////////////////////////////////////////////////////////////////////////////////////////
//
// Nestopia - NES/Famicom emulator written in C++
//
// Copyright (C) 2003-2008 Martin Freij
//
// This file is part of Nestopia.
//
// Nestopia is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// Nestopia is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Nestopia; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
////////////////////////////////////////////////////////////////////////////////////////

#include <new>
#include "NstApplicationInstance.hpp"
#include "NstWindowUser.hpp"
#include "NstSystemDll.hpp"
#include "NstObjectPod.hpp"
#include "NstIoFile.hpp"
#include "NstIoLog.hpp"
#include "NstIoArchive.hpp"
#include <initguid.h>
#include <ObjBase.h>
#include <OleAuto.h>
#include "../unrar/unrar.h"
#include "../7zip/IArchive.h"

#if NST_MSVC
#pragma comment(lib,"zlibstat")
#endif

DEFINE_GUID(CLSID_CFormat7z,0x23170F69,0x40C1,0x278A,0x10,0x00,0x00,0x01,0x10,0x07,0x00,0x00);

#define ZLIB_WINAPI
#define ZCALLBACK WINAPIV
#include "../zlib/unzip.h"

namespace Nestopia
{
	namespace Io
	{
		class Archive::Codec
		{
		public:

			enum Exception
			{
				ERR_DLL,
				ERR_CREATE,
				ERR_OPEN
			};

			virtual ~Codec() {}

			virtual bool Build(Items&) = 0;
			virtual uint Extract(uint,void*,uint) = 0;
		};

		class Archive::UnZip : public Codec
		{
			struct Stream
			{
				const uchar* const buffer;
				uint pos;
				const uint size;

				explicit Stream(const void* b=NULL,uint s=0)
				: buffer(static_cast<const uchar*>(b)), pos(0), size(s) {}
			};

			Stream stream;
			void* const handle;

			bool Build(Items& files)
			{
				uint numFiles;

				{
					unz_global_info_s info;

					if
					(
						::unzGetGlobalInfo( handle, &info ) != UNZ_OK ||
						info.number_entry == 0 ||
						::unzGoToFirstFile( handle ) != UNZ_OK
					)
						return false;

					numFiles = info.number_entry;
				}

				files.reserve( numFiles );

				char path[MAX_PATH+1];
				unz_file_info info;
				uint i=0;

				do
				{
					if (::unzGetCurrentFileInfo( handle, &info, path, MAX_PATH, NULL, 0, NULL, 0 ) == UNZ_OK && info.uncompressed_size && *path)
					{
						wchar_t unipath[MAX_PATH+1];
						::MultiByteToWideChar( CP_OEMCP, 0, path, -1, unipath, MAX_PATH );
						files.push_back( Item(this,unipath,info.uncompressed_size,i) );
					}
				}
				while (++i < numFiles && ::unzGoToNextFile( handle ) == UNZ_OK);

				return !files.empty();
			}

			uint Extract(uint index,void* buffer,uint size)
			{
				if (::unzGoToFirstFile( handle ) == UNZ_OK)
				{
					for (uint i=0; i < index; ++i)
					{
						if (::unzGoToNextFile( handle ) != UNZ_OK)
							return false;
					}

					if (::unzOpenCurrentFile( handle ) == UNZ_OK)
					{
						const int extracted = ::unzReadCurrentFile( handle, buffer, size );
						::unzCloseCurrentFile( handle );

						if (extracted == int(size))
							return size;
					}
				}

				return false;
			}

			static void* ZCALLBACK OnOpen(void* opaque,cstring,int mode)
			{
				if (mode & ZLIB_FILEFUNC_MODE_WRITE)
					return NULL;
				else
					return opaque;
			}

			static ulong ZCALLBACK OnWrite(voidpf,voidpf,const void*,ulong)
			{
				return 0;
			}

			static int ZCALLBACK OnClose(voidpf,voidpf stream)
			{
				return !stream;
			}

			static int ZCALLBACK OnTest(voidpf,voidpf stream)
			{
				return !stream;
			}

			static ulong ZCALLBACK OnStreamRead(voidpf,voidpf object,void* data,ulong length)
			{
				if (object && data)
				{
					Stream& stream = *static_cast<Stream*>( object );

