#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Preferences.h>
#include <WiFi.h>
#include <WebServer.h>
#include <ArduinoJson.h>

// Forward declarations (unchanged)
void displayLoadingScreen(unsigned long currentMillis);
void handleSettingsButton();
void handleSalesMonitoringTrigger(unsigned long currentMillis);
void loadSettings();
void saveSettings();
void loadSalesData();
void saveSalesData();
void resetSalesData();
void displaySalesMonitoring();
void handleSettingsButtons();
void adjustSettingsValue(bool increment);
void handleNormalMode(unsigned long currentMillis);
int getCurrentCreditCost();
void handleSettingsMode(unsigned long currentMillis);
void Add();
void updateTime();
void handleButton(int button, int relay, int &time, bool &active, bool &paused, int &pauseCount, int defaultTime, bool &buttonPressed, unsigned long &lastButtonTime, int creditCost, String service);
void displayInitialScreen();
void blinkInsertCoin();
void displayActiveScreen();
void updateBalanceDisplay();
void blinkPressButton();
void updateTimeDisplay();
void displayTime(int seconds, bool paused, int column, bool &blinkState, unsigned long &lastBlinkTime);
void handlePausedBlinking();
void updateLEDs(unsigned long currentMillis);
void updateSettingsDisplay();
void beep();

Preferences prefs;
LiquidCrystal_I2C lcd(0x27, 20, 4);
WebServer server(80);

// Wi-Fi AP settings (unchanged)
String ssid = "CarWashESP32";
String password = "12345678";

// ESP32-compatible pins (unchanged)
const int coinSlotPin = 2;
const int waterButton = 4;
const int soapButton = 5;
const int blowerButton = 14;
const int settingsButton = 13;
const int relayWater = 16;
const int relaySoap = 17;
const int relayBlower = 18;
const int waterLED = 25;
const int soapLED = 26;
const int blowerLED = 27;
const int buzzerPin = 19; // Buzzer pin (active-high)

// Constants (unchanged except for buzzer duration)
const int LCD_CLEAR_DELAY = 500;
const unsigned long SALES_DISPLAY_DURATION = 10000;
const unsigned long BLOWER_LONG_PRESS_TIME = 2000;
const unsigned long SOAP_LONG_PRESS_TIME = 2000;
const unsigned long BUZZER_BEEP_DURATION = 300; // Increased to 500ms for better Wokwi audio detection
const unsigned long BUZZER_COOLDOWN = 300; // Added: 1-second cooldown between beeps

int DEFAULT_WATER_TIME = 60;
int DEFAULT_SOAP_TIME = 45;
int DEFAULT_BLOWER_TIME = 75;
int WATER_CREDIT_COST = 5;
int SOAP_CREDIT_COST = 5;
int BLOWER_CREDIT_COST = 5;

const int MAX_PAUSE_COUNT = 3;
const unsigned long BLINK_INTERVAL = 450;
const unsigned long COIN_DEBOUNCE_TIME = 300;
const unsigned long BUTTON_DEBOUNCE_TIME = 200;

// Variables (unchanged except for adding buzzer cooldown tracking)
int balance = 0;
int waterTime = 0, soapTime = 0, blowerTime = 0;
bool waterActive = false, soapActive = false, blowerActive = false;
bool waterPaused = false, soapPaused = false, blowerPaused = false;
int waterPauseCount = 0, soapPauseCount = 0, blowerPauseCount = 0;

unsigned long lastCoinTime = 0, lastUpdateTime = 0, lastButtonBlinkTime = 0;
unsigned long lastInsertCoinBlinkTime = 0;
bool showInsertCoin = true, showPressButton = true;
bool screenInitialized = false;

bool waterBlinkState = false, soapBlinkState = false, blowerBlinkState = false;
unsigned long waterLastBlinkTime = 0, soapLastBlinkTime = 0, blowerLastBlinkTime = 0;

// Buzzer state tracking (unchanged)
bool waterBeeped10 = false, waterBeeped6 = false, waterBeeped2 = false;
bool soapBeeped10 = false, soapBeeped6 = false, soapBeeped2 = false;
bool blowerBeeped10 = false, blowerBeeped6 = false, blowerBeeped2 = false;

// Added: Track last beep time for cooldown
unsigned long lastBeepTime = 0;

volatile int coinsInserted = 0;
const int COIN_VALUE = 1;

bool waterButtonPressed = false;
bool soapButtonPressed = false;
bool blowerButtonPressed = false;
unsigned long lastWaterButtonTime = 0;
unsigned long lastSoapButtonTime = 0;
unsigned long lastBlowerButtonTime = 0;
unsigned long lastSettingsButtonTime = 0;

int settingsMode = 0;
int settingsField = 1;
bool settingsBlinkState = false;
unsigned long lastSettingsBlinkTime = 0;

// Loading screen state (unchanged)
bool loadingComplete = false;
int loadingPercent = 0;
unsigned long lastLoadingUpdate = 0;

// Sales monitoring variables (unchanged)
bool salesMonitoringMode = false;
unsigned long salesDisplayStartTime = 0;
int waterSales = 0;
int soapSales = 0;
int blowerSales = 0;

