#include <MD_MAX72xx.h>

#define	MAX_DEVICES	1

const int maxX = MAX_DEVICES * 8 - 1;
const int maxY = 7;

#define	CLK_PIN		13
#define	DATA_PIN	11
#define	CS_PIN		10

#define VERT_PIN A0
#define HORZ_PIN A1
#define SEL_PIN  4

MD_MAX72XX mx = MD_MAX72XX(MD_MAX72XX::PAROLA_HW, CS_PIN, MAX_DEVICES);

int x = 0;
int y = 0;

//// Buttons used for controlling the snake
#define left_button 2
#define right_button 3

volatile byte move_left = 0;
volatile byte move_right = 0;

// Varibles for snake
int snake_l = 2;
const int max_len = 30;
int snake[max_len][2];
byte cur_heading = 0;

// Variable for food blob
int blob[2] = { 0, 0 };
int is_eaten = 1;
 
// The game scene
byte scene[8] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

// Function to initialize the game variables
void init_game() {
  is_eaten = 1;
  move_left = 0;
  move_right = 0;
  cur_heading = 0;
  snake_l = 2;
  for (int i = 0; i < max_len; i++)
    for (int j = 0; j < 2; j++)
      snake[i][j] = 0;
  snake[max_len - 1][0] = 2;
  snake[max_len - 1][1] = 5;
  snake[max_len - 2][0] = 1;
  snake[max_len - 2][1] = 5;
  refresh_scene();
  while ((move_left || move_right) == 0)
    ;
  move_left = 0;
  move_right = 0;
}
 
// Function to draw snake on gamescene
void spawn_snake() { 
  // If the snake goes out of the scene, it enters from the other side
  for (int j = max_len - snake_l; j < max_len; j++) {
    if (snake[j][0] <= 0)
      snake[j][0] = 8 + snake[j][0];
    else if (snake[j][0] >= 9)
      snake[j][0] = snake[j][0] - 8;
    if (snake[j][1] <= 0)
      snake[j][1] = 8 + snake[j][1];
    else if (snake[j][1] >= 9)
      snake[j][1] = snake[j][1] - 8;
 
    // Draw the snake on the LED matrix
    scene[snake[j][0] - 1] |= (1 << (snake[j][1] - 1));
  }
}
 
// Function to update the position and length of the snake
void snake_move() {
  // If snake eats a blob...Increase length
  if (snake[max_len - 1][0] == blob[0] && snake[max_len - 1][1] == blob[1]) {
    is_eaten = 1;
    snake_l += 1;
  }
 
  // Move each pixel forward
  for (int i = snake_l - 1; i >= 1; i--) {
    snake[max_len - 1 - i][0] = snake[max_len - i][0];
    snake[max_len - 1 - i][1] = snake[max_len - i][1];
  }
 
  // Move the head according to button input
  if (move_left == 1) {
    if (cur_heading == 0) {
      cur_heading = 1;
      snake[max_len - 1][1] -= 1;
    } else if (cur_heading == 1) {
      cur_heading = 2;
      snake[max_len - 1][0] -= 1;
    } else if (cur_heading == 2) {
      cur_heading = 3;
      snake[max_len - 1][1] += 1;
    } else if (cur_heading == 3) {
      cur_heading = 0;
      snake[max_len - 1][0] += 1;
    }
    move_left = 0;
  } else if (move_right == 1) {
    if (cur_heading == 0) {
      cur_heading = 3;
      snake[max_len - 1][1] += 1;
    } else if (cur_heading == 1) {
      cur_heading = 0;
      snake[max_len - 1][0] += 1;
    } else if (cur_heading == 2) {
      cur_heading = 1;
      snake[max_len - 1][1] -= 1;
    } else if (cur_heading == 3) {
      cur_heading = 2;
      snake[max_len - 1][0] -= 1;
    }
    move_right = 0;
  } else {
    if (cur_heading == 0) {
      snake[max_len - 1][0] += 1;
    } else if (cur_heading == 1) {
      snake[max_len - 1][1] -= 1;
    } else if (cur_heading == 2) {
      snake[max_len - 1][0] -= 1;
    } else if (cur_heading == 3) {
      snake[max_len - 1][1] += 1;
    }
  }
}
 
