// Arduino libraries to control the mouse and keyboard

#include <Keyboard.h>

#include <Mouse.h>

/////////////////////////////////////////////////////////////////////////

// Pin mappings to Arduino Micro according to the assembly instructions

enum ArduinoPinMap {

  // Joystick Movement

  VerticalAxisPin = A0,

  HorizontalAxisPin = A1,

  // Click & Button Pins

  LeftButtonPin = 8,

  RightButtonPin = 9,

  UpButtonPin = 6,

  DownButtonPin = 7,

  JoystickPressPin = 13,

  // Extra Buttons

  TopButtonPin = MOSI,

  MiddleButtonPin = MISO,

  BottomButtonPin = SCK,

};

/////////////////////////////////////////////////////////////////////////

enum InputAction {

  LeftButton = 0,

  RightButton,

  UpButton,

  DownButton,

  JoystickLeft,

  JoystickRight,

  JoystickUp,

  JoystickDown,

  JoystickPress,

  TopButton,

  MiddleButton,

};

#define NOT_MAPPED 0

// Eight elements to correspond to the button. Each map to a keyboard action

// Change these to map the buttons in Keyboard Mode

const int InputMap[11] = {

    'a',              // LeftButton

    'd',              // RightButton

    'w',              // UpButton

    's',              // DownButton

    NOT_MAPPED,       // JoystickLeft

    NOT_MAPPED,       // JoystickRight

    NOT_MAPPED,       // JoystickUp

    NOT_MAPPED,       // JoystickDown

    ' ',              // JoystickPress

    MOUSE_RIGHT,      // TopButton

    MOUSE_LEFT,       // MiddleButton

};

const int InputMapModified[11] = {

    'a',              // LeftButton

    'd',              // RightButton

    KEY_ESC,          // UpButton

    's',              // DownButton

    NOT_MAPPED,       // JoystickLeft

    NOT_MAPPED,       // JoystickRight

    MOUSE_MIDDLE,     // JoystickUp

    'e',              // JoystickDown

    KEY_LEFT_SHIFT,   // JoystickPress

    MOUSE_RIGHT,      // TopButton

    MOUSE_LEFT,       // MiddleButton

};

// State of the modifier buttons

int isModifierPressed = 0;

int wasModifierPressed = 0;

// State of any buttons that can be modified

int isMouseMiddlePressed = 0;

int isEkeyPressed = 0;

int isEscPressed = 0;

int isShiftPressed = 0;

int isSpacePressed = 0;

int isWkeyPressed = 0;

// This is set on the mode toggle

const int *currentModeMap = InputMap;

const int AxisMaxInput = 1023;

const int AxisMaxOutput = 16;

const uint8_t MOUSE_MOVE_DELAY = 8;

// Global variable for the last time the mouse (aka joystick) was moved

unsigned long lastMouseMovement = 0;

int MappedThreshold = 3;               // resting threshold, mapped

int MappedCenter = AxisMaxOutput / 2;  // resting position value, mapped

void getControllerMap() {

  if (isModifierPressed) {

    currentModeMap = InputMap;

  } else {

    currentModeMap = InputMapModified;

  }

}

// Reads an axis (data pin) and scales the analog input range to a range

// from 0 to <range>

int readAxis(int axis) {

  // Read the analog input

  int reading = analogRead(axis);

  // Map the reading from the analog input range to the output range:

  int mappedReading = map(reading, 0, AxisMaxInput, 0, AxisMaxOutput);

  // If the output reading is outside from the rest position threshold, use it:

  int distanceFromCenter = mappedReading - MappedCenter;

  if (abs(distanceFromCenter) < MappedThreshold) {

    distanceFromCenter = 0;

  }

  // Return the distance for this axis:

  return distanceFromCenter;

}

// Converts a button from the InputAction enum into a mouse or keyboard press

void buttonPress(InputAction button, bool isPress) {

  getControllerMap();

  int action = currentModeMap[button];

  if ((action == MOUSE_RIGHT) || (action == MOUSE_LEFT) || (action == MOUSE_MIDDLE)) {

    if (isPress) {

      Mouse.press(action);

      if (action == MOUSE_MIDDLE) {

        isMouseMiddlePressed = 1;

      }

    } else {

      Mouse.release(action);

    }

  } else {

    if (isPress) {

      Keyboard.press(action);

