#include <WiFi.h>
#include <PubSubClient.h>
#include <ESP32Servo.h>
#include <LiquidCrystal_I2C.h>
#include <DHTesp.h>

const char* ssid = "Wokwi-GUEST";
const char* password = "";

//***Set server***
const char* mqttServer = "broker.mqtt-dashboard.com"; 
int port = 1883;

const float GAMMA = 0.7;
const float RL10 = 50;

//pins
LiquidCrystal_I2C LCD = LiquidCrystal_I2C(0x27, 16, 2);
const int redLedPin = 2;
const int greenLedPin = 4;
const int servoPin = 18;
const int DHT_pin = 15;
const int photoresistor_pin = 32;
const char* client_id = "SmartGarden";
const char* led_channel = "SmartGarden/led";
const char* servo_channel = "SmartGarden/servo";
const char* temperature_channel = "SmartGarden/temperature";
const char* light_channel = "SmartGarden/light";
const char* humidity_channel = "SmartGarden/humidity";

//components
Servo myServo;
DHTesp dhtSensor;

WiFiClient espClient;
PubSubClient client(espClient);


void wifiConnect() {
  WiFi.begin(ssid, password);
  int i = 5;
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    LCD.setCursor(i, 0);
    LCD.print(".");
    i++;
  }
  //LCD.clear();
  LCD.setCursor(5, 0);
  LCD.println(" Connected!");
  delay(2000);
  //LCD.clear();
}

void mqttReconnect() {
  int i = 5;
  while(!client.connected()) {
    LCD.setCursor(i, 1);
    LCD.print(".");
    i++;

    //***Change "123456789" by your student id***
    if(client.connect(client_id)) {
      //LCD.clear();
      LCD.setCursor(5, 1);
      LCD.println(" Connected!");
      LCD.clear();

      //***Subscribe all topic you need***
      client.subscribe(servo_channel);
      client.subscribe(led_channel);
    }
    else {
      LCD.clear();
      Serial.println("try again in 5 seconds");
      delay(5000);
    }
    delay(500);
  }
}

//this will be ran first for setting up esp32 and connecting to server
void setup() {
  
  Serial.begin(115200);

  pinMode(redLedPin, OUTPUT);
  pinMode(greenLedPin, OUTPUT);
  pinMode(photoresistor_pin, INPUT);
  myServo.attach(servoPin);
  dhtSensor.setup(DHT_pin, DHTesp::DHT22);
  
  LCD.init();
  LCD.setCursor(2, 0);
  LCD.print("SMART GARDEN");
  delay(5000);
  LCD.clear();

  //LCD.print("Connecting to ");
  LCD.setCursor(0, 0);
  LCD.print("WIFI: ");
  LCD.setCursor(0, 1);
  LCD.print("MQTT: ");

  
  wifiConnect();
  client.setServer(mqttServer, port);
  client.setCallback(callback);
}

//MQTT Receiver
void callback(char* topic, byte* message, unsigned int length) {
  Serial.println(topic);
  String strMsg;
  for(int i=0; i<length; i++) {
    strMsg += (char)message[i];
  }
  
  Serial.println(strMsg);
  if (String(topic) == String(servo_channel)) {
    if (strMsg == "SERVO_ON"){
      Serial.println("servo");
      for (int pos = 0; pos <= 180; pos += 1) {
        myServo.write(pos);
        delay(15);
      }
    }
  }

  if (String(topic) == String(led_channel)){
    if (strMsg == "LIGHT_ON"){
      digitalWrite(greenLedPin, HIGH);
      digitalWrite(redLedPin, LOW);
    }
    else if (strMsg == "LIGHT_OFF"){
      digitalWrite(redLedPin, HIGH);
      digitalWrite(greenLedPin, LOW);
    }
  }
  //***Insert code here to control other devices***
}

void stringToChar(char* &result, String str){
  result = new char[str.length() + 1];
  int i;
  for (i = 0; i < str.length(); i++){
    result[i] = str[i];
  }
  result[i] = '\0';
  
}



void loop() {
  if(!client.connected()) {
    mqttReconnect();
  }
  client.loop();


  //***Change code to publish to MQTT Server***
  TempAndHumidity data = dhtSensor.getTempAndHumidity();
  String temperatureS = String(data.temperature, 2);
  String humidityS = String(data.humidity, 1);
  String photoresistor_valueS = String(analogRead(photoresistor_pin));

  int analogValue = analogRead(photoresistor_pin) / 4;
  float voltage = analogValue / 1024.0 * 5;
  float resistance = 2000 * voltage / (1 - voltage / 5);
  float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));

  Serial.println(lux);

  float temperatureF = temperatureS.toFloat();
  float humidityF = humidityS.toFloat();

  char* temperature = new char [temperatureS.length() + 1];
  char* humidity = new char [temperatureS.length() + 1];
  char* photoresistor_value = new char [photoresistor_valueS.length() + 1];
  
  
  LCD.setCursor(0, 0);
  LCD.println("Temp: " + temperatureS + "C");
  LCD.setCursor(0, 1);
  LCD.println("Humidity: " + humidityS + "%");

  stringToChar(temperature, temperatureS);
  stringToChar(humidity, humidityS);
  stringToChar(photoresistor_value, photoresistor_valueS);
  

  client.publish(temperature_channel, temperature);
  client.publish(humidity_channel, humidity);
  client.publish(light_channel, photoresistor_value);
  
  delete [] temperature;
  delete [] humidity;
  delete [] photoresistor_value
;
  delay(2000);
}