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

#define UP_BTN 2
#define DOWN_BTN 3
#define ENTER_BTN 4
#define BACK_BTN 5
#define BUZZER 6
#define WATER_PUMP 7
#define DRAIN_VALVE 8
#define WATER_LEVEL_SENSOR A0

LiquidCrystal_I2C lcd(0x27, 16, 2);

int menuIndex = -1; // Tracks the current menu (Main, Wash Cycle, Dryer)
int selectedMenuItem = 0; // Tracks the selected menu item (0: Wash Cycle, 1: Dryer)
int stepIndex = -1; // Tracks the current step inside a menu
int washCycles = 1;
int washTimes[4] = {1, 1, 1, 1};
int drainTime = 1;
int dryTime = 5; // Dryer time in minutes
int waterLevelThreshold = 500;
unsigned long previousMillis = 0;
bool isFilling = false;
bool isDraining = false;

void setup() {
    pinMode(UP_BTN, INPUT_PULLUP);
    pinMode(DOWN_BTN, INPUT_PULLUP);
    pinMode(ENTER_BTN, INPUT_PULLUP);
    pinMode(BACK_BTN, INPUT_PULLUP);
    pinMode(BUZZER, OUTPUT);
    pinMode(WATER_PUMP, OUTPUT);
    pinMode(DRAIN_VALVE, OUTPUT);
    pinMode(WATER_LEVEL_SENSOR, INPUT);
    
    lcd.init();
    lcd.backlight();
    lcd.clear();
    lcd.print("Washing Mach V1");
    lcd.setCursor(0,1);
    lcd.print("Press Enter");
}

void loop() {
    if (!digitalRead(ENTER_BTN)) {
        if (menuIndex == -1) {
            // Enter the selected menu item
            menuIndex = selectedMenuItem;
            showMenu();
        } else if (stepIndex == -1) {
            nextMenuStep();
        } else {
            nextStep();
        }
        delay(200);
    }
    if (!digitalRead(UP_BTN)) {
        if (menuIndex == -1) {
            // Navigate up in the main menu
            selectedMenuItem = (selectedMenuItem == 0) ? 1 : 0; // Toggle between 0 and 1
            showMenu();
        } else if (stepIndex != -1) {
            adjustValue(1);
        }
        delay(200);
    }
    if (!digitalRead(DOWN_BTN)) {
        if (menuIndex == -1) {
            // Navigate down in the main menu
            selectedMenuItem = (selectedMenuItem == 0) ? 1 : 0; // Toggle between 0 and 1
            showMenu();
        } else if (stepIndex != -1) {
            adjustValue(-1);
        }
        delay(200);
    }
    if (!digitalRead(BACK_BTN)) {
        previousStep();
        delay(200);
    }
}

void showMenu() {
    lcd.clear();
    if (menuIndex == -1) {
        // Main menu
        lcd.print(selectedMenuItem == 0 ? ">1. Wash Cycles" : " 1. Wash Cycles");
        lcd.setCursor(0,1);
        lcd.print(selectedMenuItem == 1 ? ">2. Dryer" : " 2. Dryer");
    } else if (menuIndex == 0) {
        // Wash Cycle menu
        showStep();
    } else if (menuIndex == 1) {
        // Dryer menu
        showStep();
    }
}

void nextMenuStep() {
    if (menuIndex == 0) {
        stepIndex = 0;
        showStep();
    } else if (menuIndex == 1) {
        stepIndex = 5; // Dryer step index
        showStep();
    }
}

