
 * the number of items to be printed)
 * @param size -- the number of bytes of the items in the array
 * @param fmt -- a formatting string 
 * **/
void parray2(void * base, size_t nmemb, size_t size, char* fmt) {
    for (int i = 0; i < nmemb; i++) {
        char c = *((char *)base);
        printf(fmt, c);
        base += size;
    }
    printf("\n");
}

int main(int argc, char const *argv[]) {
    srand(time(NULL));
    char aa[100];
    for (int i = 0; i < 100; i++)
        aa[i] = 'a' + (rand() % 26);
    parray2(aa, 100, sizeof(char), "%c");
    parray3(aa, 10, sizeof(char), pprinter3);
    parray4(aa, 10, sizeof(char), pprinter4);

}