					if (length > stream.size - stream.pos)
						length = stream.size - stream.pos;

					std::memcpy( data, stream.buffer + stream.pos, length );
					stream.pos += length;

					return length;
				}
				else
				{
					return 0;
				}
			}

			static long ZCALLBACK OnStreamTell(voidpf,voidpf object)
			{
				if (const Stream* const stream = static_cast<const Stream*>( object ))
					return stream->pos;
				else
					return -1;
			}

			static long ZCALLBACK OnStreamSeek(voidpf,voidpf object,ulong distance,int origin)
			{
				if (Stream* const stream = static_cast<Stream*>( object ))
				{
					switch (origin)
					{
						case ZLIB_FILEFUNC_SEEK_SET: stream->pos = distance; break;
						case ZLIB_FILEFUNC_SEEK_CUR: stream->pos += distance; break;
						case ZLIB_FILEFUNC_SEEK_END: stream->pos = stream->size + distance; break;
						default: return -1L;
					}

					if (stream->pos <= stream->size)
						return 0L;

					stream->pos = stream->size;
				}

				return -1L;
			}

			static ulong ZCALLBACK OnFileRead(voidpf,voidpf file,void* data,ulong size)
			{
				if (file && data)
				{
					try
					{
						return static_cast<const File*>(file)->ReadSome( data, size );
					}
					catch (...)
					{
					}
				}

				return 0;
			}

			static long ZCALLBACK OnFileTell(voidpf,voidpf file)
			{
				if (file)
				{
					try
					{
						return long (static_cast<const File*>(file)->Position());
					}
					catch (...)
					{
					}
				}

				return -1L;
			}

			static long ZCALLBACK OnFileSeek(voidpf,voidpf file,ulong distance,int origin)
			{
				NST_COMPILE_ASSERT
				(
					ZLIB_FILEFUNC_SEEK_SET == File::BEGIN &&
					ZLIB_FILEFUNC_SEEK_CUR == File::CURRENT &&
					ZLIB_FILEFUNC_SEEK_END == File::END
				);

				if (file && origin < 3)
				{
					try
					{
						static_cast<const File*>(file)->Seek( static_cast<File::Offset>(origin), distance );
						return 0L;
					}
					catch (...)
					{
					}
				}

				return -1L;
			}

			static void* Create(const File& file)
			{
				zlib_filefunc_def_s def;

				def.zopen_file  = &OnOpen;
				def.zread_file  = &OnFileRead;
				def.zwrite_file = &OnWrite;
				def.ztell_file  = &OnFileTell;
				def.zseek_file  = &OnFileSeek;
				def.zclose_file = &OnClose;
				def.zerror_file = &OnTest;
				def.opaque      = const_cast<void*>(static_cast<const void*>(&file));

				void* handle = ::unzOpen2( NULL, &def );

				if (handle == NULL)
					throw ERR_OPEN;

				return handle;
			}

			static void* Create(Stream& stream)
			{
				zlib_filefunc_def_s def;

				def.zopen_file  = &OnOpen;
				def.zread_file  = &OnStreamRead;
				def.zwrite_file = &OnWrite;
				def.ztell_file  = &OnStreamTell;
				def.zseek_file  = &OnStreamSeek;
				def.zclose_file = &OnClose;
				def.zerror_file = &OnTest;
				def.opaque      = &stream;

				void* handle = ::unzOpen2( NULL, &def );

				if (handle == NULL)
					throw ERR_OPEN;

				return handle;
			}

		public:

			UnZip(const File& file)
			: handle(Create(file)) {}

			UnZip(const void* buffer,uint size)
			: stream(buffer,size), handle(Create(stream)) {}

