#ifndef __GPS_DEVICE_H__
#define __GPS_DEVICE_H__

#include "mbed.h"
#define GPGGA "GPGGA"

class GPSDevice {
public:
    const static int length = 80;
    const static int baud = 9600;
    
    GPSDevice(Serial *uart) : uart(uart) {}
    
    /*
     * Permet de savoir si on lit le début de la trame associée au GPS.
     */
    bool canBeRead() {
        return uart->readable() && uart->getc() == '$';
    }
    
    /*
     * Permet de déterminer le type de trame du GPS.
     */
    void readType(char type[6]){
        uart->scanf("%5s", &type);
    }
    
    /*
     * Permet de lire la trame du GPS de type GGA.
     */
    void readGPGGA() {
        char msg[100];
    
        while (uart->getc() != ',');  //waits for first comma then copies info
        uart->scanf("%s", &msg);
        
        char *tok = strtok(msg, ",");  //begins isolating fields of information delimited by a comma
        int comma = 0;
        while(tok != NULL){
            comma++;
            switch (comma) {
            case 1: UTC = tok; break;   //GMT time in seconds, saves pointer to string
            case 2: lat = tok; break;   //latitude
            case 3: latl = tok; break;   //lat letter, (N or S)
            case 4: lon = tok; break;   //longitude
            case 5: lonl = tok; break;   //lon letter (W or E)
            case 6: valid = tok; break;   //valid
            }
    
            tok = strtok(NULL, ",");    
        }
    }
    
    /*
     * Permet de vérifier que la trame lue est valide.
     */
    bool isReadValid() {
        return atoi(valid) == 1 || atoi(valid) == 2 || atoi(valid) == 3;
    }
 
    char* getUTC() {
        return UTC;
    }
    
    char* getLatitude() {
        if(strcmp(latl, "N")){
            return lat;
        } else {
            char *newLat = "";
            strcpy(newLat, "-");
            strncat(lat, newLat, sizeof(lat)/sizeof(lat[0]));
            return newLat;
        }
    }
    
    char* getLongitude() {
        if(strcmp(lonl, "E")){
            return lon;
        } else {
            char *newLon = "";
            strcpy(newLon, "-");
            strncat(lon, newLon, sizeof(lon)/sizeof(lon[0]));
            return newLon;
        }
    }

private:
    Serial *uart;
    char *UTC, *lat, *latl, *lon, *lonl, *valid;
};

#endif /* #ifndef __GPS_DEVICE_H__*/