/**************************************************************
 * 
 * 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.
 * 
 *************************************************************/



// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_cppu.hxx"

#include "IdentityMapping.hxx"

#include <hash_map>
#include <set>
#include <algorithm>

#include "rtl/unload.h"
#include "rtl/ustring.hxx"
#include "rtl/ustrbuf.hxx"
#include "osl/module.h"
#include "osl/diagnose.h"
#include "osl/mutex.hxx"
#include "osl/interlck.h"

#include "uno/dispatcher.h"
#include "uno/mapping.h"
#include "uno/lbnames.h"
#include "uno/environment.hxx"

#include "typelib/typedescription.h"

#include "cppu/EnvDcp.hxx"
#include "cascade_mapping.hxx"
#include "IdentityMapping.hxx"
#include "loadmodule.hxx"

using namespace std;
using namespace osl;
using namespace rtl;
using namespace com::sun::star::uno;


namespace cppu
{

class Mapping
{
	uno_Mapping * _pMapping;

public:
	inline Mapping( uno_Mapping * pMapping = 0 ) SAL_THROW( () );
	inline Mapping( const Mapping & rMapping ) SAL_THROW( () );
	inline ~Mapping() SAL_THROW( () );
	inline Mapping & SAL_CALL operator = ( uno_Mapping * pMapping ) SAL_THROW( () );
	inline Mapping & SAL_CALL operator = ( const Mapping & rMapping ) SAL_THROW( () )
		{ return operator = ( rMapping._pMapping ); }
	inline uno_Mapping * SAL_CALL get() const SAL_THROW( () )
		{ return _pMapping; }
	inline sal_Bool SAL_CALL is() const SAL_THROW( () )
		{ return (_pMapping != 0); }
};
//__________________________________________________________________________________________________
inline Mapping::Mapping( uno_Mapping * pMapping ) SAL_THROW( () )
	: _pMapping( pMapping )
{
	if (_pMapping)
		(*_pMapping->acquire)( _pMapping );
}
//__________________________________________________________________________________________________
inline Mapping::Mapping( const Mapping & rMapping ) SAL_THROW( () )
	: _pMapping( rMapping._pMapping )
{
	if (_pMapping)
		(*_pMapping->acquire)( _pMapping );
}
//__________________________________________________________________________________________________
inline Mapping::~Mapping() SAL_THROW( () )
{
	if (_pMapping)
		(*_pMapping->release)( _pMapping );
}
//__________________________________________________________________________________________________
inline Mapping & Mapping::operator = ( uno_Mapping * pMapping ) SAL_THROW( () )
{
	if (pMapping)
		(*pMapping->acquire)( pMapping );
	if (_pMapping)
		(*_pMapping->release)( _pMapping );
	_pMapping = pMapping;
	return *this;
}

//==================================================================================================
struct MappingEntry
{
	sal_Int32			nRef;
	uno_Mapping *		pMapping;
	uno_freeMappingFunc	freeMapping;
	OUString			aMappingName;

	MappingEntry(
		uno_Mapping * pMapping_, uno_freeMappingFunc freeMapping_,
		const OUString & rMappingName_ )
		SAL_THROW( () )
		: nRef( 1 )
		, pMapping( pMapping_ )
		, freeMapping( freeMapping_ )
		, aMappingName( rMappingName_ )
		{}
};
//--------------------------------------------------------------------------------------------------
struct FctOUStringHash : public unary_function< const OUString &, size_t >
{
	size_t operator()( const OUString & rKey ) const SAL_THROW( () )
		{ return (size_t)rKey.hashCode(); }
};
//--------------------------------------------------------------------------------------------------
struct FctPtrHash : public unary_function< uno_Mapping *, size_t >
{
	size_t operator()( uno_Mapping * pKey ) const SAL_THROW( () )
		{ return (size_t)pKey; }
};

typedef hash_map<
    OUString, MappingEntry *, FctOUStringHash, equal_to< OUString > > t_OUString2Entry;
typedef hash_map<
    uno_Mapping *, MappingEntry *, FctPtrHash, equal_to< uno_Mapping * > > t_Mapping2Entry;

typedef set< uno_getMappingFunc > t_CallbackSet;
typedef set< OUString > t_OUStringSet;

