#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1

#define SDA_PIN 9
#define SCL_PIN 10
#define POT_PIN 3
#define BUTTON_PIN 1
#define BUZZER_PIN 0
#define MENU_BUTTON_PIN 2

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

int scaledValue = 0; 
bool changing = false; 

unsigned long lastButtonPressTime = 0; 
const unsigned long debounceDelay = 200; 

unsigned long lastBlinkTime = 0; 
const unsigned long blinkInterval = 320; 

bool displayBlinkState = false; 
int menuLevel = 0; 
int LastVolumeSaved = 0;

int timess = 0;
int lastint = 0;
int previousPotValue = -1; // Initialize with an out-of-bounds value
bool isInSleepMode = false; // Flag to indicate sleep mode

void setup() {
  Serial.begin(115200);
  delay(1000); 
  Wire.begin(SDA_PIN, SCL_PIN);

  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pinMode(MENU_BUTTON_PIN, INPUT_PULLUP);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println("SSD1306 allocation failed");
    for (;;);
  }

  display.clearDisplay();
  display.setTextColor(SSD1306_WHITE);
  display.setTextSize(2);
  displayLoadingAnimation();
}

void loop() {
  checkButton();
  checkPotentiometer(); // Read potentiometer for sleep mode
  updateDisplay();
  timess += 1;
  Serial.println(timess);
  Serial.println(lastint);
  sleepmode();
}

void sleepmode() {
  if (lastint < timess - 50) {
    if (!isInSleepMode) {
      menuLevel = 0; // Reset to menu level 0
      display.fillScreen(SSD1306_BLACK); // Fill the display with black
      display.display(); // Update the display to show black screen
      isInSleepMode = true; // Set sleep mode flag
    }
  } else {
    isInSleepMode = false; // Exit sleep mode when conditions are met
  }
}

void checkButton() {
  if (isInSleepMode == false) {
    if (digitalRead(BUTTON_PIN) == LOW && menuLevel == 2) {
      if (millis() - lastButtonPressTime > debounceDelay) {
        // Toggle the changing state on button press
        changing = !changing; 
        Serial.print("State: ");
        Serial.println(changing);

        if (changing) {
          // When enabling changing, save the current scaled value
          LastVolumeSaved = scaledValue;
          Serial.print("Saved Volume: ");
          Serial.println(LastVolumeSaved);
        }

        lastButtonPressTime = millis();
      }
    }

    // Reset lastint if button pressed
    if (digitalRead(BUTTON_PIN) == LOW) {
      lastint = timess;
    }

    if (digitalRead(MENU_BUTTON_PIN) == LOW) {
      lastint = timess;
      if (millis() - lastButtonPressTime > debounceDelay) {
        menuLevel = (menuLevel + 1) % 3; 
        changing = false; // Reset changing when switching menu
        Serial.print("State: ");
        Serial.println(changing);
        Serial.print("Menu Level: ");
        Serial.println(menuLevel);
        lastButtonPressTime = millis();
      }
    }
  }
}

void checkPotentiometer() {
  // Read the potentiometer value for sleep mode only
  int potValue = analogRead(POT_PIN);

  if (menuLevel != 2) { // Not in volume menu
    // Here you can keep track of the potValue for sleep mode
    // This is where you'd handle sleep mode logic if needed.
    if (potValue != previousPotValue) {
      previousPotValue = potValue; // Update the last potentiometer value
      lastint = timess;
    }
    return; // Exit if in volume menu
  }

  // Update scaledValue only if changing is true
  if (changing) {
    scaledValue = map(potValue, 0, 4095, 0, 100);
  }
}

void updateDisplay() {
  if (isInSleepMode) {
    return; // Do not update display in sleep mode
  }

  display.clearDisplay(); // Optional: clear the display

  if (menuLevel == 0) {
    displayDefaultMenu();
  } 
  else if (menuLevel == 1) {
    displayWoLMenu();
  }
  else {
    displayVolumeMenu();
  }

  display.display();
}

void displayWoLMenu() {
  display.setTextSize(2);
  display.setCursor(15,SCREEN_HEIGHT / 2 - 18);
  display.println(F("Ready to"));
  display.setCursor(50,SCREEN_HEIGHT / 2 -1);
  display.print(F("WoL"));
  display.setTextSize(1);
  display.setCursor(0,54);
  display.print(F("Wake             Menu"));
}

void displayVolumeMenu() {
  int digitCount = (scaledValue == 0) ? 1 : (log10(scaledValue) + 1);

  if (changing && millis() - lastBlinkTime >= blinkInterval) {
    displayBlinkState = !displayBlinkState;
    lastBlinkTime = millis();
    if (!displayBlinkState) {
      makeBuzzerSound(680, 200); // Call with specific note and duration
    }
  }

  if (changing){
    display.setTextSize(1);
    display.setCursor(0,54);
    display.print(F("Save             Menu"));
  } else {
    display.setTextSize(1);
    display.setCursor(0,54);
    display.print(F("Change           Menu"));
  }
  display.setTextSize(2);
  display.setCursor(24, SCREEN_HEIGHT / 2 - 18);
  display.println(F("Volume:"));

  int valueWidth = digitCount * 12; 
  int totalWidth = valueWidth + 12; 
  int volumeX = (SCREEN_WIDTH - totalWidth) / 2; 

  display.setCursor(volumeX, SCREEN_HEIGHT / 2 - 2);
  if (changing && displayBlinkState) {
    for (int i = 0; i < digitCount; i++) {
      display.setTextSize(2);
      display.print("_"); // Print underscores for blinking
    }
    display.print("%");
  } else {
    display.setTextSize(2);
    display.print(scaledValue);
    display.print("%");
  }
}

void displayDefaultMenu() {
  display.clearDisplay(); // Clear the display for fresh drawing

  // Simulating text size 1.8 for the welcome message
  display.setTextSize(2); // Use size 2 for the welcome text
  display.setCursor(SCREEN_WIDTH / 5.5, SCREEN_HEIGHT / 2 - 18); // Adjust vertical position
  display.println(F("Welcome"));
  display.setCursor(10, SCREEN_HEIGHT / 2 - 2); // Adjust vertical position
  display.println(F("I am Echo"));

  display.setTextSize(1); // Set text size to 1 for the menu indication
  display.setCursor(0, 54);
  display.print(F("                 Menu")); // Menu indication
  display.display(); // Refresh the display to show the changes
}

void makeBuzzerSound(int note, unsigned long duration) {
  tone(BUZZER_PIN, note);
  delay(duration);
  noTone(BUZZER_PIN);
}

void playBuzzerSequence() {
  const int notes[] = {180, 300, 400};
  for (int i = 0; i < 2; i++) {
    for (int note : notes) {
      makeBuzzerSound(note, 100);
      delay(200);
    }
  }
}

void displayLoadingAnimation() {
  unsigned long startTime = millis();
  const char* loadingTexts[] = { "Loading...", "Loading.", "Loading.." };
  int loadingState = 0;

  while (millis() - startTime < 10500) {
    if (millis() % 800 < 100) {
      loadingState = (loadingState + 1) % 3;
    }

    display.clearDisplay();
    display.setCursor((SCREEN_WIDTH - strlen(loadingTexts[loadingState]) * 12) / 2, SCREEN_HEIGHT / 2 - 12);
    display.println(loadingTexts[loadingState]);
    display.display();
    delay(100);
  }

  display.clearDisplay();
  display.display();
  playBuzzerSequence();
}