//////////////////////////////////////////////////////////////////////
//
// AkFilePackageLowLevelIO.h
//
// CAkFilePackageLowLevelIO extends a Low-Level I/O device by providing 
// the ability to reference files that are part of a file package.
//
// It can extend either blocking or deferred I/O hooks (both inheriting from
// AK::StreamMgr::IAkLowLevelIOHook), since its base class is templated. 
// In either case, the base class must also implement 
// AK::StreamMgr::IAkFileLocationResolver. This interface defines both overloads
// for Open(), and this is where the package's look-up table is searched.
// If no match is found, then it falls back on the base implementation.
// 
// Clients of devices that use this class' functionnality simply need to call
// LoadFilePackage(), which loads and parses file packages that were created with 
// the AkFilePackager utility app (located in ($WWISESDK)/samples/FilePackager/). 
// The header of these file packages contains look-up tables that describe the 
// internal offset of each file it references, their block size (required alignment), 
// and their language. Each combination of AkFileID and Language ID is unique.
//
// LoadFilePackage() returns a package ID that can be used to unload it. Any number
// of packages can be loaded simultaneously. When Open() is called, the last package 
// loaded is searched first, then the previous one, and so on.
//
// The language ID was created dynamically when the package was created. The header 
// also contains a map of language names (strings) to their ID, so that the proper 
// language-specific version of files can be resolved. The language name that is stored
// matches the name of the directory that is created by the Wwise Bank Manager,
// except for the trailing slash.
//
// The type of package is also a template argument. By default, it is a disk package
// (see AkDiskPackage.h).
//
// Copyright (c) 2006 Audiokinetic Inc. / All Rights Reserved
//
//////////////////////////////////////////////////////////////////////

#include "AkFilePackageLowLevelIO.h"
#include "AkFileHelpers.h"
#include <AK/Tools/Common/AkPlatformFuncs.h>

template <class T_LLIOHOOK_FILELOC, class T_PACKAGE>
CAkFilePackageLowLevelIO<T_LLIOHOOK_FILELOC,T_PACKAGE>::CAkFilePackageLowLevelIO()
: m_bRegisteredToLangChg( false )
{
}

template <class T_LLIOHOOK_FILELOC, class T_PACKAGE>
CAkFilePackageLowLevelIO<T_LLIOHOOK_FILELOC,T_PACKAGE>::~CAkFilePackageLowLevelIO()
{
}

// Initialize/terminate.
template <class T_LLIOHOOK_FILELOC, class T_PACKAGE>
void CAkFilePackageLowLevelIO<T_LLIOHOOK_FILELOC,T_PACKAGE>::Term()
{
    UnloadAllFilePackages();
	m_packages.Term();
	if ( m_bRegisteredToLangChg )
		AK::StreamMgr::RemoveLanguageChangeObserver( this );
	T_LLIOHOOK_FILELOC::Term();
}

// Override Open (string): Search file in each LUT first. If it cannot be found, use base class services.
// If the file is found in the LUTs, open is always synchronous.
template <class T_LLIOHOOK_FILELOC, class T_PACKAGE>
AKRESULT CAkFilePackageLowLevelIO<T_LLIOHOOK_FILELOC,T_PACKAGE>::Open( 
    const AkOSChar* in_pszFileName,     // File name.
    AkOpenMode      in_eOpenMode,       // Open mode.
    AkFileSystemFlags * in_pFlags,      // Special flags. Can pass NULL.
	bool &			io_bSyncOpen,		// If true, the file must be opened synchronously. Otherwise it is left at the File Location Resolver's discretion. Return false if Open needs to be deferred.
    AkFileDesc &    out_fileDesc        // Returned file descriptor.
    )
{
    // If the file is an AK sound bank, try to find the identifier in the lookup table first.
    if ( in_eOpenMode == AK_OpenModeRead 
		&& in_pFlags )
    {
		if( in_pFlags->uCompanyID == AKCOMPANYID_AUDIOKINETIC 
			&& in_pFlags->uCodecID == AKCODECID_BANK )
		{
			// Search file in each package.
			ListFilePackages::Iterator it = m_packages.Begin();
			while ( it != m_packages.End() )
			{
				AkFileID fileID = (*it)->lut.GetSoundBankID( in_pszFileName );

