// Prajwal Swaroop Srivastava
#define BLYNK_TEMPLATE_ID "TMPL3721tv1JC"
#define BLYNK_TEMPLATE_NAME "Smart Irrigation System"
#define BLYNK_AUTH_TOKEN "SfUK7sBgQ4xVyRsJ-0lc6M8KukhTXEKD"

#include <DHT.h>
#include <WiFi.h>
#include <BlynkSimpleEsp32.h> // Blynk library for ESP32
#include <LiquidCrystal.h>    // LCD library for 4-bit mode

// Pin and sensor definitions
#define DATA_PIN 13          // Data pin for the DHT22 sensor
#define DHTTYPE DHT22        // Sensor type
#define RELAY_PIN 27         // Pin controlling the relay (water pump)
#define LED_PIN 14           // Pin controlling the status LED

// Initialize the DHT sensor
DHT sensor(DATA_PIN, DHTTYPE); 

// Initialize the LCD with pin assignments
LiquidCrystal lcd(19, 4, 18, 21, 5, 15); // RS, E, D4, D5, D6, D7

// Wi-Fi credentials
char ssid[] = "Wokwi-GUEST";  // Replace with your Wi-Fi SSID
char pass[] = "";             // Replace with your Wi-Fi password

// Irrigation thresholds
const int HUMIDITY_THRESHOLD = 50;    // Humidity threshold for irrigation
const float TEMPERATURE_THRESHOLD = 25.0; // Temperature threshold (°C)

// Timer interval (in milliseconds) for the loop
const int LOOP_DELAY = 2000;

// Flags for system states
bool isIrrigationActive = false;
bool isManualControlEnabled = false; // Tracks the state of manual control

BLYNK_WRITE(V2) {
  int buttonState = param.asInt(); // Read the button state
  if (buttonState == 1) {
    isManualControlEnabled = true; // Enable manual control
    deactivateIrrigation();        // Ensure the pump is OFF
    Serial.println("Manual control enabled: Pump is OFF.");
    lcd.clear();
    lcd.print("Manual Mode: ON");
  } else {
    isManualControlEnabled = false; // Disable manual control
    Serial.println("Manual control disabled: Automatic mode active.");
    lcd.clear();
    lcd.print("Manual Mode: OFF");
  }
}

void setup() {
  // Start the serial monitor for debugging
  Serial.begin(115200);

  // Initialize the DHT sensor
  sensor.begin();

  // Initialize the LCD
  lcd.begin(16, 2);
  lcd.print("System Starting...");
  delay(2000); // Pause to display startup message
  
  lcd.clear();
  lcd.print("Connecting WiFi...");

  // Display connection attempt
  Serial.print("Connecting to Wi-Fi: ");
  Serial.println(ssid);

  // Initialize Blynk with the authentication token and Wi-Fi credentials
  Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);

  // Configure relay and LED pins as outputs
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);

  // Ensure the relay and LED are off initially
  digitalWrite(RELAY_PIN, LOW);
  digitalWrite(LED_PIN, LOW);

  // Display system ready message
  lcd.clear();
  lcd.print("System Ready");
  Serial.println("Setup complete. System is ready.");
}

void loop() {
  Blynk.run(); // Run the Blynk process

  if (!isManualControlEnabled) { // Automatic control logic
    // Read temperature and humidity values
    float temperature = sensor.readTemperature();
    float humidity = sensor.readHumidity();

    // Check if sensor data is valid
    if (isnan(temperature) || isnan(humidity)) {
      Serial.println("Error: Failed to read from DHT sensor.");
      lcd.setCursor(0, 0);
      lcd.print("Sensor Error!");
    } else {
      // Display temperature and humidity in the serial monitor
      Serial.print("Temperature: ");
      Serial.print(temperature);
      Serial.print(" °C, Humidity: ");
      Serial.print(humidity);
      Serial.println(" %");

      // Update LCD display with temperature and humidity
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Temp: ");
      lcd.print(temperature);
      lcd.print(" C");

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

      // Send sensor data to Blynk virtual pins
      Blynk.virtualWrite(V6, temperature); // Send temperature to virtual pin V6
      Blynk.virtualWrite(V7, humidity);   // Send humidity to virtual pin V7
    }

    // Automatic control of irrigation
    if (shouldIrrigate(humidity, temperature)) {
      activateIrrigation(); // Turn on water pump and LED
    } else {
      deactivateIrrigation(); // Turn off water pump and LED
    }
  }

  delay(LOOP_DELAY);
}



// Function to decide if irrigation should be activated
bool shouldIrrigate(float humidity, float temperature) {
  if (humidity < HUMIDITY_THRESHOLD && temperature > TEMPERATURE_THRESHOLD) {
    Serial.println("Decision: Activate irrigation. Low humidity and high temperature detected.");
    return true;
  }
  Serial.println("Decision: No irrigation needed. Conditions are normal.");
  return false;
}

// Function to activate irrigation
void activateIrrigation() {
  if (!isIrrigationActive) { // Activate only if not already active
    Serial.println("Irrigation ON: Activating water pump and LED.");
    digitalWrite(RELAY_PIN, HIGH); // Turn on relay
    digitalWrite(LED_PIN, HIGH);  // Turn on LED
    Blynk.virtualWrite(V1, 1);    // Update Blynk status (ON) on virtual pin V1
    isIrrigationActive = true;    // Update irrigation state

    // Update LCD status
    lcd.clear();
    lcd.print("Irrigation: ON");
  }
}

// Function to deactivate irrigation
void deactivateIrrigation() {
  if (isIrrigationActive) { // Deactivate only if currently active
    Serial.println("Irrigation OFF: Deactivating water pump and LED.");
    digitalWrite(RELAY_PIN, LOW); // Turn off relay
    digitalWrite(LED_PIN, LOW);  // Turn off LED
    Blynk.virtualWrite(V1, 0);    // Update Blynk status (OFF) on virtual pin V1
    isIrrigationActive = false;   // Update irrigation state

    // Update LCD status
    lcd.clear();
    lcd.print("Irrigation: OFF");
  }
}