//==================================================================================================
struct MappingsData
{
	Mutex				aMappingsMutex;
	t_OUString2Entry	aName2Entry;
	t_Mapping2Entry		aMapping2Entry;

	Mutex				aCallbacksMutex;
	t_CallbackSet		aCallbacks;

	Mutex				aNegativeLibsMutex;
	t_OUStringSet		aNegativeLibs;
};
//--------------------------------------------------------------------------------------------------
static MappingsData & getMappingsData() SAL_THROW( () )
{
	static MappingsData * s_p = 0;
	if (! s_p)
	{
		MutexGuard aGuard( Mutex::getGlobalMutex() );
		if (! s_p)
		{
			//TODO  This memory is leaked; see #i63473# for when this should be
            // changed again:
			s_p = new MappingsData;
		}
	}
	return *s_p;
}

/**
 * This class mediates two different mapping via uno, e.g. form any language to uno,
 * then from uno to any other language.
 */
struct uno_Mediate_Mapping : public uno_Mapping
{
	sal_Int32	nRef;

	Environment aFrom;
	Environment aTo;

	Mapping		aFrom2Uno;
	Mapping		aUno2To;

	OUString	aAddPurpose;

	uno_Mediate_Mapping(
		const Environment & rFrom_, const Environment & rTo_,
		const Mapping & rFrom2Uno_, const Mapping & rUno2To_,
		const OUString & rAddPurpose )
		SAL_THROW( () );
};
extern "C"
{
//--------------------------------------------------------------------------------------------------
static void SAL_CALL mediate_free( uno_Mapping * pMapping )
	SAL_THROW( () )
{
	delete static_cast< uno_Mediate_Mapping * >( pMapping );
}
//--------------------------------------------------------------------------------------------------
static void SAL_CALL mediate_acquire( uno_Mapping * pMapping )
	SAL_THROW( () )
{
	if (1 == ::osl_incrementInterlockedCount(
		& static_cast< uno_Mediate_Mapping * >( pMapping )->nRef ))
	{
		uno_registerMapping(
			&pMapping, mediate_free,
			static_cast< uno_Mediate_Mapping * >( pMapping )->aFrom.get(),
			static_cast< uno_Mediate_Mapping * >( pMapping )->aTo.get(),
			static_cast< uno_Mediate_Mapping * >( pMapping )->aAddPurpose.pData );
	}
}
//--------------------------------------------------------------------------------------------------
static void SAL_CALL mediate_release( uno_Mapping * pMapping )
	SAL_THROW( () )
{
	if (! ::osl_decrementInterlockedCount(
		& static_cast< uno_Mediate_Mapping * >( pMapping )->nRef ))
	{
		uno_revokeMapping( pMapping );
	}
}
//--------------------------------------------------------------------------------------------------
static void SAL_CALL mediate_mapInterface(
	uno_Mapping * pMapping,
	void ** ppOut, void * pInterface,
	typelib_InterfaceTypeDescription * pInterfaceTypeDescr )
	SAL_THROW( () )
{
	OSL_ENSURE( pMapping && ppOut, "### null ptr!" );
	if (pMapping && ppOut)
	{
        uno_Mediate_Mapping * that = static_cast< uno_Mediate_Mapping * >( pMapping );
		uno_Mapping * pFrom2Uno = that->aFrom2Uno.get();