				if ( FindPackagedFile( (T_PACKAGE*)(*it), fileID, in_pFlags, out_fileDesc ) == AK_Success )
				{
					// Found the ID in the lut. 
					io_bSyncOpen = true;	// File is opened, now.
					return AK_Success;
				}
				++it;
			}
		}
		else if ( in_pFlags->uCompanyID == AKCOMPANYID_AUDIOKINETIC_EXTERNAL )
		{
			// Search file in each package.
			ListFilePackages::Iterator it = m_packages.Begin();
			while ( it != m_packages.End() )
			{
				AkUInt64 fileID = (*it)->lut.GetExternalID( in_pszFileName );

				if ( FindPackagedFile( (T_PACKAGE*)(*it), fileID, in_pFlags, out_fileDesc ) == AK_Success )
				{
					// Found the ID in the lut. 
					io_bSyncOpen = true;	// File is opened, now.
					return AK_Success;
				}

				++it;
			}
		}
	}

    // It is not a soundbank, or it is not in the file package LUT. Use default implementation.
    return T_LLIOHOOK_FILELOC::Open( 
		in_pszFileName,
		in_eOpenMode,
		in_pFlags,
		io_bSyncOpen,
		out_fileDesc);
}

// Override Open (ID): Search file in each LUT first. If it cannot be found, use base class services.
// If the file is found in the LUTs, open is always synchronous.
template <class T_LLIOHOOK_FILELOC, class T_PACKAGE>
AKRESULT CAkFilePackageLowLevelIO<T_LLIOHOOK_FILELOC,T_PACKAGE>::Open( 
    AkFileID        in_fileID,          // File ID.
    AkOpenMode      in_eOpenMode,       // Open mode.
    AkFileSystemFlags * in_pFlags,      // Special flags. Can pass NULL.
	bool &			io_bSyncOpen,		// If true, the file must be opened synchronously. Otherwise it is left at the File Location Resolver's discretion. Return false if Open needs to be deferred.
    AkFileDesc &    out_fileDesc        // Returned file descriptor.
    )
{
    // Try to find the identifier in the lookup table first.
    if ( in_eOpenMode == AK_OpenModeRead 
		&& in_pFlags 
		&& in_pFlags->uCompanyID == AKCOMPANYID_AUDIOKINETIC)
	{
		// Search file in each package.
		ListFilePackages::Iterator it = m_packages.Begin();
		while ( it != m_packages.End() )
		{
			if ( FindPackagedFile( (T_PACKAGE*)(*it), in_fileID, in_pFlags, out_fileDesc ) == AK_Success )
			{
				// File found. Return now.
				io_bSyncOpen = true;	// File is opened, now.
				return AK_Success;
			}
			++it;
		}
	}
	else if ( in_pFlags->uCompanyID == AKCOMPANYID_AUDIOKINETIC_EXTERNAL )
	{
		// Search file in each package.
		ListFilePackages::Iterator it = m_packages.Begin();
		while ( it != m_packages.End() )
		{	
			AkOSChar szFileName[20];
			AK_OSPRINTF(szFileName, 20, AKTEXT("%u.wem"), (unsigned int)in_fileID);
			AkUInt64 fileID = (*it)->lut.GetExternalID(szFileName);

			if ( FindPackagedFile( (T_PACKAGE*)(*it), fileID, in_pFlags, out_fileDesc ) == AK_Success )
			{
				// Found the ID in the lut. 
				io_bSyncOpen = true;	// File is opened, now.
				return AK_Success;
			}

			++it;
		}
	}

    // If it the fileID is not in the LUT, perform standard path concatenation logic.
    return T_LLIOHOOK_FILELOC::Open( 
		in_fileID,
		in_eOpenMode,
		in_pFlags,
		io_bSyncOpen,
		out_fileDesc);
}