// HTML for web interface (unchanged)
const char* htmlPage = R"rawliteral(
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Car Wash Control Panel</title>
  <style>
    * { margin: 0; padding: 0; box-sizing: border-box; }
    body {
      font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Arial, sans-serif;
      background: linear-gradient(135deg, #1e3a8a, #3b82f6);
      min-height: 100vh;
      display: flex;
      flex-direction: column;
      align-items: center;
      color: #333;
      padding: 1rem;
    }
    .container {
      max-width: 400px;
      width: 100%;
      background: #ffffff;
      border-radius: 15px;
      box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
      padding: 2rem;
      margin: 1rem 0;
      transition: transform 0.3s ease;
    }
    .container:hover { transform: translateY(-5px); }
    h1 {
      font-size: 1.8rem;
      font-weight: 700;
      color: #1e3a8a;
      text-align: center;
      margin-bottom: 0.5rem;
      text-transform: uppercase;
      letter-spacing: 1px;
    }
    h2 {
      font-size: 1.3rem;
      font-weight: 700;
      color: #1e3a8a;
      text-align: center;
      margin: 0.5rem 0 0.5rem;
    }
    hr { border: none; border-top: 1px solid #cbd5e1; margin: 1rem 0; }
    .sales-box, .wifi-box, .timer-box, .pricing-box { display: flex; flex-direction: column; gap: 1rem; }
    .sales-item {
      display: flex;
      justify-content: space-between;
      font-size: 1.1rem;
      padding: 0.75rem;
      background: #f8fafc;
      border-radius: 8px;
      transition: background 0.2s ease;
    }
    .sales-item:hover { background: #e2e8f0; }
    .sales-item span { font-weight: 700; color: #2dd4bf; }
    .wifi-item, .timer-item, .pricing-item { display: flex; flex-direction: column; gap: 0.5rem; }
    .wifi-item label, .timer-item label, .pricing-item label {
      font-size: 1rem;
      font-weight: 500;
      color: #1e3a8a;
    }
    .wifi-item input, .timer-item input, .pricing-item input {
      padding: 0.75rem;
      font-size: 1rem;
      border: 1px solid #cbd5e1;
      border-radius: 8px;
      outline: none;
      transition: border-color 0.3s ease;
    }
    .wifi-item input:focus, .timer-item input:focus, .pricing-item input:focus { border-color: #2dd4bf; }
    .password-container { position: relative; display: flex; align-items: center; }
    .password-container input { width: 100%; padding-right: 2.5rem; }
    .toggle-password {
      position: absolute;
      right: 0.75rem;
      cursor: pointer;
      color: #2dd4bf;
      font-size: 1.2rem;
      transition: color 0.3s ease;
    }
    .toggle-password:hover { color: #1e3a8a; }
    .btn {
      display: block;
      width: 100%;
      padding: 0.75rem;
      margin-top: 1rem;
      background: #ef4444;
      color: #fff;
      border: none;
      border-radius: 8px;
      font-size: 1rem;
      font-weight: 400;
      cursor: pointer;
      transition: background 0.3s ease, transform 0.2s ease;
    }
    .btn:hover { background: #dc2626; transform: scale(1.02); }
    .btn:active { transform: scale(0.98); }
    @media (max-width: 400px) {
      .container { padding: 1.5rem; }
      h1 { font-size: 1.5rem; }
      h2 { font-size: 1.1rem; }
      .sales-item, .wifi-item input, .timer-item input, .pricing-item input { font-size: 0.9rem; }
      .toggle-password { font-size: 1rem; }
    }
  </style>
</head>
<body>
  <div class="container">
    <h1>CAR WASH SALES</h1>
    <hr>
    <div class="sales-box">
      <div class="sales-item">Water Sales: <span id="waterSales">0</span></div>
      <div class="sales-item">Soap Sales: <span id="soapSales">0</span></div>
      <div class="sales-item">Blower Sales: <span id="blowerSales">0</span></div>
      <div class="sales-item">Total Sales: <span id="totalSales">0</span></div>
    </div>
    <button class="btn" onclick="resetSales()">Reset Sales</button>
  </div>
  <div class="container">
    <h2>Wi-Fi Configuration</h2>
    <hr>
    <div class="wifi-box">
      <div class="wifi-item">
        <label for="ssid">Wi-Fi SSID</label>
        <input type="text" id="ssid" maxlength="32">
      </div>
      <div class="wifi-item">
        <label for="password">Password</label>
        <div class="password-container">
          <input type="password" id="password" maxlength="64">
          <span class="toggle-password" onclick="togglePassword()">👁️</span>
        </div>
      </div>
    </div>
    <button class="btn" onclick="saveWifi()">Save Wi-Fi Settings</button>
  </div>
  <div class="container">
    <h2>Wash Timer</h2>
    <hr>
    <div class="timer-box">
      <div class="timer-item">
        <label for="waterTime">Water Time (seconds)</label>
        <input type="number" id="waterTime" min="5" max="999">
      </div>
      <div class="timer-item">
        <label for="soapTime">Soap Time (seconds)</label>
        <input type="number" id="soapTime" min="5" max="999">
      </div>
      <div class="timer-item">
        <label for="blowerTime">Blower Time (seconds)</label>
        <input type="number" id="blowerTime" min="5" max="999">
      </div>
    </div>
    <button class="btn" onclick="saveTimer()">Save Wash Timer</button>
  </div>
  <div class="container">
    <h2>Service Pricing</h2>
    <hr>
    <div class="pricing-box">
      <div class="pricing-item">
        <label for="waterPrice">Water Price (credits)</label>
        <input type="number" id="waterPrice" min="1" max="20">
      </div>
      <div class="pricing-item">
        <label for="soapPrice">Soap Price (credits)</label>
        <input type="number" id="soapPrice" min="1" max="20">
      </div>
      <div class="pricing-item">
        <label for="blowerPrice">Blower Price (credits)</label>
        <input type="number" id="blowerPrice" min="1" max="20">
      </div>
    </div>
    <button class="btn" onclick="savePricing()">Save Service Pricing</button>
  </div>
  <div class="container">
    <h2>System Control</h2>
    <hr>
    <button class="btn" onclick="rebootESP()">Reboot ESP32</button>
  </div>
  <script>
    function updateSales() {
      fetch('/sales')
        .then(response => response.json())
        .then(data => {
          document.getElementById('waterSales').innerText = data.water;
          document.getElementById('soapSales').innerText = data.soap;
          document.getElementById('blowerSales').innerText = data.blower;
          document.getElementById('totalSales').innerText = data.total;
        })
        .catch(error => console.error('Error fetching sales:', error));
    }
    function resetSales() {
      if (confirm('Are you sure you want to reset all sales data?')) {
        fetch('/reset', { method: 'POST' })
          .then(() => updateSales())
          .catch(error => console.error('Error resetting sales:', error));
      }
    }
    function togglePassword() {
      const passwordInput = document.getElementById('password');
      const toggleIcon = document.querySelector('.toggle-password');
      if (passwordInput.type === 'password') {
        passwordInput.type = 'text';
        toggleIcon.textContent = '👁️';
      } else {
        passwordInput.type = 'password';
        toggleIcon.textContent = '👁️';
      }
    }
    function loadWifiSettings() {
      fetch('/wifi-settings')
        .then(response => response.json())
        .then(data => {
          document.getElementById('ssid').value = data.ssid;
          document.getElementById('password').value = data.password;
        })
        .catch(error => console.error('Error fetching Wi-Fi settings:', error));
    }
    function saveWifi() {
      const ssid = document.getElementById('ssid').value.trim();
      const password = document.getElementById('password').value.trim();
      if (!ssid) { alert('SSID cannot be empty.'); return; }
      if (password.length < 8) { alert('Password must be at least 8 characters long.'); return; }
      if (confirm('Save Wi-Fi settings? You will need to reconnect to the new network.')) {
        fetch('/wifi', {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({ ssid: ssid, password: password })
        })
          .then(response => {
            if (response.ok) {
              alert('Wi-Fi settings saved successfully. Please reconnect to the new network.');
              setTimeout(() => window.location.reload(), 2000);
              return;
            }
            return response.text().then(text => { throw new Error(text); });
          })
          .catch(error => {
            if (error.message.includes('Failed to fetch')) {
              alert('Wi-Fi settings saved successfully. Please reconnect to the new network.');
              setTimeout(() => window.location.reload(), 2000);
            } else {
              console.error('Error saving Wi-Fi settings:', error);
              alert('Error saving Wi-Fi settings: ' + error.message);
            }
          });
      }
    }
    function loadTimerSettings() {
      fetch('/timer-settings')
        .then(response => response.json())
        .then(data => {
          document.getElementById('waterTime').value = data.water;
          document.getElementById('soapTime').value = data.soap;
          document.getElementById('blowerTime').value = data.blower;
        })
        .catch(error => console.error('Error fetching timer settings:', error));
    }
    function saveTimer() {
      const waterTime = parseInt(document.getElementById('waterTime').value);
      const soapTime = parseInt(document.getElementById('soapTime').value);
      const blowerTime = parseInt(document.getElementById('blowerTime').value);
      if (isNaN(waterTime) || waterTime < 5 || waterTime > 999) {
        alert('Water time must be between 5 and 999 seconds.');
        return;
      }
      if (isNaN(soapTime) || soapTime < 5 || soapTime > 999) {
        alert('Soap time must be between 5 and 999 seconds.');
        return;
      }
      if (isNaN(blowerTime) || blowerTime < 5 || blowerTime > 999) {
        alert('Blower time must be between 5 and 999 seconds.');
        return;
      }
      if (confirm('Save wash timer settings?')) {
        fetch('/timer', {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({ water: waterTime, soap: soapTime, blower: blowerTime })
        })
          .then(response => {
            if (response.ok) {
              alert('Wash timer settings saved successfully.');
            } else {
              return response.text().then(text => { throw new Error(text); });
            }
          })
          .catch(error => {
            console.error('Error saving timer settings:', error);
            alert('Error saving wash timer settings: ' + error.message);
          });
      }
    }
    function loadPricingSettings() {
      fetch('/pricing-settings')
        .then(response => response.json())
        .then(data => {
          document.getElementById('waterPrice').value = data.water;
          document.getElementById('soapPrice').value = data.soap;
          document.getElementById('blowerPrice').value = data.blower;
        })
        .catch(error => console.error('Error fetching pricing settings:', error));
    }
    function savePricing() {
      const waterPrice = parseInt(document.getElementById('waterPrice').value);
      const soapPrice = parseInt(document.getElementById('soapPrice').value);
      const blowerPrice = parseInt(document.getElementById('blowerPrice').value);
      if (isNaN(waterPrice) || waterPrice < 1 || waterPrice > 20) {
        alert('Water price must be between 1 and 20 credits.');
        return;
      }
      if (isNaN(soapPrice) || soapPrice < 1 || soapPrice > 20) {
        alert('Soap price must be between 1 and 20 credits.');
        return;
      }
      if (isNaN(blowerPrice) || blowerPrice < 1 || blowerPrice > 20) {
        alert('Blower price must be between 1 and 20 credits.');
        return;
      }
      if (confirm('Save service pricing settings?')) {
        fetch('/pricing', {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({ water: waterPrice, soap: soapPrice, blower: blowerPrice })
        })
          .then(response => {
            if (response.ok) {
              alert('Service pricing settings saved successfully.');
            } else {
              return response.text().then(text => { throw new Error(text); });
            }
          })
          .catch(error => {
            console.error('Error saving pricing settings:', error);
            alert('Error saving pricing settings: ' + error.message);
          });
      }
    }
    function rebootESP() {
      if (confirm('Are you sure you want to reboot the ESP32?')) {
        alert('Rebooting... Please wait.');
        fetch('/reboot', { method: 'POST' })
          .then(() => {
            setTimeout(() => window.location.reload(), 5000);
          })
          .catch(error => {
            console.error('Error initiating reboot:', error);
            alert('Reboot initiated. Please wait and reconnect if necessary.');
            setTimeout(() => window.location.reload(), 5000);
          });
      }
    }
    setInterval(updateSales, 2000);
    window.onload = () => {
      updateSales();
      loadWifiSettings();
      loadTimerSettings();
      loadPricingSettings();
    };
  </script>
</body>
</html>
)rawliteral";