		uno_Interface * pUnoI = 0;
		(*pFrom2Uno->mapInterface)( pFrom2Uno, (void **) &pUnoI, pInterface, pInterfaceTypeDescr );
		if (0 == pUnoI)
        {
            void * pOut = *ppOut;
            if (0 != pOut)
            {
                uno_ExtEnvironment * pTo = that->aTo.get()->pExtEnv;
                OSL_ENSURE( 0 != pTo, "### cannot release out interface: leaking!" );
                if (0 != pTo)
                    (*pTo->releaseInterface)( pTo, pOut );
                *ppOut = 0; // set to 0 anyway, because mapping was not successfull!
            }
        }
        else
		{
            uno_Mapping * pUno2To = that->aUno2To.get();
			(*pUno2To->mapInterface)( pUno2To, ppOut, pUnoI, pInterfaceTypeDescr );
			(*pUnoI->release)( pUnoI );
		}
	}
}
}
//__________________________________________________________________________________________________
uno_Mediate_Mapping::uno_Mediate_Mapping(
	const Environment & rFrom_, const Environment & rTo_,
	const Mapping & rFrom2Uno_, const Mapping & rUno2To_,
	const OUString & rAddPurpose_ )
	SAL_THROW( () )
	: nRef( 1 )
	, aFrom( rFrom_ )
	, aTo( rTo_ )
	, aFrom2Uno( rFrom2Uno_ )
	, aUno2To( rUno2To_ )
	, aAddPurpose( rAddPurpose_ )
{
	uno_Mapping::acquire		= mediate_acquire;
	uno_Mapping::release		= mediate_release;
	uno_Mapping::mapInterface	= mediate_mapInterface;
}

//==================================================================================================
static inline OUString getMappingName(
	const Environment & rFrom, const Environment & rTo, const OUString & rAddPurpose )
	SAL_THROW( () )
{
	OUStringBuffer aKey( 64 );
	aKey.append( rAddPurpose );
	aKey.append( (sal_Unicode)';' );
	aKey.append( rFrom.getTypeName() );
	aKey.append( (sal_Unicode)'[' );
	aKey.append( reinterpret_cast< sal_IntPtr >(rFrom.get()), 16 );
	aKey.appendAscii( RTL_CONSTASCII_STRINGPARAM("];") );
	aKey.append( rTo.getTypeName() );
	aKey.append( (sal_Unicode)'[' );
	aKey.append( reinterpret_cast< sal_IntPtr >(rTo.get()), 16 );
	aKey.append( (sal_Unicode)']' );
	return aKey.makeStringAndClear();
}
//==================================================================================================
static inline OUString getBridgeName(
	const Environment & rFrom, const Environment & rTo, const OUString & rAddPurpose )
	SAL_THROW( () )
{
	OUStringBuffer aBridgeName( 16 );
	if (rAddPurpose.getLength())
	{
		aBridgeName.append( rAddPurpose );
		aBridgeName.append( (sal_Unicode)'_' );
	}
	aBridgeName.append( EnvDcp::getTypeName(rFrom.getTypeName()) );
	aBridgeName.append( (sal_Unicode)'_' );
	aBridgeName.append( EnvDcp::getTypeName(rTo.getTypeName()) );
	return aBridgeName.makeStringAndClear();
}
//==================================================================================================
static inline void setNegativeBridge( const OUString & rBridgeName )
	SAL_THROW( () )
{
	MappingsData & rData = getMappingsData();
	MutexGuard aGuard( rData.aNegativeLibsMutex );
	rData.aNegativeLibs.insert( rBridgeName );
}
//==================================================================================================
static inline oslModule loadModule( const OUString & rBridgeName )
	SAL_THROW( () )
{
	sal_Bool bNeg;
	{
	MappingsData & rData = getMappingsData();
	MutexGuard aGuard( rData.aNegativeLibsMutex );
	const t_OUStringSet::const_iterator iFind( rData.aNegativeLibs.find( rBridgeName ) );
	bNeg = (iFind != rData.aNegativeLibs.end());
	}

	if (! bNeg)
	{
		oslModule hModule = cppu::detail::loadModule( rBridgeName );

		if (hModule)
			return hModule;

		setNegativeBridge( rBridgeName ); // no load again
	}
	return 0;
}
//==================================================================================================
static Mapping loadExternalMapping(
	const Environment & rFrom, const Environment & rTo, const OUString & rAddPurpose )
	SAL_THROW( () )
{
	OSL_ASSERT( rFrom.is() && rTo.is() );
	if (rFrom.is() && rTo.is())
	{
		// find proper lib
		oslModule hModule = 0;
		OUString aName;