// Override Close: Do not close handle if file descriptor is part of the current packaged file.
template <class T_LLIOHOOK_FILELOC, class T_PACKAGE>
AKRESULT CAkFilePackageLowLevelIO<T_LLIOHOOK_FILELOC,T_PACKAGE>::Close(
    AkFileDesc & in_fileDesc      // File descriptor.
    )
{
	// Do not close handle if it is that of the file package (closed only in UnloadFilePackage()).
    if ( !IsInPackage( in_fileDesc ) )
        return T_LLIOHOOK_FILELOC::Close( in_fileDesc );
    
	return AK_Success;
}

// Override GetBlockSize: Get the block size of the LUT if a file package is loaded.
template <class T_LLIOHOOK_FILELOC, class T_PACKAGE>
AkUInt32 CAkFilePackageLowLevelIO<T_LLIOHOOK_FILELOC,T_PACKAGE>::GetBlockSize(
    AkFileDesc &  in_fileDesc     // File descriptor.
    )
{
	if ( IsInPackage( in_fileDesc ) )
	{
		// This file is part of a package. At Open(), we used the 
		// AkFileDesc.uCustomParamSize field to store the block size.
		return in_fileDesc.uCustomParamSize;
	}
	return T_LLIOHOOK_FILELOC::GetBlockSize( in_fileDesc );
}

// Updates language of all loaded packages. Packages keep a language ID to help them find 
// language-specific assets quickly.
template <class T_LLIOHOOK_FILELOC, class T_PACKAGE>
void CAkFilePackageLowLevelIO<T_LLIOHOOK_FILELOC,T_PACKAGE>::OnLanguageChange( 
	const AkOSChar * const in_pLanguageName	// New language name.
	)
{
	// Set language on all loaded packages.
	ListFilePackages::Iterator it = m_packages.Begin();
	while ( it != m_packages.End() )
	{
		(*it)->lut.SetCurLanguage( in_pLanguageName );
		++it;
	}
}

// Searches the LUT to find the file data associated with the FileID.
// Returns AK_Success if the file is found.
template <class T_LLIOHOOK_FILELOC, class T_PACKAGE> 
template <class T_FILEID>
AKRESULT CAkFilePackageLowLevelIO<T_LLIOHOOK_FILELOC,T_PACKAGE>::FindPackagedFile( 
	T_PACKAGE *			in_pPackage,	// Package to search into.
    T_FILEID			in_fileID,		// File ID.
    AkFileSystemFlags * in_pFlags,		// Special flags. Can pass NULL.
    AkFileDesc &		out_fileDesc	// Returned file descriptor.
    )
{
	AKASSERT( in_pPackage && in_pFlags );
	const CAkFilePackageLUT::AkFileEntry<T_FILEID> * pEntry = in_pPackage->lut.LookupFile( in_fileID, in_pFlags );

	if ( pEntry )
	{
		// Fill file descriptor.
        out_fileDesc.deviceID   = T_LLIOHOOK_FILELOC::m_deviceID;
        in_pPackage->GetHandleForFileDesc( out_fileDesc.hFile );
        out_fileDesc.iFileSize	= pEntry->uFileSize;
        out_fileDesc.uSector	= pEntry->uStartBlock;
		out_fileDesc.pCustomParam = NULL;
		// NOTE: We use the uCustomParamSize to store the block size.
		// We will determine whether this file was opened from a package by comparing 
		// uCustomParamSize with 0 (see IsInPackage()).
        out_fileDesc.uCustomParamSize = pEntry->uBlockSize;
        return AK_Success;
    }
    return AK_FileNotFound;
}

// File package loading:
// Opens a package file, parses its header, fills LUT.
// Overrides of Open() will search files in loaded LUTs first, then use default Low-Level I/O 
// services if they cannot be found.
// Any number of packages can be loaded at a time. Each LUT is searched until a match is found.
// Returns AK_Success if successful, AK_InvalidLanguage if the current language 
// does not exist in the LUT (not necessarily an error), AK_Fail for any other reason.
// Also returns a package ID which can be used to unload it (see UnloadFilePackage()).
template <class T_LLIOHOOK_FILELOC, class T_PACKAGE>
AKRESULT CAkFilePackageLowLevelIO<T_LLIOHOOK_FILELOC,T_PACKAGE>::LoadFilePackage(
    const AkOSChar *    in_pszFilePackageName,	// File package name. 
	AkUInt32 &			out_uPackageID,			// Returned package ID.
	AkMemPoolId			in_memPoolID /*= AK_DEFAULT_POOL_ID	*/ // Memory pool in which the LUT is written. Passing AK_DEFAULT_POOL_ID will create a new pool automatically. 
    )
{
	// Open package file.
	AkFilePackageReader filePackageReader;
	AKRESULT eRes = filePackageReader.Open( in_pszFilePackageName, true );	// Open from SFX-only directory.
	if ( eRes != AK_Success )
        return eRes;

	filePackageReader.SetName( in_pszFilePackageName );

