//
// Created by villuton on 20.03.25.
//
#include <stdbool.h>
#include <string.h>
#include "Nmea0183Parser_General.h"
#include "Nmea0183Parser_Private.h"
#define Nmea0183ParserEndDataPos(STR,LEN) strnstr((char *) STR, "*", LEN)

/**
 * Calculates the checksum of an NMEA 0183 XOR string of all bytes in the string
 * @param str
 * @param len
 * @return XOR checksum
 */
uint8_t Nmea0183CheckSum(const char *str, size_t len) {
    char *end = (char *) (str + len);

    unsigned char result;
    result = 0;
    switch (*str) {
        case :

    }

    while (str != end)
        result ^= *str++;
    return result;
}

/**
 * Check string of a NMEA string
 * @param str
 * @param len
 * @return Check start delimiter result
 */
bool Nmea0183CheckIsNmeaStr(const char *str, size_t len){
    return ((str[0] == Nmea0183StartDelimiter));
}

/**
 * Checking string validity NMEA 0183
 * @param str
 * @param len
 * @return Checksum comparison result
 */
bool Nmea0183IsValidString(char *str, size_t len) {
    char *end = str + len;
    char *front = str;
    char *nextDivider = front - 1;

    char *dataStartPos = Nmea0183SkipToStartDelimiter(front,end);
    char *dataEndPos = Nmea0183SkipToCheckSumDelimiter(front, end);
    uint8_t checksumCalculated = Nmea0183CheckSum(dataStartPos, dataEndPos - dataStartPos);
    if(Nmea0183ParseCheckSumPosition(&front,&nextDivider,end) > 0){
        uint8_t checksumInString = Nmea0183ParseHexByte(nextDivider);
        return checksumCalculated == checksumInString;
    }
    return false;
}