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

// LCD setup
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Pin Definitions
int batteryPin = A0; // Pin untuk membaca tegangan baterai
int ledPin1 = 13;    // LED hijau
int ledPin2 = 8;     // LED merah
int ledPin3 = 7;     // LED biru (indikasi tegangan rendah)
int buzzerPin = 12;  // Pin untuk buzzer

// Button Definitions
#define BUTTON_MENU 2
#define BUTTON_SELECT 3
#define BUTTON_OK 4
#define BUTTON_ADD 5

// Menu variables
int menuIndex = 0;
int totalMenus = 3;
const char *menus[] = {"Pengaturan", "Nama Anggota", "Uji Baterai"};

// Battery voltage variables
float batteryVoltage = 0.0;
float voltageDividerRatio = 2.0; // Rasio pembagi tegangan (contoh 2:1)
float maxBatteryVoltage = 5.0;   // Tegangan maksimum yang dapat diukur (5V)
float lowBatteryVoltage = 3.0;   // Tegangan minimum baterai

void setup() {
    // Pin Modes
    pinMode(ledPin1, OUTPUT);
    pinMode(ledPin2, OUTPUT);
    pinMode(ledPin3, OUTPUT);
    pinMode(buzzerPin, OUTPUT);

    pinMode(BUTTON_MENU, INPUT_PULLUP);
    pinMode(BUTTON_SELECT, INPUT_PULLUP);
    pinMode(BUTTON_OK, INPUT_PULLUP);
    pinMode(BUTTON_ADD, INPUT_PULLUP);

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

    // Initialize Serial
    Serial.begin(9600);
}

void loop() {
    // Button handling
    if (debounceButton(BUTTON_MENU)) {
        menuIndex = (menuIndex + 1) % totalMenus; // Cycle through menus
        displayMenu();
    }
    if (debounceButton(BUTTON_SELECT)) {
        handleMenuSelection();
    }

    // Measure and display battery voltage if in "Uji Baterai" menu
    if (menuIndex == 2) {
        measureBatteryVoltage();
    }
}

// Function to handle menu selection
void handleMenuSelection() {
    switch (menuIndex) {
        case 0:
            displayPengaturan();
            break;
        case 1:
            displayNamaAnggota();
            break;
        case 2:
            displayBatteryVoltage();
            break;
    }
}

// Function to display the menu
void displayMenu() {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Menu:");
    lcd.setCursor(0, 1);
    lcd.print("> ");
    lcd.print(menus[menuIndex]);
}

// Function to measure battery voltage
void measureBatteryVoltage() {
    int rawADC = analogRead(batteryPin);
    batteryVoltage = (rawADC / 1023.0) * 5.0 * voltageDividerRatio; // Menghitung tegangan baterai

    // Batasi pembacaan hingga maksimum 5V
    if (batteryVoltage > 5.0) {
        batteryVoltage = 5.0;
    }

    Serial.print("Battery Voltage: ");
    Serial.println(batteryVoltage);
}

// Function to display battery voltage
void displayBatteryVoltage() {
    while (true) {
        measureBatteryVoltage();

        // Display the voltage on LCD
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Baterai:");
        lcd.setCursor(0, 1);
        lcd.print(batteryVoltage, 2);
        lcd.print("V");

        // Update LED and buzzer based on battery voltage
        if (batteryVoltage >= maxBatteryVoltage) {
            setLEDState(true, false, false);  // LED hijau menyala
            digitalWrite(buzzerPin, LOW);    // Buzzer mati
        } else if (batteryVoltage >= lowBatteryVoltage) {
            setLEDState(false, true, false); // LED merah menyala
            digitalWrite(buzzerPin, LOW);    // Buzzer mati
        } else {
            setLEDState(false, false, true); // LED biru menyala
            digitalWrite(buzzerPin, HIGH);   // Buzzer menyala
        }

        // Wait and check for button input
        delay(500);
        if (debounceButton(BUTTON_SELECT)) {
            displayMenu();
            return;
        }
    }
}

// Function to set LED states
void setLEDState(bool green, bool red, bool blue) {
    digitalWrite(ledPin1, green);
    digitalWrite(ledPin2, red);
    digitalWrite(ledPin3, blue);
}

// Function to display member names and change them with BUTTON_OK
void displayNamaAnggota() {
    const char *anggota[] = {"Sulhan Efendi", "Zaki Dhaifullah", "Irvan Zukhri"};
    int totalAnggota = sizeof(anggota) / sizeof(anggota[0]);
    int currentAnggotaIndex = 0;

    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Anggota:");
    lcd.setCursor(0, 1);
    lcd.print(anggota[currentAnggotaIndex]);

    while (true) {
        if (debounceButton(BUTTON_OK)) {
            currentAnggotaIndex = (currentAnggotaIndex + 1) % totalAnggota;

            lcd.clear();
            lcd.setCursor(0, 0);
            lcd.print("Anggota:");
            lcd.setCursor(0, 1);
            lcd.print(anggota[currentAnggotaIndex]);
        }

        // Exit to menu with BUTTON_SELECT
        if (debounceButton(BUTTON_SELECT)) {
            displayMenu();
            return;
        }
    }
}

// Function to display settings
void displayPengaturan() {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Pengaturan");
    lcd.setCursor(0, 1);
    lcd.print("MaxV:");
    lcd.print(maxBatteryVoltage, 2);

    while (true) {
        if (debounceButton(BUTTON_SELECT)) {
            displayMenu();
            return;
        }
    }
}

// Debounce function
bool debounceButton(int buttonPin) {
    static unsigned long lastPressTimes[6] = {0}; // Array untuk melacak waktu tombol
    unsigned long currentTime = millis();

    if (digitalRead(buttonPin) == LOW && (currentTime - lastPressTimes[buttonPin] > 200)) {
        lastPressTimes[buttonPin] = currentTime;
        return true;
    }
    return false;
}