#include "a3.h"
#include <stdio.h>
#include <memory.h>
#include <malloc.h>
#include <stdint.h>

void memdump(unsigned char *string) {
    printf("ADDR\t\t00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F  0123456789ABCDEF\n");

    int columns = 16;
    int rows = 4;
    char symbols[columns * rows];

    if((long) string % 16 != 0) {
        string = string - ((long) string % 16);
    }


    for(int i = 0; i < rows; i++) {
        printf("%p\t", (void *) &string[i * columns]);//print address

        if((long) string % 16 != 0) {
            printf("oh nein, kein mod 16");
        }


        for (int j = i * columns; j < (i + 1) * columns; j++) {
            printf("%02x ", string[j]);//print char number
            if(string[j] < 0x20 || string[j] > 0x7e)//check for printable characters
                symbols[j] = '.';
            else symbols[j] = string[j];
        }
        printf(" ");

        //print characters
        for (int j = i * columns; j < (i + 1) * columns; j++) {
            printf("%c", symbols[j]);
        }
        printf("\n");
    }
}


int memreplace(char *string, char cin, char cout, char **caddr) {
    int found = 0;
    for (int i = 0; i < strlen(string); ++i) {
        //if char is to be replaced
        if(string[i] == cin) {
            string[i] = cout;//replace char
            found++;
            *caddr = &string[i];//setting last found address
        }
    }
    return found;
}

int main(int argc, char **argv) {
    if(argc != 4) {
        printf("Not enough arguments or to many arguments");
        return -1;
    }

    memdump((unsigned char *) argv[0]);

    printf("\tLaenge der Zeichenkette (inkl \\0): %i Byte(s)\n", (int) strlen(argv[1]));
    printf("\tErsetzen: '%c' mit '%c'\n", *argv[2], *argv[3]);

    unsigned char *copy = malloc(4 * 16 * sizeof(char));//allocate memory for all chars
    strcpy((char *) copy, argv[1]);

    char *lastAddress = NULL;
    int count = memreplace((char *) copy, *argv[2], *argv[3], &lastAddress);
    printf("\tSuchzeichen wurde %i mal gefunden und ersetzt\n", count);
    printf("\tzuletzt an Addresse %p \n", (void *) lastAddress);
    memdump(copy);

    free(copy);

    return 0;
}