/*
    Copyright (c) 2005-2020 Intel Corporation

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/

// common Windows parts
#include "winvideo.h"
// include GDI+ headers
#include <gdiplus.h>
// and another headers
#include <stdio.h>

// tag linking library
#pragma comment(lib, "gdiplus.lib")

// global specific variables
Gdiplus::Bitmap *           g_pBitmap;           // main drawing bitmap
ULONG_PTR                   gdiplusToken;
Gdiplus::GdiplusStartupInput gdiplusStartupInput;// GDI+

//! display system error
bool DisplayError(LPSTR lpstrErr, HRESULT hres)
{
    static bool InError = false;
    int retval = 0;
    if (!InError)
    {
        InError = true;
        LPCSTR lpMsgBuf;
        if(!hres) hres = GetLastError();
        FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
                               NULL, hres, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) &lpMsgBuf, 0, NULL );
        retval = MessageBox(g_hAppWnd, lpstrErr, lpMsgBuf, MB_OK|MB_ICONERROR);
        LocalFree( (HLOCAL)lpMsgBuf );
        InError = false;
    }
    return false;
}

//! Win event processing function
LRESULT CALLBACK InternalWndProc(HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
{
    switch (iMsg)
    {
        case WM_MOVE:
            // Check to make sure our window exists before we tell it to repaint.
            // This will fail the first time (while the window is being created).
            if (hwnd) {
                InvalidateRect(hwnd, NULL, FALSE);
                UpdateWindow(hwnd);
            }
            return 0L;

        case WM_PAINT:
            {
                PAINTSTRUCT ps;
                Gdiplus::Graphics graphics( BeginPaint(hwnd, &ps) );
                // redraw just requested area. This call is as fast as simple DrawImage() call.
                if(g_video->updating) graphics.DrawImage(g_pBitmap, ps.rcPaint.left, ps.rcPaint.top, ps.rcPaint.left, ps.rcPaint.top,
                                    ps.rcPaint.right, ps.rcPaint.bottom, Gdiplus::UnitPixel);
                EndPaint(hwnd, &ps);
            }
            return 0L;

        // Process all mouse and keyboard events
        case WM_LBUTTONDOWN:    g_video->on_mouse( (int)LOWORD(lParam), (int)HIWORD(lParam), 1); break;
        case WM_LBUTTONUP:      g_video->on_mouse( (int)LOWORD(lParam), (int)HIWORD(lParam), -1); break;
        case WM_RBUTTONDOWN:    g_video->on_mouse( (int)LOWORD(lParam), (int)HIWORD(lParam), 2); break;
        case WM_RBUTTONUP:      g_video->on_mouse( (int)LOWORD(lParam), (int)HIWORD(lParam), -2); break;
        case WM_MBUTTONDOWN:    g_video->on_mouse( (int)LOWORD(lParam), (int)HIWORD(lParam), 3); break;
        case WM_MBUTTONUP:      g_video->on_mouse( (int)LOWORD(lParam), (int)HIWORD(lParam), -3); break;
        case WM_CHAR:           g_video->on_key( (int)wParam); break;

        // some useless stuff
        case WM_ERASEBKGND:     return 1;  // keeps erase-background events from happening, reduces chop
        case WM_DISPLAYCHANGE:  return 0;

        // Now, shut down the window...
        case WM_DESTROY:        PostQuitMessage(0); return 0;
    }
    // call user defined proc, if exists
    return g_pUserProc? g_pUserProc(hwnd, iMsg, wParam, lParam) : DefWindowProc(hwnd, iMsg, wParam, lParam);
}

///////////// video functions ////////////////

bool video::init_window(int sizex, int sizey)
{
    assert(win_hInstance != 0);
    g_sizex = sizex; g_sizey = sizey;
    if (!WinInit(win_hInstance, win_iCmdShow, gWndClass, title, true)) {
        DisplayError("Unable to initialize the program's window.");
        return false;
    }
    ShowWindow(g_hAppWnd, SW_SHOW);
    Gdiplus::GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
    g_pImg = new unsigned int[sizex*sizey];
    g_pBitmap = new Gdiplus::Bitmap(g_sizex, g_sizey, 4*g_sizex, PixelFormat32bppRGB, (BYTE*)g_pImg );
    running = true;
    return true;
}

void video::terminate()
{
    if(g_pBitmap) { delete g_pBitmap; g_pBitmap = 0; }
    Gdiplus::GdiplusShutdown(gdiplusToken);
    g_video = 0; running = false;
    if(g_pImg) { delete[] g_pImg; g_pImg = 0; }
}

//////////// drawing area constructor & destructor /////////////

drawing_area::drawing_area(int x, int y, int sizex, int sizey)
    : base_index(y*g_sizex + x), max_index(g_sizex*g_sizey), index_stride(g_sizex),
      pixel_depth(24), ptr32(g_pImg), start_x(x), start_y(y), size_x(sizex), size_y(sizey)
{
    assert(x < g_sizex); assert(y < g_sizey);
    assert(x+sizex <= g_sizex); assert(y+sizey <= g_sizey);

    index = base_index; // current index
}

void drawing_area::update()
{
    if(g_video->updating) {
        RECT r;
        r.left = start_x; r.right  = start_x + size_x;
        r.top  = start_y; r.bottom = start_y + size_y;
        InvalidateRect(g_hAppWnd, &r, false);
    }
}
