// input button pins, these will all be set up with pulldown resistors
const int Input_Button = 2;
const int Zero_Button = 3;
const int Jump_Button = 4;
const int Stop_Button = 5;
//array for LED pins

int currentROW = 0;
int currentCOLUMN = 0;
int totalCOLUMNinput = 0; //used to limit total number of columns according to user input

const int LEDPins[6][4] = { //6 rows and 4 columns of pins
  {22,23,24,25}, // this array will use arduino mega's digital pins 22-45
  {26,27,28,29},
  {30,31,32,33},
  {34,35,36,37},
  {38,39,40,41},
  {42,43,44,45},
};

void waitForInput(){
  while(Serial.available() <= 0){
    //puts user in endless while loop when there is no input
  }
}

void clearSerialBuffer(){
  while(Serial.available() > 0){
    Serial.read(); //reads any leftover /n's or spaces and doesn't feed them into other inputs
  }
}

//move to next position function
//show current position function
void showROWandCOLUMN(){ //shows the current position after button presses
  Serial.print("Current position: Row");
  Serial.print(currentROW + 1); // this shows the rows as 1-6 instead of 0-5
  Serial.print(", Column ");
  Serial.print(currentCOLUMN + 1); // this shows the columns as 1-4 instead of 0-3
}

void incrementCOLUMNandROWS(){
  if (currentCOLUMN < totalCOLUMNinput) {
    currentCOLUMN++;
  } 
  else if (currentCOLUMN >= totalCOLUMNinput){
    currentCOLUMN = 0; //column is 0 because it goes to the next row

      if (currentROW = 6){ //if row is greater than 5, reset back to zero
        currentROW = 0;
      }
      else{
        currentROW = currentROW + 1; //if it is still less than 5, increment by 1
      }
  }

  showROWandCOLUMN(); //show column after adjustments
}

void setup(){

  Serial.begin(9600);
  bool validinput = false;// used to check if user's input is in the range of 1-4 

  // Sets up all button pins as inputs
  pinMode(Input_Button, INPUT);
  pinMode(Zero_Button, INPUT);
  pinMode(Jump_Button, INPUT);
  pinMode(Stop_Button, INPUT);

  for (int row = 0; row < 6; row++) { //goes thru the entire array of LEDs and sets the pin connections as inputs
    for (int col = 0; col < 4; col++) {
      pinMode(LEDPins[row][col], OUTPUT); 
    }
  }

  while(validinput == false){ //asks user how many columns to use for the array
    Serial.println("How many columns do you want to use? (1-4):");
    waitForInput();

    totalCOLUMNinput = Serial.parseInt(); //takes user integer input and stores in variable
    clearSerialBuffer(); //reads extra characters

    if ((totalCOLUMNinput >= 1) && (totalCOLUMNinput <= 4)){ //inputs in between 1-4
      Serial.print("Using ");
      Serial.print(totalCOLUMNinput);
      Serial.println(" columns.");
      validinput = true;
    }else{
      Serial.println("Invalid Input! Please enter a number between 1 to 4 and press <enter>");
    }
  }

void loop(){
  if (digitalRead(Input_Button) == 1){ //turn the LED on if input button is pressed at iteration
    digitalWrite(LEDPins[currentROW][currentCOLUMN], 1);
    Serial.println("LED ON!");
    incrementCOLUMNandROWS();
    delay(200);
  }

  if (digitalRead(Zero_Button) == 1){ //turn the LED OFF if input button is pressed at iteration
    digitalWrite(LEDPins[currentROW][currentCOLUMN], 0);
    Serial.println("LED OFF!");
    incrementCOLUMNandROWS();
    delay(200);
  }

  if (digitalRead(Jump_Button) == 1){ //turn the LED OFF if input button is pressed at iteration
      if (currentROW = 6){ //if row is greater than 5, reset back to zero
        currentROW = 0;
        currentCOLUMN = 0;
        Serial.println("Jumped to next row!");
        showROWandCOLUMN();
        delay(200); 
      }
      else {
        currentROW = currentROW + 1; //if it is still less than 5, increment by 1
        currentCOLUMN = 0;
        Serial.println("Jumped to next row!");
        showROWandCOLUMN();
        delay(200); 
      }
  }

  if (digitalRead(Stop_Button) == 1){ //return to stop if stop button is pressed
  Serial.println("Program Stopped!");
  return;
  }
}