calculator.asm

global main
extern printf
extern scanf
extern puts
extern exit

section .text
main:
    mov ebp, esp        ; ebp --> entry point
    sub esp, 16         ; rezerwacja 16 bajtow na 4 zmienne potrzebne w programie (inty rozmiar 4 bajtow)

    mov dword [ebp-12], 0   ; int wybor = 0
    mov dword [ebp-8],  0   ; int liczba1 = 0
    mov dword [ebp-4],  0   ; int liczba2 = 0
    mov dword [ebp],    0   ; int wynik = 0
    push calc_msg
    call printf
    add esp, 4
    push choice_msg
    call printf
    add esp, 4
    push choices
    call puts
    add esp, 4
    push next_choice_msg
    call printf
    add esp, 4
    lea eax, [ebp-12]               ; oblicz offset [ebp-12] i wloz do eax
    push eax                        ; (&wybor)
    push format_int                 ; ("%i")
    call scanf                      ; scanf("%i", &wybor)
    add esp, 8
    push write_first_number_msg     ; 'Write first number: '
    call printf
    add esp, 4
    lea eax, [ebp-8]                ; oblicz offset [ebp-8] i wloz do eax
    push eax                        ; (&liczba1)
    push format_int                 ; ("%i")
    call scanf                      ; scanf("%i", &liczba1)
    add esp, 8
    push write_second_number_msg    ; 'Write second number: '
    call printf
    add esp, 4
    lea eax, [ebp-4]                ; oblicz offset [ebp-4] i wloz do eax
    push eax                        ; (&liczba1)
    push format_int                 ; ("%i")
    call scanf                      ; scanf("%i", &liczba2)
    add esp, 8

    ; zaczyna sie cos jak switch case w C

    mov eax, [ebp-12]               ; eax --> *(wybor)
    cmp eax, 2
    jz subtraction
    cmp eax, 2
    jg cmp_with_3_label
    cmp eax, 1
    jz addition
    jmp default_label

    cmp_with_3_label:
        cmp eax, 3
        jz multiplication
        jmp cmp_with_4_label

    cmp_with_4_label:
        cmp eax, 4
        jz divide
        jmp default_label

    subtraction:
        mov eax, [ebp-8]    ; eax --> *(liczba1)
        sub eax, [ebp-4]    ; eax --> *(liczba1) - *(liczba2)
        mov [ebp], eax      ; *(wynik) = *(liczba1) - *(liczba2)
        jmp write_result

    addition:
        mov eax, [ebp-8]
        add eax, [ebp-4]    ; eax --> *(liczba1) + *(liczba2)
        mov [ebp], eax
        jmp write_result

    multiplication:
        mov eax, [ebp-8]
        imul eax            ; eax --> *(liczba1) * *(liczba2) (instrukcja imul, bo dzialamy na signed int)
        mov [ebp], eax
        jmp write_result

    divide:
        mov eax, [ebp-8]
        idiv eax            ; eax --> *(liczba1) / *(liczba2) (instrukcja idiv, bo dzialamy na signed int)
        mov [ebp], eax
        jmp write_result

    default_label:
        push bad_option
        call puts           ; puts, bo na koniec \n co powoduje wyczyszczenie bufora
        add esp, 4
        call exit

    write_result:
        push dword [ebp]
        push write_result_msg
        call printf
        add esp, 8
        call exit

section .data
calc_msg db "~~~~~~~~CALCULATOR~~~~~~~~", 0xa, 0
choice_msg db "Choose one of the operation", 0xa, 0
choices db "1. Addition", 0xa
        db "2. Subtraction", 0xa
        db "3. Multiplication", 0xa
        db "4. Divide", 0
next_choice_msg db "Your choice: ", 0
write_first_number_msg db "Write first number: ", 0
write_second_number_msg db "Write second number: ", 0
bad_option db "You chose bad option.", 0
write_result_msg db "Result: %i", 0xa, 0
format_int db "%i", 0