void setup() {
    Serial.begin(115200); // Initialize Serial for debugging
    pinMode(coinSlotPin, INPUT_PULLUP);
    pinMode(waterButton, INPUT_PULLUP);
    pinMode(soapButton, INPUT_PULLUP);
    pinMode(blowerButton, INPUT_PULLUP);
    pinMode(settingsButton, INPUT_PULLUP);
    pinMode(relayWater, OUTPUT);
    pinMode(relaySoap, OUTPUT);
    pinMode(relayBlower, OUTPUT);
    pinMode(waterLED, OUTPUT);
    pinMode(soapLED, OUTPUT);
    pinMode(blowerLED, OUTPUT);
    pinMode(buzzerPin, OUTPUT);

    digitalWrite(relayWater, LOW);
    digitalWrite(relaySoap, LOW);
    digitalWrite(relayBlower, LOW);
    digitalWrite(waterLED, HIGH);
    digitalWrite(soapLED, HIGH);
    digitalWrite(blowerLED, HIGH);
    digitalWrite(buzzerPin, LOW);

    // Modified: Use tone() for buzzer test at startup
    tone(buzzerPin, 1000); // 1000 Hz tone
    delay(500);
    noTone(buzzerPin);
    Serial.println("Buzzer test in setup");

    lcd.init();
    lcd.backlight();
    
    prefs.begin("carwash", false);
    loadSettings();
    loadSalesData();

    String savedSsid = prefs.getString("wifi_ssid", "");
    String savedPassword = prefs.getString("wifi_password", "");
    if (savedSsid != "" && savedPassword != "") {
        ssid = savedSsid;
        password = savedPassword;
    }

