#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <DHT.h>

// I2C LCD address and dimensions
LiquidCrystal_I2C lcd(0x27, 16, 2);  // Address 0x27 or 0x3F

// DHT22 Sensor pin and type
#define DHT_PIN 15  // GPIO 15
#define DHT_TYPE DHT22  // DHT22 sensor type

// Relay Pins
#define RELAY_TEMP_PIN 33  // GPIO 33 - Relay for temperature control
#define RELAY_HUMID_PIN 32  // GPIO 32 - Relay for humidity control
#define RELAY_FAN_PIN 25    // GPIO 25 - Fan control relay
#define RELAY_LDR_PIN 26    // GPIO 26 - Relay control for light intensity

// LDR pin
#define LDR_PIN 34  // GPIO 34 - Analog pin for light intensity

// Thresholds
#define TEMP_THRESHOLD_LOW 28.0  // Fan low speed threshold (28°C)
#define TEMP_THRESHOLD_HIGH 35.0 // Fan high speed threshold (35°C)
#define HUMIDITY_THRESHOLD 50.0  // Humidity threshold for relay control
#define LIGHT_THRESHOLD 500      // Light intensity threshold for relay control

// Initialize DHT sensor
DHT dht(DHT_PIN, DHT_TYPE);

void setup() {
  // Start Serial Monitor
  Serial.begin(115200);

  // Initialize the LCD
  lcd.init();
  lcd.backlight();

  // Initialize DHT sensor
  dht.begin();

  // Set relay pins as outputs
  pinMode(RELAY_TEMP_PIN, OUTPUT);
  pinMode(RELAY_HUMID_PIN, OUTPUT);
  pinMode(RELAY_FAN_PIN, OUTPUT);
  pinMode(RELAY_LDR_PIN, OUTPUT);

  // Ensure relays are initially off
  digitalWrite(RELAY_TEMP_PIN, LOW);
  digitalWrite(RELAY_HUMID_PIN, LOW);
  digitalWrite(RELAY_FAN_PIN, LOW);
  digitalWrite(RELAY_LDR_PIN, LOW);

  // LCD initialization message
  lcd.setCursor(0, 0);
  lcd.print("Initializing...");
  delay(2000);  // 2 second delay for initialization
  lcd.clear();
}

void loop() {
  // Read sensor values
  float humidity = dht.readHumidity();
  float temperatureC = dht.readTemperature();
  int lightIntensity = analogRead(LDR_PIN);  // Read light intensity from LDR

  // Check for sensor failure
  if (isnan(humidity) || isnan(temperatureC)) {
    lcd.setCursor(0, 0);
    lcd.print("Sensor Error");
    return;
  }

  // Control temperature relay
  if (temperatureC > TEMP_THRESHOLD_LOW) {
    digitalWrite(RELAY_TEMP_PIN, HIGH);  // Temperature control relay ON
  } else {
    digitalWrite(RELAY_TEMP_PIN, LOW);   // Temperature control relay OFF
  }

  // Control humidity relay
  if (humidity > HUMIDITY_THRESHOLD) {
    digitalWrite(RELAY_HUMID_PIN, HIGH);  // Humidity control relay ON
  } else {
    digitalWrite(RELAY_HUMID_PIN, LOW);   // Humidity control relay OFF
  }

  // Control LDR relay based on light intensity
  if (lightIntensity < LIGHT_THRESHOLD) {
    digitalWrite(RELAY_LDR_PIN, HIGH);  // Light intensity control relay ON
  } else {
    digitalWrite(RELAY_LDR_PIN, LOW);   // Light intensity control relay OFF
  }

  // Fan control (simulating different speeds by toggling HIGH/LOW for Wokwi)
  if (temperatureC > TEMP_THRESHOLD_LOW && temperatureC <= TEMP_THRESHOLD_HIGH) {
    // Simulating low speed by turning fan on for a short time
    digitalWrite(RELAY_FAN_PIN, HIGH);
    delay(1000);  // Fan ON for 1 second (simulated low speed)
    digitalWrite(RELAY_FAN_PIN, LOW);
  } else if (temperatureC > TEMP_THRESHOLD_HIGH) {
    // Fan runs continuously at high speed (ON)
    digitalWrite(RELAY_FAN_PIN, HIGH);
  } else {
    // Turn off the fan when temperature is below the threshold
    digitalWrite(RELAY_FAN_PIN, LOW);
  }

  // Display data on LCD
  lcd.setCursor(0, 0);
  lcd.print("T:");
  lcd.print(temperatureC, 1);  // Temperature with 1 decimal
  lcd.print("C H:");
  lcd.print(humidity, 0);      // Humidity as an integer
  lcd.print("%");

  lcd.setCursor(0, 1);
  lcd.print("L:");
  lcd.print(lightIntensity);   // Display light intensity
  lcd.print(" Fan:");
  if (temperatureC > TEMP_THRESHOLD_HIGH) {
    lcd.print("High ");
  } else if (temperatureC > TEMP_THRESHOLD_LOW) {
    lcd.print("Low  ");
  } else {
    lcd.print("Off  ");
  }

  // Serial output for debugging
  Serial.print("Temp: ");
  Serial.print(temperatureC);
  Serial.print("C, Humidity: ");
  Serial.print(humidity);
  Serial.print("%, Light Intensity: ");
  Serial.print(lightIntensity);
  Serial.print(", Fan: ");
  if (temperatureC > TEMP_THRESHOLD_HIGH) {
    Serial.println("Full Speed");
  } else if (temperatureC > TEMP_THRESHOLD_LOW) {
    Serial.println("Low Speed");
  } else {
    Serial.println("Off");
  }

  delay(2000);  // 2-second delay before next sensor reading
}