#include "Window.h"

INT Window::init(HINSTANCE hInstance, UINT width, UINT height)
{
	// 1. describe window class
	WNDCLASS wc = {};
	wc.hInstance = hInstance;
	wc.lpszClassName = TEXT("D3D9"); // class name for identify
	wc.lpfnWndProc = WindowProc; // function for windows to send messages to our application
	wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC; // technical window properties, here update window if window change horizontally or vertically and window should have its own device context
	wc.hbrBackground = CreateSolidBrush(RGB(0, 255, 0));
	wc.hCursor = LoadCursor(nullptr, IDC_ARROW);
	wc.hIcon = LoadIcon(nullptr, IDI_APPLICATION);

	// 2. register window class
	if (!RegisterClass(&wc)) return 100;

	// 3. adjust window size (optional)
	DWORD style;
	style = WS_OVERLAPPEDWINDOW; // window with border & title
	//style = WS_POPUP; // borderless window

	// 4. create window instance
	_hWnd = CreateWindow(
		wc.lpszClassName, // class name for window instance
		wc.lpszClassName, // window title
		style, // visual window style
		100, 100, // window position (left-top corner)
		width, height, // window size
		nullptr, // handle to parent window
		nullptr, // handle to menu instance
		hInstance,
		nullptr // pointer to optional parameter
	);
	if (_hWnd == nullptr) return 110;

	// 5. show window
	ShowWindow(_hWnd, SW_SHOW);
	SetFocus(_hWnd);

	return 0;
}

BOOL Window::run()
{
	// 6. run window
	// message queue
	// https://learn.microsoft.com/en-us/windows/win32/winmsg/about-messages-and-message-queues
	// GetMessage - wait for a message send by windows (syncronous)
	// PeekMessage - get last message from queue or nothing
	// TranslateMessage - translates keyboard input (scan (hardware) vs. virtual key code)
	// DispatchMessage - send message to window proc

	MSG msg;
	if (PeekMessage(&msg, nullptr, 0, UINT_MAX, PM_REMOVE))
	{
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}

	Sleep(10);

	return msg.message != WM_QUIT;
}

void Window::deInit()
{
}

LRESULT WindowProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
	switch (msg)
	{
	case WM_CLOSE:
		DestroyWindow(hWnd);
		return 0;
	case WM_DESTROY:
		PostQuitMessage(0);
		return 0;
	case WM_KEYDOWN:
		if (wParam == VK_ESCAPE)
		{
			DestroyWindow(hWnd);
			return 0;
		}
		break;
	}

	return DefWindowProc(hWnd, msg, wParam, lParam);
}