    WiFi.softAP(ssid.c_str(), password.c_str());
    IPAddress IP = WiFi.softAPIP();

    server.on("/", HTTP_GET, []() {
        server.send(200, "text/html", htmlPage);
    });
    server.on("/sales", HTTP_GET, []() {
        String json = "{\"water\":" + String(waterSales) + 
                      ",\"soap\":" + String(soapSales) + 
                      ",\"blower\":" + String(blowerSales) + 
                      ",\"total\":" + String(waterSales + soapSales + blowerSales) + "}";
        server.send(200, "application/json", json);
    });
    server.on("/reset", HTTP_POST, []() {
        resetSalesData();
        server.send(200, "text/plain", "Sales reset");
    });
    server.on("/wifi-settings", HTTP_GET, []() {
        String json = "{\"ssid\":\"" + ssid + "\",\"password\":\"" + password + "\"}";
        server.send(200, "application/json", json);
    });
    server.on("/wifi", HTTP_POST, []() {
        if (server.hasArg("plain")) {
            String body = server.arg("plain");
            DynamicJsonDocument doc(512);
            DeserializationError error = deserializeJson(doc, body);
            if (!error) {
                String newSsid = doc["ssid"].as<String>();
                String newPassword = doc["password"].as<String>();
                if (newSsid != "" && newPassword.length() >= 8) {
                    prefs.putString("wifi_ssid", newSsid);
                    prefs.putString("wifi_password", newPassword);
                    ssid = newSsid;
                    password = newPassword;
                    server.send(200, "text/plain", "Wi-Fi settings updated");
                    WiFi.softAPdisconnect(true);
                    delay(100);
                    WiFi.softAP(newSsid.c_str(), newPassword.c_str());
                    return;
                } else {
                    server.send(400, "text/plain", "Invalid SSID or password (minimum 8 characters)");
                    return;
                }
            } else {
                server.send(400, "text/plain", "Invalid JSON format");
                return;
            }
        }
        server.send(400, "text/plain", "No data received");
    });
    server.on("/timer-settings", HTTP_GET, []() {
        String json = "{\"water\":" + String(DEFAULT_WATER_TIME) + 
                      ",\"soap\":" + String(DEFAULT_SOAP_TIME) + 
                      ",\"blower\":" + String(DEFAULT_BLOWER_TIME) + "}";
        server.send(200, "application/json", json);
    });
    server.on("/timer", HTTP_POST, []() {
        if (server.hasArg("plain")) {
            String body = server.arg("plain");
            DynamicJsonDocument doc(512);
            DeserializationError error = deserializeJson(doc, body);
            if (!error) {
                int waterTime = doc["water"];
                int soapTime = doc["soap"];
                int blowerTime = doc["blower"];
                if (waterTime >= 5 && waterTime <= 999 &&
                    soapTime >= 5 && soapTime <= 999 &&
                    blowerTime >= 5 && blowerTime <= 999) {
                    DEFAULT_WATER_TIME = waterTime;
                    DEFAULT_SOAP_TIME = soapTime;
                    DEFAULT_BLOWER_TIME = blowerTime;
                    prefs.putInt("waterTime", DEFAULT_WATER_TIME);
                    prefs.putInt("soapTime", DEFAULT_SOAP_TIME);
                    prefs.putInt("blowerTime", DEFAULT_BLOWER_TIME);
                    server.send(200, "text/plain", "Timer settings updated");
                    return;
                } else {
                    server.send(400, "text/plain", "Timer values must be between 5 and 999");
                    return;
                }
            } else {
                server.send(400, "text/plain", "Invalid JSON format");
                return;
            }
        }
        server.send(400, "text/plain", "No data received");
    });
    server.on("/pricing-settings", HTTP_GET, []() {
        String json = "{\"water\":" + String(WATER_CREDIT_COST) + 
                      ",\"soap\":" + String(SOAP_CREDIT_COST) + 
                      ",\"blower\":" + String(BLOWER_CREDIT_COST) + "}";
        server.send(200, "application/json", json);
    });
    server.on("/pricing", HTTP_POST, []() {
        if (server.hasArg("plain")) {
            String body = server.arg("plain");
            DynamicJsonDocument doc(512);
            DeserializationError error = deserializeJson(doc, body);
            if (!error) {
                int waterPrice = doc["water"];
                int soapPrice = doc["soap"];
                int blowerPrice = doc["blower"];
                if (waterPrice >= 1 && waterPrice <= 20 &&
                    soapPrice >= 1 && soapPrice <= 20 &&
                    blowerPrice >= 1 && blowerPrice <= 20) {
                    WATER_CREDIT_COST = waterPrice;
                    SOAP_CREDIT_COST = soapPrice;
                    BLOWER_CREDIT_COST = blowerPrice;
                    prefs.putInt("waterCredit", WATER_CREDIT_COST);
                    prefs.putInt("soapCredit", SOAP_CREDIT_COST);
                    prefs.putInt("blowerCredit", BLOWER_CREDIT_COST);
                    server.send(200, "text/plain", "Pricing settings updated");
                    return;
                } else {
                    server.send(400, "text/plain", "Pricing values must be between 1 and 20");
                    return;
                }
            } else {
                server.send(400, "text/plain", "Invalid JSON format");
                return;
            }
        }
        server.send(400, "text/plain", "No data received");
    });
    server.on("/reboot", HTTP_POST, []() {
        server.send(200, "text/plain", "Rebooting");
        delay(100);
        ESP.restart();
    });

    server.begin();

    attachInterrupt(digitalPinToInterrupt(coinSlotPin), Add, FALLING);
}

void loop() {
    unsigned long currentMillis = millis();
    server.handleClient();

    if (!loadingComplete) {
        displayLoadingScreen(currentMillis);
        return;
    }

    handleSalesMonitoringTrigger(currentMillis);

    if (salesMonitoringMode) {
        static unsigned long soapPressStartTime = 0;
        static bool soapLongPressHandled = false;
        static bool soapWasPressed = false;

        bool currentSoapState = digitalRead(soapButton) == LOW;

        if (currentSoapState && !soapWasPressed) {
            soapPressStartTime = currentMillis;
            soapLongPressHandled = false;
            soapWasPressed = true;
        } else if (currentSoapState && soapWasPressed) {
            if (!soapLongPressHandled && (currentMillis - soapPressStartTime >= SOAP_LONG_PRESS_TIME)) {
                soapLongPressHandled = true;
                resetSalesData();
                displaySalesMonitoring();
            }
        } else if (!currentSoapState) {
            soapWasPressed = false;
            soapLongPressHandled = false;
        }

        if (currentMillis - salesDisplayStartTime >= SALES_DISPLAY_DURATION) {
            salesMonitoringMode = false;
            lcd.clear();
            if (balance == 0 && waterTime == 0 && soapTime == 0 && blowerTime == 0) {
                displayInitialScreen();
            } else {
                displayActiveScreen();
            }
        }
        return;
    }

    handleSettingsButton();

    if (settingsMode == 0) {
        handleNormalMode(currentMillis);
    } else {
        handleSettingsMode(currentMillis);
    }
}