      // If any of the modified keys have been pressed, save them so they can be

      // released if the modifier button is let go

      switch (action) {

        case 'e':

          isEkeyPressed = 1;

          break;

        case KEY_LEFT_SHIFT:

          isShiftPressed = 1;

          break;

        case ' ':

          isSpacePressed = 1;

          break;

        case KEY_ESC:

          isEscPressed = 1;

          break;

        case 'w':

          isWkeyPressed = 1;

          break;

      }

    } else {

      Keyboard.release(action);

    }

  }

}

void handleJoystick() {

  int horizontalInput = readAxis(HorizontalAxisPin);

  int verticalInput = readAxis(VerticalAxisPin);

  if (isModifierPressed) {

    // Take the horizontal and vertical input and move the mouse

    Mouse.move(horizontalInput, verticalInput, 0);

  } else {

    Mouse.move(0, 0, horizontalInput / 2);

    buttonPress(JoystickUp, verticalInput < -MappedThreshold);

    buttonPress(JoystickDown, verticalInput > MappedThreshold);

  }

}

void handleButtons() {

  // Get the state of the modifier Button (BottomButtonPin)

  // and store the previous state of the modifier button (to see if it changed)

  pinMode(MiddleButtonPin, OUTPUT);

  digitalWrite(MiddleButtonPin, LOW);

  delayMicroseconds(25);

  wasModifierPressed = isModifierPressed;

  isModifierPressed = digitalRead(BottomButtonPin);

  pinMode(MiddleButtonPin, INPUT_PULLUP);

  // Get the states of the rest of the buttons

  buttonPress(RightButton, digitalRead(RightButtonPin) == LOW);

  buttonPress(LeftButton, digitalRead(LeftButtonPin) == LOW);

  buttonPress(UpButton, digitalRead(UpButtonPin) == LOW);

  buttonPress(DownButton, digitalRead(DownButtonPin) == LOW);

  buttonPress(JoystickPress, digitalRead(JoystickPressPin) == LOW);

  buttonPress(TopButton, digitalRead(TopButtonPin) == LOW);

  buttonPress(MiddleButton, digitalRead(MiddleButtonPin) == LOW);

  // If the modifier button changed, then release any buttons that have been modified

  // to prevent them from getting "stuck"

  if (isModifierPressed != wasModifierPressed) {

    if (isMouseMiddlePressed) {

        Mouse.release(MOUSE_MIDDLE);

    }

    if (isEkeyPressed) {

        Keyboard.release('e');

    }

    if (isShiftPressed) {

        Keyboard.release(KEY_LEFT_SHIFT);

    }

    if (isSpacePressed) {

        Keyboard.release(' ');

    }

    if (isEscPressed) {

        Keyboard.release(KEY_ESC);

    }

    if (isWkeyPressed) {

        Keyboard.release('w');

    }

  }

}

// Called from the loop to handle input from the pins. We break up the

// handling into joystick and buttons

void processInput() {

  unsigned long currentTime = millis();

  int delayTime = MOUSE_MOVE_DELAY;

  // The scroll wheel moves really fast, so increase the mouse movement delay

  // if the modifier button is pressed

  if (!isModifierPressed) {

    delayTime = delayTime * 12;

  }

  if (currentTime - lastMouseMovement >= delayTime) {

    // Space out joystick actions. This is especially for the joystick

    // button, which sends multiple events for one press

    handleJoystick();

    lastMouseMovement = currentTime;

  }

  handleButtons();

}

// Arduino setup, called in the beginning on the startup

void setup() {

  // Setup input for all the pins

  pinMode(HorizontalAxisPin, INPUT);

  pinMode(VerticalAxisPin, INPUT);

  pinMode(LeftButtonPin, INPUT_PULLUP);

  pinMode(RightButtonPin, INPUT_PULLUP);

  pinMode(UpButtonPin, INPUT_PULLUP);

  pinMode(DownButtonPin, INPUT_PULLUP);

  pinMode(JoystickPressPin, INPUT_PULLUP);

  pinMode(TopButtonPin, INPUT_PULLUP);

  pinMode(MiddleButtonPin, INPUT_PULLUP);

  pinMode(BottomButtonPin, INPUT_PULLUP);

  Mouse.begin();

  Keyboard.begin();

}

// Main Arduino Program Loop

void loop() {

  // Loop forever, checking the pins for input

  processInput();

}