// ESP32-S3 + ILI9341 240x320 display test.
// Install Adafruit ILI9341, Adafruit GFX Library and their dependencies.
// Display: SCK=12, SDI/MOSI=11, CS=10, DC=9, RESET=8, GND=GND.
// Touch: T_CLK=12, T_DIN=11, T_DO=13, T_CS=7, T_IRQ=6.
// Install XPT2046_Touchscreen by Paul Stoffregen as well.
// Display SDO and SD card are not connected. Backlight is externally powered.
#include <SPI.h>
#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
#include <XPT2046_Touchscreen.h>

constexpr int TFT_SCK = 12;
constexpr int TFT_MOSI = 11;
constexpr int TFT_CS = 10;
constexpr int TFT_DC = 9;
constexpr int TFT_RST = 8;
constexpr int TOUCH_MISO = 13;
constexpr int TOUCH_CS = 7;
constexpr int TOUCH_IRQ = 6;

Adafruit_ILI9341 tft(&SPI, TFT_DC, TFT_CS, TFT_RST);
// Poll first to test SPI independently of the IRQ wire.
XPT2046_Touchscreen touch(TOUCH_CS);
bool wasPressed = false;
bool alternateColor = false;
uint32_t touchCount = 0;
uint32_t lastReport = 0;

void drawFace(uint16_t color);

void setup() {
  Serial.begin(115200);
  delay(300);
  pinMode(TFT_CS, OUTPUT);
  digitalWrite(TFT_CS, HIGH);
  pinMode(TOUCH_CS, OUTPUT);
  digitalWrite(TOUCH_CS, HIGH);
  pinMode(TOUCH_IRQ, INPUT_PULLUP);
  SPI.begin(TFT_SCK, TOUCH_MISO, TFT_MOSI, TFT_CS);
  tft.begin(10000000);  // Start conservatively at 10 MHz for jumper wires.
  tft.setRotation(1);  // Landscape: 320 x 240. Use 3 if upside down.
  touch.begin(SPI);
  touch.setRotation(1);

  const uint16_t colors[] = {ILI9341_RED, ILI9341_GREEN, ILI9341_BLUE};
  for (uint16_t color : colors) {
    tft.fillScreen(color);
    delay(400);
  }

  tft.fillScreen(ILI9341_NAVY);
  drawFace(ILI9341_YELLOW);
  Serial.println("Touch test ready. Raw coordinates are not calibrated pixels.");
}

void drawFace(uint16_t color) {
  const int cx = tft.width() / 2;
  const int cy = 105;
  tft.fillCircle(cx, cy, 82, color);
  tft.fillCircle(cx - 28, cy - 22, 10, ILI9341_BLACK);
  tft.fillCircle(cx + 28, cy - 22, 10, ILI9341_BLACK);

  // Parabolic smile: the center is lower than the corners.
  for (int x = -42; x <= 42; ++x) {
    int y = cy + 43 - (x * x) / 65;
    tft.fillCircle(cx + x, y, 3, ILI9341_BLACK);
  }

  tft.fillRect(0, 199, tft.width(), 41, ILI9341_NAVY);
  tft.setTextColor(ILI9341_WHITE, ILI9341_NAVY);
  tft.setTextSize(2);
  tft.setCursor(16, 207);
  tft.print("Touches: ");
  tft.print(touchCount);
}

void loop() {
  bool pressed = touch.touched();
  if (pressed) {
    TS_Point point = touch.getPoint();
    if (!wasPressed) {
      ++touchCount;
      alternateColor = !alternateColor;
      drawFace(alternateColor ? ILI9341_CYAN : ILI9341_YELLOW);
    }
    if (millis() - lastReport >= 150) {
      lastReport = millis();
      Serial.printf("raw x=%d y=%d pressure=%d IRQ=%d\n",
                    point.x, point.y, point.z, digitalRead(TOUCH_IRQ));
    }
  }
  wasPressed = pressed;
  delay(20);
}