#include <math.h>
void init_port(void);
void outdata(char);
void outcontrol(char);
void init_lcd(void);
void lcd_control_write(void);
void write_data(char);
void write_string(char);
void set_cursor_second_row(void);
char str[50] = "hiii, this is full adder";
void setup() {
  //For keypad and Adder
  volatile char *dirF, *dirK, *dirA, *dirC, *dirB, *dirL;
  dirF = 0x30;
  dirK = 0x107;
  dirA = 0x21;
  dirC = 0x27;
  dirB = 0x24;
  dirL = 0x10A;
  *dirF = 0xFF;
  *dirK = 0xFF;
  *dirA = 0x00;
  *dirC = 0xFF;
  *dirB = 0xFF;
  *dirL = 0x00;

  //For operation of LCD
  init_port();
  init_lcd();
  set_cursor_first_row();
  write_string(str);

}

void write_string( char *ptr) {
  volatile long count = 0;

  while (*ptr != 0) {
    if (count == 16) {
      set_cursor_second_row();
      lcd_control_write();
    }
    write_data(*ptr);                // Write character to the LCD
    ptr++;
    count++;

  }
}


void init_port(void) {
  volatile char *portC_dir = (volatile char *)0x27;
  volatile char *portE_dir = (volatile char *)0x2D;
  *portC_dir = 0xFF;
  *portE_dir = 0x03;
}
void outdata(char out_data) {
  volatile char *portC_data;
  portC_data = 0x28;
  *portC_data = out_data;
}
void outcontrol(char out_data) {
  volatile char *portE_data;
  portE_data = 0x2E;
  *portE_data = out_data;
}
void init_lcd(void) {
  outdata(0x38);  //function set: 8bit ,2line , 5*8
  lcd_control_write();  //giving pulse to enable
  outdata(0x0F);   //display on ,cursor blinking
  lcd_control_write();
  outdata(0x01);  //clear display
  lcd_control_write();
  outdata(0x06);   //auto increment after writing 1 char; entry mode
  lcd_control_write();


}
void lcd_control_write(void) {
  outcontrol(0x01);
  delay(1);
  outcontrol(0x00);
  delay(1);
}
void write_data(char wr_data) {
  outdata(wr_data);
  outcontrol(0x02);    //giving pulse to enable and sending data
  delay(1);
  outcontrol(0x03);
  delay(1);
  outcontrol(0x02);
  delay(1);
}
void set_cursor_second_row(void) {
  outdata(0xC0);  // Address of the second row in 16x2 LCD(DDRAM)
  lcd_control_write();
}

void set_cursor_first_row(void) {
  outdata(0x00);  // Address of the second row in 16x2 LCD(DDRAM)
  lcd_control_write();
}

void loop() {
  // Empty loop since main code runs in setup
  volatile char *outF, *outK, *inA, *outC, *outB, *inL;
  outF = 0x31;
  outK = 0x108;
  inA = 0x20;
  outC = 0x28;
  outB = 0x25;
  inL = 0x109;


  volatile int col, row;
   char keys[4][4] = {
  {'1', '2', '3', '+'},
  {'4', '5', '6', '-'},
  {'7', '8', '9', '*'},
  {'.', '0', '=', '/'}
};

  volatile long i, j;
  int num1 = -1, num2 = -1;
  int num3 = -1, num4 = -1;
  uint8_t sum;
  bool firstNumberComplete = false;
  bool inputComplete = false;

  while (1) {
    for (i = 0; i < 4 ; i++) {
      *outB = 1 << i;

      if (*inA != 0) {
        col = *inA;
        row = 1 << i;
        char key = keys[int(log(row) / log(2))][int(log(col) / log(2))];

        if (key >= '0' && key <= '9') {
          int digit = key - '0';

          if (!firstNumberComplete) {
            if (num1 == -1) {
              num1 = digit;
              sprintf(str, "%d", num1);
              init_lcd();
              write_string(" ");
              write_string(str);
            }
            else {
              num2 = digit;
              sprintf(str, "%d", num2);
              write_string(str);
              int firstNumber = num1 * 10 + num2;
              *outF = firstNumber;
              firstNumberComplete = true;
              num1 = -1;
              num2 = -1;

            }
          } else {
            // Getting the second two-digit number
            if (num3 == -1) {
              num3 = digit;  // Store first digit of second number

              outdata(0x05);   //auto increment stopped(it worked but not confirmed)
              lcd_control_write();
              set_cursor_second_row();
              lcd_control_write();
              write_string("+");
              sprintf(str, "%d", num3);
              write_string(str);
            } else {
              num4 = digit;  // Store second digit of second number
              sprintf(str, "%d", num4);
              write_string(str);
              int secondNumber = num3 * 10 + num4;
              *outK = secondNumber; //2nd input to adder
              // Reset for next set of numbers
              num3 = -1;
              num4 = -1;
              firstNumberComplete = false;
              inputComplete = true;
            }
          }


          // Debounce delay

          delay(50);
          // Wait for key release
          while (*inA != 0);
        }
        if (inputComplete) {
          sum = *inL;
          sprintf(str, "%d", sum);
          delay(300);
          init_lcd();
          write_string(str);
          inputComplete = false;
        }
        delay(10);  // Short delay between each iteration
      }


    }

  }
}