#include "itoa.h"

/*
 * The heapless_itoa function is copied from the shellmatta project.
 */

/**
 * @brief           itoa like function to convert int to an ascii string
 * @warning         you have to provide a large enough buffer
 * @param[in]       value
 * @param[in,out]   buffer
 * @param[in]       base
 * @return          number of bytes in string
 */
uint32_t heapless_itoa(int32_t value, char *buffer, uint32_t base)
{
    char tempBuffer[34u];
    uint32_t i;
    uint32_t bufferIdx = 0u;
    int8_t digitValue;

    /** -# check the base for plausibility */
    if((base >= 2) && (base <= 16))
    {
        /** -# check for sign */
        if(value < 0)
        {
            value       = value * (-1);
            buffer[0u]  = '-';
            bufferIdx   += 1u;
        }

        /** -# loop through all digits in reverse order */
        i = 0u;
        do
        {
            digitValue = (int8_t) (value % base);
            tempBuffer[i] = (digitValue < 10) ? ('0' + digitValue) : ('A' + (digitValue - 10));
            value /= base;
            i ++;
        }while(value > 0);

        /** -# store the string in the correct order onto the buffer */
        while(i > 0u)
        {
            buffer[bufferIdx] = tempBuffer[i - 1u];
            i --;
            bufferIdx ++;
        }
    }
    return bufferIdx;
}

static char num_to_hex_digit(uint8_t num, bool capitalized)
{
	char ret = 'U';

	switch (num) {
	case 0 ... 9:
		ret = '0' + num;
		break;
	case 0xA ... 0xF:
		if (capitalized)
			ret = 'A' + num - 0xA;
		else
			ret = 'a' + num - 0xA;
		break;
	default:
		break;
	}

	return ret;
}

uint32_t bytes_to_hex_string(uint8_t *input, uint32_t count, char *output_buffer, bool capitalized)
{
	uint32_t idx;
	uint8_t b;

	for (idx = 0; idx < count; idx++) {
		b = input[idx];
		output_buffer[2*idx] = num_to_hex_digit(b >> 4, capitalized);
		output_buffer[2*idx+1] = num_to_hex_digit(b & 0xF, capitalized);
	}

	return 0;
}