;nasm 2.11.08

section .bss
   var1 resb 2
   opp resb 2
   var2 resb 2
   period resb 2;2
   answer resb 1;2

  section .data
  msg db "= ",
  len equ $- msg

  skp db " ", 0xA
  len3 equ $- msg


section .text
	global _start
_start:

  next:

  mov eax, 4
  mov ebx, 1
  mov ecx, skp
  mov edx, 2
  int 0x80

  mov eax, 3; gets the first variable
  mov ebx, 0
  mov ecx, var1
  mov edx, 2
  int 0x80

  mov eax, [var1]
  cmp al, '.'
  je per

  mov eax, 3; gets the opperator
  mov ebx, 0
  mov ecx, opp
  mov edx, 2
  int 0x80

  mov eax, 3 ; gets the second variable
  mov ebx, 0
  mov ecx, var2
  mov edx, 2
  int 0x80

  mov eax, 3 ; gets the period at the end if it is there if no thtere is a space
  mov ebx, 0
  mov ecx, period
  mov edx, 1
  int 0x80

  ;/////////////////////////////////////////////////////////

  mov eax, 4; prints first varible for output
  mov ebx, 1
  mov ecx, var1
  mov edx, 2
  int 0x80

  mov eax, 4; prints operator for output
  mov ebx, 1
  mov ecx, opp
  mov edx, 2
  int 0x80

  mov eax, 4 ; prints second varible for output
  mov ebx, 1
  mov ecx, var2
  mov edx, 2
  int 0x80


  ;//////////////////////////////////////////////////////////
  mov eax, [opp] ; puts the opperator into eax tocheck what it is

  cmp al, '+' ; if + jump to add
  je add_n

  cmp al, '-' ; if - jump to subtract
  je sub_n

  cmp al, '*' ; if * jump to multiply
  je mult

  cmp al, '/' ; if / jump to divide
  je divi

  per: ; if there is a period jump to the end
  jmp end

  add_n: ; calls add function
  call add_num

  sub_n: ; calls ssubtract function
  call sub_num

  mult: ; calls multiply function
  call mult_num

  divi: ; calls divide function
  call divi_num

  ;//////////////////////////////////////////////////////////////////
  add_num:
  mov al, [var1] ; gets first var and puts it into decimal to preform operation
  sub al, '0'

  mov bl, [var2]; gets second var and puts it into decimal to preform operation
  sub bl, '0'

  add al, bl ; preforms opperation
  add al, '0' ; puts it back into ascii
  mov [answer], al; places it into answer

  mov eax, 4 ; prints the equal sign
  mov ebx, 1
  mov ecx, msg
  mov edx, len
  int 0x80

  mov eax, 4 ; prints the answer
  mov ebx, 1
  mov ecx, answer
  mov edx, 1
  int 0x80


  mov al, 0

  ;/////////////TESTING





  ;////////END TESTING

  jmp next
  ;///////////////////////////////////////

  sub_num:
  mov al, [var1]; gets first var and puts it into decimal to preform operation
  sub al, '0'

  mov bl, [var2]; gets second var and puts it into decimal to preform operation
  sub bl, '0'

  sub al, bl; preforms opperation; preforms opperation
  add al, '0'; puts it back into ascii; puts it back into ascii
  mov [answer], al; places it into answer

  mov eax, 4 ; prints the equal sign
  mov ebx, 1
  mov ecx, msg
  mov edx, len
  int 0x80

  mov eax, 4 ; prints the answer
  mov ebx, 1
  mov ecx, answer
  mov edx, 1
  int 0x80

  jmp next
  ;///////////////////////////////////////

  mult_num:
  mov al, [var1]; gets first var and puts it into decimal to preform operation
  sub al, '0'

  mov bl, [var2]; gets second var and puts it into decimal to preform operation
  sub bl, '0'

  mul bl; preforms opperation
  add al, '0'; puts it back into ascii
  mov [answer], al; places it into answer

  mov eax, 4 ; prints the equal sign ; prints the equal sign
  mov ebx, 1
  mov ecx, msg
  mov edx, len
  int 0x80

  mov eax, 4 ; prints the answer
  mov ebx, 1
  mov ecx, answer
  mov edx, 1
  int 0x80

  jmp next
  ;///////////////////////////////////////
  ;DIVIDE
  divi_num:

  mov ax, [var1]; gets first var and puts it into decimal to preform operation
  sub ax, '0'

  mov bx, [var2]; gets second var and puts it into decimal to preform operation
  sub bl, '0'

  div bx; preforms opperation
  add bx, '0'; puts it back into ascii
  mov [answer], bx; places it into answer

  mov eax, 4 ; prints the equal sign
  mov ebx, 1
  mov ecx, msg
  mov edx, len
  int 0x80

  mov eax, 4 ; prints the answer
  mov ebx, 1
  mov ecx, answer
  mov edx, 2
  int 0x80

  jmp next
  ;///////////////////////////////////////////////////

end:
	mov eax,1            ; The system call for exit (sys_exit)
	mov ebx,0            ; Exit with return code of 0 (no error)
	int 80h;