%include "io64.inc"
section .text
global CMAIN
;ZROBIONE UNIWERSALNYM WZOREM ZELLERA
    ; k + [(13 * m - 1 )/5] + D + D/4 + C/4 - 2*C
    ; GDZIE:
    ; k = DAY
    ; m = MONTH
    ; C = PIERWSZE DWIE CYFRY ROKU
    ; D = OSTATNIE DWIE CYFRY ROKU

CMAIN:
    PRINT_STRING info
    NEWLINE
    mov eax,3
    mov ebx,0
    mov ecx, buffer
    mov edx,10
    int 0x080

    CALL allocate_data
    call obliczanie
    call dzien_tygodnia


    end:
    xor rax, rax
    ret


    obliczanie:
    mov al,[day]
    add [wynik],al
    mov al,[year_last]
    add [wynik],al
    xor dx,dx
    mov al,[year_last]
    mov ah,0
    mov cx,4
    div cx
    add [wynik],ax
    xor dx,dx
    mov al,[year_first]
    mov ah,0
    mov cx,4
    div cx
    add [wynik],ax
    xor dx,dx
    mov al,[year_first]
    mov ah,0
    mov cx,2
    mul cx
    sub [wynik],ax
    mov al,[month]
    mov ah,0
    mov cx,13
    mul cx
    sub ax,1
    xor dx,dx
    mov cx,5
    div cx
    add [wynik],ax
    ret

    dzien_tygodnia:
    xor dx,dx
    mov ax,[wynik]
    mov cx,7
    div cx
    mov bl,dl

    mov bh,0
    cmp bl,bh

    je sunday
        mov bh,1
    cmp bl,bh

    je monday
        mov bh,2
    cmp bl,bh
    je tuesday
        mov bh,3
    cmp bl,bh
    je wednesday
        mov bh,4
    cmp bl,bh
    je thursday
        mov bh,5
    cmp bl,bh
    je friday
        mov bh,6
    cmp bl,bh
    je saturday
    jmp end
    sunday:
    PRINT_STRING sun
    jmp end
    monday:
        PRINT_STRING mon
    jmp end
    tuesday:
        PRINT_STRING tue
    jmp end
    wednesday:
        PRINT_STRING wed
    jmp end
    thursday:
        PRINT_STRING thu
    jmp end
    friday:
        PRINT_STRING fri
    jmp end
    saturday:
        PRINT_STRING sat
    jmp end

    ret



    allocate_data:
    mov al,[buffer]
    sub al,'0'
    mov ah,10
    mul ah
    add [day],al
    mov al,[buffer+1]
    sub al,'0'
    add [day],al

    mov al,[buffer+3]
    sub al,'0'
    mov ah,10
    mul ah
    add [month],al
    mov al,[buffer+4]
    sub al,'0'
    add [month],al

    mov ah,0
    mov al,[buffer+6]
    sub al,'0'
    mov cx,10
    mul cx
    add [year_first],ax
    mov ah,0
    mov al,[buffer+7]
    sub al,'0'
    add [year_first],ax
    mov ah,0
    mov al,[buffer+8]
    sub al,'0'
    mov cx,10
    mul cx
    add [year_last],ax
    mov al,[buffer+9]
    sub al,'0'
    add [year_last],al
    ret

    section .data
    info db 'Podaj date w formacie DD-MM-YYYY',0
    day db 0
    month db 0
    year_first db 0
    year_last db 0
    wynik dw 0
    sun db 'Niedziela',0
    mon db 'Poniedziałek',0
    tue db 'Wtorek',0
    wed db 'Środa',0
    thu db 'Czwartek',0
    fri db 'Piątek',0
    sat db 'Sobota',0

    section .bss
    buffer: resb 10