#pragma once

#include <Arduino.h>

struct GPSData {
	float latitude;  // in degrees, poistive is N
	float longitude; // in degrees, positive is E
	short altitude;  // in meters from sea level
};

class GPSSerial {
private:
	enum Field {
		HEADER,
		TIME,
		LATITUDE,
		LAT_INDICATOR,
		LONGITUDE,
		LONG_INDICATOR,
		FIX_STATUS,
		SAT_USED,
		HDOP,
		ALTITUDE,
		ALT_UNIT,
		ALTREF,
		ALTREF_UNIT,
		DIFFAGE,
		DIFFSTATION,
		CHECKSUM,
	};

	HardwareSerial* port;
	char field_buffer[32];
	unsigned char field_len;
	Field field;
	unsigned char checksum; // rolling checksum


	bool read_field();
	void update_checksum();

public:
	GPSData data;
	GPSSerial(HardwareSerial* hw_port) { port = hw_port; }
	~GPSSerial();
	bool is_data_ready(void);
};