#include <Arduino.h>
#include <LiquidCrystal_I2C.h>
#include "DHT.h"

// -------- Pins --------
#define TRIG_PIN 5
#define ECHO_PIN 18
#define DHT_PIN 4
#define DHT_TYPE DHT22
#define RED_LED_PIN 2
#define GREEN_LED_PIN 15
#define BLUE_LED_PIN 19  

// -------- Limits --------
#define TEMP_LIMIT 35
#define HUM_LIMIT 60

LiquidCrystal_I2C lcd(0x27, 16, 2);
DHT dht(DHT_PIN, DHT_TYPE);

float temperature = 0;
float humidity = 0;
float distance = 0;


// ───────── Door Monitoring Task ─────────
void ultrasonicTask(void *pvParameters) {

  for (;;) {

    digitalWrite(TRIG_PIN, LOW);
    delayMicroseconds(2);

    digitalWrite(TRIG_PIN, HIGH);
    delayMicroseconds(10);
    digitalWrite(TRIG_PIN, LOW);

    long duration = pulseIn(ECHO_PIN, HIGH, 30000);

    if (duration > 0) {

      distance = (duration * 0.034) / 2;

      Serial.print("Door Distance: ");
      Serial.println(distance);

      if (distance > 200) {

        Serial.println("Door OPEN!");
        digitalWrite(BLUE_LED_PIN, HIGH);   // Blue LED ON

      } 
      else {

        Serial.println("Door CLOSED");
        digitalWrite(BLUE_LED_PIN, LOW);    // Blue LED OFF
      }
    }

    vTaskDelay(pdMS_TO_TICKS(1000));
  }
}


// ───────── Temperature & Humidity Task ─────────
void dhtTask(void *pvParameters) {

  for (;;) {

    float h = dht.readHumidity();
    float t = dht.readTemperature();

    if (!isnan(h) && !isnan(t)) {

      temperature = t;
      humidity = h;

      Serial.printf("Temp: %.1fC | Humidity: %.1f%%\n", t, h);

      if (t < TEMP_LIMIT && h < HUM_LIMIT) {

        digitalWrite(GREEN_LED_PIN, HIGH);
        digitalWrite(RED_LED_PIN, LOW);

        Serial.println("SYSTEM NORMAL");

      } 
      else {

        digitalWrite(GREEN_LED_PIN, LOW);
        digitalWrite(RED_LED_PIN, HIGH);

        if (t >= TEMP_LIMIT && h >= HUM_LIMIT) {
          Serial.println("TEMP & HUMIDITY HIGH");
        }
        else if (t >= TEMP_LIMIT) {
          Serial.println("TEMPERATURE HIGH");
        }
        else if (h >= HUM_LIMIT) {
          Serial.println("HUMIDITY HIGH");
        }
      }
    }

    vTaskDelay(pdMS_TO_TICKS(2000));
  }
}


// ───────── LCD Display Task ─────────
void lcdTask(void *pvParameters) {

  for (;;) {

    lcd.clear();

    lcd.setCursor(0,0);
    lcd.print("T:");
    lcd.print(temperature);
    lcd.print("C H:");
    lcd.print(humidity);

    lcd.setCursor(0,1);

    if (temperature < TEMP_LIMIT && humidity < HUM_LIMIT) {
      lcd.print("SYSTEM NORMAL");
    }
    else if (temperature >= TEMP_LIMIT && humidity >= HUM_LIMIT) {
      lcd.print("TEMP&HUM HIGH");
    }
    else if (temperature >= TEMP_LIMIT) {
      lcd.print("TEMP HIGH");
    }
    else if (humidity >= HUM_LIMIT) {
      lcd.print("HUMID HIGH");
    }

    vTaskDelay(pdMS_TO_TICKS(2000));
  }
}


// ───────── Setup ─────────
void setup() {

  Serial.begin(115200);

  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(GREEN_LED_PIN, OUTPUT);
  pinMode(BLUE_LED_PIN, OUTPUT);   // Blue LED pin

  digitalWrite(RED_LED_PIN, LOW);
  digitalWrite(GREEN_LED_PIN, LOW);
  digitalWrite(BLUE_LED_PIN, LOW);

  dht.begin();

  lcd.init();
  lcd.backlight();

  xTaskCreate(ultrasonicTask, "DoorTask", 2048, NULL, 1, NULL);
  xTaskCreate(dhtTask, "EnvTask", 2048, NULL, 1, NULL);
  xTaskCreate(lcdTask, "LCDTask", 4096, NULL, 1, NULL);
}

void loop() {
  vTaskDelete(NULL);
}