#include "Window.h"

INT Window::init(HINSTANCE hInstance, UINT width, UINT height)
{
    // 1. describe window class
    WNDCLASS wc = {};
    wc.hInstance = hInstance;
    wc.lpszClassName = TEXT("D3D11"); // class name
    wc.lpfnWndProc = WindowProc; // global communication (message queue) function
    wc.hbrBackground = CreateSolidBrush(RGB(0, 255, 0)); // handle to background color
    wc.hCursor = LoadCursor(nullptr, IDC_ARROW); // handle to cursor icon
    wc.hIcon = LoadIcon(nullptr, IDI_APPLICATION); // handle to application icon
    wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC; // technical behaviour

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

    // 3. adjust window size (optional)


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

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

    return 0;
}

BOOL Window::run()
{
    // 6. run window
    // GetMessage - synchronous call to get the latest message, but holds the execution until there is a new message
    // PeekMessage - return also the latest message, but also returns false if there is no message available
    // TranslateMessage - translates keyboard input
    // DispatchMessage - sends message to window procedure

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

    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;

    default:
        break;
    }

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