#include "Adafruit_TinyUSB.h"

/* USB HID */
hid_gamepad_report_t report;
Adafruit_USBD_HID usb_hid;



//GPIO Pins
/* Controller Buttons */
//const int topBtnPin = 38;
const int bottomBtnPin = 42;
const int joyYpin = 35;  // Analog
const int joyXpin = 34;  // Analog
const int joySEL = 33;   // Analog

/* LED */
//const int powerled = 3;

/* Joystick Deadzone */
int joyCenterX;
int joyCenterY;

/* Gamepad report Structure */
// typedef struct {
//   int16_t x;
//   int16_t y;
//   uint8_t buttons;
// } GamepadReport;

//GamepadReport report;

// Handle Deadzone
int applyDeadzone(int val, int center, int deadzone = 150) {
  if (abs(val - center) < deadzone) {
    return center;
  }
  return val;
}

// Normalize to -32768 - 32767 (standard for gamepads)
int16_t normalizeAxis(int raw, int center) {
  int val = raw - center;  // shift center to 0

  // clamp to avoid overflow
  if (val > 2048) val = 2048;
  if (val < -2048) val = -2048;

  float scaled = (float)val / 2048.0;  // normalize to -1.0 to +1.0
  return (int16_t)(scaled * 32767);
}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  while (!Serial && millis() < 5000); // Wait up to 5 seconds for Serial Monitor
  Serial.println("Staring Controller...\n");

  //pinMode(topBtnPin, INPUT_PULLUP);
  pinMode(joySEL, INPUT_PULLUP);
  pinMode(bottomBtnPin, INPUT_PULLUP);
  //pinMode(powerled, OUTPUT);

  //Idle LED ON
  //digitalWrite(powerled, HIGH);

  // Calibrate center (don't touch joystick)
  delay(500);
  joyCenterY = analogRead(joyYpin);
  joyCenterX = analogRead(joyXpin);

  // Setup HID as generic gamepad
  static const uint8_t desc_hid_report[] = {
    TUD_HID_REPORT_DESC_GAMEPAD()
  };

  TinyUSBDevice.setManufacturerDescriptor("");
  TinyUSBDevice.setProductDescriptor("USB Atari 2600 Dual controller");

  usb_hid.setPollInterval(2);
  usb_hid.setReportDescriptor(desc_hid_report, sizeof(desc_hid_report));
  usb_hid.begin();
}

void loop() {
  Serial.println("Controller code entered loop\n");
  // Buttons (LOW = pressed because of pullup)
  //if (!usb_hid.ready()) return;

  // Reset report
  memset(&report, 0, sizeof(report));

  //bool topPressed = !digitalRead(topBtnPin);
  bool joyPressed = !digitalRead(joySEL);
  bool bottomPressed = !digitalRead(bottomBtnPin);

  int rawX = applyDeadzone(analogRead(joyXpin), joyCenterX);
  int rawY = applyDeadzone(analogRead(joyYpin), joyCenterY);

  report.x = normalizeAxis(rawX, joyCenterX);
  report.y = normalizeAxis(rawY, joyCenterY);

  report.buttons = 0;
  
  if (joyPressed) {
    Serial.println("joystick pressed");
    report.buttons |= 0x01;
  }

  if (bottomPressed) {
    Serial.println("bottom button pressed");
    report.buttons |= 0x02;
  }

  usb_hid.sendReport(0, &report, sizeof(report));

  delay(10); // this speeds up the simulation
}