// Rest of the functions (unchanged until beep())
void displayLoadingScreen(unsigned long currentMillis) {
    const int barLength = 16;
    const char block = 0xFF;
    const int delayPerStep = 50;
    static bool reached100Percent = false;

    if (loadingPercent == 0) {
        lcd.clear();
        lcd.setCursor(4, 0);
        lcd.print("Initializing!");
        lcd.setCursor(1, 2);
        lcd.print("[");
        lcd.setCursor(18, 2);
        lcd.print("]");
    }

    if (currentMillis - lastLoadingUpdate >= delayPerStep) {
        lastLoadingUpdate = currentMillis;
        int blocksToShow = map(loadingPercent, 0, 100, 0, barLength);
        lcd.setCursor(2, 2);
        for (int i = 0; i < barLength; i++) {
            lcd.print(i < blocksToShow ? block : ' ');
        }
        lcd.setCursor(8, 3);
        if (loadingPercent <= 100) {
            lcd.print(loadingPercent);
        } else {
            lcd.print("100");
        }
        lcd.print("%");
        if (loadingPercent < 100) lcd.print(" ");

        if (loadingPercent < 100) {
            loadingPercent++;
        } else {
            reached100Percent = true;
        }

        if (reached100Percent) {
            static unsigned long pauseStart = 0;
            if (pauseStart == 0) pauseStart = currentMillis;
            if (currentMillis - pauseStart >= LCD_CLEAR_DELAY) {
                lcd.clear();
                loadingComplete = true;
                loadingPercent = 0;
                reached100Percent = false;
                displayInitialScreen();
                digitalWrite(waterLED, LOW);
                digitalWrite(soapLED, LOW);
                digitalWrite(buzzerPin, LOW);
            }
        }
    }
}

void handleSettingsButton() {
    static unsigned long pressStartTime = 0;
    static bool longPressHandled = false;
    const unsigned long LONG_PRESS_TIME = 900;
    const unsigned long COOLDOWN_PERIOD = 500;
    static bool buttonWasPressed = false;

    static unsigned long lastExitTime = 0;
    if (millis() - lastExitTime < COOLDOWN_PERIOD) return;

    bool currentButtonState = digitalRead(settingsButton) == LOW;

    if (currentButtonState && !buttonWasPressed && (millis() - lastSettingsButtonTime > BUTTON_DEBOUNCE_TIME)) {
        buttonWasPressed = true;
        pressStartTime = millis();
        lastSettingsButtonTime = millis();
        longPressHandled = false;

        if (settingsMode == 0) {
            settingsMode = 1;
            lcd.clear();
            updateSettingsDisplay();
            digitalWrite(relayWater, LOW);
            digitalWrite(relaySoap, LOW);
            digitalWrite(relayBlower, LOW);
            beep();
            Serial.println("Beep on entering settings mode");
        } else {
            settingsMode = (settingsMode % 3) + 1;
            updateSettingsDisplay();
        }
    } else if (!currentButtonState && buttonWasPressed) {
        buttonWasPressed = false;
        if (millis() - pressStartTime >= LONG_PRESS_TIME && !longPressHandled) {
            longPressHandled = true;
            if (settingsMode != 0) {
                settingsMode = 0;
                saveSettings();
                lcd.clear();
                displayActiveScreen();
                digitalWrite(relayWater, waterTime > 0 ? HIGH : LOW);
                digitalWrite(relaySoap, soapTime > 0 ? HIGH : LOW);
                digitalWrite(relayBlower, blowerTime > 0 ? HIGH : LOW);
                beep();
                Serial.println("Beep on exiting settings mode");
                lastExitTime = millis();
            }
        }
    }
}

void loadSettings() {
    DEFAULT_WATER_TIME = prefs.getInt("waterTime", 60);
    DEFAULT_SOAP_TIME = prefs.getInt("soapTime", 45);
    DEFAULT_BLOWER_TIME = prefs.getInt("blowerTime", 75);
    WATER_CREDIT_COST = prefs.getInt("waterCredit", 5);
    SOAP_CREDIT_COST = prefs.getInt("soapCredit", 5);
    BLOWER_CREDIT_COST = prefs.getInt("blowerCredit", 5);
    
    if (DEFAULT_WATER_TIME == -1) DEFAULT_WATER_TIME = 60;
    if (DEFAULT_SOAP_TIME == -1) DEFAULT_SOAP_TIME = 45;
    if (DEFAULT_BLOWER_TIME == -1) DEFAULT_BLOWER_TIME = 75;
    if (WATER_CREDIT_COST == -1) WATER_CREDIT_COST = 5;
    if (SOAP_CREDIT_COST == -1) SOAP_CREDIT_COST = 5;
    if (BLOWER_CREDIT_COST == -1) BLOWER_CREDIT_COST = 5;

    DEFAULT_WATER_TIME = constrain(DEFAULT_WATER_TIME, 5, 999);
    DEFAULT_SOAP_TIME = constrain(DEFAULT_SOAP_TIME, 5, 999);
    DEFAULT_BLOWER_TIME = constrain(DEFAULT_BLOWER_TIME, 5, 999);
    WATER_CREDIT_COST = constrain(WATER_CREDIT_COST, 1, 20);
    SOAP_CREDIT_COST = constrain(SOAP_CREDIT_COST, 1, 20);
    BLOWER_CREDIT_COST = constrain(BLOWER_CREDIT_COST, 1, 20);
}

void saveSettings() {
    prefs.putInt("waterTime", DEFAULT_WATER_TIME);
    prefs.putInt("soapTime", DEFAULT_SOAP_TIME);
    prefs.putInt("blowerTime", DEFAULT_BLOWER_TIME);
    prefs.putInt("waterCredit", WATER_CREDIT_COST);
    prefs.putInt("soapCredit", SOAP_CREDIT_COST);
    prefs.putInt("blowerCredit", BLOWER_CREDIT_COST);
}

