// Tetris.cpp : 程序入口、窗口初始化与消息处理

#include "stdafx.h"
#include "Tetris.h"

#define MAX_LOADSTRING 100

HINSTANCE hInst;
TCHAR szTitle[MAX_LOADSTRING];
TCHAR szWindowClass[MAX_LOADSTRING];

ATOM                MyRegisterClass(HINSTANCE hInstance);
BOOL                InitInstance(HINSTANCE, int);
LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK    About(HWND, UINT, WPARAM, LPARAM);

int APIENTRY _tWinMain(HINSTANCE hInstance,
    HINSTANCE hPrevInstance,
    LPTSTR lpCmdLine,
    int nCmdShow)
{
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);
    // TODO(作业1): 补全 Win32 程序入口函数。
    LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
    LoadString(hInstance, IDC_TETRIS, szWindowClass, MAX_LOADSTRING);
    MyRegisterClass(hInstance);

    if (!InitInstance(hInstance, nCmdShow))
    {
        return FALSE;
    }

    HACCEL hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_TETRIS));
    MSG msg;

    while (GetMessage(&msg, nullptr, 0, 0))
    {
        if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return (int)msg.wParam;
}

ATOM MyRegisterClass(HINSTANCE hInstance)
{
    // TODO(作业2): 注册窗口类。
    UNREFERENCED_PARAMETER(hInstance);
    WNDCLASSEX wcex;

    wcex.cbSize = sizeof(WNDCLASSEX);
    wcex.style = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc = WndProc;
    wcex.cbClsExtra = 0;
    wcex.cbWndExtra = 0;
    wcex.hInstance = hInstance;
    wcex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_TETRIS));
    wcex.hCursor = LoadCursor(nullptr, IDC_ARROW);
    wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wcex.lpszMenuName = MAKEINTRESOURCE(IDC_TETRIS);
    wcex.lpszClassName = szWindowClass;
    wcex.hIconSm = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_SMALL));

    return RegisterClassEx(&wcex);
}

BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
    // TODO(作业3): 创建并显示主窗口。
    
    RECT rect = { 0, 0, GRID * nWidth, GRID * nHeight };
    AdjustWindowRect(&rect, WS_OVERLAPPEDWINDOW, TRUE);

    hInst = hInstance;

    HWND hWnd = CreateWindow(
        szWindowClass,
        szTitle,
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT,
        0,
        rect.right - rect.left,
        rect.bottom - rect.top,
        nullptr,
        nullptr,
        hInstance,
        nullptr);

    if (!hWnd)
    {
        return FALSE;
    }

    ShowWindow(hWnd, nCmdShow);
    UpdateWindow(hWnd);

    return TRUE;
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    // TODO(作业4): 补全主窗口消息处理函数。
    switch (message)
    {
    case WM_COMMAND:
    {
        int wmId = LOWORD(wParam);

        switch (wmId)
        {
        case IDM_ABOUT:
            DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
            break;
        case IDM_EXIT:
            DestroyWindow(hWnd);
            break;
        default:
            return DefWindowProc(hWnd, message, wParam, lParam);
        }
    }
    break;
    case WM_PAINT:
    {
        PAINTSTRUCT ps;
        HDC hdc = BeginPaint(hWnd, &ps);
        TDrawScreen(hdc, hWnd);
        EndPaint(hWnd, &ps);
    }
    break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }

    return 0;
}

INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
    UNREFERENCED_PARAMETER(lParam);
    // TODO(作业5): 补全“关于”对话框的消息处理。
    UNREFERENCED_PARAMETER(hDlg);
    UNREFERENCED_PARAMETER(message);
    UNREFERENCED_PARAMETER(wParam);
    return (INT_PTR)FALSE;
}