/**************************************************************
 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 * 
 *************************************************************/


#ifndef _REGISTRY_HXX_
#define _REGISTRY_HXX_

#ifdef _MSC_VER
#pragma warning(push, 1) /* disable warnings within system headers */
#endif
#include <windows.h>
#ifdef _MSC_VER
#pragma warning(pop)
#endif

#include <memory>
#include <vector>
#include <string>

#include "registryvalueimpl.hxx"

//---------------------------------------
// forward declaration
//---------------------------------------

class RegistryKeyImpl;

//---------------------------------------
// typedefs
//---------------------------------------

typedef std::auto_ptr<RegistryKeyImpl>  	RegistryKey;
typedef std::vector<std::wstring>				StringList;
typedef std::auto_ptr<StringList>				StringListPtr;

//---------------------------------------
// 
//---------------------------------------

class RegistryKeyImpl
{
public:   
	
	//############################################
	// Destruction
	//############################################

    virtual ~RegistryKeyImpl();


	//############################################
	// Queries
	//############################################


	/** The name of the key at hand, maybe empty
		if this is any of the root keys
	*/
	std::wstring GetName() const;

	/** The number of sub values of the key at hand
		
		@precond IsOpen = true

		@throws 
	*/
	virtual size_t GetSubValueCount() const = 0;

	/** The number of sub-keys of the key at hand

		@precond IsOpen = true

		@throws
	*/
	virtual size_t GetSubKeyCount() const = 0;
	
	bool IsOpen() const;

	/** Do we have write access on the key at hand
	*/
	bool IsWriteable() const;

	/** The StringList will be allocated on the heap,
		so this is in fact a transfer of ownership
		to the caller

		@precond IsOpen = true

		@throws RegistryIOException
	*/
	virtual StringListPtr GetSubKeyNames() const = 0;

	/** The StringList will be allocated on the heap,
		so this is in fact a transfer of ownership
		to the caller

		@precond IsOpen = true

		@throws RegistryIOException
	*/
	virtual StringListPtr GetSubValueNames() const = 0;

	/** Get the specified registry value

		@precond IsOpen = true
	*/
	virtual RegistryValue GetValue(const std::wstring& Name) const = 0;

	/** Get the specified registry value, return the given
		default value if value not found

		@precond IsOpen = true
	*/
	virtual RegistryValue GetValue(const std::wstring& Name, const RegistryValue& Default) const = 0;
	
	/** Convenience function to determine if the
		Registry key at hand has the specified 
		value

		@precond IsOpen = true

		throws RegistryAccessDenyException
	*/
	bool HasValue(const std::wstring& Name) const;

	/** Convenience function to determine if the
		Registry key at hand has the specified 
		sub-key

		@precond IsOpen = true

		throws RegistryAccessDenyException
	*/
	bool HasSubKey(const std::wstring& Name) const;


	//############################################
	// Commands
	//############################################


	/** Open the registry key, has no effect if 
		the key is already open
		
		@precond IsOpen = false

		@throws RegistryWriteAccessDenyException
				RegistryAccessDenyException
	*/
	virtual void Open(bool Writeable = true) = 0;

	/** Close the registry key at hand, further
		using it without re-opening may cause
		RegistryIOExceptions to be thrown

		This is a template method that calls 
		ImplClose which has to be overwritten 
		by sub-classes
	*/
	void Close();
	
	/** Open the specified sub-key of the registry key
		at hand

		@precond IsOpen = true
				 HasSubKey(Name) = true

		@throws RegistryIOException
				RegistryKeyNotFoundException
				RegistryAccessDeniedException
	*/
	virtual RegistryKey OpenSubKey(const std::wstring& Name, bool Writeable = true) = 0;

	/** Creates a new sub-key below the key at hand

		@precond IsOpen = true
				 IsWriteable = true

		@throws  RegistryIOException
				 RegistryWriteAccessDenyException
	*/
	virtual RegistryKey CreateSubKey(const std::wstring& Name) = 0;

	/** Deletes a sub-key below the key at hand, the
		key must not have sub-keys

		@precond IsOpen = true
				 IsWriteable = true

		@throws  RegistryIOException
				 RegistryWriteAccessDenyException
	*/
	virtual void DeleteSubKey(const std::wstring& Name) = 0;

	/** Deletes a sub-key below the key at hand with all
		its sub-keys

		@precond IsOpen = true
				 IsWriteable = true;

		@throws  RegistryIOException
				 RegistryWriteAccessDenyException
	*/
	virtual void DeleteSubKeyTree(const std::wstring& Name) = 0;

	/** Delete the specified value

		@precond IsOpen = true
				 IsWriteable = true
				 HasValue(Name) = true

		@throws	RegistryIOException
				RegistryWriteAccessDeniedException
				RegistryValueNotFoundException
	*/
	virtual void DeleteValue(const std::wstring& Name) = 0;

	/** Set the specified registry value

		@precond IsOpen = true
				 IsWriteable = true

		@throws  RegistryIOException
				 RegistryWriteAccessDenyException
	*/
	virtual void SetValue(const RegistryValue& Value) = 0;


	/** Copies the specified value from RegistryKey to 
		the registry key at hand, if a value with this 
		name already exist under the registry key at hand
		it will be overwritten

		@precond IsOpen = true
				 IsWriteable = true
				 RegistryKey.HasSubValue(Name) = true

		@throws RegistryIOException
				RegistryWriteAccessDeniedException
				RegistryValueNotFoundException
	*/
	virtual void CopyValue(const RegistryKey& RegistryKey, const std::wstring& Name);

	/** Copies the specified value from RegistryKey to 
		the registry key at hand under a new name, 
		if a value with this name already exist there
		it will be overwritten

		@precond IsOpen = true
				 IsWriteable = true
				 RegistryKey.HasSubValue(Name) = true

		@throws RegistryIOException
				RegistryWriteAccessDeniedException
				RegistryValueNotFoundException
	*/
	virtual void CopyValue(const RegistryKey& RegistryKey, const std::wstring& Name, const std::wstring& NewName);

	//############################################
	// Creation 
	// only possible through WindowsRegistry class	
	//############################################


protected:
	/** Create instance of the specified Registry key

		@throws  RegistryWriteAccessDenyException
				 RegistryAccessDenyException
				 RegistryKeyNotFoundException
	*/
    RegistryKeyImpl(HKEY RootKey, const std::wstring& KeyName);

	/** Create instance of the specified Registry key.
		RootKey should only one of the predefined 
		keys HKEY_CLASSES_ROOT, HKEY_CURRENT_USER,
		HKEY_LOCAL_MACHINE, HKEY_USERS

		@throws  RegistryWriteAccessDenyException
				 RegistryAccessDenyException
				 RegistryKeyNotFoundException
	*/
	RegistryKeyImpl(HKEY RootKey);
	
	/** Create an instances of the specified Registry key,
		the key is assumed to be already opened.
	*/
	RegistryKeyImpl(HKEY RootKey, HKEY SubKey, const std::wstring& KeyName, bool Writeable = true);

	/** Is this one of the root keys
		HKEY_CLASSES_ROOT
		HKEY_CURRENT_USER
		etc.
	*/
	bool IsRootKey() const;

protected: 
    HKEY			m_hRootKey;
    HKEY		    m_hSubKey;
	std::wstring	m_KeyName;
	bool				m_IsWriteable;

// prevent copy and assignment
private:
    RegistryKeyImpl(const RegistryKeyImpl&);
    RegistryKeyImpl& operator=(const RegistryKeyImpl&);

//######################################
// Friend declarations
//######################################

friend class WindowsRegistry;
};

#endif