void loadSalesData() {
    waterSales = prefs.getInt("waterSales", 0);
    soapSales = prefs.getInt("soapSales", 0);
    blowerSales = prefs.getInt("blowerSales", 0);
}

void saveSalesData() {
    prefs.putInt("waterSales", waterSales);
    prefs.putInt("soapSales", soapSales);
    prefs.putInt("blowerSales", blowerSales);
}

void resetSalesData() {
    waterSales = 0;
    soapSales = 0;
    blowerSales = 0;
    saveSalesData();
}

void displaySalesMonitoring() {
    lcd.clear();
    lcd.setCursor(4, 0);
    lcd.print("WATER   = ");
    lcd.print(waterSales);
    lcd.setCursor(4, 1);
    lcd.print("SOAP    = ");
    lcd.print(soapSales);
    lcd.setCursor(4, 2);
    lcd.print("BLOWER  = ");
    lcd.print(blowerSales);
    lcd.setCursor(4, 3);
    lcd.print("TOTAL   = ");
    lcd.print(waterSales + soapSales + blowerSales);
}

void handleSalesMonitoringTrigger(unsigned long currentMillis) {
    static unsigned long blowerPressStartTime = 0;
    static bool blowerLongPressHandled = false;
    static bool blowerWasPressed = false;

    bool currentBlowerState = digitalRead(blowerButton) == LOW;

    if (settingsMode != 0) return;

    if (currentBlowerState && !blowerWasPressed) {
        blowerPressStartTime = currentMillis;
        blowerLongPressHandled = false;
        blowerWasPressed = true;
    } else if (currentBlowerState && blowerWasPressed) {
        if (!blowerLongPressHandled && (currentMillis - blowerPressStartTime >= BLOWER_LONG_PRESS_TIME)) {
            blowerLongPressHandled = true;
            salesMonitoringMode = true;
            salesDisplayStartTime = currentMillis;
            displaySalesMonitoring();
        }
    } else if (!currentBlowerState) {
        blowerWasPressed = false;
        blowerLongPressHandled = false;
    }
}

void handleSettingsButtons() {
    if (settingsMode == 0) return;

    if (digitalRead(waterButton) == LOW && (millis() - lastWaterButtonTime > BUTTON_DEBOUNCE_TIME)) {
        lastWaterButtonTime = millis();
        settingsField = (settingsField == 1) ? 2 : 1;
        updateSettingsDisplay();
    }

    if (digitalRead(soapButton) == LOW && (millis() - lastSoapButtonTime > BUTTON_DEBOUNCE_TIME)) {
        lastSoapButtonTime = millis();
        adjustSettingsValue(true);
        updateSettingsDisplay();
    }

    if (digitalRead(blowerButton) == LOW && (millis() - lastBlowerButtonTime > BUTTON_DEBOUNCE_TIME)) {
        lastBlowerButtonTime = millis();
        adjustSettingsValue(false);
        updateSettingsDisplay();
    }
}

void adjustSettingsValue(bool increment) {
    if (settingsField == 1) {
        switch(settingsMode) {
            case 1: 
                WATER_CREDIT_COST = constrain(WATER_CREDIT_COST + (increment ? 1 : -1), 1, 20);
                break;
            case 2: 
                SOAP_CREDIT_COST = constrain(SOAP_CREDIT_COST + (increment ? 1 : -1), 1, 20);
                break;
            case 3: 
                BLOWER_CREDIT_COST = constrain(BLOWER_CREDIT_COST + (increment ? 1 : -1), 1, 20);
                break;
        }
    } else {
        switch(settingsMode) {
            case 1: 
                DEFAULT_WATER_TIME = constrain(DEFAULT_WATER_TIME + (increment ? 1 : -1), 5, 999);
                break;
            case 2: 
                DEFAULT_SOAP_TIME = constrain(DEFAULT_SOAP_TIME + (increment ? 1 : -1), 5, 999);
                break;
            case 3: 
                DEFAULT_BLOWER_TIME = constrain(DEFAULT_BLOWER_TIME + (increment ? 1 : -1), 5, 999);
                break;
        }
    }
}

void handleNormalMode(unsigned long currentMillis) {
    if (balance == 0 && waterTime == 0 && soapTime == 0 && blowerTime == 0) {
        if (!screenInitialized) {
            displayInitialScreen();
            screenInitialized = true;
        }
        if (currentMillis - lastInsertCoinBlinkTime > BLINK_INTERVAL) {
            lastInsertCoinBlinkTime = currentMillis;
            showInsertCoin = !showInsertCoin;
            blinkInsertCoin();
        }
    } else {
        screenInitialized = false;
    }

    if (coinsInserted > 0) {
        balance += coinsInserted * COIN_VALUE;
        coinsInserted = 0;
        updateBalanceDisplay();
    }

    if (currentMillis - lastUpdateTime >= 1000) {
        lastUpdateTime = currentMillis;
        updateTime();
    }

    if (balance >= 5 && (balance >= getCurrentCreditCost() || waterTime > 0 || soapTime > 0 || blowerTime > 0)) {
        if (currentMillis - lastButtonBlinkTime > BLINK_INTERVAL) {
            lastButtonBlinkTime = currentMillis;
            showPressButton = !showPressButton;
            blinkPressButton();
        }
    } else {
        showPressButton = true;
        blinkPressButton();
    }

    handleButton(waterButton, relayWater, waterTime, waterActive, waterPaused, waterPauseCount, DEFAULT_WATER_TIME, waterButtonPressed, lastWaterButtonTime, WATER_CREDIT_COST, "water");
    handleButton(soapButton, relaySoap, soapTime, soapActive, soapPaused, soapPauseCount, DEFAULT_SOAP_TIME, soapButtonPressed, lastSoapButtonTime, SOAP_CREDIT_COST, "soap");
    handleButton(blowerButton, relayBlower, blowerTime, blowerActive, blowerPaused, blowerPauseCount, DEFAULT_BLOWER_TIME, blowerButtonPressed, lastBlowerButtonTime, BLOWER_CREDIT_COST, "blower");

    handlePausedBlinking();
    updateLEDs(currentMillis);

    if (balance == 0) {
        if (currentMillis - lastInsertCoinBlinkTime > BLINK_INTERVAL) {
            lastInsertCoinBlinkTime = currentMillis;
            showInsertCoin = !showInsertCoin;
            blinkInsertCoin();
        }
    }
}

int getCurrentCreditCost() {
    if (waterActive) return WATER_CREDIT_COST;
    if (soapActive) return SOAP_CREDIT_COST;
    if (blowerActive) return BLOWER_CREDIT_COST;
    return WATER_CREDIT_COST;
}