		if (EnvDcp::getTypeName(rFrom.getTypeName()).equalsAsciiL( RTL_CONSTASCII_STRINGPARAM(UNO_LB_UNO) ))
			hModule = loadModule( aName = getBridgeName( rTo, rFrom, rAddPurpose ) );
		if (! hModule)
			hModule = loadModule( aName = getBridgeName( rFrom, rTo, rAddPurpose ) );
		if (! hModule)
			hModule = loadModule( aName = getBridgeName( rTo, rFrom, rAddPurpose ) );

		if (hModule)
		{
			OUString aSymbolName( RTL_CONSTASCII_USTRINGPARAM(UNO_EXT_GETMAPPING) );
			uno_ext_getMappingFunc fpGetMapFunc =
				(uno_ext_getMappingFunc)::osl_getFunctionSymbol(
                    hModule, aSymbolName.pData );

			if (fpGetMapFunc)
			{
				Mapping aExt;
				(*fpGetMapFunc)( (uno_Mapping **)&aExt, rFrom.get(), rTo.get() );
				OSL_ASSERT( aExt.is() );
				if (aExt.is())
                {
                    ::rtl_registerModuleForUnloading( hModule );
					return aExt;
                }
			}
			::osl_unloadModule( hModule );
			setNegativeBridge( aName );
		}
	}
	return Mapping();
}

//==================================================================================================
static Mapping getDirectMapping(
	const Environment & rFrom, const Environment & rTo, const OUString & rAddPurpose = OUString() )
	SAL_THROW( () )
{
	OSL_ASSERT( rFrom.is() && rTo.is() );
	if (rFrom.is() && rTo.is())
	{
		MappingsData & rData = getMappingsData();
		ClearableMutexGuard aGuard( rData.aMappingsMutex );

		// try to find registered mapping
		const t_OUString2Entry::const_iterator iFind( rData.aName2Entry.find(
			getMappingName( rFrom, rTo, rAddPurpose ) ) );

		if (iFind == rData.aName2Entry.end())
		{
			aGuard.clear();
			return loadExternalMapping( rFrom, rTo, rAddPurpose );
		}
		else
		{
			return Mapping( (*iFind).second->pMapping );
		}
	}
	return Mapping();
}

//--------------------------------------------------------------------------------------------------
static inline Mapping createMediateMapping(
	const Environment & rFrom, const Environment & rTo,
	const Mapping & rFrom2Uno, const Mapping & rUno2To,
	const OUString & rAddPurpose )
	SAL_THROW( () )
{
	uno_Mapping * pRet = new uno_Mediate_Mapping(
		rFrom, rTo, rFrom2Uno, rUno2To, rAddPurpose ); // ref count initially 1
	uno_registerMapping(
		&pRet, mediate_free, rFrom.get(), rTo.get(), rAddPurpose.pData );
	Mapping aRet( pRet );
	(*pRet->release)( pRet );
	return aRet;
}
//==================================================================================================
static Mapping getMediateMapping(
	const Environment & rFrom, const Environment & rTo, const OUString & rAddPurpose )
	SAL_THROW( () )
{
	Environment aUno;
	Mapping aUno2To;

	// backwards: from dest to source of mapping chain

	// connect to uno
	OUString aUnoEnvTypeName( RTL_CONSTASCII_USTRINGPARAM(UNO_LB_UNO) );
	if (rTo.getTypeName() == aUnoEnvTypeName) // to is uno
	{
		aUno = rTo;
		// no Uno2To mapping necessary
	}
	else
	{
		// get registered uno env
		::uno_getEnvironment( (uno_Environment **)&aUno, aUnoEnvTypeName.pData, 0 );

		aUno2To = getDirectMapping( aUno, rTo );
		// : uno <-> to
		if (! aUno2To.is())
			return Mapping();
	}

	// connect to uno
	if (rAddPurpose.getLength()) // insert purpose mapping between new ano_uno <-> uno
	{
		// create anonymous uno env
		Environment aAnUno;
		::uno_createEnvironment( (uno_Environment **)&aAnUno, aUnoEnvTypeName.pData, 0 );

