//
// Created by bruno on 6.2.2025.
//

#include "hexdump.h"
#include <stdio.h>
#include <ctype.h>
#include <malloc.h>

#define BYTES_PER_LINE 16  // Adjust for different widths


char *hexdump_to_string(const unsigned char *data, size_t size) {
    // Estimate max output size: each line is approx. 80 chars
    size_t estimated_size = (size / BYTES_PER_LINE + 1) * 80;

    // Allocate memory for output string
    char *output = malloc(estimated_size);
    if (!output) return NULL;

    size_t offset = 0; // Track the write position

    for (size_t i = 0; i < size; i += BYTES_PER_LINE) {
        offset += snprintf(output + offset, estimated_size - offset, "%08zx   ", i);

        // Print hex values
        for (size_t j = 0; j < BYTES_PER_LINE; j++) {
            if (i + j < size)
                offset += snprintf(output + offset, estimated_size - offset, "%02x ", data[i + j]);
            else
                offset += snprintf(output + offset, estimated_size - offset, "   "); // Padding
            if (j == 7) offset += snprintf(output + offset, estimated_size - offset, " "); // Extra space
        }

        offset += snprintf(output + offset, estimated_size - offset, " |");

        // Print ASCII representation
        for (size_t j = 0; j < BYTES_PER_LINE; j++) {
            if (i + j < size)
                offset += snprintf(output + offset, estimated_size - offset, "%c",
                                   isprint(data[i + j]) ? data[i + j] : '.');
            else
                offset += snprintf(output + offset, estimated_size - offset, " ");
        }

        offset += snprintf(output + offset, estimated_size - offset, "|\n");
    }

    return output;
}