/*
BT module settings (AT mode):
+NAME=OBD2_BT
+VER=8.0.2,FSC-BT836B
+MAC=DC0D30000FA9
+BAUD=115200
+PIN=1189

HC-05 bluetooth module: 
  address: 5856:00:017A39
  IAC: 9E8B33

AT Commands to connect permanently to the OBD2 module:
    AT+RESET
    AT+ORGL (Set to original)
    AT+ROLE=1 (Set to Master)
    AT+CMODE=0 (Set connect to a specific address)
    AT+BIND=dc0d,30,000fa9
    AT+INIT (Need to connect)
    AT+PAIR=dc0d,30,000fa9,30 (,30 means 30 second timeout)
    AT+LINK=dc0d,30,000fa9

Be sure to disconnect the TX and RX pins from the BT module when programming the arduino.
*/
#ifndef OBD2_BT_H
#define OBD2_BT_H

#ifdef __cplusplus
 extern "C" {
#endif

// #include <Arduino.h>
// #include "obd2_util.h"

/* pins */
#define PIN_BT_RX 19
#define PIN_BT_TX 18

#define BT_STATE_PIN 3 /* state connection pin from bluetooth module -> level high on connected */

#define BT_BAUD 115200

#define BT_STATE_LENGTH 13 /* length of the string identifier used for the states */

enum BluetoothState
{
    BT_INITIALISING = 0,
    BT_CONNECTING = 1,
    BT_CONNECTED = 2
};

/**
 * @brief struct to hold bluetooth module data
 * 
 * @param state the current state of the bluetooth module
 * @param on_state_change function pointer to the function to be called when the state changes
 */
typedef struct obt2_bt_tag
{
    enum BluetoothState state;
    void (*on_state_change)();
} obd2_bt_t;

/**
 * @brief initializes the bluetooth module driver   
 * 
 * @param bt pointer to struct holding bluetooth driver data
 */
void obd2_bt_init(obd2_bt_t *bt);

/**
 * @brief processes the bluetooth module communication with the OBD2 reader
 * 
 * @param bt pointer to struct holding bluetooth driver data
 */
void obd2_bt_process(obd2_bt_t *bt);

/**
 * @brief copies the current state of the bluetooth module to the state string
 * 
 * @param bt pointer to struct holding bluetooth driver data
 * @param state resulting string to hold the text representation of the state
 */
void obd2_bt_get_state(obd2_bt_t *bt, char *state);

#ifdef __cplusplus
 }
#endif

#endif // OBD2_BT_H