#include <OneWire.h>
#include <DallasTemperature.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Servo.h>

#define ONE_WIRE_BUS 2
#define SERVO_PIN 3
#define LIGHT_PIN 4           // LED for day-night shifting
#define WATER_LEVEL_PIN 5     // Push button pin
#define HEATING_RELAY_PIN 6   // Relay to control the heating element
#define COOLING_RELAY_PIN 7   // Relay to control the cooling element
#define HEATING_LED_PIN 8     // LED to simulate the heating element
#define COOLING_LED_PIN 9     // LED to simulate the cooling element
#define BUZZER_PIN 10         // Buzzer pin
#define OXYGEN_SENSOR_PIN A0  // Analog pin for oxygen sensor (using a potentiometer for simulation)
#define OXYGEN_LED_PIN 11     // LED pin to simulate oxygen pump

OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);
Servo feederServo;
LiquidCrystal_I2C lcd(0x27, 16, 2);

unsigned long previousMillis = 0;  // Variable to store the previous time
const long interval = 10000;       // Interval in milliseconds (10 seconds)

const float TEMP_THRESHOLD_LOW = 22.0;  // Lower temperature threshold
const float TEMP_THRESHOLD_HIGH = 28.0; // Upper temperature threshold

bool waterLevelLow = false; // Flag to indicate if water level is low
bool buzzerState = false;   // Flag to indicate buzzer state

void setup() 
{
  sensors.begin();
  
  pinMode(LIGHT_PIN, OUTPUT);
  pinMode(WATER_LEVEL_PIN, INPUT_PULLUP); // Set pin mode to INPUT_PULLUP for the push button
  pinMode(HEATING_RELAY_PIN, OUTPUT);
  pinMode(COOLING_RELAY_PIN, OUTPUT);
  pinMode(HEATING_LED_PIN, OUTPUT);
  pinMode(COOLING_LED_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);  // Initialize buzzer pin
  pinMode(OXYGEN_SENSOR_PIN, INPUT); // Initialize oxygen sensor pin (potentiometer)
  pinMode(OXYGEN_LED_PIN, OUTPUT); // Initialize LED pin to simulate oxygen pump
  
  feederServo.attach(SERVO_PIN);

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

  lcd.setCursor(0, 0);
  lcd.print("Smart Aquarium");
  delay(2000);
  lcd.clear();
}

void loop() 
{
  unsigned long currentMillis = millis();  // Get the current time

  // Temperature Control
  sensors.requestTemperatures();
  float temperature = sensors.getTempCByIndex(0);

  // Control the heating element based on temperature thresholds
  if (temperature < TEMP_THRESHOLD_LOW) 
  {
    digitalWrite(HEATING_RELAY_PIN, HIGH);  // Turn on the heating relay (and heating element)
    digitalWrite(HEATING_LED_PIN, HIGH);    // Turn on the LED to simulate heating
  } 
  else 
  {
    digitalWrite(HEATING_RELAY_PIN, LOW);   // Turn off the heating relay (and heating element)
    digitalWrite(HEATING_LED_PIN, LOW);     // Turn off the LED to simulate heating
  }

  // Control the cooling element based on temperature thresholds
  if (temperature > TEMP_THRESHOLD_HIGH) 
  {
    digitalWrite(COOLING_RELAY_PIN, HIGH);  // Turn on the cooling relay (and cooling element)
    digitalWrite(COOLING_LED_PIN, HIGH);    // Turn on the LED to simulate cooling
  } 
  else 
  {
    digitalWrite(COOLING_RELAY_PIN, LOW);   // Turn off the cooling relay (and cooling element)
    digitalWrite(COOLING_LED_PIN, LOW);     // Turn off the LED to simulate cooling
  }

  // Check water level using push button
  waterLevelLow = digitalRead(WATER_LEVEL_PIN) == LOW;

  // Check if water level has changed
  if (waterLevelLow) 
  {
    // Water level is low
    lcd.setCursor(0, 0);
    lcd.print("Please ADD WATER!!!");
    delay(2000);  
    lcd.clear();
    buzzerState = !buzzerState; // Toggle buzzer state
    digitalWrite(BUZZER_PIN, buzzerState ? HIGH : LOW); // Turn on/off buzzer
  } 
  else
   {
    // Water level is okay
    if (buzzerState) 
    {
      // Turn off buzzer if it was buzzing
      buzzerState = false;
      digitalWrite(BUZZER_PIN, LOW);
    }
  }

  // Simulate day-night lighting cycle
  int hour = (millis() / 1000 / 60) % 24; // Simulate hour of the day
  if (hour >= 1 && hour < 2) {
    digitalWrite(LIGHT_PIN, HIGH); // Daytime
  } 
  else 
  {
    digitalWrite(LIGHT_PIN, LOW); // Nighttime
  }

  // Read oxygen level from potentiometer
  int oxygenSensorValue = analogRead(OXYGEN_SENSOR_PIN);
  float oxygenLevel = map(oxygenSensorValue, 0, 1023, 0, 100); // Simulate oxygen level from 0 to 100%

  // Update LCD
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(temperature);
  lcd.print("C");

  lcd.setCursor(0, 1);
  lcd.print("Water: ");
  lcd.print(waterLevelLow ? "Low" : "Ok");
  delay(2000);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("O2: ");
  lcd.print(oxygenLevel);
  lcd.print("%");
  
  // Simulate oxygen pump
 digitalWrite(OXYGEN_LED_PIN, oxygenLevel > 80 ? LOW : HIGH); // Turn off the LED if oxygen level is above 50%
  delay(2000);  // Main loop delay
  lcd.clear();
}

void feedFish() 
{
  lcd.setCursor(0, 0);
  lcd.print("Feeding fish...");
  delay(2000);  // Main loop delay
  feederServo.write(90);  // Rotate servo to dispense food
  delay(2000);  // Adjust as needed
  feederServo.write(0);   // Return to initial position
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Done feeding.");
  delay(2000);
  lcd.clear();
}