RSS Reader Plug-in for Internet Explorer

// MainFrm.h : interface of the CMainFrame class
//
/////////////////////////////////////////////////////////////////////////////

#pragma once
#include <vld.h>
#include <vector>
#include <string>
#include <atlmisc.h>
#include <wininet.h>
#include <iphlpapi.h>

#include "AmHttpSocket.h"

#pragma comment(lib,"WS2_32.Lib")


#define RRP_RSSFETCH WM_USER + 10
#define RRP_FETCHCOMPLETE WM_USER + 11
#define RRP_REFRESH WM_USER + 12
#define RRP_REMOVE WM_USER + 13
#define RRP_TOOLBAR_REG WM_USER + 14
#define RRP_TOOLBAR_UNREG WM_USER + 15
#define RRP_FETCHER_PROCESS_BUSY WM_USER + 16
#define RRP_FETCHER_PROCESS_FREE WM_USER + 17
#define RRP_CLEAN WM_USER + 18


#include "ras.h"
#define RASCN_Connection        0x00000001
DWORD (WINAPI *RasNotify)(HRASCONN, HANDLE, DWORD);


using namespace std;




//Structures used in message exchange
typedef struct RssInfo {
	UINT message;
	string localName;
	string remoteName;
	FILETIME systemTime;
}RssInfo;



typedef struct TRssInfo {
	UINT message;
	char localName[50];//cant be more than 10 actually
	char remoteName[1024];//I've heard this is the URL limit
	HWND toolbarHandle;
}TRssInfo;



class CMainFrame : public CFrameWindowImpl<CMainFrame>,
				   public CMessageFilter,
				   public CIdleHandler
{
public:
	DECLARE_FRAME_WND_CLASS("RRPRssFetcherWindowClass", IDR_MAINFRAME)

	virtual BOOL PreTranslateMessage(MSG* pMsg)	{
		return CFrameWindowImpl<CMainFrame>::PreTranslateMessage(pMsg);
	}

	virtual BOOL OnIdle()	{
		return FALSE;
	}

	CMainFrame() {
		retryCount = 0;
		oneMinCount = 0;
		::GetSystemTimeAsFileTime(&startTime);
	}
	~CMainFrame() {
//		rssDir.~basic_string();
	}

	BEGIN_MSG_MAP(CMainFrame)
		MESSAGE_HANDLER(WM_CREATE, OnCreate)
		MESSAGE_HANDLER(WM_COPYDATA, OnWmCopy)
		MESSAGE_HANDLER(WM_CLOSE, OnClose)
		MESSAGE_HANDLER(WM_TIMER, OnTimer)
		MESSAGE_HANDLER(RRP_TOOLBAR_REG,OnToolbarReg)
		MESSAGE_HANDLER(RRP_TOOLBAR_UNREG,OnToolbarUnReg)
		MESSAGE_HANDLER(RRP_CLEAN,OnClean)
		MESSAGE_HANDLER(RRP_RSSFETCH,OnRssFetchRequest)
		MESSAGE_HANDLER(RRP_REMOVE ,OnRssRemove)
		CHAIN_MSG_MAP(CFrameWindowImpl<CMainFrame>)
	END_MSG_MAP()

// Handler prototypes (uncomment arguments if needed):
//	LRESULT MessageHandler(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)
//	LRESULT CommandHandler(WORD /*wNotifyCode*/, WORD /*wID*/, HWND /*hWndCtl*/, BOOL& /*bHandled*/)
//	LRESULT NotifyHandler(int /*idCtrl*/, LPNMHDR /*pnmh*/, BOOL& /*bHandled*/)

	LRESULT	OnToolbarReg(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/) {
//		::MessageBox(NULL,"Toolbar Reg","Message",MB_ICONHAND);
		referenceCount++;
		return 0;
	}
	
	
	LRESULT	OnToolbarUnReg(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/) {
//		::MessageBox(NULL,"Toolbar UnReg","Message",MB_ICONHAND);
		referenceCount--;
		if(referenceCount <= 0)
			PostMessage(WM_CLOSE);
		return 0;
	}

	LRESULT	OnTimer(UINT /*uMsg*/, WPARAM wParam, LPARAM lParam, BOOL& /*bHandled*/) {
		if(wParam == 2) {
			if(referenceCount <= 0)
				PostMessage(WM_CLOSE);
			oneMinCount++;
			if(oneMinCount%12 == 0) {
				::PostMessage(m_toolbarHandle,RRP_FETCHER_PROCESS_FREE,0,0);
				retryCount = 0;
			}
			return 0;
		}
		::GetSystemTimeAsFileTime(&startTime);
		return 0;
	}

