#include <Arduino_GFX_Library.h>
#include <Adafruit_ST7789.h>
#include <Arduino.h>

#include <BLEDevice.h>
#include <BLEUtils.h>
#include <BLEServer.h>

#define TFT_DC   D7
#define TFT_RST  D9

unsigned long SEC=40;
unsigned long MIN=0;
unsigned long HOUR=0;

unsigned long DAY=0;
unsigned long MONT=0;
unsigned long YEAR=2026;

unsigned long preMil = 0;
const long interval = 1000;

Arduino_DataBus *bus = new Arduino_HWSPI(TFT_DC, -1);
Arduino_GFX *gfx = new Arduino_ST7789(bus, TFT_RST, 0, true, 240, 240, 0, 0);

#define SERVICE_UUID        "791cadd7-de87-49f9-8986-94b7ae11940b"
#define CHAR_TEST_UUID "3e4eac5b-eaa2-4e0c-a705-dcac4f606e01"
#define CHAR_TIME_UUID "3e4eac5b-eaa2-4e0c-a705-dcac4f606e02"

#define deviceName "ESP32-Watch"

class CharacteristicCallbacks: public BLECharacteristicCallbacks {
    void onWrite(BLECharacteristic *pCharacteristic) override {
      String value = pCharacteristic->getValue();

      if (value.length() == 0) return;

      //Time characteristic check
      if (pCharacteristic->getUUID().equals(BLEUUID(CHAR_TIME_UUID))) {
      Serial.print("Uhrzeit empfangen: ");
      Serial.println(value);
      }
    }
};

void setup() {
  Serial.begin(115200);

  gfx->begin();
  gfx->setFont(NULL);
  gfx->fillScreen(ST77XX_BLACK);

  gfx->setTextColor(ST77XX_GREEN, ST77XX_BLACK);

  initDevice();
}

void loop() {
  drawText(10,10, 2, "{");
  drawText(30,30,2,"Time: {");

  gfx->setCursor(50, 50);
  gfx->printf("Hour: %d%c\n", HOUR, ',');

  gfx->setCursor(50, 70);
  gfx->printf("Min: %d%c\n", MIN, ',');

  gfx->setCursor(50, 90);
  gfx->printf("Sec: %d%c\n", SEC);
  
  drawText(30,110,2,"},");

  drawText(30,130,2,"Date: {");

  gfx->setCursor(50, 150);
  gfx->printf("Day: %d%c\n", DAY, ',');

  gfx->setCursor(50, 170);
  gfx->printf("Mont: %d%c\n", MONT, ',');

  gfx->setCursor(50, 190);
  gfx->printf("Year: %d%c\n", YEAR);

  drawText(10,210,2,"}");

  updateClock();
}
void initDevice(){
  BLEDevice::init(deviceName);
  BLEServer *pServer = BLEDevice::createServer();
  BLEService *pService = pServer->createService(SERVICE_UUID);

  //Test characteristic
  BLECharacteristic *pCharacteristic = pService->createCharacteristic(
    CHAR_TEST_UUID, 
    BLECharacteristic::PROPERTY_READ);
  pCharacteristic->setValue("Hello World");

  //Time
  BLECharacteristic *pCharacteristicTime = pService->createCharacteristic(CHAR_TIME_UUID, 
    BLECharacteristic::PROPERTY_READ |
    BLECharacteristic::PROPERTY_WRITE);
  pCharacteristicTime->setCallbacks(new CharacteristicCallbacks());
  pCharacteristicTime->setValue("TIME");

  pService->start();
  // BLEAdvertising *pAdvertising = pServer->getAdvertising();  // this still is working for backward compatibility
  BLEAdvertising *pAdvertising = BLEDevice::getAdvertising();
  pAdvertising->addServiceUUID(SERVICE_UUID);
  pAdvertising->setScanResponse(true);
  pAdvertising->setMinPreferred(0x12);
  BLEDevice::startAdvertising();
  Serial.println("Characteristic defined! Now you can read it in your phone!");
}

void updateClock(){
  unsigned long curMil = millis();

  if (curMil - preMil >= interval) {
        preMil = curMil;
        SEC++;
    }
  if (SEC >= 60) {SEC = 0; MIN++;}
  if (MIN >= 60) {MIN = 0; HOUR++;}
  if (HOUR >= 24) {HOUR = 0; DAY++;}
}
void drawText(int width, int hight,int size, const char* text) {
    gfx->setCursor(width, hight); 
    gfx->setTextSize(size);
    gfx->println(text);
}