			~UnZip()
			{
				::unzClose( handle );
			}
		};

		class Archive::UnRar : public Codec
		{
		public:

			explicit UnRar(const Path&);

		private:

			class Dll : System::Dll
			{
				typedef HANDLE (PASCAL *OpenArchiveExFunc)(RAROpenArchiveDataEx*);
				typedef int    (PASCAL *CloseArchiveFunc)(HANDLE);
				typedef int    (PASCAL *ReadHeaderFunc)(HANDLE,RARHeaderData*);
				typedef int    (PASCAL *ReadHeaderExFunc)(HANDLE,RARHeaderDataEx*);
				typedef int    (PASCAL *ProcessFileFunc)(HANDLE,int,char*,char*);
				typedef int    (PASCAL *ProcessFileWFunc)(HANDLE,int,wchar_t*,wchar_t*);
				typedef void   (PASCAL *SetProcessDataProcFunc)(HANDLE,PROCESSDATAPROC);

			public:

				OpenArchiveExFunc      OpenArchiveEx;
				CloseArchiveFunc       CloseArchive;
				ReadHeaderFunc         ReadHeader;
				ReadHeaderExFunc       ReadHeaderEx;
				ProcessFileFunc        ProcessFile;
				ProcessFileWFunc       ProcessFileW;
				SetProcessDataProcFunc SetProcessDataProc;

				bool Load()
				{
					if (*this)
					{
						return true;
					}
					else if (System::Dll::Load( L"unrar.dll" ))
					{
						if
						(
							NULL != (OpenArchiveEx      = Fetch< OpenArchiveExFunc      >( "RAROpenArchiveEx"      )) &&
							NULL != (CloseArchive       = Fetch< CloseArchiveFunc       >( "RARCloseArchive"       )) &&
							NULL != (ReadHeader         = Fetch< ReadHeaderFunc         >( "RARReadHeader"         )) &&
							NULL != (ReadHeaderEx       = Fetch< ReadHeaderExFunc       >( "RARReadHeaderEx"       )) &&
							NULL != (ProcessFile        = Fetch< ProcessFileFunc        >( "RARProcessFile"        )) &&
							NULL != (ProcessFileW       = Fetch< ProcessFileWFunc       >( "RARProcessFileW"       )) &&
							NULL != (SetProcessDataProc = Fetch< SetProcessDataProcFunc >( "RARSetProcessDataProc" ))
						)
							return true;

						Unload();
					}

					return false;
				}
			};

			static Dll dll;

			void* Open(uint);
			uint  Extract(uint,void*,uint);
			bool  Build(Items&);

			Path path;
		};

		Archive::UnRar::Dll Archive::UnRar::dll;

		Archive::UnRar::UnRar(const Path& string)
		: path(string)
		{
			if (!dll.Load())
				throw ERR_DLL;
		}

		void* Archive::UnRar::Open(uint mode)
		{
			Object::Pod<RAROpenArchiveDataEx> data;

			data.ArcName = NULL;
			data.ArcNameW = path.Ptr();
			data.OpenMode = mode;
			data.CmtBuf = NULL;

			return dll.OpenArchiveEx( &data );
		}

		bool Archive::UnRar::Build(Items& files)
		{
			if (void* const handle = Open( RAR_OM_LIST ))
			{
				try
				{
					Object::Pod<RARHeaderDataEx> header;

					for (uint i=0; dll.ReadHeaderEx( handle, &header ) == 0; ++i)
					{
						if (header.UnpSize && *header.FileName)
							files.push_back( Item(this,header.FileNameW,header.UnpSize,i) );

						if (dll.ProcessFile( handle, RAR_SKIP, NULL, NULL ))
							break;
					}
				}
				catch (...)
				{
					files.clear();
				}

				dll.CloseArchive( handle );

				return !files.empty();
			}

			return false;
		}

		uint Archive::UnRar::Extract(uint index,void* buffer,uint size)
		{
			static struct
			{
				uchar* buffer;
				uint pos;
				uint size;
			}   stream;

			struct Callback
			{
				static int PASCAL OnRead(uchar* input,int size)
				{
					if (input && size > 0 && size <= stream.size)
					{
						std::memcpy( stream.buffer + stream.pos, input, size );
						stream.pos += size;
						return 1;
					}
					else
					{
						return 0;
					}
				};
			};

