#define CLK 13
#define DIN 11
#define CS  10
#define X_SEGMENTS   4  
#define Y_SEGMENTS   2
#define NUM_SEGMENTS (X_SEGMENTS * Y_SEGMENTS)
#define rb 5
#define gb 4
#define yb 6
#define bb 7

byte fb[8 * NUM_SEGMENTS];
//coord matrix for lit up leds
int matrix[16][32];
// array of snake coordinates (fir line for x, second line for y)
int snake[2][16*32];
int len = 1;
bool gameOver = false;

int dir = 0; // 0 - left, 1 - up, 2 - right, 3 - down

unsigned long start = millis();



void shiftAll(byte send_to_address, byte send_this_data){
  digitalWrite(CS, LOW);
  for (int i = 0; i < NUM_SEGMENTS; i++) {
    shiftOut(DIN, CLK, MSBFIRST, send_to_address);
    shiftOut(DIN, CLK, MSBFIRST, send_this_data);
  }
  digitalWrite(CS, HIGH);
}

void matrixToDisplay(){
  int v;
  int fb_ind = 63;
  for(int line_ind = 0; line_ind < 16; ++line_ind){
    for(int col_ind = 0; col_ind < 32; col_ind += 8){
      v = 0;
      for(int i=0; i<8; ++i){
        v |= ((matrix[line_ind][col_ind + 7 - i] > 0) << i);  //sau la shiftare 7-i
        fb[fb_ind] = v;
      }
      --fb_ind;
    }
  }

}
 
void show() {
  matrixToDisplay();
  for (byte row = 0; row < 8; row++) {
    digitalWrite(CS, LOW);
    byte segment = NUM_SEGMENTS;  
    while (segment--) {

      //compute row and column
      byte x = segment % X_SEGMENTS;
      byte y = segment / X_SEGMENTS * 8;

      //compute address given the above
      byte addr = (row + y) * X_SEGMENTS;
 
      // odd rows of segments
      if (segment & X_SEGMENTS) { 
        shiftOut(DIN, CLK, MSBFIRST, 8 - row);    //?????
        shiftOut(DIN, CLK, LSBFIRST, fb[addr + x]);
      } else { 

        shiftOut(DIN, CLK, MSBFIRST, 1 + row);
        shiftOut(DIN, CLK, MSBFIRST, fb[addr - x + X_SEGMENTS - 1]);
      }

    }
    digitalWrite(CS, HIGH);
  }
}

int start_line = 8;
int start_col = 0;
int top = 0;
int bottom = 0;


void generateCaveColumn(int column){

  srand(analogRead(0));
  int prob = 50; //50% by default

  for(int line = 0; line < 8; ++line){
    
    if(line > 0 && column > 0){ //inner walls
      //the previous wall level exists
      //and there are still 2 spaces left between the walls
      //and the previous wall doesnt connect with the current wall
      if(matrix[line-1][column] == 1 && matrix[line+2][column] != 1
      && matrix[bottom][column-1] != 1){
        bool generated = rand()%100 > prob;
        if(generated){
          matrix[line][column] = 1;       
          top = line;
        } 
      }else if(matrix[15-line+1][column] == 1 && matrix[15-line-1][column] != 1
      && matrix[top][column-1] != 1){
        bool generated = rand()%100 > prob;
        if(generated){
          matrix[15 - line][column] = (rand()%100 > prob);
          bottom = 15 - line;
        }
      }
    }else{ //outer walls
      matrix[line][column] = (rand()%100 > prob);
    }

  }
}

void shifCave(){
  for(int line = 0; line < 16; ++line){
    for(int col = 0; col < 31 ; --col){ //moving all walls tow the left by 1 unit
      matrix[line][col] = matrix[line][col+1];
    }
    matrix[line][31] = 0; //clearing the last line
  }
}


void setup() {
  Serial.begin(115200);
  pinMode(CLK, OUTPUT);
  pinMode(DIN, OUTPUT);
  pinMode(CS, OUTPUT);
 
  // Setup each MAX7219
  shiftAll(0x0f, 0x00); //display test register - test mode off
  shiftAll(0x0b, 0x07); //scan limit register - display digits 0 thru 7
  shiftAll(0x0c, 0x01); //shutdown register - normal operation
  shiftAll(0x0a, 0x0f); //intensity register - max brightness
  shiftAll(0x09, 0x00); //decode mode register - No decode
  for(int col = 0; col < 32; ++col){
    generateCaveColumn(col);
    show();
  }
  
  pinMode(7, INPUT);
  pinMode(6, INPUT);
  pinMode(5, INPUT);
  pinMode(4, INPUT);
}

void loop() {

}