/**
 * An Azure IoT example for sending telemetry for 2 temperature and humidity values.
 * Use these URLs to get ESP32 board installs:
 * https://dl.espressif.com/dl/package_esp32_index.json
 * http://arduino.esp8266.com/stable/package_esp8266com_index.json
 * Base for this code is SimpleMQTT sketch from the File->Examples->ESP32 Azure IoT Arduino
 * The device MAC is deviceId in the JSON event for the IOThub identify 
 * Libraries needed:
 * Adafruit Unified Sensors 1.1.4
 * Adafruit DHT sensor library 1.4.0
 * Download NTPClient-master.zip from https://github.com/taranais/NTPClient 
 * Unzip NTPClient-master.zip to Documents->Arduino->libraries and rename the folder to NTPClient
 */
#include <WiFi.h>
#include <Esp32MQTTClient.h>
#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <NTPClient.h>

// Please input the SSID and password of WiFi
const char* ssid     = "<your-network-SSID>";
const char* password = "<your-wifi-network-password>";

/*Strings containing Hostname, Device Id & Device Key for 2 IOT devices defined in the Azure IOThub */
//static const char* connectionString = "<connection-string-fromAzure-IOTdevice#1>";
static const char* connectionString = "<connection-string-fromAzure-IOTdevice#2>";
 
#define DHTPIN 14     // Digital pin connected to the DHT sensor

// Uncomment the type of sensor in use:
//#define DHTTYPE    DHT11     // DHT 11
#define DHTTYPE    DHT22     // DHT 22 (AM2302)
//#define DHTTYPE    DHT21     // DHT 21 (AM2301)

DHT dht(DHTPIN, DHTTYPE);  // Object for DHT sensor

WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP);

static char deviceMAC[23]; // chip MAC keeper

static long int messageId = 0;
String temperature;
String humidity;

// Variables to save date and time
String formattedDate;
//String dayStamp;
//String timeStamp;

static bool hasIoTHub;

void setup() {
  delay(3000);
  Serial.begin(115200);
  Serial.println("Starting connecting WiFi.");
  delay(10);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println(" WiFi connected");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
  uint64_t chipid = ESP.getEfuseMac(); // The chip ID is essentially its MAC address(length: 6 bytes).
  uint16_t chip = (uint16_t)(chipid >> 32);
  snprintf(deviceMAC, 23, "%04X%08X", chip, (uint32_t)chipid); // get chip MAC
  Serial.print("Chip MAC: ");
  Serial.println(deviceMAC);

  dht.begin();
  // make DHT22 dummy reads to ensure correct readings later on
  dht.readTemperature();
  dht.readHumidity();

  if (!Esp32MQTTClient_Init((const uint8_t*)connectionString))
  {
    hasIoTHub = false;
    Serial.println("Initializing IoT hub failed.");
  }
  else hasIoTHub = true;
}

void loop() {
  if (hasIoTHub)
  {
    char buff[256];
    String Json_mqtt_msg = String("{\"deviceId\":\"") + deviceMAC + String("\",\"deviceNTP\":\"");
    while(!timeClient.update()) {
      timeClient.forceUpdate();
    }
    // The formattedDate comes with the following format:
    // 2018-05-28T16:00:13Z
    // We need to extract date and time
    formattedDate = timeClient.getFormattedDate();
    Json_mqtt_msg += formattedDate;    // add NTP datetime
    /*
    // Extract date
    int splitT = formattedDate.indexOf("T");
    dayStamp = formattedDate.substring(0, splitT);
      // Extract time
    timeStamp = formattedDate.substring(splitT+1, formattedDate.length()-1);
    */
    float humidity = dht.readHumidity();   // Read temperature as Celsius (the default)
    float temperature = dht.readTemperature();
  
    // For Fahrenheit reading: float f = dht.readTemperature(true);
    // If any reads from dht1 failed , set value to -99.0
    if (isnan(humidity)) humidity = -99.0;
    if (isnan(temperature)) temperature = -99.0;
   // Json_mqtt_msg += String(",\"date\":\"") + dayStamp + String("\",\"time\":\"") + timeStamp;
    Json_mqtt_msg += String("\",\"temperature\":") + String((int)temperature) + String(",\"humidity\":") + String((int)humidity)+ String("}");
    Serial.println(String("Sending: ") + Json_mqtt_msg);
    Json_mqtt_msg.toCharArray(buff, (Json_mqtt_msg.length()+1));
    if (Esp32MQTTClient_SendEvent(buff)) {  }
    else    {  Serial.println("Failure..."); }
  }
  else   Serial.println("Waiting for MQTT connection");
  delay(5000);
}