			uint extracted = 0;

			if (void* const handle = Open( RAR_OM_EXTRACT ))
			{
				stream.buffer = static_cast<uchar*>(buffer);
				stream.pos = 0;
				stream.size = size;

				dll.SetProcessDataProc( handle, Callback::OnRead );

				try
				{
					Object::Pod<RARHeaderData> header;
					header.CmtBuf = NULL;

					for (uint i=0; ; ++i)
					{
						if (dll.ReadHeader( handle, &header ))
							break;

						if (i < index)
						{
							if (dll.ProcessFile( handle, RAR_SKIP, NULL, NULL ))
								break;
						}
						else
						{
							Path path( Application::Instance::GetTmpPath() );

							if (dll.ProcessFileW( handle, RAR_EXTRACT, NULL, path.Ptr() ) == 0)
							{
								if (stream.pos == stream.size)
									extracted = size;

								if (!File::Delete( path.Ptr() ))
									Log() << "Archive: warning, couldn't delete temporary RAR file: " << path << '!';
							}

							break;
						}
					}
				}
				catch (...)
				{
				}

				dll.CloseArchive( handle );
			}

			return extracted;
		}

		class Archive::Un7zip : public Codec
		{
		public:

			explicit Un7zip(const File&);
			Un7zip(const void*,uint);

		private:

			~Un7zip();

			IInArchive& archive;
			IInStream* const stream;

			static IInArchive* Create();

			class InStream : public IInStream, private IStreamGetSize
			{
				ulong refCount;

				HRESULT STDMETHODCALLTYPE QueryInterface(REFGUID,void**)
				{
					return E_NOINTERFACE;
				}

				HRESULT STDMETHODCALLTYPE GetSize(UInt64* save)
				{
					if (save)
					{
						*save = size;
						return S_OK;
					}
					else
					{
						return E_INVALIDARG;
					}
				}

				ulong STDMETHODCALLTYPE AddRef()
				{
					return ++refCount;
				}

				ulong STDMETHODCALLTYPE Release()
				{
					return --refCount;
				}

			protected:

				const uint size;

			public:

				explicit InStream(uint s)
				: refCount(0), size(s) {}
			};

			class InFileStream : public InStream
			{
				const File& file;

				HRESULT STDMETHODCALLTYPE Read(void* data,UInt32 length,UInt32* save)
				{
					if (data != NULL || length == 0)
					{
						try
						{
							length = file.ReadSome( data, length );
						}
						catch (File::Exception)
						{
							return E_FAIL;
						}

						if (save)
							*save = length;

						return S_OK;
					}
					else
					{
						return E_INVALIDARG;
					}
				}

				HRESULT STDMETHODCALLTYPE Seek(Int64 offset,UInt32 origin,UInt64* pos)
				{
					NST_COMPILE_ASSERT( File::BEGIN == 0 && File::CURRENT == 1 && File::END == 2 );

					if (origin < 3)
					{
						try
						{
							origin = file.Seek( static_cast<File::Offset>(origin), int(offset) );
						}
						catch (File::Exception)
						{
							return E_FAIL;
						}

						if (pos)
							*pos = origin;

						return S_OK;
					}
					else
					{
						return E_INVALIDARG;
					}
				}

			public:

				explicit InFileStream(const File& f)
				: InStream(f.Size()), file(f) {}
			};

			class InMemStream : public InStream
			{
				const uchar* const buffer;
				uint pos;

				HRESULT STDMETHODCALLTYPE Read(void* data,UInt32 length,UInt32* save)
				{
					if (data != NULL || length == 0)
					{
						if (length > size - pos)
							length = size - pos;

						std::memcpy( data, buffer + pos, length );
						pos += length;

						if (save)
							*save = length;

						return S_OK;
					}
					else
					{
						return E_INVALIDARG;
					}
				}

				HRESULT STDMETHODCALLTYPE Seek(Int64 offset,UInt32 origin,UInt64* save)
				{
					if (origin < 3)
					{
						pos = (origin == 0 ? 0 : origin == 1 ? pos : size) + int(offset);

						if (pos > size)
							pos = size;

						if (save)
							*save = pos;

						return S_OK;
					}
					else
					{
						return E_INVALIDARG;
					}
				}

			public:

