#include <windows.h>
#include <string.h>
#include "jni.h"
#include ".\java\GetKey.h"		//JNI implementation of RegDBGetKeyValueEx
#include ".\java\SetKey.h"		//JNI implementation of RegDBSetKeyValueEx

// Global Variable to store the DLL's Instance handle
HINSTANCE ghDLLInst ;

char *rgchModuleName = "RegConnect";									//Name of module

// Function prototypes
int WINAPI RegDBGetKeyValueEx(LPCTSTR, HKEY ,LPCTSTR, LPCTSTR, LPTSTR) ;
int WINAPI RegDBSetKeyValueEx(LPCTSTR, HKEY ,LPCTSTR, LPCTSTR, LPCTSTR) ;

// -----------------------------------------------------------------
// Function: LibMain
//
// Purpose : This is the DLL's entry point.  It is analogous to WinMain for applications.
//
// Params  : hInstance   ==  The handle to the DLL's instance.
//           wDataSeg    ==  Basically it is a pointer to the DLL's data segment.
//           wHeapSize   ==  Size of the DLL's heap in bytes.
//           lpszCmdLine ==  The command line passed to the DLL by Windows.  This is rarely used.
//
// Returns : 1 indicating DLL initialization is successful.
//
// Comments: LibMain is called by Windows.  Do not call it in your application!
// -----------------------------------------------------------------
//int FAR PASCAL LibMain (HANDLE hInstance, WORD wDataSeg, WORD wHeapSize, LPSTR lpszCmdLine)
BOOL WINAPI DllMain(HINSTANCE hinstDLL,	// handle to DLL module 
					DWORD fdwReason,	// reason for calling function 
					LPVOID lpvReserved) // reserved 
   
{
	ghDLLInst = hinstDLL ;
    // Perform actions based on the reason for calling.
    switch( fdwReason )  
    { 
        case DLL_PROCESS_ATTACH:
			// Initialize once for each new process.
			// Return FALSE to fail DLL load.
            break;

        case DLL_THREAD_ATTACH:
         // Do thread-specific initialization.
            break;

        case DLL_THREAD_DETACH:
         // Do thread-specific cleanup.
            break;

        case DLL_PROCESS_DETACH:
         // Perform any necessary cleanup.
            break;
    }
    return TRUE;  // Successful DLL_PROCESS_ATTACH.
}

//////////////////////////////////////////////////////////////////////////
//  Function:  RegDBGetKeyValueEx
//
//  Description: Retrieves the string associated with the specified key in a remote registry.
//
//  Parameters:
//    lpMachineName	-	Name of machine we want to interrogate 
//    hRegKey		-	Registry key type, i.e. HKEY_LOCAL_MACHINE
//	  lpKeyName		-	Tree to Key we want to get i.e. software\ibm\db2
//    lpValueName	-	Value we want to get i.e. DB2 path name
//    lpszKeyValue	-	Value we will get back - may need pre-dimensioning
//  Returns:
//    non zero error code on failure, 0 on success
//////////////////////////////////////////////////////////////////////////
int WINAPI RegDBGetKeyValueEx(LPCTSTR lpMachineName, HKEY hRegKey, LPCTSTR lpKeyName, LPCTSTR lpValueName, LPTSTR lpszKeyValue)
{
// Local variables
HKEY		hRemoteKey = NULL ;
HKEY		hKey = NULL ;
DWORD       dwKeySize;            // Size of key value
DWORD       dwKeyDataType;        // Type of data stored in key
LONG        lRC;                  // Return code
char		cMachine[128] = {0} ;

	//  Initialize variables
    dwKeyDataType = 0;
    dwKeySize = 0;

	if(lpMachineName)
		if(lpMachineName[0] != 0)
			wsprintf(cMachine,"\\\\%s",lpMachineName) ;

	// Connect to the remote registry
	lRC = RegConnectRegistry(cMachine, hRegKey, &hRemoteKey) ;
    if (lRC != ERROR_SUCCESS)
		return lRC ;
	
    //Open the key
	lRC = RegOpenKeyEx(hRemoteKey, lpKeyName, 0, KEY_ALL_ACCESS, &hKey);
    if (lRC == ERROR_SUCCESS)
		{
		// Got key, get value.  First, get the size of the key.
		lRC = RegQueryValueEx(hKey, lpValueName, NULL, &dwKeyDataType, NULL, &dwKeySize);

		if(dwKeyDataType == REG_DWORD)		//DWORD
			{
			char cData[128] = {0} ;
			lRC = RegQueryValueEx(hKey, lpValueName, NULL, &dwKeyDataType, (LPBYTE)cData, &dwKeySize);
			ltoa((LONG)cData[0], lpszKeyValue, 10) ;
			}
		else
			// Now get the actual key value
			lRC = RegQueryValueEx(hKey, lpValueName, NULL, &dwKeyDataType, (LPBYTE)lpszKeyValue, &dwKeySize);
		}

