/*  Rui Santos & Sara Santos - Random Nerd Tutorials
    THIS EXAMPLE WAS TESTED WITH THE FOLLOWING HARDWARE:
      ESP32-2432S028R 2.8 inch 240×320 also known as the Cheap Yellow Display (CYD): https://makeradvisor.com/tools/cyd-cheap-yellow-display-esp32-2432s028r/
      SET UP INSTRUCTIONS: https://RandomNerdTutorials.com/cyd/
    The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
    Complete project details: https://RandomNerdTutorials.com/touchscreen-on-off-button-cheap-yellow-display-esp32-2432s028r/
*/

#include <SPI.h>

/*  Install the "TFT_eSPI" library by Bodmer to interface with the TFT Display - https://github.com/Bodmer/TFT_eSPI
    *** IMPORTANT: User_Setup.h available on the internet will probably NOT work with the examples available at Random Nerd Tutorials ***
    *** YOU MUST USE THE User_Setup.h FILE PROVIDED IN THE LINK BELOW IN ORDER TO USE THE EXAMPLES FROM RANDOM NERD TUTORIALS ***
    FULL INSTRUCTIONS AVAILABLE ON HOW CONFIGURE THE LIBRARY: https://RandomNerdTutorials.com/cyd/ */
#include <TFT_eSPI.h>

// Install the "XPT2046_Touchscreen" library by Paul Stoffregen to use the Touchscreen - https://github.com/PaulStoffregen/XPT2046_Touchscreen
// Note: this library doesn't require further configuration
#include <XPT2046_Touchscreen.h>

TFT_eSPI tft = TFT_eSPI();

// Touchscreen pins
#define XPT2046_IRQ 36   // T_IRQ
#define XPT2046_MOSI 32  // T_DIN
#define XPT2046_MISO 39  // T_OUT
#define XPT2046_CLK 25   // T_CLK
#define XPT2046_CS 33    // T_CS

SPIClass touchscreenSPI = SPIClass(VSPI);
XPT2046_Touchscreen touchscreen(XPT2046_CS, XPT2046_IRQ);

#define SCREEN_WIDTH 320
#define SCREEN_HEIGHT 240
#define FONT_SIZE 3

// Button position and size
#define FRAME_X 60
#define FRAME_Y 60
#define FRAME_W 200
#define FRAME_H 120

// Red zone size
#define REDBUTTON_X FRAME_X
#define REDBUTTON_Y FRAME_Y
#define REDBUTTON_W (FRAME_W / 2)
#define REDBUTTON_H FRAME_H

// Green zone size
#define GREENBUTTON_X (REDBUTTON_X + REDBUTTON_W)
#define GREENBUTTON_Y FRAME_Y
#define GREENBUTTON_W (FRAME_W / 2)
#define GREENBUTTON_H FRAME_H

// RGB LED Pins
#define CYD_LED_BLUE 17
#define CYD_LED_RED 4
#define CYD_LED_GREEN 16

// Touchscreen coordinates: (x, y) and pressure (z)
int x, y, z;

// Stores current button state
bool buttonState = false;

// Print Touchscreen info about X, Y and Pressure (Z) on the Serial Monitor
void printTouchToSerial(int touchX, int touchY, int touchZ) {
  Serial.print("X = ");
  Serial.print(touchX);
  Serial.print(" | Y = ");
  Serial.print(touchY);
  Serial.print(" | Pressure = ");
  Serial.print(touchZ);
  Serial.println();
}

// Draw button frame
void drawFrame() {
  tft.drawRect(FRAME_X, FRAME_Y, FRAME_W, FRAME_H, TFT_BLACK);
}

// Draw a red button
void drawRedButton() {
  tft.fillRect(REDBUTTON_X, REDBUTTON_Y, REDBUTTON_W, REDBUTTON_H, TFT_RED);
  tft.fillRect(GREENBUTTON_X, GREENBUTTON_Y, GREENBUTTON_W, GREENBUTTON_H, TFT_WHITE);
  drawFrame();
  tft.setTextColor(TFT_BLACK);
  tft.setTextSize(FONT_SIZE);
  tft.setTextDatum(MC_DATUM);
  tft.drawString("ON", GREENBUTTON_X + (GREENBUTTON_W / 2), GREENBUTTON_Y + (GREENBUTTON_H / 2));
  buttonState = false;
}

// Draw a green button
void drawGreenButton() {
  tft.fillRect(GREENBUTTON_X, GREENBUTTON_Y, GREENBUTTON_W, GREENBUTTON_H, TFT_GREEN);
  tft.fillRect(REDBUTTON_X, REDBUTTON_Y, REDBUTTON_W, REDBUTTON_H, TFT_WHITE);
  drawFrame();
  tft.setTextColor(TFT_BLACK);
  tft.setTextSize(FONT_SIZE);
  tft.setTextDatum(MC_DATUM);
  tft.drawString("OFF", REDBUTTON_X + (REDBUTTON_W / 2) + 1, REDBUTTON_Y + (REDBUTTON_H / 2));
  buttonState = true;
}

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

  // Start the SPI for the touchscreen and init the touchscreen
  touchscreenSPI.begin(XPT2046_CLK, XPT2046_MISO, XPT2046_MOSI, XPT2046_CS);
  touchscreen.begin(touchscreenSPI);
  // Set the Touchscreen rotation in landscape mode
  // Note: in some displays, the touchscreen might be upside down, so you might need to set the rotation to 3: touchscreen.setRotation(3);
  touchscreen.setRotation(1);

  // Start the tft display
  tft.init();
  // Set the TFT display rotation in landscape mode
  tft.setRotation(1);

  // Clear the screen before writing to it
  tft.fillScreen(TFT_BLACK);

  // Draw button 
  drawGreenButton();

  pinMode(CYD_LED_GREEN, OUTPUT);
  digitalWrite(CYD_LED_GREEN, LOW);
}

void loop() {
  // Checks if Touchscreen was touched, and prints X, Y and Pressure (Z) info on the TFT display and Serial Monitor
  if (touchscreen.tirqTouched() && touchscreen.touched()) {
    // Get Touchscreen points
    TS_Point p = touchscreen.getPoint();
    // Calibrate Touchscreen points with map function to the correct width and height
    x = map(p.x, 200, 3700, 1, SCREEN_WIDTH);
    y = map(p.y, 240, 3800, 1, SCREEN_HEIGHT);
    z = p.z;

    printTouchToSerial(x, y, z);

    if (buttonState) {
      Serial.println("ON");
      if ((x > REDBUTTON_X) && (x < (REDBUTTON_X + REDBUTTON_W))) {
        if ((y > (REDBUTTON_Y)) && (y <= (REDBUTTON_Y + REDBUTTON_H))) {
          Serial.println("Red button pressed");
          drawRedButton();
          digitalWrite(CYD_LED_GREEN, HIGH);
        }
      }
    }
    else {
      Serial.println("OFF");
      if ((x > (GREENBUTTON_X)) && (x < (GREENBUTTON_X + GREENBUTTON_W))) {
        if ((y > (GREENBUTTON_Y)) && (y <= (GREENBUTTON_Y + GREENBUTTON_H))) {
          Serial.println("Green button pressed");
          drawGreenButton();
          digitalWrite(CYD_LED_GREEN, LOW);
        }
      }
    }
  }
}