	T_PACKAGE * pPackage;
	eRes = _LoadFilePackage( in_pszFilePackageName, filePackageReader, AK_DEFAULT_PRIORITY, in_memPoolID, pPackage );
	if ( eRes == AK_Success
		|| eRes == AK_InvalidLanguage )
	{
		AKASSERT( pPackage );
		// Add to packages list.
		m_packages.AddFirst( pPackage );
		
		out_uPackageID = pPackage->ID();
	}
	return eRes;
}
	
// Loads a file package, with a given file package reader.
template <class T_LLIOHOOK_FILELOC, class T_PACKAGE>
AKRESULT CAkFilePackageLowLevelIO<T_LLIOHOOK_FILELOC,T_PACKAGE>::_LoadFilePackage(
    const AkOSChar*			in_pszFilePackageName,	// File package name. 
	AkFilePackageReader &	in_reader,				// File package reader.
	AkPriority				in_readerPriority,		// File package reader priority heuristic.
	AkMemPoolId				in_memPoolID,			// Memory pool in which the LUT is written. Passing AK_DEFAULT_POOL_ID will create a new pool automatically. 
	T_PACKAGE *&			out_pPackage			// Returned package
    )
{
	// Read header chunk definition.
	struct AkFilePackageHeader
	{
		AkUInt32 uFileFormatTag;
		AkUInt32 uHeaderSize;
	};

	AkUInt32 uReadBufferSize = AkMax( 2 * in_reader.GetBlockSize(), sizeof(AkFilePackageHeader) );
	AkUInt8 * pBufferForHeader = (AkUInt8*)AkAlloca( uReadBufferSize );
	AkUInt32 uSizeToRead;
	bool bAligned = ( sizeof(AkFilePackageHeader) % in_reader.GetBlockSize() ) > 0;
	if ( bAligned )
	{
		// Header size is not a multiple of the required block size. Allocate an aligned buffer on the stack.
		pBufferForHeader += ( in_reader.GetBlockSize() - (AkUIntPtr)pBufferForHeader % in_reader.GetBlockSize() );
		uSizeToRead = in_reader.GetBlockSize();
	}
	else
	{
		// Header size is a multiple of the required block size. 
		uSizeToRead = sizeof(AkFilePackageHeader);
	}

	AkUInt32 uSizeRead;
	AKRESULT eRes = in_reader.Read( pBufferForHeader, uSizeToRead, uSizeRead, in_readerPriority );
	if ( eRes != AK_Success
		|| uSizeRead < sizeof(AkFilePackageHeader) )
	{
		AKASSERT( !"Could not read package, or package is invalid" );
		in_reader.Close();
        return AK_Fail;
	}

	const AkFilePackageHeader & uFileHeader = *(AkFilePackageHeader*)pBufferForHeader;

	if ( uFileHeader.uFileFormatTag != AKPK_FILE_FORMAT_TAG 
		|| 0 == uFileHeader.uHeaderSize )
	{
		AKASSERT( !"Invalid file package header" );
		in_reader.Close();
        return AK_Fail;
	}

	// Create file package.
	AkUInt32 uReservedHeaderSize;
	AkUInt8 * pFilePackageHeader;
	out_pPackage = T_PACKAGE::Create(
		in_reader,
		in_pszFilePackageName,
		in_memPoolID,
		uFileHeader.uHeaderSize + AKPK_HEADER_CHUNK_DEF_SIZE,	// NOTE: The header size written in the file package excludes the AKPK_HEADER_CHUNK_DEF_SIZE.
		uReservedHeaderSize,
		pFilePackageHeader );
	if ( !out_pPackage )
	{
		AKASSERT( !"Could not create file package" );
		in_reader.Close();
        return AK_Fail;
	}

