//==============================================================
//
// SAMPLE SOURCE CODE - SUBJECT TO THE TERMS OF SAMPLE CODE LICENSE AGREEMENT,
// http://software.intel.com/en-us/articles/intel-sample-source-code-license-agreement/
//
// Copyright Intel Corporation
//
// THIS FILE IS PROVIDED "AS IS" WITH NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT
// NOT LIMITED TO ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE, NON-INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS.
//
// =============================================================


/////// Common internal implementation of Windows-specific stuff //////////////
///////                  Must be the first included header       //////////////

#ifndef __WINVIDEO_H__
#define __WINVIDEO_H__

#ifndef _CRT_SECURE_NO_DEPRECATE
#define _CRT_SECURE_NO_DEPRECATE
#endif
// Check that the target Windows version has all API calls requried.
#ifndef _WIN32_WINNT
# define _WIN32_WINNT 0x0400
#endif
#if _WIN32_WINNT<0x0400
# define YIELD_TO_THREAD() Sleep(0)
#else
# define YIELD_TO_THREAD() SwitchToThread()
#endif
#include "video.h"
#include <fcntl.h>
#include <io.h>
#include <iostream>
#include <fstream>

#pragma comment(lib, "gdi32.lib")
#pragma comment(lib, "user32.lib")

// maximum mumber of lines the output console should have
static const WORD MAX_CONSOLE_LINES = 500;
const COLORREF              RGBKEY = RGB(8, 8, 16); // at least 8 for 16-bit palette
HWND                        g_hAppWnd;           // The program's window handle
HANDLE                      g_handles[2] = {0,0};// thread and wake up event
unsigned int *              g_pImg = 0;          // drawing memory
int                         g_sizex, g_sizey;
static video *              g_video = 0;
WNDPROC                     g_pUserProc = 0;
HINSTANCE                   video::win_hInstance = 0;
int                         video::win_iCmdShow = 0;
static WNDCLASSEX *         gWndClass = 0;
static HACCEL               hAccelTable = 0;
static DWORD                g_msec = 0;
static int g_fps = 0, g_updates = 0, g_skips = 0;

bool DisplayError(LPSTR lpstrErr, HRESULT hres = 0); // always returns false
LRESULT CALLBACK InternalWndProc(HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam);

//! Create window
bool WinInit(HINSTANCE hInstance, int nCmdShow, WNDCLASSEX *uwc, const char *title, bool fixedsize)
{
    WNDCLASSEX wndclass;  // Our app's windows class
    if(uwc) {
        memcpy(&wndclass, uwc, sizeof(wndclass));
        g_pUserProc = uwc->lpfnWndProc;
    } else {
        memset(&wndclass, 0, sizeof(wndclass));
        wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
        wndclass.lpszClassName = title;
    }
    wndclass.cbSize = sizeof(wndclass);
    wndclass.hInstance = hInstance;
    wndclass.lpfnWndProc = InternalWndProc;
    wndclass.style |= CS_HREDRAW | CS_VREDRAW;
    wndclass.hbrBackground = CreateSolidBrush(RGBKEY);

    if( !RegisterClassExA(&wndclass) ) return false;
    int xaddend = GetSystemMetrics(fixedsize?SM_CXFIXEDFRAME:SM_CXFRAME)*2;
    int yaddend = GetSystemMetrics(fixedsize?SM_CYFIXEDFRAME:SM_CYFRAME)*2 + GetSystemMetrics(SM_CYCAPTION);
    if(wndclass.lpszMenuName) yaddend += GetSystemMetrics(SM_CYMENU);

    // Setup the new window's physical parameters - and tell Windows to create it
    g_hAppWnd = CreateWindowA(wndclass.lpszClassName,  // Window class name
                             title,  // Window caption
                             !fixedsize ? WS_OVERLAPPEDWINDOW :  // Window style
                             WS_OVERLAPPED|WS_CAPTION|WS_SYSMENU|WS_MINIMIZEBOX,
                             CW_USEDEFAULT,  // Initial x pos: use default placement
                             0,              // Initial y pos: not used here
                             g_sizex+xaddend,// Initial x size
                             g_sizey+yaddend,// Initial y size
                             NULL,      // parent window handle
                             NULL,      // window menu handle
                             hInstance, // program instance handle
                             NULL);     // Creation parameters
    return g_hAppWnd != NULL;
}

//! create console window with redirection
static bool RedirectIOToConsole(void)
{
    int hConHandle; size_t lStdHandle;
    CONSOLE_SCREEN_BUFFER_INFO coninfo;
    FILE *fp;
    // allocate a console for this app
    AllocConsole();

    // set the screen buffer to be big enough to let us scroll text
    GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &coninfo);
    coninfo.dwSize.Y = MAX_CONSOLE_LINES;
    SetConsoleScreenBufferSize(GetStdHandle(STD_OUTPUT_HANDLE), coninfo.dwSize);

    // redirect unbuffered STDOUT to the console
    lStdHandle = (size_t)GetStdHandle(STD_OUTPUT_HANDLE);
    hConHandle = _open_osfhandle(lStdHandle, _O_TEXT);
    if(hConHandle <= 0) return false;
    fp = _fdopen( hConHandle, "w" );
    *stdout = *fp;
    setvbuf( stdout, NULL, _IONBF, 0 );

