#include <Core/Core.h>
#include <windows.h>
#include <mshtml.h>
#include <exdisp.h>

using std::string;
using std::wstring;
using std::runtime_error;

class IExplorer {
	IWebBrowser2 *webBrowserPtr;
	IHTMLDocument3 *htmlDocPtr;
	IDispatch *dispatchPtr;
	
	void StartAsynchronousNavigation (wstring url);
public:
	void Navigate (wstring url);
	void WaitUntilNotBusy ();
	void WaitUntilReady ();
	void InitWebBrowser ();
	void UpdateHTMLDocPtr ();
	bool ChangeElementAttribute (wstring elementId, wstring attributeName, wstring newValue)
	typedef IExplorer CLASSNAME;
	IExplorer (wstring url);
};

#include "IExplorer.h"

// By Elyo Ravuna
// You may use this code as you wish, but please do not remove this comment

#include <Core/Core.h>
#include <windows.h>
#include <Mshtml.h>
#include <iostream>
#include <winnls.h>
#include <exdisp.h>
#include <string>
#include <stdexcept>
#include <time.h>
#include <windows.h>
#include <mshtml.h>
#include <exdisp.h>
#include <comdef.h>

#define TIMEOUT_SECONDS 30
#define SLEEP_MILLISECONDS 500

using std::string;
using std::wstring;
using std::runtime_error;

IExplorer::IExplorer (wstring url) {
  InitWebBrowser ();
  WaitUntilNotBusy ();
  Navigate (url);
}

void IExplorer::InitWebBrowser () {
  CLSID rclsid;
  OleInitialize (NULL);
  if (CLSIDFromProgID(OLESTR("InternetExplorer.Application"), &rclsid) != S_OK)
    throw runtime_error ("CLSIDFromProgID");
  if (CoCreateInstance(rclsid, NULL, CLSCTX_SERVER, IID_IWebBrowser2, (LPVOID*)&webBrowserPtr) != S_OK)
    throw runtime_error ("CoCreateInstance");
  if (webBrowserPtr->put_Visible(VARIANT_TRUE) != S_OK)
    throw runtime_error ("put_Visible");
}

void IExplorer::WaitUntilNotBusy () {
  VARIANT_BOOL busy;
  time_t startTime = time(NULL);
  do {
   Sleep (SLEEP_MILLISECONDS);
   if (webBrowserPtr->get_Busy (&busy) != S_OK)
     throw runtime_error ("get_Busy");
  } while ((busy==VARIANT_TRUE) && (difftime(time(NULL), startTime)<TIMEOUT_SECONDS));
  if (busy == VARIANT_TRUE)
    throw runtime_error ("Timeout while waiting 'get_Busy=false'");
}

void IExplorer::WaitUntilReady () {
  READYSTATE isReady;
  time_t startTime = time(NULL);
  do {
    if (webBrowserPtr->get_ReadyState(&isReady) != S_OK)
      throw runtime_error ("get_ReadyState");
    Sleep (SLEEP_MILLISECONDS);
  } while ((isReady!=READYSTATE_COMPLETE) && (difftime(time(NULL), startTime)<TIMEOUT_SECONDS));
  if (isReady != READYSTATE_COMPLETE)
    throw runtime_error ("Timeout while waiting READYSTATE_COMPLETE");
}

void IExplorer::UpdateHTMLDocPtr () {
  if (webBrowserPtr->get_Document(&dispatchPtr) != S_OK)
    throw runtime_error ("get_Document");
  if (dispatchPtr->QueryInterface(IID_IHTMLDocument3, (void **)&htmlDocPtr) != S_OK)
    throw runtime_error ("QueryInterface, IID_IHTMLDocument3");
}

void IExplorer::Navigate (wstring url) {
  StartAsynchronousNavigation (url);
  WaitUntilReady ();
  UpdateHTMLDocPtr ();
}

void IExplorer::StartAsynchronousNavigation (wstring url) {
  VARIANT vEmpty;
  VariantInit (&vEmpty);
  BSTR bstrUrl = SysAllocString (url.data());
  if (!bstrUrl)
    throw runtime_error ("SysAllocString, StartAsynchronousNavigation");
  webBrowserPtr->Navigate (bstrUrl, &vEmpty, &vEmpty, &vEmpty, &vEmpty);
  SysFreeString (bstrUrl);
}

bool IExplorer::ChangeElementAttribute (wstring elementId, wstring attributeName, wstring newValue) {
	bool success;
	try {
	    if(!webBrowserPtr || !htmlDocPtr)
			throw;
	    
	    IHTMLElement *elementPtr;
	    
	    _variant_t varNewValue = newValue.data();
	    BSTR bstrElementId = SysAllocString (elementId.data());
	    BSTR bstrAttributeName = SysAllocString (attributeName.data());
	    
	    if(!bstrElementId || !bstrAttributeName)
			throw;
	    if (htmlDocPtr->getElementById(bstrElementId, &elementPtr) != S_OK)
			throw;
	    
	    elementPtr->setAttribute(bstrAttributeName, varNewValue);
		
	    SysFreeString (bstrElementId);
	    SysFreeString (bstrAttributeName);
	    success=true;
	} catch (...) {
		success=false;
	}
	return success;
}

        IExplorer ie(L"http://www.google.fr");
	Sleep(3000);
	ie.ChangeElementAttribute(L"lst-ib", L"value", "HELLO_WORLD");