	RegCloseKey(hKey) ;
	RegCloseKey(hRemoteKey) ;
	return lRC ;
}   // End of function RegDBGetKeyValueEx

//////////////////////////////////////////////////////////////////////////
//  Function:  RegDBSetKeyValueEx
//
//  Description: Sets the string associated with the specified key in a remote registry.
//
//  Parameters:
//    lpMachineName	-	Name of machine we want to interrogate 
//    hRegKey		-	Registry key type, i.e. HKEY_LOCAL_MACHINE
//	  lpKeyName		-	Tree to Key we want to set i.e. software\ibm\db2
//    lpValueName	-	Value key we want to set i.e. DB2 path name
//    lpszKeyValue	-	Value we will set in the registry

//  Returns:
//    non zero error code on failure, 0 on success
//////////////////////////////////////////////////////////////////////////
int WINAPI RegDBSetKeyValueEx(LPCTSTR lpMachineName, HKEY hRegKey, LPCTSTR lpKeyName, LPCTSTR lpValueName, LPCTSTR lpszKeyValue)
{
// Local variables
HKEY		hRemoteKey = NULL ;
HKEY		hKey = NULL ;
LONG        lRC;                  // Return code
char		cMachine[128] = {0} ;
DWORD		dwDisp;

	if(lpMachineName)
		if(lpMachineName[0] != 0)
			wsprintf(cMachine,"\\\\%s",lpMachineName) ;

	// Connect to the remote registry
	lRC = RegConnectRegistry(cMachine, hRegKey, &hRemoteKey) ;
    if (lRC != ERROR_SUCCESS)
		return lRC ;
	
    //  Initialize variables
	lRC = RegCreateKeyEx(hRemoteKey, lpKeyName, 0, REG_NONE,
			REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS, NULL, &hKey, &dwDisp) ;

    if (lRC == ERROR_SUCCESS)
		{
		// Got key, set value.
		lRC = RegSetValueEx(hKey, lpValueName, 0, REG_SZ, (LPBYTE)lpszKeyValue, strlen(lpszKeyValue) + 1) ;
		RegCloseKey(hKey) ;
		}

	RegCloseKey(hRemoteKey) ;
	return lRC ;
}   // End of function RegDBGetKeyValueEx

// Java implementation of RegDBGetKeyValueEx
JNIEXPORT jobject JNICALL Java_GetKey_RegDBGetKeyValueEx(JNIEnv* env, jobject this_obj, 
			jstring jMachineName, jint hRegKey, jstring jKeyName, jstring jValueName)
{
LPCTSTR lpMachineName ;
LPCTSTR lpKeyName ;
LPCTSTR lpValueName ;
char cKeyValue[255] ;
jobject ret ;

	lpMachineName = (*env)->GetStringUTFChars(env, jMachineName, NULL) ;
	lpKeyName = (*env)->GetStringUTFChars(env, jKeyName, NULL) ;
	lpValueName = (*env)->GetStringUTFChars(env, jValueName, NULL) ;

	RegDBGetKeyValueEx(lpMachineName, (HKEY)hRegKey, lpKeyName, lpValueName, cKeyValue) ;
	
	(*env)->ReleaseStringUTFChars(env, jMachineName, NULL) ;
	(*env)->ReleaseStringUTFChars(env, jKeyName, NULL) ;
	(*env)->ReleaseStringUTFChars(env, jValueName, NULL) ;
	ret = (*env)->NewStringUTF(env, cKeyValue) ;
	return ret ;
}	// End of function Java_GetKey_RegDBGetKeyValueEx

// Java implementation of RegDBSetKeyValueEx
JNIEXPORT jint JNICALL Java_SetKey_RegDBSetKeyValueEx(JNIEnv* env, jobject this_obj, 
			jstring jMachineName, jint hRegKey, jstring jKeyName, jstring jValueName, jstring jKeyValue)
{
LPCTSTR lpMachineName ;
LPCTSTR lpKeyName ;
LPCTSTR lpValueName ;
LPCTSTR lpszKeyValue ;
int iRet ;

	lpMachineName = (*env)->GetStringUTFChars(env, jMachineName, NULL) ;
	lpKeyName = (*env)->GetStringUTFChars(env, jKeyName, NULL) ;
	lpValueName = (*env)->GetStringUTFChars(env, jValueName, NULL) ;
	lpszKeyValue = (*env)->GetStringUTFChars(env, jKeyValue, NULL) ;

	iRet = RegDBSetKeyValueEx(lpMachineName, (HKEY)hRegKey, lpKeyName, lpValueName, lpszKeyValue) ;
	
	(*env)->ReleaseStringUTFChars(env, jMachineName, NULL) ;
	(*env)->ReleaseStringUTFChars(env, jKeyName, NULL) ;
	(*env)->ReleaseStringUTFChars(env, jValueName, NULL) ;
	(*env)->ReleaseStringUTFChars(env, jKeyValue, NULL) ;
	return iRet ;
}	// End of function Java_SetKey_RegDBGetKeyValueEx