void showStep() {
    lcd.clear();
    if (stepIndex == 0) {
        lcd.print(">Wash Cycles:"); 
        lcd.setCursor(0,1); 
        lcd.print(washCycles);
    } else if (stepIndex >= 1 && stepIndex <= washCycles) {
        lcd.print(">Wash ");
        lcd.print(stepIndex);
        lcd.print(" Time:");
        lcd.setCursor(0,1);
        lcd.print(washTimes[stepIndex - 1]);
        lcd.print(" min");
    } else if (stepIndex == 5) {
        lcd.print(">Dryer Time:");
        lcd.setCursor(0,1);
        lcd.print(dryTime);
        lcd.print(" min");
    } else {
        lcd.print("Press Enter");
        lcd.setCursor(0,1);
        lcd.print("to Start");
    }
}

void adjustValue(int change) {
    if (stepIndex == 0) {
        washCycles = constrain(washCycles + change, 1, 4);
    } else if (stepIndex >= 1 && stepIndex <= washCycles) {
        washTimes[stepIndex - 1] = constrain(washTimes[stepIndex - 1] + change, 1, 10);
    } else if (stepIndex == 5) {
        dryTime = constrain(dryTime + change, 1, 60); // Dryer time can be set from 1 to 60 minutes
    }
    showStep();
}

void nextStep() {
    if (stepIndex < washCycles + 1) {
        stepIndex++;
        showStep();
    } else if (stepIndex == 5) {
        // Dryer step is complete, go back to main menu
        menuIndex = -1;
        stepIndex = -1;
        lcd.clear();
        lcd.print("Washing Mach V1");
        lcd.setCursor(0,1);
        lcd.print("Press Enter");
    } else {
        executeProcess();
    }
}

void previousStep() {
    if (stepIndex > 0) {
        stepIndex--;
        showStep();
    } else if (menuIndex != -1) {
        menuIndex = -1;
        stepIndex = -1;
        lcd.clear();
        lcd.print("Washing Mach V1");
        lcd.setCursor(0,1);
        lcd.print("Press Enter");
    }
}

void executeProcess() {
    lcd.clear();
    lcd.print("Filling...");
    digitalWrite(WATER_PUMP, HIGH);
    previousMillis = millis();
    while (analogRead(WATER_LEVEL_SENSOR) < waterLevelThreshold) {
        if (millis() - previousMillis >= 500) {
            previousMillis = millis();
        }
    }
    digitalWrite(WATER_PUMP, LOW);
    lcd.clear();
    lcd.print("Level Reached");
    delay(2000);
    
    for (int i = 0; i < washCycles; i++) {
        performStep("Wash ", washTimes[i]);
        drainWater();
    }
    
    // Start Dryer
    lcd.clear();
    lcd.print("Drying...");
    performStep("Dry ", dryTime);
    
    lcd.clear();
    lcd.print("Cycle Done!");
    beepAlert();
}

void performStep(const char* stepName, int duration) {
    lcd.clear();
    lcd.print(stepName);
    lcd.print("Time Left:");
    digitalWrite(WATER_PUMP, HIGH);
    unsigned long startMillis = millis();
    while (millis() - startMillis < duration * 60000) {
        unsigned long elapsedMillis = millis() - startMillis;
        unsigned long remainingMillis = duration * 60000 - elapsedMillis;
        int remainingSeconds = remainingMillis / 1000;
        lcd.setCursor(0,1);
        lcd.print(remainingSeconds / 60);
        lcd.print(":");
        if (remainingSeconds % 60 < 10) {
            lcd.print("0");
        }
        lcd.print(remainingSeconds % 60);
        delay(1000); // Update every second
    }
    digitalWrite(WATER_PUMP, LOW);
}

void drainWater() {
    lcd.clear();
    lcd.print("Draining...");
    digitalWrite(DRAIN_VALVE, HIGH);
    unsigned long startMillis = millis();
    while (millis() - startMillis < drainTime * 1000) {
        // Wait without blocking
    }
    digitalWrite(DRAIN_VALVE, LOW);
}

void beepAlert() {
    for (int i = 0; i < 5; i++) {
        digitalWrite(BUZZER, HIGH);
        delay(500);
        digitalWrite(BUZZER, LOW);
        delay(500);
    }
}