#include "Window.h"

INT Window::init(HINSTANCE hInstance, UINT width, UINT height)
{
	// 1. describe window class
	WNDCLASS wc = {};
	wc.hInstance = hInstance; // application instance
	wc.lpszClassName = TEXT("D3D11"); // name of window class
	wc.lpfnWndProc = WindowProc; // message queue handler function
	wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC; // behaviour style and not visual style
	wc.hbrBackground = CreateSolidBrush(RGB(255,0,0)); // set window background color
	wc.hCursor = LoadCursor(nullptr, IDC_ARROW); // set window cursor
	wc.hIcon = LoadIcon(nullptr, IDI_APPLICATION); // set window icon

	// 2. register window class
	if (!RegisterClass(&wc)) return 10;

	// 3. adjust window size (optional)
	DWORD style = WS_POPUP;
	RECT rect = { 100, 100, width + 100, height + 100 }; // left-top corner, right-bottom corner
	AdjustWindowRect(&rect, style, FALSE);

	// 4. create window instance
	_hWnd = CreateWindow(
		wc.lpszClassName, // name of window class
		wc.lpszClassName, // window title
		style, // visual window style
		rect.left, rect.top, // window position
		rect.right - rect.left, rect.bottom - rect.top, // window size
		nullptr, // parent window handle
		nullptr, // menu instance handle
		hInstance, // application instance
		nullptr // optional parameter
	);

	if (_hWnd == nullptr) return 12;

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

	return 0;
}

BOOL Window::run()
{
	// 6. run window

	// message queue
	// GetMessage - event based message method, return something if a new a message occur
	// PeekMessage - returns a boolean, to signale if a message is available or not
	// TranslateMessage - translate hardware keyboard codes (scan code) into virtual key table
	// DispatchMessage - send message to WindowProc
	// https://learn.microsoft.com/en-us/windows/win32/winmsg/messages-and-message-queues

	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, // handle to window instance
	UINT msg, // message id
	WPARAM wParam, // main paramater
	LPARAM lParam // additional parameters
)
{
	switch (msg)
	{
	case WM_CLOSE:
		DestroyWindow(hWnd);
		break;

	case WM_DESTROY:
		PostQuitMessage(0);
		break;

	case WM_KEYDOWN:
		if (wParam == VK_ESCAPE) DestroyWindow(hWnd);
		break;

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

	return 0;
}