#include <Wire.h>
#include <PubSubClient.h>
#include <WiFi.h>
#include <DHT.h>
#include <OneWire.h>
#include <DallasTemperature.h>
#include <LiquidCrystal_I2C.h>  // Include the LCD library

// WiFi and MQTT Configuration
const char* ssid = "Wokwi-GUEST";       // WiFi SSID
const char* password = "";              // WiFi Password
const char* mqtt_server = "broker.emqx.io"; // MQTT Broker address

WiFiClient espClient;
PubSubClient client(espClient);

// Sensor Pin Definitions
#define DHTPIN 5               // DHT22 data pin
#define ONE_WIRE_BUS 4         // DS18B20 data pin
#define LDR_PIN 34             // LDR (analog) pin

// Sensor Setup
DHT dht(DHTPIN, DHT22);        // DHT22 sensor
OneWire oneWire(ONE_WIRE_BUS); // DS18B20
DallasTemperature sensors(&oneWire);

// LCD Setup (Assuming you are using an I2C LCD with address 0x27)
LiquidCrystal_I2C lcd(0x27, 16, 2); // 16 columns, 2 rows LCD

// Time variables for reducing print redundancy
unsigned long lastPrintTime = 0; 
const long printInterval = 5000;  // Interval to print data (in milliseconds)

// Function to Connect to WiFi
void setup_wifi() {
  if (WiFi.status() == WL_CONNECTED) return; // Skip if already connected
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected");
}

// Function to Maintain MQTT Connection
void reconnect() {
  if (client.connected()) return;  // Skip if already connected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (client.connect("ESP32Greenhouse")) {
      Serial.println("connected");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

// Function to Read Sensors
float readTemperature() {
  sensors.requestTemperatures();        // Request temperature reading
  return sensors.getTempCByIndex(0);    // Read from first DS18B20 sensor
}

float readHumidity() {
  return dht.readHumidity();            // Read humidity from DHT22
}

float readLightPercentage() {
  int rawLight = analogRead(LDR_PIN);   // Read raw LDR value (0-4095)
  return (1.0 - (rawLight / 4095.0)) * 100.0;  // Invert the reading (max light = 100%)
}

void setup() {
  Serial.begin(115200);
  
  setup_wifi();  // Establish WiFi connection

  client.setServer(mqtt_server, 1883); // Set up MQTT server

  // Initialize Sensors
  dht.begin();
  sensors.begin();

  // Initialize LCD
  lcd.init();
  lcd.backlight();  // Turn on backlight
  lcd.setCursor(0, 0);
  lcd.print("Greenhouse Data");

  Serial.println("Setup complete");
}

void loop() {
  unsigned long currentTime = millis();
  
  if (currentTime - lastPrintTime >= printInterval) {
    // Read sensor data
    float temperature = readTemperature();
    float humidity = readHumidity();
    float lightPercentage = readLightPercentage();

    // Prepare JSON payload for MQTT
    String payload = String("{") +
                     "\"temperature\":" + String(temperature, 1) + "," +
                     "\"humidity\":" + String(humidity, 1) + "," +
                     "\"light\":" + String(lightPercentage, 1) +
                     "}";

    // Publish data to MQTT topic
    client.publish("greenhouse/sensors", payload.c_str());
    Serial.println("Published: " + payload);

    // Display data on LCD
    lcd.clear();  // Clear previous display
    lcd.setCursor(0, 0);
    lcd.print("Temp: " + String(temperature, 1) + "C");

    lcd.setCursor(0, 1);
    lcd.print("Hum: " + String(humidity, 1) + "%");

    lastPrintTime = currentTime;  // Update the last print time
  }

  if (!client.connected()) {
    reconnect(); // Ensure MQTT connection
  }

  client.loop(); // Keep MQTT connection alive
  delay(100);    // Small delay to prevent overloading
}