    // redirect unbuffered STDERR to the console
    lStdHandle = (size_t)GetStdHandle(STD_ERROR_HANDLE);
    hConHandle = _open_osfhandle(lStdHandle, _O_TEXT);
    if(hConHandle > 0) {
        fp = _fdopen( hConHandle, "w" );
        *stderr = *fp;
        setvbuf( stderr, NULL, _IONBF, 0 );
    }

    // redirect unbuffered STDIN to the console
    lStdHandle = (size_t)GetStdHandle(STD_INPUT_HANDLE);
    hConHandle = _open_osfhandle(lStdHandle, _O_TEXT);
    if(hConHandle > 0) {
        fp = _fdopen( hConHandle, "r" );
        *stdin = *fp;
        setvbuf( stdin, NULL, _IONBF, 0 );
    }

    // make cout, wcout, cin, wcin, wcerr, cerr, wclog and clog
    // point to console as well
    std::ios::sync_with_stdio();
    return true;
}


video::video()
    : red_mask(0xff0000), red_shift(16), green_mask(0xff00),
      green_shift(8), blue_mask(0xff), blue_shift(0), depth(24)
{
    assert(g_video == 0);
    g_video = this; title = "Video"; running = threaded = calc_fps = false; updating = true;
}

//! optionally call it just before init() to set own 
void video::win_set_class(WNDCLASSEX &wcex)
{
    gWndClass = &wcex;
}

void video::win_load_accelerators(int idc)
{
    hAccelTable = LoadAccelerators(win_hInstance, MAKEINTRESOURCE(idc));
}

bool video::init_console()
{
    if(RedirectIOToConsole()) {
        if(!g_pImg && g_sizex && g_sizey)
            g_pImg = new unsigned int[g_sizex * g_sizey];
        if(g_pImg) running = true;
        return true;
    }
    return false;
}

video::~video()
{
    if(g_video) terminate();
}

DWORD WINAPI thread_video(LPVOID lpParameter)
{
    video *v = (video*)lpParameter;
    v->on_process();
    return 0;
}

static bool loop_once(video *v)
{
    // screen update notify
    if(int updates = g_updates) {
        g_updates = 0;
        if(g_video->updating) { g_skips += updates-1; g_fps++; }
        else g_skips += updates;
        UpdateWindow(g_hAppWnd);
    }
    // update fps
    DWORD msec = GetTickCount();
    if(v->calc_fps && msec >= g_msec+1000) {
        double sec = (msec - g_msec)/1000.0;
        char buffer[256], n = _snprintf(buffer, 128, "%s: %d fps", v->title, int(double(g_fps + g_skips)/sec));
        if(g_skips) _snprintf(buffer+n, 128, " - %d skipped = %d updates", int(g_skips/sec), int(g_fps/sec));
        SetWindowTextA(g_hAppWnd, buffer);
        g_msec = msec; g_skips = g_fps = 0;
    }
    // event processing, including painting
    MSG msg;
    if(PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)){
        if( msg.message == WM_QUIT ) { v->running = false; return false; }
        if( !hAccelTable || !TranslateAccelerator(msg.hwnd, hAccelTable, &msg) ){
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
        return true; // try again
    }
    return false;
}

//! Do standard event loop
void video::main_loop()
{
    // let Windows draw and unroll the window
    InvalidateRect(g_hAppWnd, 0, false);
    g_msec = GetTickCount(); // let's stay for 0,5 sec
    while(g_msec + 500 > GetTickCount()) { loop_once(this); Sleep(1); }
    g_msec = GetTickCount();
    // now, start main process
    if(threaded) {
        g_handles[0] = CreateThread (
            NULL,             // LPSECURITY_ATTRIBUTES security_attrs
            0,                // SIZE_T stacksize
            (LPTHREAD_START_ROUTINE) thread_video,
            this,               // argument
            0, 0);
        if(!g_handles[0]) { DisplayError((char*)"Can't create thread"); return; }
        else // harmless race is possible here
            g_handles[1] = CreateEvent(NULL, false, false, NULL);
        while(running) {
            while(loop_once(this));
            YIELD_TO_THREAD(); // give time for processing when running on single CPU
            DWORD r = MsgWaitForMultipleObjects(2, g_handles, false, INFINITE, QS_ALLINPUT^QS_MOUSEMOVE);
            if(r == WAIT_OBJECT_0) break; // thread terminated
        }
        running = false;
        if(WaitForSingleObject(g_handles[0], 3000) == WAIT_TIMEOUT){
            // there was not enough time for graceful shutdown, killing the example with code 1.
            exit(1);
        }
        if(g_handles[0]) CloseHandle(g_handles[0]);
        if(g_handles[1]) CloseHandle(g_handles[1]);
        g_handles[0] = g_handles[1] = 0;
    }
    else on_process();
}

//! Refresh screen picture
bool video::next_frame()
{
    if(!running) return false;
    g_updates++; // Fast but inaccurate counter. The data race here is benign.
    if(!threaded) while(loop_once(this));
    else if(g_handles[1]) {
        SetEvent(g_handles[1]);
        YIELD_TO_THREAD(); 
    }
    return true;
}

//! Change window title
void video::show_title()
{
    if(g_hAppWnd)
        SetWindowTextA(g_hAppWnd, title);
}

#endif //__WINVIDEO_H__
