module buildj_util

const (
    ZERO = 0
    KB = 1024
    MB = KB * KB
)

pub fn check_os() {
    $if linux {
       return 
    }
    $if mac {
        return
    }
    println('[ERROR] Not supported OS.')
    exit(1)
}

pub fn get_readable_size(size int) string {
    if size <= ZERO {
        return '${size} Byte'
    } else if size < KB {
        return '${size} Bytes'
    } else if size < MB {
        size_in_kb := f64_str_2f(f64(size) / f64(KB))
        return '${size_in_kb} KB'
    } else {
        size_in_mb := f64_str_2f(f64(size) / f64(MB))
        return '${size_in_mb} MB'
    }
}

fn f64_str_2f(d f64) string {
    buf := malloc(sizeof(f64) * 5 + 1)
    C.sprintf(buf, '%.2f', d)
    return tos(buf, C.strlen(buf))
}