#include <GxEPD2_BW.h>
#include <Fonts/FreeMonoBold9pt7b.h>

// 2.9'' EPD Module
// ESP32 CS(SS)=5,SCL(SCK)=18,SDA(MOSI)=23,BUSY=15,RES(RST)=2,DC=0
GxEPD2_BW<GxEPD2_290_BS, GxEPD2_290_BS::HEIGHT> display(GxEPD2_290_BS(/*CS=5*/ 5, /*DC=*/ 0, /*RES=*/ 2, /*BUSY=*/ 15)); // DEPG0290BS 128x296, SSD1680

#define BUTTON_PIN  22 // ESP32 pin GPIO22, which connected to button
#define LED_PIN     32 // ESP32 pin GPIO23, which connected to led

// variables will change:
int led_state = LOW;    // the current state of LED
int button_state;       // the current state of button
int last_button_state;  // the previous state of button

void setup() {
  Serial.begin(9600);                // initialize serial

  pinMode(BUTTON_PIN, INPUT_PULLUP); // set ESP32 pin to input pull-up mode
  pinMode(LED_PIN, OUTPUT);          // set ESP32 pin to output mode

  button_state = digitalRead(BUTTON_PIN);

  //display.init(115200); // default 10ms reset pulse, e.g. for bare panels with DESPI-C02
  display.init(115200, true, 2, false); // USE THIS for Waveshare boards with "clever" reset circuit, 2ms reset pulse
  helloWorld();
  display.hibernate();
}

const char HelloWorld[] = "Success!!!";
const char ELedState[] = "The button is pressed: ";

void helloWorld()
{
  display.setRotation(1);
  display.setFont(&FreeMonoBold9pt7b);
  display.setTextColor(GxEPD_BLACK);
  int16_t tbx, tby; uint16_t tbw, tbh;
  display.getTextBounds(HelloWorld, 0, 0, &tbx, &tby, &tbw, &tbh);
  // center the bounding box by transposition of the origin:
  uint16_t x = ((display.width() - tbw) / 2) - tbx;
  uint16_t y = ((display.height() - tbh) / 2) - tby;
  display.setFullWindow();
  display.firstPage();
  do
  {
    display.fillScreen(GxEPD_WHITE);
    display.setCursor(x, y);
    display.print(HelloWorld);
  }
  while (display.nextPage());
}

void eLedState()
{
  display.setRotation(1);
  display.setFont(&FreeMonoBold9pt7b);
  display.setTextColor(GxEPD_BLACK);
  int16_t tbx, tby; uint16_t tbw, tbh;
  display.getTextBounds(ELedState, 0, 0, &tbx, &tby, &tbw, &tbh);
  // center the bounding box by transposition of the origin:
  uint16_t x = ((display.width() - tbw) / 2) - tbx;
  uint16_t y = ((display.height() - tbh) / 2) - tby;
  display.setFullWindow();
  display.firstPage();
  do
  {
    display.fillScreen(GxEPD_WHITE);
    display.setCursor(x, y);
    display.print(ELedState);
    display.print(led_state);
  }
  while (display.nextPage());
}

void loop() {
  last_button_state = button_state;      // save the last state
  button_state = digitalRead(BUTTON_PIN); // read new state

  if (last_button_state == HIGH && button_state == LOW) {
    Serial.println("The button is pressed");

    // toggle state of LED
    led_state = !led_state;

    // control LED arccoding to the toggled state
    digitalWrite(LED_PIN, led_state);
    Serial.println(led_state);
    eLedState();
    display.hibernate();
  }
  delay(100);
}