#include <WiFi.h>
#include <DHTesp.h>
#include <WiFiUdp.h>
#include <LiquidCrystal.h>
#include "PubSubClient.h"
#include "ThingSpeak.h"

// Define pins
#define DHTPIN 15
#define buzzer 2
#define relay 4

// Define some common notification
char* WATER_LOW = "Water level is low! Please add more water!";
char* HUMID_LOW = "Humidity level is low! Turn on humidifier";
char* HUMID_HIGH = "Humidity level is high! Turn off humidifier";
char* current_noti = nullptr;

// ThingSpeak APIs
unsigned long ChannelNumber = 2240308;
const char* WriteApiKey = "ULYCYQFTU9I2628P";
unsigned long lastMillisInternet = 0;
unsigned long lastMillisFog = 0;
unsigned long lastMillisBuzz = 0;

// Wifi and MQTT server
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqttServer = "test.mosquitto.org";
const int MQTTport = 1883;

// Global humid level variables
int upperHumidlv = 60;
int lowerHumidlv = 40;

// Trigger an IFTTT notification
const char* IFTTThost = "maker.ifttt.com";
const char* water = "/trigger/LowWater/with/key/e8JvVmWXHQ-dcP6btXIXAjKLdaaZJDt-0I4hOvaFxov";
const int IFTTTport = 80;

DHTesp dhtSensor;
WiFiClient espClient;
PubSubClient mqttClient(espClient);
LiquidCrystal lcd(25, 13, 12, 14, 27, 26); 

// Wifi connection function
void wifiConnect() {
  Serial.print("Connecting to WiFi...");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }
  Serial.println(" Connected!");
}

// Send notification to your phone through IFTTT
void sendNotification(const char* request){
  while (!espClient.connect(IFTTThost, IFTTTport))
    delay(1000);

  espClient.print("GET " + String(request) + " HTTP/1.1\r\n" +
              "Host: " + IFTTThost + "\r\n" +
              "Connection: Close\r\n\r\n");
  delay(500);
}

// Recieve message from node-red
void callback(char* topic, byte* message, unsigned int length) {
  String stMessage;
  for (int i = 0; i < length; i++) {
    stMessage += (char)message[i];
  }
  String topicName(topic);
  if(topicName == "21127243_21127296_21127300/status"){
    if(stMessage == "on"){
      turnOn();
    }
    else turnOff();
  }

  if(topicName == "21127243_21127296_21127300/upper") {
    upperHumidlv = stMessage.toInt();
    Serial.println(upperHumidlv);
  }
  if(topicName == "21127243_21127296_21127300/lower") {
    lowerHumidlv = stMessage.toInt();
    Serial.println(lowerHumidlv);
  }
}

// Send notification to node-red
void buzz(char* noti){
  //tone(buzzer, 100, 500);
  Serial.println(noti);
  ledcAttachPin(buzzer, 0);
  ledcWriteNote(0, NOTE_D, 4);
  delay(200);
  ledcWriteNote(0, NOTE_F, 4);
  delay(200);
  ledcDetachPin(buzzer);
}

void mqttReconnect() {
  Serial.print("Attempting MQTT connection... ");
  if (mqttClient.connect("21127243_21127296_21127300")) {
    Serial.println("Connected!");
    mqttClient.subscribe("21127243_21127296_21127300/onoff");
    mqttClient.subscribe("21127243_21127296_21127300/upper");
    mqttClient.subscribe("21127243_21127296_21127300/lower");
  } else {
    Serial.println("Failed");
  }
}

// Send temperature and humidity data to ThingSpeak
void TSWrite(float t, float h){
  ThingSpeak.setField(1, h);
  ThingSpeak.setField(2, t);
  int returncode = ThingSpeak.writeFields(ChannelNumber, WriteApiKey);

  if(returncode == 200)
    Serial.println("Uploaded to ThingSpeak");
  else Serial.println("Error! HTTP code error " + String(returncode));
}

void turnOn(){
  digitalWrite(relay, HIGH);
}

void turnOff(){
  lcd.noDisplay();
  digitalWrite(relay, LOW);
}

// Basic setup
void setup() {
  Serial.begin(9600);
  pinMode(buzzer, OUTPUT);
  pinMode(relay, OUTPUT);
  ledcSetup(0, 200, 14);
  lcd.begin(16, 2);

  //wifiConnect();

  mqttClient.setServer(mqttServer, MQTTport);
  mqttClient.setCallback(callback);

  dhtSensor.setup(DHTPIN, DHTesp::DHT22);
  ThingSpeak.begin(espClient);
}

void loop() {
  if (!mqttClient.connected()) {
    mqttReconnect();
  }
  mqttClient.loop();
  // Preset water level for testing
  int waterlv = 10;

  // Read temperature and humidity through DHT22
  TempAndHumidity data = dhtSensor.getTempAndHumidity();
  float t = data.temperature;
  float h = data.humidity;

  lcd.setCursor(0, 0);
  lcd.print("Temp: " + String(t) + "\xDF" + "C  ");
  lcd.setCursor(0, 1);
  lcd.print("Humid: " + String(h) + "%  ");

  if (waterlv < 25) {
    if (!lastMillisBuzz) {
      current_noti = WATER_LOW;
      buzz(current_noti);
      lastMillisBuzz = 1;
    }
    else if (millis() - lastMillisBuzz > 2000){
      current_noti = WATER_LOW;
      buzz(current_noti);
      lastMillisBuzz = millis();
      sendNotification(water);
    }
    digitalWrite(relay, LOW);
  }

  else {
    if (millis() - lastMillisFog > 15000) {
      if (h > upperHumidlv) {
        current_noti = HUMID_HIGH;
        buzz(HUMID_HIGH);
        digitalWrite(relay, LOW);
        //sendNotification(highHumidRequest);
      }
      else if (h < lowerHumidlv) {
        current_noti = HUMID_LOW;
        buzz(HUMID_LOW);
        digitalWrite(relay, HIGH);
        //sendNotification(lowHumidRequest);
      }
      lastMillisFog = millis();
    }
  }

  if (millis() - lastMillisInternet > 20000) {
    // Send temperature and humidty data to web
    if (mqttClient.connected()) {
      char buffer[100];
      sprintf(buffer, "{\"temperature\":%f,\"humidity\":%f,\"waterlv\":%d}", t, h, waterlv);  
      mqttClient.publish("21127243_21127296_21127300/sensor", buffer);
      if(current_noti != nullptr) {
        mqttClient.publish("21127243_21127296_21127300/notification", current_noti);
        current_noti = nullptr;
      }
    mqttClient.loop();
    Serial.println("Sent data to NODE-RED");

    TSWrite(t, h);
    lastMillisInternet = millis();
    }
  delay(500);
  }
}