// Function to generate a blob and draw the blob on the gamescene
void blob_generator() {
  // If blob is eaten by the snake, generate one
  if (is_eaten) {
    blob[0] = random(1, 9);
    blob[1] = random(1, 9);
  }
 
  // Draw the blob on the gamescene
  scene[blob[0] - 1] |= (1 << (blob[1] - 1));
  is_eaten = 0;
}
 
// Function to redraw the gamescene to the LED matrix with updated variables
void refresh_scene() {
  for (int i = 0; i < 8; i++)
    scene[i] = 0x00;
  snake_move();
  spawn_snake();
  blob_generator();
  for (int i = 1; i < 9; i++)
    //SendData(i, scene[i - 1]);
    mx.setPoint(i, scene[i - 1], true);
    mx.update();
}
 
// Callback for interrupt attached to left button
void update_left() {
  move_left = 1;
}
 
// Callback for interrupt attached to right button
void update_right() {
  move_right = 1;
}




void setup() {
  mx.begin();
  mx.control(MD_MAX72XX::INTENSITY, MAX_INTENSITY / 2);
  mx.clear();

  pinMode(VERT_PIN, INPUT);
  pinMode(HORZ_PIN, INPUT);
  pinMode(SEL_PIN, INPUT_PULLUP);

//
 // Random seed generation...Uses the noise in the analog channel 0 to create a random seed
  randomSeed(analogRead(0));
 
  // Attach interrupts to the buttons
  attachInterrupt(digitalPinToInterrupt(left_button), update_left, FALLING);
  attachInterrupt(digitalPinToInterrupt(right_button), update_right, FALLING);
 
  // Enable interrupt
  sei();
 
  // Start the game
  init_game();
}





// the loop function runs over and over again forever
void loop() {
  int horz = analogRead(HORZ_PIN);
  int vert = analogRead(VERT_PIN);
  

  // Check if snake is at max length
  if (snake_l == max_len) {
    // If yes, display win and restart
    byte win_scene[8] = { B11100011, B00100100, B01000010, B11100100, B00000011, 0, B00011100, 0 };
    for (int i = 1; i < 9; i++)
      //SendData(i, win_scene[i - 1]);
      mx.setPoint(i, win_scene[i - 1], true);
      mx.update();
    delay(5000);
    init_game();
  }
 
  // Check if snake has collided with itself
  for (int i = 0; i < max_len - 1; i++) {
    if (snake[i][0] == snake[max_len - 1][0] && snake[i][1] == snake[max_len - 1][1]) {
      // If yes, blink all leds and restart the game
      delay(1000);
      for (int j = 0; j < 4; j++) {
        //SendData(DISPLAY_TEST, 0x01);
        mx.setPoint(0, 0x01, true);
        mx.update();
        delay(500);
        //SendData(DISPLAY_TEST, 0x00);
        mx.setPoint(0, 0x00, true);
        mx.update();
        delay(500);
      }
      init_game();
      break;
    }
  }
  
  // Keep refreshing the matrix with updated data....
  refresh_scene();
  // ...Every 0.5 secs
  delay(250);
  
  
  /*if (vert < 300) {
    y = min(y + 1, maxY);
  }
  if (vert > 700) {
    y = max(y - 1, 0);
  }
  if (horz > 700) {
    x = min(x + 1, maxX);
  }
  if (horz < 300) {
    x = max(x - 1, 0);
  }
  if (digitalRead(SEL_PIN) == LOW) {
    mx.clear();
  }
  mx.setPoint(y, x, true);
  mx.update();
  delay(100);*/

}