#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
#include <TM1637Display.h>

#define TFT_CS   15
#define TFT_DC   2
#define TFT_RST  4
#define BUTTON_PIN 13
#define TM1637_CLK 21
#define TM1637_DIO 22

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);
TM1637Display display(TM1637_CLK, TM1637_DIO);

bool screenState = false;
unsigned long previousMillis = 0;
const long blinkInterval = 500;
bool currentScreen = 0; // 0 = Startbildschirm, 1 = Konfigurationsbildschirm

// Timer Variablen
bool timerRunning = false;
unsigned long timerStartTime = 0;
unsigned long timerDuration = 30000; // 30 Sekunden in Millisekunden
unsigned long lastSegmentUpdate = 0;
const long segmentUpdateInterval = 10; // 10ms für Hundertstel

void setup() {
  Serial.begin(115200);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  
  // Display Reset
  pinMode(TFT_RST, OUTPUT);
  digitalWrite(TFT_RST, HIGH);
  delay(100);
  digitalWrite(TFT_RST, LOW);
  delay(100);
  digitalWrite(TFT_RST, HIGH);
  delay(100);
  
  tft.begin();
  tft.setRotation(3);
  
  // TM1637 initialisieren
  display.setBrightness(0x0f); // Maximale Helligkeit
  display.showNumberDecEx(0, 0b01000000, true); // 00.00 anzeigen
  
  drawStartScreen();
}

void loop() {
  unsigned long currentMillis = millis();
  
  // Blinkender Kasten nur auf Startbildschirm
  if (currentScreen == 0) {
    if (currentMillis - previousMillis >= blinkInterval) {
      previousMillis = currentMillis;
      screenState = !screenState;
      drawStartBox(screenState);
    }
  }
  
  // Timer auf Segmentanzeige aktualisieren
  if (currentScreen == 1 && timerRunning) {
    if (currentMillis - lastSegmentUpdate >= segmentUpdateInterval) {
      lastSegmentUpdate = currentMillis;
      updateSegmentDisplay();
    }
  }

  // Button abfragen
  if (digitalRead(BUTTON_PIN) == LOW) {
    delay(50); // Entprellung
    if (digitalRead(BUTTON_PIN) == LOW) {
      if (currentScreen == 0) {
        // Wechsel zu Konfigurationsbildschirm
        currentScreen = 1;
        drawConfigScreen();
      } else {
        // Im Konfigurationsbildschirm: Timer starten/stoppen
        if (!timerRunning) {
          startTimer();
        } else {
          stopTimer();
        }
      }
    }
  }
}

void drawStartScreen() {
  tft.fillScreen(ILI9341_BLACK);
  
  // Titel
  tft.setTextColor(ILI9341_RED);
  tft.setTextSize(3);
  tft.setCursor(50, 50);
  tft.println("HNGR13 BOMB");

  // Unterer Text
  tft.setTextColor(ILI9341_WHITE);
  tft.setTextSize(2);
  tft.setCursor(80, 100);
  tft.println("Bereit zum Starten");
}

void drawStartBox(bool visible) {
  int x = 100, y = 150, w = 120, h = 40;
  if (visible) {
    tft.fillRect(x, y, w, h, ILI9341_GREEN);
    tft.setTextColor(ILI9341_BLACK);
    tft.setTextSize(2);
    tft.setCursor(x + 40, y + 12);
    tft.println("START");
  } else {
    tft.fillRect(x, y, w, h, ILI9341_BLACK);
    tft.drawRect(x, y, w, h, ILI9341_GREEN);
  }
}

void drawConfigScreen() {
  tft.fillScreen(ILI9341_BLACK);
  
  // Titel
  tft.setTextColor(ILI9341_BLUE);
  tft.setTextSize(3);
  tft.setCursor(50, 50);
  tft.println("KONFIGURATION");

  // Timer Status
  tft.setTextColor(ILI9341_WHITE);
  tft.setTextSize(2);
  tft.setCursor(80, 100);
  tft.println("Timer: BEREIT");
  
  // Segmentanzeige Info
  tft.setCursor(80, 130);
  tft.println("TM1637: 00.00");

  // Start/Stop Button
  tft.fillRect(100, 180, 120, 40, ILI9341_GREEN);
  tft.setTextColor(ILI9341_BLACK);
  tft.setTextSize(2);
  tft.setCursor(120, 192);
  tft.println("START");
}

void updateConfigScreenTimer() {
  tft.fillRect(80, 100, 200, 25, ILI9341_BLACK);
  tft.setTextColor(ILI9341_WHITE);
  tft.setTextSize(2);
  tft.setCursor(80, 100);
  
  if (timerRunning) {
    tft.println("Timer: LÄUFT");
    
    // Button auf STOP ändern
    tft.fillRect(100, 180, 120, 40, ILI9341_RED);
    tft.setTextColor(ILI9341_WHITE);
    tft.setCursor(125, 192);
    tft.println("STOP");
  } else {
    tft.println("Timer: BEREIT");
    
    // Button auf START ändern
    tft.fillRect(100, 180, 120, 40, ILI9341_GREEN);
    tft.setTextColor(ILI9341_BLACK);
    tft.setCursor(120, 192);
    tft.println("START");
  }
}

void startTimer() {
  timerRunning = true;
  timerStartTime = millis();
  updateConfigScreenTimer();
}

void stopTimer() {
  timerRunning = false;
  updateConfigScreenTimer();
}

void updateSegmentDisplay() {
  if (!timerRunning) return;
  
  unsigned long elapsed = millis() - timerStartTime;
  unsigned long remaining = (timerDuration > elapsed) ? (timerDuration - elapsed) : 0;
  
  // In Sekunden und Hundertstel umrechnen
  unsigned long seconds = remaining / 1000;
  unsigned long hundredths = (remaining % 1000) / 10;
  
  // Format: SS.HH (z.B. 30.00)
  int displayValue = (seconds * 100) + hundredths;
  
  // Mit Punkt in der Mitte anzeigen
  display.showNumberDecEx(displayValue, 0b01000000, true);
  
  // Timer abgelaufen?
  if (remaining == 0) {
    timerRunning = false;
    updateConfigScreenTimer();
    
    // Alarm anzeigen
    for (int i = 0; i < 5; i++) {
      display.showNumberDec(8888, true); // Alle Segmente an
      delay(200);
      display.clear();
      delay(200);
    }
    display.showNumberDecEx(0, 0b01000000, true); // Zurück zu 00.00
  }
}