#include "utils.h"
#include <unistd.h>
#include <stdint.h>
#include <math.h>

#define MIN(a,b) (((a)<(b))?(a):(b))
#define MAX(a,b) (((a)>(b))?(a):(b))

/* Taken from sox */
const char* level(int channel, int peak)
{
    static char const * const text[][2] = {
        /* White: 2dB steps */
        {"", ""}, {"-", "-"}, {"=", "="}, {"-=", "=-"},
        {"==", "=="}, {"-==", "==-"}, {"===", "==="}, {"-===", "===-"},
        {"====", "===="}, {"-====", "====-"}, {"=====", "====="},
        {"-=====", "=====-"}, {"======", "======"},
        /* Red: 1dB steps */
        {"!=====", "=====!"},
    };
    int const red = 1, white = NUMOF(text) - red;

    double linear = ((double)peak) / INT16_MAX;

    int vu_dB = linear ? floor(2 * white + red + linear_to_dB(linear)) : 0;

    int index = vu_dB < 2 * white ?
        MAX(vu_dB / 2, 0) :
        MIN(vu_dB - white, red + white - 1);

    return text[index][channel];
}

size_t strlen_utf8(const char *s) {
    size_t result = 0;

    // ignore continuation bytes - only count single/leading bytes
    while (*s)
        if ((*s++ & 0xC0) != 0x80)
            result++;

    return result;
}