	LRESULT	OnClean(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/) {
		int n = rssInfoVector.size();
		for(int i = 0;i<n;i++) {
//			if(rssInfoVector[i]) {
			if(true) {
				rssInfoVector[i].systemTime.dwHighDateTime = 0;
				rssInfoVector[i].systemTime.dwLowDateTime = 0;
			}
		}
		return 0;
	}


	UINT ConnNotification(HWND toolbarHandle) {
	  SECURITY_ATTRIBUTES SecAtt;
      SecAtt.nLength = sizeof(SECURITY_ATTRIBUTES);
	  SecAtt.lpSecurityDescriptor = NULL;
	  SecAtt.bInheritHandle = FALSE;
	  HANDLE hActive = CreateEvent(&SecAtt, TRUE, FALSE, "Connect");
	  HANDLE hInst = LoadLibrary("rasapi32.dll");
 	  RasNotify = (DWORD (WINAPI *)(HRASCONN, HANDLE, DWORD)) GetProcAddress ((HMODULE) hInst, "RasConnectionNotificationA");
	  DWORD ret = ::RasNotify((HRASCONN)INVALID_HANDLE_VALUE, hActive, RASCN_Connection);
	  if(ret == 0) 
	      WaitForSingleObject(hActive, INFINITE);
	  ::FreeLibrary((HMODULE)hInst);
	  return 0;
	}



	
	//Invoked when the rss fetch request comes
	LRESULT	OnRssFetchRequest(UINT /*uMsg*/, WPARAM wParam, LPARAM lParam, BOOL& /*bHandled*/) { 
		RssInfo *obj = reinterpret_cast<RssInfo *>(lParam);
		HWND toolbarHandle = reinterpret_cast<HWND>(wParam);

		::PostMessage(toolbarHandle,RRP_FETCHER_PROCESS_BUSY,0,0);

		char *receivedData = httpRequest.GetPage(obj->remoteName.c_str());
		if(!receivedData) {
			delete obj;
			::PostMessage(toolbarHandle,RRP_FETCHER_PROCESS_FREE,0,0);
			return 0;
		}
		//Checkinng if the downloaded file is the xml file
		if(strstr(receivedData,"<?xml") != receivedData) {
//			delete receivedData;
			delete obj;
			::PostMessage(toolbarHandle,RRP_FETCHER_PROCESS_FREE,0,0);
			return 0;
		}

		if(strcmp(receivedData,"Error") == 0) {
	//		delete receivedData;
			delete obj;
			::PostMessage(toolbarHandle,RRP_FETCHER_PROCESS_FREE,0,0);
			return 0;
		}
		//Creating the file name
		string dir = getInstallationDirectory();
		string myFile = dir;
		myFile +=  "\\rss\\";
		myFile += obj->localName;
		FILE *fp = fopen(myFile.c_str(),"w");
		fprintf(fp,"%s",receivedData);
		fclose(fp);

		//RRP_FETCHCOMPLETE also tells that process is free now!!
		::PostMessage(toolbarHandle,RRP_FETCHCOMPLETE,0,0);
		bool found = false;
		int n = rssInfoVector.size();
		for(int i = 0;i<n;i++) {
//			if(rssInfoVector[i]) {
			if(true) {
				if(rssInfoVector[i].remoteName.compare(obj->remoteName)) {
					found = true;
					GetSystemTimeAsFileTime(&(rssInfoVector[i].systemTime));
				}
			}
		}
		
		if(found == false) {
			RssInfo tobj;
			tobj.localName = obj->localName;
			tobj.remoteName = obj->remoteName;
			tobj.systemTime = obj->systemTime;
			GetSystemTimeAsFileTime(&(tobj.systemTime));
			rssInfoVector.push_back(tobj);
		}
		delete obj;
		return 0;
	}

	//Invoked when rss remove request comes
	LRESULT	OnRssRemove(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM lParam, BOOL& /*bHandled*/) { 
/*		int n = rssInfoVector.size();
		RssInfo *obj = reinterpret_cast<RssInfo*>(lParam);
		for(int i=0;i<n;i++)
			if(rssInfoVector[i].remoteName.compare(obj->remoteName)) {
				rssInfoVector.erase(i);
				break;
			}*/
		return 0;
	}