	AkUInt32 uHeaderSize = uFileHeader.uHeaderSize;
	AkUInt32 uHeaderReadOffset = AKPK_HEADER_CHUNK_DEF_SIZE;

	// If we had already read more than sizeof(AkFilePackageHeader), copy the rest now.
	if ( uSizeRead > sizeof(AkFilePackageHeader) )
	{
		pBufferForHeader += sizeof(AkFilePackageHeader);
		AkUInt32 uSizeToCopy = uSizeRead - sizeof(AkFilePackageHeader);
		AKPLATFORM::AkMemCpy( pFilePackageHeader+AKPK_HEADER_CHUNK_DEF_SIZE, pBufferForHeader, uSizeToCopy );
		// Adjust header size and read offset.
		if ( uSizeToCopy > uHeaderSize )
			uSizeToCopy = uHeaderSize;
		uHeaderSize -= uSizeToCopy;
		uHeaderReadOffset += uSizeToCopy;
		// Round it up to required block size. It should be equal to the size that was reserved (minus what was already read).
		uHeaderSize = ( ( uHeaderSize + in_reader.GetBlockSize() - 1 ) / in_reader.GetBlockSize() ) * in_reader.GetBlockSize();
		AKASSERT( uHeaderSize == uReservedHeaderSize - uSizeRead );
	}

	// Stream in remaining of the header.
	if ( uHeaderSize > 0 )
	{
		AKASSERT( uHeaderReadOffset % in_reader.GetBlockSize() == 0 );
		if ( in_reader.Read( pFilePackageHeader+uHeaderReadOffset, uHeaderSize, uSizeRead, in_readerPriority ) != AK_Success
			|| uSizeRead < uHeaderSize )
		{
			AKASSERT( !"Could not read file package" );
			out_pPackage->Destroy();
			return AK_Fail;
		}
	}

	// Parse LUT.
	eRes = out_pPackage->lut.Setup( pFilePackageHeader, uFileHeader.uHeaderSize + AKPK_HEADER_CHUNK_DEF_SIZE );
	if ( eRes != AK_Success )
	{
		out_pPackage->Destroy();
		return eRes;
	}

	// Register to language change notifications if it wasn't already done
	if ( !m_bRegisteredToLangChg )
	{
		if ( AK::StreamMgr::AddLanguageChangeObserver( LanguageChangeHandler, this ) != AK_Success )
		{
			out_pPackage->Destroy();
			return AK_Fail;
		}
		m_bRegisteredToLangChg = true;
	}

	// Use the current language path (if defined) to set the language ID, 
    // for language specific file mapping.
	return out_pPackage->lut.SetCurLanguage( AK::StreamMgr::GetCurrentLanguage() );
}

// Unload a file package.
template <class T_LLIOHOOK_FILELOC, class T_PACKAGE>
AKRESULT CAkFilePackageLowLevelIO<T_LLIOHOOK_FILELOC,T_PACKAGE>::UnloadFilePackage( 
	AkUInt32	in_uPackageID			// Package ID.
	)
{
	ListFilePackages::IteratorEx it = m_packages.BeginEx();
	while ( it != m_packages.End() )
	{
		if ( (*it)->ID() == in_uPackageID )
		{
			CAkFilePackage * pPackage = (*it);
			it = m_packages.Erase( it );

			// Destroy package.
			pPackage->Destroy();

			return AK_Success;
		}
		else
			++it;
	}

	AKASSERT( !"Invalid package ID" );
	return AK_Fail;
}

// Unload all file packages.
template <class T_LLIOHOOK_FILELOC, class T_PACKAGE>
AKRESULT CAkFilePackageLowLevelIO<T_LLIOHOOK_FILELOC,T_PACKAGE>::UnloadAllFilePackages()
{
	ListFilePackages::IteratorEx it = m_packages.BeginEx();
	while ( it != m_packages.End() )
	{
		CAkFilePackage * pPackage = (*it);
		it = m_packages.Erase( it );

		// Destroy package.
		pPackage->Destroy();
	}

	return AK_Success;
}