/**
   @file Environment_Monitoring.ino
   @author rakwireless.com
   @brief This sketch demonstrate how to get environment data from BME680
      and send the data to lora gateway.
   @version 0.1
   @date 2020-07-28
   @copyright Copyright (c) 2020
**/

#include <Arduino.h>
#include <LoRaWan-RAK4630.h> // Click to install library: http://librarymanager/ALL#SX126x-Arduino
#include <SPI.h>

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME680.h> // Click to install library: http://librarymanager/All#Adafruit_BME680
#include <U8g2lib.h>		   // Click to install library: http://librarymanager/ALL#u8g2

U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0);
Adafruit_BME680 bme;

// RAK4630 supply two LED
#ifndef LED_BUILTIN
#define LED_BUILTIN 35
#endif

#ifndef LED_BUILTIN2
#define LED_BUILTIN2 36
#endif

bool doOTAA = true;   // OTAA is used by default.
#define SCHED_MAX_EVENT_DATA_SIZE APP_TIMER_SCHED_EVENT_DATA_SIZE /**< Maximum size of scheduler events. */
#define SCHED_QUEUE_SIZE 60										  /**< Maximum number of events in the scheduler queue. */
#define LORAWAN_DATERATE DR_3									  /*LoRaMac datarates definition, from DR_0 to DR_5*/
#define LORAWAN_TX_POWER TX_POWER_0								  /*LoRaMac tx power definition, from TX_POWER_0 to TX_POWER_15*/
#define JOINREQ_NBTRIALS 5										  /**< Number of trials for the join request. */
DeviceClass_t g_CurrentClass = CLASS_A;					/* class definition*/
LoRaMacRegion_t g_CurrentRegion = LORAMAC_REGION_EU868;    /* Region:EU868*/
lmh_confirm g_CurrentConfirm = LMH_CONFIRMED_MSG;				  /* confirm/unconfirm packet definition*/
uint8_t gAppPort = LORAWAN_APP_PORT;							  /* data port*/

/**@brief Structure containing LoRaWan parameters, needed for lmh_init()
*/
static lmh_param_t g_lora_param_init = {LORAWAN_ADR_OFF, LORAWAN_DATERATE, LORAWAN_PUBLIC_NETWORK, JOINREQ_NBTRIALS, LORAWAN_TX_POWER, LORAWAN_DUTYCYCLE_OFF};

// Foward declaration
static void lorawan_has_joined_handler(void);
void lorawan_join_fail(void);
static void lorawan_rx_handler(lmh_app_data_t *app_data);
static void lorawan_confirm_class_handler(DeviceClass_t Class);
static void send_lora_frame(void);

/**@brief Structure containing LoRaWan callback functions, needed for lmh_init()
*/
static lmh_callback_t g_lora_callbacks = {BoardGetBatteryLevel, BoardGetUniqueId, BoardGetRandomSeed,
                                        lorawan_rx_handler, lorawan_has_joined_handler, lorawan_confirm_class_handler, lorawan_join_fail
                                       };

//OTAA keys !!!! KEYS ARE MSB !!!!
uint8_t nodeDeviceEUI[8] = {0xE9, 0x3C, 0x83, 0xCF, 0xDE, 0xC5, 0xDF, 0xB5};
uint8_t nodeAppEUI[8] = {0x7B, 0x84, 0x17, 0x9A, 0xC2, 0x4B, 0x0B, 0x34};
uint8_t nodeAppKey[16] = {0xD0, 0x5D, 0xAE, 0xA1, 0xC3, 0xBC, 0xD9, 0xD3, 0x62, 0x67, 0xB3, 0x5F, 0x06, 0x1A, 0x92, 0x34};

// ABP keys
uint32_t nodeDevAddr = 0x260116F8;
uint8_t nodeNwsKey[16] = {0x7E, 0xAC, 0xE2, 0x55, 0xB8, 0xA5, 0xE2, 0x69, 0x91, 0x51, 0x96, 0x06, 0x47, 0x56, 0x9D, 0x23};
uint8_t nodeAppsKey[16] = {0xFB, 0xAC, 0xB6, 0x47, 0xF3, 0x58, 0x45, 0xC7, 0x50, 0x7D, 0xBF, 0x16, 0x8B, 0xA8, 0xC1, 0x7C};

// Private defination
#define LORAWAN_APP_DATA_BUFF_SIZE 64										  /**< buffer size of the data to be transmitted. */
#define LORAWAN_APP_INTERVAL 20000											  /**< Defines for user timer, the application data transmission interval. 20s, value in [ms]. */
static uint8_t m_lora_app_data_buffer[LORAWAN_APP_DATA_BUFF_SIZE];			  //< Lora user application data buffer.
static lmh_app_data_t m_lora_app_data = {m_lora_app_data_buffer, 0, 0, 0, 0}; //< Lora user application data structure.

