; Comments start with a semicolon!
BITS 64 			;
CPU X64 			;

section .rodata

sun_path: db "/tmp/.X11-unix/X0", 0
static sun_path:data

section .text

%define AF_UNIX			1
%define SOCK_STREAM		1

%define SYSCALL_WRITE   1
%define SYSCALL_SOCKET		41
%define SYSCALL_CONNECT 42
%define SYSCALL_EXIT		60



global _start

; Create a UNIX domain socket and connect to the X11 server.
; @returns the socket file descriptor
x11_connect_to_server:
static x11_connect_to_server:function
  push rbp
  mov rbp, rsp
  
  ; Open a Unix socket: socket(2)
  mov rax, SYSCALL_SOCKET
  mov rdi, AF_UNIX ; Unix socket
  mov rsi, SOCK_STREAM ; TCP like
  mov rdx, 0 ; Automatic protocol
  syscall

  cmp rax, 0 ; Check if we made the socket
  jle die

  mov rdi, rax ; Store the socket fs in rdi for the remainder of the function

  sub rsp, 112 ; Store the struct sockaddr_un on the stack

  mov WORD [rsp], AF_UNIX ; Set the sockaddr_un.sun_family to AF_UNIX
  ; Fil lsoccaddr_un.sun_path with: "/tmp/.X11-unix/X0"
  lea rsi, sun_path
  mov r12, rdi ; Save the socket fd from rdi to r12
  lea rdi, [rsp + 2]
  cld
  mov ecx, 19
  rep movsb ; Copy.

  ; Connect ot the server
  mov rax, SYSCALL_CONNECT
  mov rdi, r12
  lea rsi, [rsp]
  %define SIZEOF_SOCKADDR_UN 2+108
  mov rdx, SIZEOF_SOCKADDR_UN
  syscall

  cmp rax, 0
  jne die

  mov rax, rdi

  add rsp, 112

  pop rbp
  ret

; Send the handshake to the X11 server and read the returned system information
; @param rdi The socket fd
; @returns The window root id (uint32_t) in rax
x11_send_handshake:
static x11_send_handshake:function
  push rdp
  mov rbp, rsp

  sub rsp, 1<<15
  mov BYTE [rsp + 0], 'l' ; Tell X11 we are little endian
  mov WORD [rsp + 2], 11; Set the major version to 11

  ; Send the 

die:
  mov rax, SYSCALL_EXIT
  mov rdi, 1
  syscall

_start:
  call x11_connect_to_server

  ; Exit the program
  mov rax, SYSCALL_EXIT
  mov rdi, 0
  syscall