	LRESULT OnCreate(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/) {
		init();
		referenceCount = 0;
//		rssInfoVector = std::vector<RssInfo*>();
		SetTimer(1,1000*60*10);
		SetTimer(2,5000);
//		request = Request();
//		register object for message filtering and idle updates
		CMessageLoop* pLoop = _Module.GetMessageLoop();
		ATLASSERT(pLoop != NULL);
		pLoop->AddMessageFilter(this);
		return 0;
	}

	//De-Multiplexing messages
	//Need to see if the files are really present on the disk or not
	LRESULT OnWmCopy(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM lParam, BOOL& /*bHandled*/) {
		COPYDATASTRUCT *cds = reinterpret_cast<COPYDATASTRUCT *>(lParam);
		RssInfo *obj;
//		rssInfo->toolbarHandle;		
		if(cds->cbData = sizeof(TRssInfo)) {
			TRssInfo *rssInfo = reinterpret_cast<TRssInfo *>(cds->lpData);
			int n = rssInfoVector.size();
			bool loaded = false;
			for(int i = 0;i<n;i++) {
//				if(rssInfoVector[i]) {
				if(true) {
					if(rssInfoVector[i].remoteName.compare(rssInfo->remoteName) == 0) {
						if(rssInfoVector[i].systemTime.dwHighDateTime > startTime.dwHighDateTime) {
							loaded = true;
							break;
						}
						else
							if((rssInfoVector[i].systemTime.dwHighDateTime == startTime.dwHighDateTime) &&
								(rssInfoVector[i].systemTime.dwLowDateTime > startTime.dwLowDateTime)) {
									loaded = true;
									break;
							}
					}
				}
			}
			if(loaded) {
				::PostMessage(rssInfo->toolbarHandle,RRP_FETCHCOMPLETE,0,0);
				return 0;
			}
			switch(rssInfo->message) {
				case RRP_RSSFETCH: 
					if(prevRomoteFilename.compare(rssInfo->remoteName) == 0)
						retryCount++;
					//If the retry request comes for the same file 
					//more than 5 times It means that Probably internet connection
					//is not there,so send FREE messaged after 1 min
					if(retryCount >= 5) {
						m_toolbarHandle = rssInfo->toolbarHandle;
						::PostMessage(rssInfo->toolbarHandle,RRP_FETCHER_PROCESS_BUSY,0,0);
						return 0;
					}
					prevRomoteFilename = rssInfo->remoteName;
					obj =  getRssInfo(rssInfo->localName,rssInfo->remoteName);
					PostMessage(RRP_RSSFETCH,reinterpret_cast<WPARAM>(rssInfo->toolbarHandle),(LPARAM)obj);
					break;
				case RRP_REMOVE: 
					obj =  getRssInfo(rssInfo->localName,rssInfo->remoteName);
					PostMessage(RRP_RSSFETCH,reinterpret_cast<WPARAM>(rssInfo->toolbarHandle),(LPARAM)obj);
					break;
			}
		}
		
		return 0;
	}

	LRESULT OnClose(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM lParam, BOOL& /*bHandled*/) {
		if(referenceCount <= 0) {
			DestroyWindow();

		}
		return 0;
	}

	RssInfo * getRssInfo(char *localName,char *remoteName) {
		RssInfo *rssInfo = new RssInfo();
		ZeroMemory(rssInfo,sizeof(RssInfo));
		rssInfo->localName = localName;
		rssInfo->remoteName = remoteName;
		return rssInfo;
	}

	string getInstallationDirectory() {
		return rssDir;
	}

	void init() {
		CRegKey currentVersionRegEntry;
		TCHAR programFilesAddress[2048];
		currentVersionRegEntry.Create(HKEY_LOCAL_MACHINE, 
			_T("Software\\Microsoft\\Windows\\CurrentVersion"));
		DWORD length= 2048;
		if(ERROR_SUCCESS ==
			currentVersionRegEntry.QueryValue(programFilesAddress, _T("ProgramFilesDir"),&length)) { 
				rssDir = programFilesAddress;
				rssDir += _T("\\RssReader for IE");
		}
		else {
		//C:\\Program Files is taken as default
			rssDir = _T("C:\\Program Files\\RssReader for IE");
		}
//		rssDir = rssDirectory;
	}

private:
		int referenceCount;
		std::vector<RssInfo> rssInfoVector;
		string rssDir;
		string prevRomoteFilename;
		int retryCount;
		ULONG oneMinCount;
		HWND m_toolbarHandle ;
		FILETIME CMainFrame::startTime;
		//File Time is much easier to handle
		CAmHttpSocket httpRequest;
};