TimerEvent_t appTimer;
static uint32_t timers_init(void);
static uint32_t count = 0;
static uint32_t count_fail = 0;

void setup()
{
  // Initialize the built in LED
  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(LED_BUILTIN, LOW);

  // Initialize Serial for debug output
  Serial.begin(115200);

  time_t serial_timeout = millis();
  // On nRF52840 the USB serial is not available immediately
  while (!Serial)
  {
    if ((millis() - serial_timeout) < 5000)
    {
      delay(100);
      digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN));
    }
    else
    {
      break;
    }
  }

  Serial.println("=====================================");
  Serial.println("Welcome to RAK4630 LoRaWan!!!");
  if (doOTAA)
  {
  Serial.println("Type: OTAA");
  }
  else
  {
    Serial.println("Type: ABP");
  }

  switch (g_CurrentRegion)
  {
    case LORAMAC_REGION_AS923:
  Serial.println("Region: AS923");
      break;
    case LORAMAC_REGION_AU915:
  Serial.println("Region: AU915");
      break;
    case LORAMAC_REGION_CN470:
  Serial.println("Region: CN470");
      break;
    case LORAMAC_REGION_EU433:
  Serial.println("Region: EU433");
      break;
    case LORAMAC_REGION_IN865:
  Serial.println("Region: IN865");
      break;
    case LORAMAC_REGION_EU868:
  Serial.println("Region: EU868");
      break;
    case LORAMAC_REGION_KR920:
  Serial.println("Region: KR920");
      break;
    case LORAMAC_REGION_US915:
  Serial.println("Region: US915");
      break;
  }
  Serial.println("=====================================");

  // Initialize LoRa chip.
  lora_rak4630_init();

  /* bme680 init */
  init_bme680();

  u8g2.begin();

  //creat a user timer to send data to server period
  uint32_t err_code;

  err_code = timers_init();
  if (err_code != 0)
  {
    Serial.printf("timers_init failed - %d\n", err_code);
    return;
  }

  // Setup the EUIs and Keys
  if (doOTAA)
  {
  lmh_setDevEui(nodeDeviceEUI);
  lmh_setAppEui(nodeAppEUI);
  lmh_setAppKey(nodeAppKey);
  }
  else
  {
    lmh_setNwkSKey(nodeNwsKey);
    lmh_setAppSKey(nodeAppsKey);
    lmh_setDevAddr(nodeDevAddr);
  }

  // Initialize LoRaWan
  err_code = lmh_init(&g_lora_callbacks, g_lora_param_init, doOTAA, g_CurrentClass, g_CurrentRegion);
  if (err_code != 0)
  {
    Serial.printf("lmh_init failed - %d\n", err_code);
    return;
  }

  // Start Join procedure
  u8g2.clearBuffer();					// clear the internal memory
  u8g2.setFont(u8g2_font_ncenB10_tr); // choose a suitable font

  u8g2.drawStr(20, 39, "Joining ...");
  u8g2.sendBuffer(); // transfer internal memory to the display
  
  lmh_join();
}

void loop()
{
  // Put your application tasks here, like reading of sensors,
  // Controlling actuators and/or other functions. 
}

/**@brief LoRa function for failed Join event
*/
void lorawan_join_fail(void)
{
  Serial.println("OTAA join failed!");
}

/**@brief LoRa function for handling HasJoined event.
*/
void lorawan_has_joined_handler(void)
{
  Serial.println("OTAA Mode, Network Joined!");
  u8g2.clearBuffer();					// clear the internal memory
  u8g2.setFont(u8g2_font_ncenB10_tr); // choose a suitable font

  u8g2.drawStr(20, 39, "Joined");
  u8g2.sendBuffer(); // transfer internal memory to the display
  //delay(2000);

  lmh_error_status ret = lmh_class_request(g_CurrentClass);
  if (ret == LMH_SUCCESS)
  {
    delay(1000);
    TimerSetValue(&appTimer, LORAWAN_APP_INTERVAL);
    TimerStart(&appTimer);
  }
}

/**@brief Function for handling LoRaWan received data from Gateway
   @param[in] app_data  Pointer to rx data
*/
void lorawan_rx_handler(lmh_app_data_t *app_data)
{
  Serial.printf("LoRa Packet received on port %d, size:%d, rssi:%d, snr:%d, data:%s\n",
                app_data->port, app_data->buffsize, app_data->rssi, app_data->snr, app_data->buffer);
}

void lorawan_confirm_class_handler(DeviceClass_t Class)
{
  Serial.printf("switch to class %c done\n", "ABC"[Class]);
  // Informs the server that switch has occurred ASAP
  m_lora_app_data.buffsize = 0;
  m_lora_app_data.port = gAppPort;
  lmh_send(&m_lora_app_data, g_CurrentConfirm);
}

void send_lora_frame(void)
{
  if (lmh_join_status_get() != LMH_SET)
  {
    //Not joined, try again later
    return;
  }
  if (!bme.performReading()) {
    return;
  }
  bme680_get();

  lmh_error_status error = lmh_send(&m_lora_app_data, g_CurrentConfirm);
  if (error == LMH_SUCCESS)
  {
    count++;
    Serial.printf("lmh_send ok count %d\n", count);
  }
  else
  {
    count_fail++;
    Serial.printf("lmh_send fail count %d\n", count_fail);
  }
}