		Mapping aAnUno2Uno( getDirectMapping( aAnUno, aUno, rAddPurpose ) );
		if (! aAnUno2Uno.is())
			return Mapping();

		if (aUno2To.is()) // to is not uno
		{
			// create another purposed mediate mapping
			aUno2To = createMediateMapping( aAnUno, rTo, aAnUno2Uno, aUno2To, rAddPurpose );
			// : ano_uno <-> uno <-> to
		}
		else
		{
			aUno2To = aAnUno2Uno;
			// : ano_uno <-> to (i.e., uno)
		}
		aUno = aAnUno;
	}

	Mapping aFrom2Uno( getDirectMapping( rFrom, aUno ) );
	if (aFrom2Uno.is() && aUno2To.is())
	{
		return createMediateMapping( rFrom, rTo, aFrom2Uno, aUno2To, rAddPurpose );
		// : from <-> some uno ...
	}

	return Mapping();
}
}

using namespace ::cppu;

extern "C"
{
//##################################################################################################
void SAL_CALL uno_getMapping(
	uno_Mapping ** ppMapping, uno_Environment * pFrom, uno_Environment * pTo,
	rtl_uString * pAddPurpose )
	SAL_THROW_EXTERN_C()
{
	OSL_ENSURE( ppMapping && pFrom && pTo, "### null ptr!" );
	if (*ppMapping)
	{
		(*(*ppMapping)->release)( *ppMapping );
		*ppMapping = 0;
	}

	Mapping aRet;
	Environment aFrom( pFrom ), aTo( pTo );

	OUString aAddPurpose;
	if (pAddPurpose)
		aAddPurpose = pAddPurpose;

	MappingsData & rData = getMappingsData();

	// try registered mapping
	{
	MutexGuard aGuard( rData.aMappingsMutex );
	const t_OUString2Entry::const_iterator iFind( rData.aName2Entry.find(
		getMappingName( aFrom, aTo, aAddPurpose ) ) );
	if (iFind != rData.aName2Entry.end())
		aRet = (*iFind).second->pMapping;
	}

	// See if an identity mapping does fit.
	if (!aRet.is() && pFrom == pTo && !aAddPurpose.getLength()) 
		aRet = createIdentityMapping(pFrom);
		
	if (!aRet.is())
	{
		getCascadeMapping(ppMapping, pFrom, pTo, pAddPurpose);

		if (*ppMapping)
			return;
	}

	if (! aRet.is()) // try callback chain
	{
		MutexGuard aGuard( rData.aCallbacksMutex );
		for ( t_CallbackSet::const_iterator iPos( rData.aCallbacks.begin() );
			  iPos != rData.aCallbacks.end(); ++iPos )
		{
			(**iPos)( ppMapping, pFrom, pTo, aAddPurpose.pData );
			if (*ppMapping)
				return;
		}
	}

	if (! aRet.is())
	{
		aRet = loadExternalMapping( aFrom, aTo, aAddPurpose ); // direct try
		if (! aRet.is())
			aRet = getMediateMapping( aFrom, aTo, aAddPurpose ); // try via uno
	}

	if (aRet.is())
	{
		(*aRet.get()->acquire)( aRet.get() );
		*ppMapping = aRet.get();
	}
}
//##################################################################################################
void SAL_CALL uno_getMappingByName(
	uno_Mapping ** ppMapping, rtl_uString * pFrom, rtl_uString * pTo,
	rtl_uString * pAddPurpose )
	SAL_THROW_EXTERN_C()
{
	OSL_ENSURE( ppMapping && pFrom && pTo, "### null ptr!" );
	if (*ppMapping)
	{
		(*(*ppMapping)->release)( *ppMapping );
		*ppMapping = 0;
	}

	uno_Environment * pEFrom = 0;
	uno_getEnvironment( &pEFrom, pFrom, 0 );
	OSL_ENSURE( pEFrom, "### cannot get source environment!" );
	if (pEFrom)
	{
		uno_Environment * pETo = 0;
		uno_getEnvironment( &pETo, pTo, 0 );
		OSL_ENSURE( pETo, "### cannot get target environment!" );
		if (pETo)
		{
			::uno_getMapping( ppMapping, pEFrom, pETo, pAddPurpose );
			(*pETo->release)( pETo );
		}
		(*pEFrom->release)( pEFrom );
	}
}

