// Define pins for sensor, relay, and button
#define previousButtonPin 3   // Previous relay button
#define buzzerPin 12           // Buzzer pin
#define relaysCount 4          // Total number of relays
int relayPins[relaysCount] = {11, 10, 9, 8}; // Relay pins

#define bottomSensorPower 12  // Power pin for the bottom sensor
#define bottomSensorPin A0    // Analog pin for the bottom sensor

#define topSensorPower 13     // Power pin for the top sensor
#define topSensorPin A1       // Analog pin for the top sensor

#define nextButtonPin 2       // Next relay button

// Variables for relay control
int currentRelay = 0;        // Index of the current relay
unsigned long relayTimer = 0; // Timer to track relay duration
unsigned long relayDuration = 10000; // 10 seconds in milliseconds

// Variables for water sensor levels
int bottomSensorValue = 0;
int topSensorValue = 0;

// Flags for relay operation
bool isTwoRelaysActive = false; // Tracks if two relays should be open
bool isFirstRun = true;         // Tracks the first run for immediate activation

void setup() {
  // Initialize sensor pins
  pinMode(bottomSensorPower, OUTPUT);
  pinMode(topSensorPower, OUTPUT);
  digitalWrite(bottomSensorPower, LOW);
  digitalWrite(topSensorPower, LOW);

  // Initialize relay pins
  for (int i = 0; i < relaysCount; i++) {
    pinMode(relayPins[i], OUTPUT);
    digitalWrite(relayPins[i], LOW); // Ensure all relays are OFF
  }

  // Initialize buzzer pins
  pinMode(buzzerPin, OUTPUT);
  digitalWrite(buzzerPin, LOW);
  pinMode(nextButtonPin, INPUT_PULLUP);
  pinMode(previousButtonPin, INPUT_PULLUP);

  // Start serial communication
  Serial.begin(9600);
}

void loop() {
  // Read sensor values
  bottomSensorValue = 0;
  // topSensorValue = readSensor(topSensorPower, topSensorPin);

  // Print sensor readings
  // Serial.print("Bottom Sensor: ");
  // Serial.println(bottomSensorValue);
  // Serial.print("Top Sensor: ");
  // Serial.println(topSensorValue);

  // Check water level and control relays
  if (bottomSensorValue == 0) { 
    // Below bottom sensor
    soundAlarm();
    isTwoRelaysActive = false;  // Activate only one relay in this case
    operateRelays(1);
  }
  else if (topSensorValue > 500) {
    // Above top sensor
    isTwoRelaysActive = true;  // Activate two relays when water level is high
    operateRelays(2);
  }
  else {
    // Between bottom and top sensors
    isTwoRelaysActive = false;  // Activate only one relay
    operateRelays(1);
  }

  // Handle button presses
  handleButtons();
}

// Function to read sensor values
int readSensor(int sensorPower, int sensorPin) {
  digitalWrite(sensorPower, HIGH);  // Turn the sensor ON
  delay(10);                        // Wait for stable reading
  int value = analogRead(sensorPin);// Read the analog value
  digitalWrite(sensorPower, LOW);   // Turn the sensor OFF
  return value;                     // Return the sensor reading
}

// Function to sound alarm
void soundAlarm() {
  tone(buzzerPin, 1000); // Sound buzzer at 1000 Hz
  delay(500);
  noTone(buzzerPin);     // Turn buzzer off
  delay(500);
}

// Function to operate relays
void operateRelays(int numberOfRelays) {
  // Check if it's the first run or if enough time has passed to activate relays
  if (isFirstRun || millis() - relayTimer >= relayDuration) {
    // Turn off all relays first
    for (int i = 0; i < relaysCount; i++) {
      digitalWrite(relayPins[i], LOW);
    }  
relayDuration = 10000;
    // Open the required number of relays
    for (int i = 0; i < numberOfRelays; i++) {
      int relayIndex = (currentRelay + i) % relaysCount;
      digitalWrite(relayPins[relayIndex], HIGH);
      Serial.println(relayIndex);
    }

    // Update timer and relay index
    relayTimer = millis();  // Set relay timer to current time
    currentRelay = (currentRelay + numberOfRelays) % relaysCount;

    // Disable first-run flag after the initial activation
    isFirstRun = false;
  }
}

void handleButtons() {
  // Check for "Next" button press
  if (digitalRead(nextButtonPin) == LOW) {
    delay(200); // Debounce delay

    Serial.println("nextbutton");

    // Check if millis() is less than relayDuration
    if (millis() - relayTimer < relayDuration) {
      relayDuration = 0;  // Set relayDuration to 0
    }

    // Determine how many relays to activate
    int numberOfActiveRelays = isTwoRelaysActive ? 2 : 1;

    // Reset the relay timer to immediately switch the relay
    relayTimer = 0; // Reset timer
    operateRelays(numberOfActiveRelays); // Operate the next relays
  }

  // Check for "Previous" button press
  if (digitalRead(previousButtonPin) == LOW) {
    delay(200); // Debounce delay

    Serial.println("previousbutton");

    // Determine how many relays to activate
    int numberOfActiveRelays = isTwoRelaysActive ? 2 : 1;

    // Calculate the new currentRelay index for "Previous" operation
    if (numberOfActiveRelays == 1) 
    {
      // Subtract 2 if a single relay is active
      currentRelay = (currentRelay - 2 + relaysCount) % relaysCount;
    } else {
      // Subtract 4 if two relays are active
      currentRelay = (currentRelay - 4 + relaysCount) % relaysCount;
    }

    // Reset the timer to immediately move to the previous relay
    relayTimer = 0; // Reset timer
    operateRelays(numberOfActiveRelays); // Operate the previous relays
  }
}