require './win32_ffi'

class Window
  include Win32

  def initialize
    @wclass_name = FFI::MemoryPointer.from_string('WindowClass')
    @wname = FFI::MemoryPointer.from_string('WindowTitle')

    @black = GetStockObject(4)
    @white = GetStockObject(0)

    @hInstance = GetModuleHandleA(nil)

    @wc = WNDCLASS.new
    @wc[:style] = 0
    @wc[:hIcon] = 0
    @wc[:cbClsExtra] = 0
    @wc[:cbWndExtra] = 0
    @wc[:lpszClassName] = @wclass_name.to_ptr
    @wc[:lpszMenuName] = @wname.to_ptr
    @wc[:hbrBackground] = @white
    @wc[:hCursor] = LoadCursorA(nil, 32512)
    @wc[:hInstance] = @hInstance
    @wc[:lpfnWndProc] = method(:WindowProc)
    
    @hwMain = CreateWindowExA(0, @wclass_name, @wname, 0x10CF0000, 100, 100, 500, 500, 0, 0, 0, nil)

    raise StandardError.new 'Unable to create a Window' if !RegisterClassA(@wc.to_ptr)
    raise StandardError.new 'Unable to create a Window' if @hwMain.nil?

    get_message
  end

  def WindowProc(hwnd, msg, wp, lp)
    case msg
    when 0x0001
      p 'Window created'
    when 0x0002
      PostQuitMessage(0)
    else
      return DefWindowProcA(hwnd, msg, wp, lp)
    end

    return 0
  end

  def get_message
    msg = MSG.new
    msg[:hwnd] = 0
    msg[:message] = 0
    msg[:wparam] = 0
    msg[:lparam] = 0
    msg[:time] = 0
    msg[:pt] = 0

    while GetMessageA(msg.to_ptr, 0, 0, 0) != 0
      TranslateMessageA(msg.to_ptr)
      DispatchMessageA(msg.to_ptr)
    end
  end
end

w = Window.new(title: 'WindowCustomTitle')