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

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define OLED_RESET    -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

const int encoderPinA = 2; // Pin A des Drehreglers
const int encoderPinB = 4; // Pin B des Drehreglers
const int encoderButtonPin = 5; // SW-Pin des Drehreglers
volatile int encoderPos = 0; // Zähler für die Drehreglerposition
int lastEncoderPos = 0; // Speichert die letzte Position des Drehreglers
bool lastButtonState = HIGH; // Zustand des SW-Knopfes
unsigned long lastButtonPressTime = 0; // Zeitpunkt des letzten Knopfdrucks
bool menuActive = false; // Menü aktiv oder nicht
const unsigned long longPressTime = 1000; // Zeit in ms, die als langer Druck gilt

// Menü-Struktur
String menuItems[] = {"Fade-Zeit", "Snooze-Zeit", "Snooze-Wiederholungen", "Lautstaerke", "Playlist"};
int menuItemsCount = 5; // Anzahl der Menüpunkte
int currentMenuItem = 0; // Aktuell ausgewählter Menüpunkt

// Einstellbare Werte
int fadeTime = 10; // in Sekunden
int snoozeTime = 5; // in Minuten
int snoozeRepetitions = 5;
int volume = 80; // in Prozent

void setup() {
  Serial.begin(115200);
  pinMode(encoderPinA, INPUT);
  pinMode(encoderPinB, INPUT);
  pinMode(encoderButtonPin, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(encoderPinA), doEncoder, CHANGE);
  
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { 
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  display.clearDisplay();
  display.setTextSize(2);
  display.setCursor(0, 0);
  display.println("12:00"); // Startbildschirm mit Platzhalter-Uhrzeit
  display.display();
  delay(2000);
}

void loop() {
  handleButtonPress();
  if (menuActive && encoderPos != lastEncoderPos) {
    lastEncoderPos = encoderPos;
    currentMenuItem = (currentMenuItem + 1) % menuItemsCount;
    displayMenu();
  }
}

void handleButtonPress() {
  bool currentButtonState = digitalRead(encoderButtonPin);
  if (currentButtonState == LOW && lastButtonState == HIGH) {
    lastButtonPressTime = millis();
  }
  if (currentButtonState == LOW && (millis() - lastButtonPressTime > longPressTime)) {
    // Langer Druck
    if (!menuActive) {
      menuActive = true;
      displayMenu();
    }
  }
  if (currentButtonState == HIGH && lastButtonState == LOW) {
    if (menuActive) {
      // Kurzer Druck
      applyMenuItem();
    }
  }
  lastButtonState = currentButtonState;
}

void displayMenu() {
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);

  for (int i = 0; i < menuItemsCount; i++) {
    if (i == currentMenuItem) {
      display.fillRect(0, i * 10, SCREEN_WIDTH, 10, WHITE);
      display.setTextColor(BLACK);
      display.setCursor(0, i * 10);
      display.println(menuItems[i] + ": " + getMenuItemValue(i));
      display.setTextColor(WHITE);
    } else {
      display.setCursor(0, i * 10);
      display.println(menuItems[i] + ": " + getMenuItemValue(i));
    }
  }

  display.display();
}

String getMenuItemValue(int item) {
  switch (item) {
    case 0: return String(fadeTime) + " s";
    case 1: return String(snoozeTime) + " min";
    case 2: return String(snoozeRepetitions);
    case 3: return String(volume) + "%";
    case 4: return "Spotify"; // Hier könnte die Integration mit Spotify erfolgen
    default: return "";
  }
}

void applyMenuItem() {
  switch (currentMenuItem) {
    case 0: fadeTime = (fadeTime + 1) % 60; break;
    case 1: snoozeTime = (snoozeTime + 1) % 60; break;
    case 2: snoozeRepetitions = (snoozeRepetitions + 1) % 10; break;
    case 3: volume = (volume + 10) % 100; break;
    case 4: /* Integration mit Spotify hier */ break;
  }
  displayMenu();
}

void doEncoder() {
  static unsigned long lastInterruptTime = 0;
  unsigned long interruptTime = millis();
  if (interruptTime - lastInterruptTime > 200) {
    if (digitalRead(encoderPinA) == digitalRead(encoderPinB)) {
      encoderPos++;
    } else {
      encoderPos--;
    }
  }
  lastInterruptTime = interruptTime;
}