#include "serialnumber.h"

int serial_add8(uint8_t s, uint8_t n) {
    if (n > 127)
        return -1;
    uint16_t sum = s+n;
    return (uint8_t)(sum%256);
}

int serial_add16(uint16_t s, uint16_t n) {
    if (n > 32767)
        return -1;
    uint32_t sum = s+n;
    return (uint16_t)(sum%65536);
}

int serial_add32(uint32_t s, uint32_t n) {
    if (n > 2147483647)
        return -1;
    uint64_t sum = s+n;
    return (uint32_t)(sum%4294967296);
}

serial_comp_res_t serial_comp8(uint8_t s1, uint8_t s2) {
    if (s1 == s2)
        return EQUAL;
    if ((s1 < s2 && s1 - s2 < 128) || (s1 > s2 && s1 - s2 > 128)) {
        return LESS;
    }
    if ((s1 < s2 && s1 - s2 > 128) || (s1 > s2 && s1 - s2 < 128)) {
        return GREATER;
    }
    return UNDEF;
}

serial_comp_res_t serial_comp16(uint16_t s1, uint16_t s2) {
    if (s1 == s2)
        return EQUAL;
    if ((s1 < s2 && s1 - s2 < 32768) || (s1 > s2 && s1 - s2 > 32768)) {
        return LESS;
    }
    if ((s1 < s2 && s1 - s2 > 32768) || (s1 > s2 && s1 - s2 < 32768)) {
        return GREATER;
    }
    return UNDEF;
}

serial_comp_res_t serial_comp32(uint32_t s1, uint32_t s2) {
    if (s1 == s2)
        return EQUAL;
    if ((s1 < s2 && s1 - s2 < 2147483648) || (s1 > s2 && s1 - s2 > 2147483648)) {
        return LESS;
    }
    if ((s1 < s2 && s1 - s2 > 2147483648) || (s1 > s2 && s1 - s2 < 2147483648)) {
        return GREATER;
    }
    return UNDEF;
}