void handleSettingsMode(unsigned long currentMillis) {
    if (currentMillis - lastSettingsBlinkTime > BLINK_INTERVAL) {
        lastSettingsBlinkTime = currentMillis;
        settingsBlinkState = !settingsBlinkState;
        updateSettingsDisplay();
    }
    handleSettingsButtons();
}

void Add() {
    noInterrupts();
    coinsInserted++;
    interrupts();
}

void updateTime() {
    bool timeNeedsUpdate = false;

    if (waterActive && !waterPaused && waterTime > 0) {
        waterTime--;
        timeNeedsUpdate = true;
        if (waterTime <= 10 && waterTime >= 9 && !waterBeeped10) {
            beep();
            waterBeeped10 = true;
            Serial.println("Water beep at 10s");
        } else if (waterTime <= 6 && waterTime >= 5 && !waterBeeped6) { // Corrected condition
            beep();
            waterBeeped6 = true;
            Serial.println("Water beep at 6s");
        } else if (waterTime <= 2 && waterTime >= 1 && !waterBeeped2) {
            beep();
            waterBeeped2 = true;
            Serial.println("Water beep at 2s");
        }
    } else if (waterTime == 0) {
        waterBeeped10 = false;
        waterBeeped6 = false;
        waterBeeped2 = false;
    }

    if (soapActive && !soapPaused && soapTime > 0) {
        soapTime--;
        timeNeedsUpdate = true;
        if (soapTime <= 10 && soapTime >= 9 && !soapBeeped10) {
            beep();
            soapBeeped10 = true;
            Serial.println("Soap beep at 10s");
        } else if (soapTime <= 6 && soapTime >= 5 && !soapBeeped6) {
            beep();
            soapBeeped6 = true;
            Serial.println("Soap beep at 6s");
        } else if (soapTime <= 2 && soapTime >= 1 && !soapBeeped2) {
            beep();
            soapBeeped2 = true;
            Serial.println("Soap beep at 2s");
        }
    } else if (soapTime == 0) {
        soapBeeped10 = false;
        soapBeeped6 = false;
        soapBeeped2 = false;
    }

    if (blowerActive && !blowerPaused && blowerTime > 0) {
        blowerTime--;
        timeNeedsUpdate = true;
        if (blowerTime <= 10 && blowerTime >= 9 && !blowerBeeped10) {
            beep();
            blowerBeeped10 = true;
            Serial.println("Blower beep at 10s");
        } else if (blowerTime <= 6 && blowerTime >= 5 && !blowerBeeped6) {
            beep();
            blowerBeeped6 = true;
            Serial.println("Blower beep at 6s");
        } else if (blowerTime <= 2 && blowerTime >= 1 && !blowerBeeped2) {
            beep();
            blowerBeeped2 = true;
            Serial.println("Blower beep at 2s");
        }
    } else if (blowerTime == 0) {
        blowerBeeped10 = false;
        blowerBeeped6 = false;
        blowerBeeped2 = false;
    }

    if (waterTime == 0 && waterActive) {
        waterActive = false;
        digitalWrite(relayWater, LOW);
    }
    if (soapTime == 0 && soapActive) {
        soapActive = false;
        digitalWrite(relaySoap, LOW);
    }
    if (blowerTime == 0 && blowerActive) {
        blowerActive = false;
        digitalWrite(relayBlower, LOW);
    }

    if (balance == 0 && waterTime == 0 && soapTime == 0 && blowerTime == 0) {
        displayInitialScreen();
    } else if (timeNeedsUpdate) {
        updateTimeDisplay();
    }
}

void handleButton(int button, int relay, int &time, bool &active, bool &paused, int &pauseCount, int defaultTime, bool &buttonPressed, unsigned long &lastButtonTime, int creditCost, String service) {
    if (digitalRead(button) == LOW) {
        if (!buttonPressed && (millis() - lastButtonTime > BUTTON_DEBOUNCE_TIME)) {
            buttonPressed = true;
            lastButtonTime = millis();

            if (!active && balance >= creditCost) {
                balance -= creditCost;
                time += defaultTime;
                active = true;
                paused = false;
                pauseCount = 0;
                digitalWrite(relay, HIGH);
                updateBalanceDisplay();
                beep();
                Serial.println("Beep on " + service + " button press");
                if (service == "water") {
                    waterSales += creditCost;
                } else if (service == "soap") {
                    soapSales += creditCost;
                } else if (service == "blower") {
                    blowerSales += creditCost;
                }
                saveSalesData();
            } else if (active) {
                if (!paused && pauseCount < MAX_PAUSE_COUNT) {
                    paused = true;
                    pauseCount++;
                    digitalWrite(relay, LOW);
                } else if (paused) {
                    paused = false;
                    digitalWrite(relay, HIGH);
                }
            }
            updateTimeDisplay();
        }
    } else {
        buttonPressed = false;
    }
}

void displayInitialScreen() {
    lcd.setCursor(3, 0);
    lcd.print(" 3in1 CARWASH");
    lcd.setCursor(0, 2);
    lcd.print("WATER  SOAP   BLOWER");
    lcd.setCursor(0, 3);
    lcd.print("00:00  00:00  00:00");
    lcd.setCursor(0, 1);
    lcd.print("  --Insert Coin!--");
}

void blinkInsertCoin() {
    lcd.setCursor(0, 1);
    if (showInsertCoin) {
        lcd.print("  --Insert Coin!--  ");
    } else {
        lcd.print("                  ");
    }
}

void displayActiveScreen() {
    lcd.setCursor(3, 0);
    if (balance >= 5) {
        lcd.print("PRESS A BUTTON");
    } else if (balance > 0) {
        lcd.print("PRESS A BUTTON");
    } else {
        lcd.print(" 3in1 CARWASH ");
    }
    lcd.setCursor(2, 1);
    if (balance > 0) {
        lcd.print("   Credit: ");
        lcd.print(balance);
    } else {
        lcd.print("--Insert Coin!--");
    }
    lcd.setCursor(0, 2);
    lcd.print("WATER  SOAP   BLOWER");
    updateTimeDisplay();
}

void updateBalanceDisplay() {
    lcd.setCursor(2, 1);
    lcd.print("   Credit: ");
    lcd.print(balance);
    lcd.print("     ");
}

