/*
  Filename: textSpecificLocation
  Author: George Howard
  Date: 26/03/2024
  Description: This is a simple program to test writing to and LCD screen on the Arduino.
 */

#include <Arduino.h>
#include <LiquidCrystal.h>
#include <util/delay.h>

LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

int main (void) {
  WriteLCDInt (0, 0, 65536);
  WriteLCDInt (14, 0, 123456);
  WriteLCDInt (0, 0, -756);
}

void WriteLCDInt (int col, int row, long val) {
  lcd.begin(16, 2);

  // Check if col and row are within range
  inRange(col, row, val);

  // Setting the cursor to the user specified position
  lcd.setCursor(col, row);

  // Adjustments for negative integers
  val = isNegative(val);

  // Printing val
  printDigits(col, row, val);

  // 2.5 second delay for readibility
  _delay_ms(2500);
}

// Function to make adjustments for negative values
long isNegative(long val) {
    long value = val;

    if (val < 0) {
      value = val * -1;
      lcd.print("-");
    }

    return value;
}

// Function to check if the column and row are valid
void inRange(int col, int row, long val) {
  if (row < 0 || row > 1 || col < 0 || col > 15) {
    lcd.setCursor(0, 0);
    lcd.print("Out of range!");
    return;
  }
}

// Function to check how many digits are within a value
int intDigits(long value) {
    int digits = 0;

    if (value == 0) {
        digits = 1;
    }

    while (value != 0) {
        value /= 10;
        digits++;
    }

    return digits;
}

// Function to return the value of an individual digit given a value and digit position
int individualDigit(long value, int position) {
    int digit = 0;

    for (int i = 0; i <= position; i++) {
        digit = value % 10;
        value /= 10;
    }

    return digit;
}

// Function to print the value of the user interger with text wrappin if necessary
void printDigits(int col, int row, long val) {
  int remainingSpace = 16 - col;
  int valueLength = intDigits(val);
  
  if (valueLength > remainingSpace) {
    for (int i = valueLength - 1; i >= valueLength - remainingSpace; i--) {
      lcd.print(individualDigit(val, i));
    }

  row += 1;
  lcd.setCursor(0, row);

  for (int i = valueLength - remainingSpace - 1; i >= 0; i--) {
    lcd.print(individualDigit(val, i));
  }

  } else {
      for (int i = valueLength - 1; i >= 0; i--) {
      lcd.print(individualDigit(val, i));
    }
  }
}