/**@brief Function for handling user timerout event.
*/
void tx_lora_periodic_handler(void)
{
  TimerSetValue(&appTimer, LORAWAN_APP_INTERVAL);
  TimerStart(&appTimer);
  Serial.println("Sending frame now...");
  send_lora_frame();
}

/**@brief Function for the Timer initialization.
   @details Initializes the timer module. This creates and starts application timers.
*/
uint32_t timers_init(void)
{
  TimerInit(&appTimer, tx_lora_periodic_handler);
  return 0;
}

void init_bme680(void)
{
  Wire.begin();

  if (!bme.begin(0x76)) {
    Serial.println("Could not find a valid BME680 sensor, check wiring!");
    return;
  }

  // Set up oversampling and filter initialization
  bme.setTemperatureOversampling(BME680_OS_8X);
  bme.setHumidityOversampling(BME680_OS_2X);
  bme.setPressureOversampling(BME680_OS_4X);
  bme.setIIRFilterSize(BME680_FILTER_SIZE_3);
  bme.setGasHeater(320, 150); // 320*C for 150 ms
}

String data = "";

void bme680_get()
{
  char oled_data[32] = {0};
  Serial.print("result: ");
  uint32_t i = 0;
  memset(m_lora_app_data.buffer, 0, LORAWAN_APP_DATA_BUFF_SIZE);
  m_lora_app_data.port = gAppPort;

  double temp = bme.temperature;
  double pres = bme.pressure / 100.0;
  double hum = bme.humidity;
  uint32_t gas = bme.gas_resistance;

  data = "Tem:" + String(temp) + "C " + "Hum:" + String(hum) + "% " + "Pres:" + String(pres) + "KPa " + "Gas:" + String(gas) + "Ohms";
  Serial.println(data);

  // display bme680 sensor data on OLED
  u8g2.clearBuffer();					// clear the internal memory
  u8g2.setFont(u8g2_font_ncenB10_tr); // choose a suitable font

  memset(oled_data, 0, sizeof(oled_data));
  sprintf(oled_data, "T=%.2fC", temp);
  u8g2.drawStr(3, 15, oled_data);

  memset(oled_data, 0, sizeof(oled_data));
  snprintf(oled_data, 64, "RH=%.2f%%", hum);
  u8g2.drawStr(3, 30, oled_data);

  memset(oled_data, 0, sizeof(oled_data));
  sprintf(oled_data, "P=%.2fhPa", pres);
  u8g2.drawStr(3, 45, oled_data);

  memset(oled_data, 0, sizeof(oled_data));
  sprintf(oled_data, "G=%dOhms", gas);
  u8g2.drawStr(3, 60, oled_data);

  u8g2.sendBuffer(); // transfer internal memory to the display

  uint16_t t = temp * 100;
  uint16_t h = hum * 100;
  uint32_t pre = pres * 100;

  //result: T=28.25C, RH=50.00%, P=958.57hPa, G=100406 Ohms
  m_lora_app_data.buffer[i++] = 0x01;
  m_lora_app_data.buffer[i++] = (uint8_t)(t >> 8);
  m_lora_app_data.buffer[i++] = (uint8_t)t;
  m_lora_app_data.buffer[i++] = (uint8_t)(h >> 8);
  m_lora_app_data.buffer[i++] = (uint8_t)h;
  m_lora_app_data.buffer[i++] = (uint8_t)((pre & 0xFF000000) >> 24);
  m_lora_app_data.buffer[i++] = (uint8_t)((pre & 0x00FF0000) >> 16);
  m_lora_app_data.buffer[i++] = (uint8_t)((pre & 0x0000FF00) >> 8);
  m_lora_app_data.buffer[i++] = (uint8_t)(pre & 0x000000FF);
  m_lora_app_data.buffer[i++] = (uint8_t)((gas & 0xFF000000) >> 24);
  m_lora_app_data.buffer[i++] = (uint8_t)((gas & 0x00FF0000) >> 16);
  m_lora_app_data.buffer[i++] = (uint8_t)((gas & 0x0000FF00) >> 8);
  m_lora_app_data.buffer[i++] = (uint8_t)(gas & 0x000000FF);
  m_lora_app_data.buffsize = i;
}

function Decoder(bytes, port) {
      var decoded = {};
      decoded.temperature = (bytes[1] << 8 | (bytes[2])) / 100
      decoded.humidity = (bytes[3] << 8 | (bytes[4])) / 100
      decoded.pressure = (bytes[8] | (bytes[7] << 8) | (bytes[6] << 16) | (bytes[5] << 24)) / 100
      decoded.gas = bytes[12] | (bytes[11] << 8) | (bytes[10] << 16) | (bytes[9] << 24)
  // TODO: Transform bytes to decoded payload below
  var decodedPayload = {
    "temperature": decoded.temperature,
    "humidity": decoded.humidity,
    "pressure": decoded.pressure,
    "gas": decoded.gas
  };
  // END TODO

  return Serialize(decodedPayload)
}