#define UNICODE
#include <windows.h>
#include <oleacc.h>
#include <string>

using namespace std;

#define DLLEXPORT extern "C" __declspec(dllexport)

#pragma data_seg(".shared")
static HHOOK messageHookID=0;
static HWND hookedWindow=NULL;
#pragma data_seg()
#pragma comment(linker, "/section:.shared,rws")

HINSTANCE moduleHandle=NULL;
 int wm=0;

#pragma comment(linker,"/entry:_DllMainCRTStartup@12")
BOOL DllMain(HINSTANCE hModule,DWORD reason,LPVOID lpReserved) {
	if(reason==DLL_PROCESS_ATTACH) {
		Beep(100,100);
		moduleHandle=hModule;
		wm=RegisterWindowMessage(L"wm_MSAAWalker_message");
	}
	return TRUE;
}

VARIANT makeChildIDVariant(int childID) {
	VARIANT v;
	v.vt=VT_I4;
	v.lVal=childID;
 	return v;
}

int walkMSAATree(IAccessible* pacc,VARIANT varChild,int level, FILE* logFile) {
	int count=1;
	wstring infoString;
	BSTR s;
	VARIANT varRole;
	wchar_t roleText[100];
	long numChildren;
	VARIANT* children;
	IAccessible* paccChild;
	if((pacc->get_accName(varChild,&s)==S_OK)&&(s>0)) {
		infoString.append(s);
		SysFreeString(s);
		infoString.append(L" ");
	}
	if(pacc->get_accRole(varChild,&varRole)==S_OK) {
		if(varRole.vt==VT_I4) {
			GetRoleText(varRole.lVal,roleText,100);
			infoString.append(roleText);
			infoString.append(L" ");
		} else if(varRole.vt==VT_BSTR) {
			infoString.append(varRole.bstrVal);
			infoString.append(L" ");
		}
		VariantClear(&varRole);
	}
	if((pacc->get_accValue(varChild,&s)==S_OK)&&(s>0)) {
		infoString.append(s);
		SysFreeString(s);
		infoString.append(L" ");
	}
	int bufLen=WideCharToMultiByte(28591,0,infoString.c_str(),-1,NULL,0,NULL,NULL);
	char* buf=(char*)malloc(sizeof(char)*bufLen);
	WideCharToMultiByte(28591,0,infoString.c_str(),-1,buf,bufLen,NULL,NULL);
	fprintf(logFile,"Visit: %s\n",buf);
	free(buf);
	if((varChild.vt==VT_I4)&&(varChild.lVal>0)) {
		return count;
	}
	pacc->get_accChildCount(&numChildren);
	if(numChildren<1) {
		return count;
	}
	children=(VARIANT*)malloc(sizeof(VARIANT)*numChildren);
	if(AccessibleChildren(pacc,0,numChildren,children,&numChildren)==S_OK) {
		level+=1;
		fprintf(logFile,"Down: level %d, contains %d items\n",level,numChildren);
		for(int i=0;i<numChildren;i++) {
			if(i>0) {
				fprintf(logFile,"Next\n");
			}
			if(children[i].vt==VT_DISPATCH) {
				if(children[i].pdispVal->QueryInterface(IID_IAccessible,(void**)(&paccChild))==S_OK) {
					children[i].pdispVal->Release();
					count+=walkIAccessibles(paccChild,makeChildIDVariant(0),level,logFile);
					paccChild->Release();
				}
				VariantClear(&(children[i]));
			} else  if((children[i].vt==VT_I4)&&(children[i].lVal>0)) {
				count+=walkIAccessibles(pacc,children[i],level,logFile);
			}
			VariantClear(&(children[i]));
		}
		level-=1;
		fprintf(logFile,"Up: level %d\n",level);
	}
	free(children);
	return count;
}

DLLEXPORT void startWalkMSAATree(HWND hwnd, long objectID, long childID,char* logFileName) {
	IAccessible* pacc;
	VARIANT varChild;
	FILE* logFile;
	int count=0;
	Beep(440,250);
	CoInitializeEx(NULL,COINIT_APARTMENTTHREADED);
	 logFile = fopen(logFileName,"w");
	fprintf(logFile,"walkMSAATree: window %d, object ID %d, child ID %d\n",hwnd,objectID,childID);
	if(AccessibleObjectFromEvent(hwnd,objectID,childID,&pacc,&varChild)!=S_OK) {
		fprintf(logFile,"walkMSAATree: error in AccessibleObjectFromEvent");
		Beep(220,250);
		return;
	}
	count=walkMSAATree(pacc,varChild,0,logFile);
	pacc->Release();
	fprintf(logFile,"Total count: %d",count);
	fclose(logFile);
	Beep(880,250);
}

LRESULT CALLBACK hook_message(int code, WPARAM wParam,LPARAM lParam) {
	CWPSTRUCT* pmsg=(CWPSTRUCT*)lParam;
	if((code==HC_ACTION)&&(pmsg->hwnd==hookedWindow)&&(pmsg->message==wm)) {
		startWalkMSAATree(pmsg->hwnd,pmsg->wParam,pmsg->lParam,"c:\\users\\mick\\MSAAWalker_inProcess.txt");
		return 1;
	} else {
		return CallNextHookEx(messageHookID,code,wParam,lParam);
	}
}

DLLEXPORT void inProcessStartWalkMSAATree(HWND hwnd, long objectID, long childID) {
	DWORD processID, threadID;
	FILE* logFile=fopen("debug_inprocessWalkMSAATree.txt","w");
	fprintf(logFile,"hwnd: %d, object ID: %d, child ID: %d\n",hwnd,objectID,childID);
	threadID=GetWindowThreadProcessId(hwnd,&processID);
	fprintf(logFile,"threadID: %d, process ID: %d\n",threadID,processID);
	messageHookID=SetWindowsHookEx(WH_CALLWNDPROC,(HOOKPROC)hook_message,moduleHandle,threadID);
	fprintf(logFile,"message hook ID: %d\n",messageHookID);
	hookedWindow=hwnd;
	fprintf(logFile,"hooked window: %d, window message: %d\n",hookedWindow,wm);
	SendMessage(hwnd,wm,objectID,childID);
	UnhookWindowsHookEx(messageHookID);
	fclose(logFile);
}

DLLEXPORT void outOfProcessStartWalkMSAATree(HWND hwnd, long objectID, long childID) {
	startWalkMSAATree(hwnd, objectID, childID,"c:\\users\\mick\\MSAAWalker_outOfProcess.txt");
}