// Code based on
// https://github.com/adafruit/DHT-sensor-library/blob/master/examples/DHTtester/DHTtester.ino
// https://gist.github.com/igrr/7f7e7973366fc01d6393
// https://github.com/iot-playground/Arduino/blob/master/ESP8266ArduinoIDE/DS18B20_temperature_sensor/DS18B20_temperature_sensor.ino

// esp8266 + dht22 + mqtt


#include <PubSubClient.h>
#include <ESP8266WiFi.h>

#include <Arduino.h>
#include <Wire.h>
#include "Adafruit_SHT31.h"

#define BUTTONPIN 13 
#define GREENLEDPIN 14    
#define REDLEDPIN 15 
#define RELAYPIN 5

const char* ssid = "**************";
const char* password = "**************";

char* topic = "basement";

char* server = "192.168.178.32";
char* hellotopic = "basement/SHT21";

Adafruit_SHT31 sht31 = Adafruit_SHT31();

#define REPORT_INTERVAL 30 // in sec
int buttonState = 0;  
String clientName;

void callback(char* topic, byte* payload, unsigned int length) {
  // handle message arrived
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  for (int i=0;i<length;i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();
}

void handleInterrupt() {
  digitalWrite(REDLEDPIN, !digitalRead(REDLEDPIN));
}


WiFiClient wifiClient;
PubSubClient client(server, 1883, callback, wifiClient);

float oldH ;
float oldT ;

void setup() {
  Wire.begin(2,4);
  Serial.begin(38400);
  pinMode(BUTTONPIN, INPUT_PULLUP);
  pinMode(REDLEDPIN, OUTPUT);
  pinMode(GREENLEDPIN, OUTPUT);
  pinMode(RELAYPIN, OUTPUT);

  attachInterrupt(digitalPinToInterrupt(BUTTONPIN), handleInterrupt, FALLING);
  
  while (!Serial)
    delay(10);     // 

  Serial.println("SHT31 test");
  if (! sht31.begin(0x44)) {   
    Serial.println("Couldn't find SHT31");
    while (1) delay(1);
  }
  
  Serial.println("SHT22 test!");
  delay(20);

  Serial.println();
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

  clientName += "esp8266-";
  uint8_t mac[6];
  WiFi.macAddress(mac);
  clientName += macToStr(mac);
  clientName += "-";
  clientName += String(micros() & 0xff, 16);

  Serial.print("Connecting to ");
  Serial.print(server);
  Serial.print(" as ");
  Serial.println(clientName);

  if (client.connect((char*) clientName.c_str())) {
    Serial.println("Connected to MQTT broker");
    Serial.print("Topic is: ");
    Serial.println(topic);
    
    if (client.publish(hellotopic, "hello from ESP8266")) {
      Serial.println("Publish ok");
    }
    else {
      Serial.println("Publish failed");
    }
  }
  else {
    Serial.println("MQTT connect failed");
    Serial.println("Will reset and try again...");
    abort();
  }

  sht31.heater(false);
  oldH = -1;
  oldT = -1;
}

void loop() {

  if (client.state()==0){
    digitalWrite(GREENLEDPIN, HIGH);
  } else {
    digitalWrite(GREENLEDPIN, LOW);
  }

  float t = sht31.readTemperature();
  float h = sht31.readHumidity();

  if (! isnan(t)) {  // check if 'is not a number'
    Serial.print("Temp *C = "); Serial.println(t);
  } else { 
    Serial.println("Failed to read temperature");
  }
  
  if (! isnan(h)) {  // check if 'is not a number'
    Serial.print("Hum. % = "); Serial.println(h);
  } else { 
    Serial.println("Failed to read humidity");
  }
  Serial.println();
  delay(1000);
  
  

  String payload = "{\"humidity\":";
  payload += h;
  payload += ",\"temperature\":";
  payload += t;
  payload += "}";
 
  if (t != oldT || h != oldH )
  {
    sendTemperature(payload);
    oldT = t;
    oldH = h;
  }

  int cnt = REPORT_INTERVAL;

  while (cnt--)
    delay(1000);
}


void sendTemperature(String payload) {
  if (!client.connected()) {
    if (client.connect((char*) clientName.c_str())) {
      Serial.println("Connected to MQTT broker again");
      Serial.print("Topic is: ");
      Serial.println(topic);
    }
    else {
      Serial.println("MQTT connect failed");
      Serial.println("Will reset and try again...");
      abort();
    }
  }

  if (client.connected()) {
    Serial.print("Sending payload: ");
    Serial.println(payload);

    if (client.publish(topic, (char*) payload.c_str())) {
      Serial.println("Publish ok");
      digitalWrite(GREENLEDPIN, LOW);
      delay(500);
      digitalWrite(GREENLEDPIN, HIGH);
    }
    else {
      Serial.println("Publish failed");
    }
    
  }

}




String macToStr(const uint8_t* mac)
{
  String result;
  for (int i = 0; i < 6; ++i) {
    result += String(mac[i], 16);
    if (i < 5)
      result += ':';
  }
  return result;
}

[{"id":"86bb9f5f.38b4","type":"mqtt in","z":"35df45de.89998a","name":"","topic":"basement","qos":"2","broker":"2f4461ce.bc17be","x":94,"y":82,"wires":[["92e7e46f.634a38"]]},{"id":"92e7e46f.634a38","type":"json","z":"35df45de.89998a","name":"","x":241,"y":82,"wires":[["60e0bb9c.517d84","e4e95ac8.46ec18"]]},{"id":"28ccaef3.ec5fd2","type":"http request","z":"35df45de.89998a","name":"Post temperature of basement to REXpi","method":"POST","ret":"obj","url":"http://user:password@192.168.178.54:8008/api/tasks/ventilation_task/CNR_basementTemp:ycn?data&mime=application/json","tls":"","x":901,"y":117,"wires":[[]]},{"id":"9bbbf26d.900ec","type":"http request","z":"35df45de.89998a","name":"Post Relative humidity of basement to REXpi","method":"POST","ret":"obj","url":"http://user:password@192.168.178.54:8008/api/tasks/ventilation_task/CNR_basementRHum:ycn?data&mime=application/json","tls":"","x":909,"y":81,"wires":[[]]},{"id":"e4e95ac8.46ec18","type":"function","z":"35df45de.89998a","name":"Temperature","func":"return {\n    payload: '{\"v\":' + msg.payload.temperature + '}',\n    headers: {\n         \"Content-type\" : \"application/json\"\n    }\n};","outputs":1,"noerr":0,"x":448,"y":118,"wires":[["28ccaef3.ec5fd2"]]},{"id":"60e0bb9c.517d84","type":"function","z":"35df45de.89998a","name":"Relative Humidity","func":"return {\n    payload: '{\"v\":' + msg.payload.humidity + '}',\n    headers: {\n         \"Content-type\" : \"application/json\"\n    }\n};","outputs":1,"noerr":0,"x":470,"y":82,"wires":[["9bbbf26d.900ec"]]},{"id":"2f4461ce.bc17be","type":"mqtt-broker","z":"35df45de.89998a","broker":"192.168.178.32","port":"1883","clientid":"","usetls":false,"compatmode":true,"keepalive":"60","cleansession":true,"willTopic":"","willQos":"0","willPayload":"","birthTopic":"","birthQos":"0","birthPayload":""}]