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

// Function declarations
void byteArrayToHexString_point(const unsigned char* byteArray, size_t length, char* hexString);
void byteArrayToHexString_snprintf(const unsigned char* byteArray, size_t length, char* hexString);
void byteArrayToHexString_idx(const unsigned char* byteArray, size_t length, char* hexString);

int main() {
    // Example large byte array
    size_t length = 256; // 1 million bytes
    unsigned char *byteArray = (unsigned char*)malloc(length * sizeof(unsigned char));
    for (size_t i = 0; i < length; i++) {
        byteArray[i] = i % 256; // Filling with example data
    }

    // Allocate memory for the hex string (2 characters per byte + 1 for the null terminator)
    char* hexString = (char*)malloc((length * 2 + 1) * sizeof(char));
    if (hexString == NULL || byteArray == NULL) {
        fprintf(stderr, "Memory allocation failed\n");
        return EXIT_FAILURE;
    }

    int loop_times=1000;

    // Measure the time taken for the conversion
    clock_t start = clock();
    for(int i=0; i<loop_times; i++)
    {
    	byteArrayToHexString_point(byteArray, length, hexString);
    }
    clock_t end = clock();

    // Print the time taken
    double time_spent = (double)(end - start) / CLOCKS_PER_SEC;
    printf("byteArrayToHexString_point Time taken: %f seconds\n", time_spent/loop_times);

    start = clock();
    for(int i=0; i<loop_times; i++)
    {
	    byteArrayToHexString_snprintf(byteArray, length, hexString);
    }
    end = clock();

    // Print the time taken
    time_spent = (double)(end - start) / CLOCKS_PER_SEC;
    printf("byteArrayToHexString_snprintf: Time taken: %f seconds\n", time_spent/loop_times);

    start = clock();
    for(int i=0; i<loop_times; i++)
    {
	    byteArrayToHexString_idx(byteArray, length, hexString);
    }
    end = clock();

    // Print the time taken
    time_spent = (double)(end - start) / CLOCKS_PER_SEC;
    printf("byteArrayToHexString_idx Time taken: %f seconds\n", time_spent/loop_times);



    // Free the allocated memory
    free(hexString);
    free(byteArray);

    return 0;
}

// Function to convert byte array to hex string
void byteArrayToHexString_point(const unsigned char* byteArray, size_t length, char* hexString) {
    const char hexChars[] = "0123456789abcdef";
    char* ptr = hexString;
    
    for (size_t i = 0; i < length; i++) {
        *ptr++ = hexChars[(byteArray[i] >> 4) & 0x0F];
        *ptr++ = hexChars[byteArray[i] & 0x0F];
    }
    *ptr = '\0';  // Null-terminate the string
}

// Function to convert byte array to hex string
void byteArrayToHexString_snprintf(const unsigned char* byteArray, size_t length, char* hexString) {
    for (size_t i = 0; i < length; i++) {
        sprintf(hexString + (i * 2), "%02x", byteArray[i]);
    }
    hexString[length * 2] = '\0';  // Null-terminate the string
}

void byteArrayToHexString_idx(const unsigned char* byteArray, size_t length, char* hexString) {
    const char hexChars[] = "0123456789abcdef";
    for (size_t i = 0; i < length; i++) {
        hexString[i * 2] = hexChars[(byteArray[i] >> 4) & 0x0F];
        hexString[i * 2 + 1] = hexChars[byteArray[i] & 0x0F];
    }
    hexString[length * 2] = '\0';  // Null-terminate the string
}