//##################################################################################################
void SAL_CALL uno_registerMapping(
	uno_Mapping ** ppMapping, uno_freeMappingFunc freeMapping,
	uno_Environment * pFrom, uno_Environment * pTo, rtl_uString * pAddPurpose )
	SAL_THROW_EXTERN_C()
{
	MappingsData & rData = getMappingsData();
	ClearableMutexGuard aGuard( rData.aMappingsMutex );

	const t_Mapping2Entry::const_iterator iFind( rData.aMapping2Entry.find( *ppMapping ) );
	if (iFind == rData.aMapping2Entry.end())
	{
		OUString aMappingName(
			getMappingName( pFrom, pTo, pAddPurpose ? OUString(pAddPurpose) : OUString() ) );
#if OSL_DEBUG_LEVEL > 1
		OString cstr( OUStringToOString( aMappingName, RTL_TEXTENCODING_ASCII_US ) );
		OSL_TRACE( "> inserting new mapping: %s", cstr.getStr() );
#endif
		// count initially 1
		MappingEntry * pEntry = new MappingEntry( *ppMapping, freeMapping, aMappingName );
		rData.aName2Entry[ aMappingName ] = pEntry;
		rData.aMapping2Entry[ *ppMapping ] = pEntry;
	}
	else
	{
		MappingEntry * pEntry = (*iFind).second;
		++pEntry->nRef;

		if (pEntry->pMapping != *ppMapping) // exchange mapping to be registered
		{
			(*pEntry->pMapping->acquire)( pEntry->pMapping );
			--pEntry->nRef; // correct count; kill mapping to be registered
			aGuard.clear();
			(*freeMapping)( *ppMapping );
			*ppMapping = pEntry->pMapping;
		}
	}
}
//##################################################################################################
void SAL_CALL uno_revokeMapping(
	uno_Mapping * pMapping )
	SAL_THROW_EXTERN_C()
{
	MappingsData & rData = getMappingsData();
	ClearableMutexGuard aGuard( rData.aMappingsMutex );

	const t_Mapping2Entry::const_iterator iFind( rData.aMapping2Entry.find( pMapping ) );
	OSL_ASSERT( iFind != rData.aMapping2Entry.end() );
	MappingEntry * pEntry = (*iFind).second;
	if (! --pEntry->nRef)
	{
		rData.aMapping2Entry.erase( pEntry->pMapping );
		rData.aName2Entry.erase( pEntry->aMappingName );
		aGuard.clear();
#if OSL_DEBUG_LEVEL > 1
		OString cstr( OUStringToOString( pEntry->aMappingName, RTL_TEXTENCODING_ASCII_US  ) );
		OSL_TRACE( "> revoking mapping %s", cstr.getStr() );
#endif
		(*pEntry->freeMapping)( pEntry->pMapping );
		delete pEntry;
	}
}

//##################################################################################################
void SAL_CALL uno_registerMappingCallback(
	uno_getMappingFunc pCallback )
	SAL_THROW_EXTERN_C()
{
	OSL_ENSURE( pCallback, "### null ptr!" );
	MappingsData & rData = getMappingsData();
	MutexGuard aGuard( rData.aCallbacksMutex );
	rData.aCallbacks.insert( pCallback );
}
//##################################################################################################
void SAL_CALL uno_revokeMappingCallback(
	uno_getMappingFunc pCallback )
	SAL_THROW_EXTERN_C()
{
	OSL_ENSURE( pCallback, "### null ptr!" );
	MappingsData & rData = getMappingsData();
	MutexGuard aGuard( rData.aCallbacksMutex );
	rData.aCallbacks.erase( pCallback );
}
} // extern "C"