/* Perform three Digit Addition. Ex: 161 + 656 = 817 659 + 765 = 1424
*/

#include "data.h"   // Contains common variables and funcions
#include "setup.h"  // Contains Macros and Functions to intialize Data Direction, Input and Output Registers
#include "keypad.h"
#include "quad_sev_seg.h"
#define MAX_SWITCH_COUNT 7
#define SIZE(X) (uint8_t) sizeof(X)/sizeof(X[0])
void read_input_sequence(volatile uint16_t*, unsigned char*, volatile uint16_t*);
uint16_t addition(uint16_t*, uint8_t);


int main(void)
{
  init_port();

  volatile uint16_t nums[2] = {0};
  uint8_t switch_count = 0;
  uint16_t sum = 0;
  unsigned char sign;
  while (1)
  {
    if (switch_count < MAX_SWITCH_COUNT)
    {
        read_input_sequence(nums, &sign, &switch_count);
    }
    else if(switch_count == MAX_SWITCH_COUNT)
    {
        for (long i = 0; i < 10; i++ )
          {
            show_multiplexed_number(nums[0]);   // To display 1st number
          }
           for (long i = 0; i < 10; i++ )
          {
            show_multiplexed_number(nums[1]);   // To display 2nd number
          }
        if (sign == PLUS_SIGN)
        {
          sum = addition(nums, SIZE(nums));
          for (long i = 0; i < 10;  i++)
            show_multiplexed_number(sum);     // To display sum of both numbers
        }
    }
  }
}

void read_input_sequence(volatile uint16_t *nums, unsigned char *sign, uint8_t *sw)
{
  volatile uint16_t n = NO_KEY_PRESSED;
  static uint8_t index = 0;
  uint8_t digit = 0;
  while (*sw < MAX_SWITCH_COUNT && digit < 3)
  {
    n = read_keypad();
    time_delay(2);
    if (n != NO_KEY_PRESSED && n != INVALID_KEY_PRESSED)
    {
     
      if (n != PLUS_SIGN && digit < 3)
      {
      nums[index] = nums[index] * 10 + n;
          digit++;
      }
      
      else if (*sw == 3 && n == PLUS_SIGN)
      {
        *sign = n;
        (index)++;
        digit = 0;
        }
         (*sw)++;
    }
  }
}

uint16_t addition(uint16_t *nums, uint8_t size)
{
  uint16_t sum = 0;
  for (char i = 0; i < size; i++)
  {
    sum += nums[i];
  }
  return sum;
}