void blinkPressButton() {
    lcd.setCursor(3, 0);
    if (balance >= 5 && showPressButton) {
        lcd.print("PRESS A BUTTON");
    } else if (balance >= 5 && !showPressButton) {
        lcd.print("              ");
    } else if (balance > 0) {
        lcd.print("PRESS A BUTTON");
    } else {
        lcd.print(" 3in1 CARWASH ");
    }
}

void updateTimeDisplay() {
    lcd.setCursor(0, 3);
    displayTime(waterTime, waterPaused, 0, waterBlinkState, waterLastBlinkTime);
    lcd.setCursor(7, 3);
    displayTime(soapTime, soapPaused, 7, soapBlinkState, soapLastBlinkTime);
    lcd.setCursor(14, 3);
    displayTime(blowerTime, blowerPaused, 14, blowerBlinkState, blowerLastBlinkTime);
}

void displayTime(int seconds, bool paused, int column, bool &blinkState, unsigned long &lastBlinkTime) {
    if (paused) {
        if (millis() - lastBlinkTime > BLINK_INTERVAL) {
            lastBlinkTime = millis();
            blinkState = !blinkState;
        }
        lcd.setCursor(column, 3);
        if (blinkState) {
            lcd.print("     ");
        } else {
            int mins = seconds / 60;
            int secs = seconds % 60;
            lcd.print(mins / 10);
            lcd.print(mins % 10);
            lcd.print(":");
            lcd.print(secs / 10);
            lcd.print(secs % 10);
        }
    } else {
        lcd.setCursor(column, 3);
        int mins = seconds / 60;
        int secs = seconds % 60;
        lcd.print(mins / 10);
        lcd.print(mins % 10);
        lcd.print(":");
        lcd.print(secs / 10);
        lcd.print(secs % 10);
    }
}

void handlePausedBlinking() {
    unsigned long currentMillis = millis();
    
    if (waterPaused) {
        if (currentMillis - waterLastBlinkTime > BLINK_INTERVAL) {
            waterLastBlinkTime = currentMillis;
            waterBlinkState = !waterBlinkState;
            lcd.setCursor(0, 3);
            if (waterBlinkState) {
                lcd.print("     ");
            } else {
                int mins = waterTime / 60;
                int secs = waterTime % 60;
                lcd.print(mins / 10);
                lcd.print(mins % 10);
                lcd.print(":");
                lcd.print(secs / 10);
                lcd.print(secs % 10);
            }
        }
    }
    
    if (soapPaused) {
        if (currentMillis - soapLastBlinkTime > BLINK_INTERVAL) {
            soapLastBlinkTime = currentMillis;
            soapBlinkState = !soapBlinkState;
            lcd.setCursor(7, 3);
            if (soapBlinkState) {
                lcd.print("     ");
            } else {
                int mins = soapTime / 60;
                int secs = soapTime % 60;
                lcd.print(mins / 10);
                lcd.print(mins % 10);
                lcd.print(":");
                lcd.print(secs / 10);
                lcd.print(secs % 10);
            }
        }
    }
    
    if (blowerPaused) {
        if (currentMillis - blowerLastBlinkTime > BLINK_INTERVAL) {
            blowerLastBlinkTime = currentMillis;
            blowerBlinkState = !blowerBlinkState;
            lcd.setCursor(14, 3);
            if (blowerBlinkState) {
                lcd.print("     ");
            } else {
                int mins = blowerTime / 60;
                int secs = blowerTime % 60;
                lcd.print(mins / 10);
                lcd.print(mins % 10);
                lcd.print(":");
                lcd.print(secs / 10);
                lcd.print(secs % 10);
            }
        }
    }
}

void updateLEDs(unsigned long currentMillis) {
    bool waterLEDState = LOW;
    bool soapLEDState = LOW;
    bool blowerLEDState = LOW;

    if (waterPaused) {
        waterLEDState = waterBlinkState ? HIGH : LOW;
    }
    if (soapPaused) {
        soapLEDState = soapBlinkState ? HIGH : LOW;
    }
    if (blowerPaused) {
        blowerLEDState = blowerBlinkState ? HIGH : LOW;
    }

    if (!waterPaused) {
        waterLEDState = waterActive ? LOW : (balance >= WATER_CREDIT_COST ? HIGH : LOW);
    }
    if (!soapPaused) {
        soapLEDState = soapActive ? LOW : (balance >= SOAP_CREDIT_COST ? HIGH : LOW);
    }
    if (!blowerPaused) {
        blowerLEDState = blowerActive ? LOW : (balance >= BLOWER_CREDIT_COST ? HIGH : LOW);
    }

    digitalWrite(waterLED, waterLEDState);
    digitalWrite(soapLED, soapLEDState);
    digitalWrite(blowerLED, blowerLEDState);
}

void updateSettingsDisplay() {
    lcd.setCursor(0, 0);
    lcd.print("      SETTINGS      ");
    
    lcd.setCursor(0, 1);
    lcd.print("MODE: ");
    switch(settingsMode) {
        case 1: lcd.print("WATER "); break;
        case 2: lcd.print("SOAP  "); break;
        case 3: lcd.print("BLOWER"); break;
    }
    
    lcd.setCursor(0, 2);
    lcd.print("Credit: ");
    if (settingsField == 1 && settingsBlinkState) {
        lcd.print("    ");
    } else {
        switch(settingsMode) {
            case 1: lcd.print(WATER_CREDIT_COST); break;
            case 2: lcd.print(SOAP_CREDIT_COST); break;
            case 3: lcd.print(BLOWER_CREDIT_COST); break;
        }
        lcd.print("    ");
    }
    
    lcd.setCursor(0, 3);
    lcd.print("Time(sec): ");
    if (settingsField == 2 && settingsBlinkState) {
        lcd.print("    ");
    } else {
        switch(settingsMode) {
            case 1: lcd.print(DEFAULT_WATER_TIME); break;
            case 2: lcd.print(DEFAULT_SOAP_TIME); break;
            case 3: lcd.print(DEFAULT_BLOWER_TIME); break;
        }
        lcd.print("    ");
    }
}

// Modified: Use tone() with cooldown to ensure reliable sound in Wokwi
void beep() {
    unsigned long currentMillis = millis();
    if (currentMillis - lastBeepTime >= BUZZER_COOLDOWN) {
        tone(buzzerPin, 1000); // 1000 Hz tone
        delay(BUZZER_BEEP_DURATION);
        noTone(buzzerPin);
        lastBeepTime = currentMillis;
        Serial.println("Buzzer activated");
    }
}