				InMemStream(const void* b,uint s)
				: InStream(s), buffer(static_cast<const uchar*>(b)), pos(0) {}
			};

			class OutStream : public IArchiveExtractCallback
			{
				class SeqStream : public ISequentialOutStream
				{
					uchar* const output;
					uint pos;
					const uint size;
					ulong refCount;

					HRESULT STDMETHODCALLTYPE QueryInterface(REFGUID,void**)
					{
						return E_NOINTERFACE;
					}

					HRESULT STDMETHODCALLTYPE Write(const void* data,UInt32 length,UInt32* save)
					{
						if (data != NULL || size == 0)
						{
							NST_VERIFY( length <= size - pos );

							if (length > size - pos)
								length = size - pos;

							std::memcpy( output + pos, data, length );
							pos += length;

							if (save)
								*save = length;

							return S_OK;
						}
						else
						{
							return E_INVALIDARG;
						}
					}

					ulong STDMETHODCALLTYPE AddRef()
					{
						return ++refCount;
					}

					ulong STDMETHODCALLTYPE Release()
					{
						return --refCount;
					}

				public:

					SeqStream(void* d,uint s)
					: output(static_cast<uchar*>(d)), pos(0), size(s), refCount(0) {}

					uint Size() const
					{
						return pos;
					}
				};

				SeqStream seqStream;
				const uint index;
				ulong refCount;

				HRESULT STDMETHODCALLTYPE QueryInterface(REFGUID,void**)
				{
					return E_NOINTERFACE;
				}

				HRESULT STDMETHODCALLTYPE PrepareOperation(Int32)
				{
					return S_OK;
				}

				HRESULT STDMETHODCALLTYPE SetTotal(UInt64)
				{
					return S_OK;
				}

				HRESULT STDMETHODCALLTYPE SetCompleted(const UInt64*)
				{
					return S_OK;
				}

				HRESULT STDMETHODCALLTYPE SetOperationResult(Int32)
				{
					return S_OK;
				}

				HRESULT STDMETHODCALLTYPE GetStream(UInt32 id,ISequentialOutStream** ptr,Int32 mode)
				{
					switch (mode)
					{
						case NArchive::NExtract::NAskMode::kExtract:
						case NArchive::NExtract::NAskMode::kTest:

							if (id != index || ptr == NULL)
								return S_FALSE;
							else
								*ptr = &seqStream;

						case NArchive::NExtract::NAskMode::kSkip:
							return S_OK;

						default:
							return E_INVALIDARG;
					}
				}

				ulong STDMETHODCALLTYPE AddRef()
				{
					return ++refCount;
				}

				ulong STDMETHODCALLTYPE Release()
				{
					return --refCount;
				}

			public:

				OutStream(uint index,void* data,uint size)
				: seqStream(data,size), index(index), refCount(0) {}

				uint Size() const
				{
					return seqStream.Size();
				}
			};

			void Open();
			void Close();
			bool Build(Items&);
			uint Extract(uint,void*,uint);
		};

		IInArchive* Archive::Un7zip::Create()
		{
			static System::Dll dll;

			if (!dll && !dll.Load( L"7zxa.dll" ))
				throw ERR_DLL;

			typedef UINT32 (WINAPI *CreateObjectFunc)(const GUID*,const GUID*,void**);
			CreateObjectFunc const CreateObject = dll.Fetch<CreateObjectFunc>("CreateObject");

			void* object;

			if (CreateObject == NULL || FAILED(CreateObject( &CLSID_CFormat7z, &IID_IInArchive, &object )))
				throw ERR_CREATE;

			return static_cast<IInArchive*>(object);
		}

		Archive::Un7zip::Un7zip(const void* data,uint size)
		: archive(*Create()), stream(new (std::nothrow) InMemStream(data,size))
		{
			Open();
		}

		Archive::Un7zip::Un7zip(const File& file)
		: archive(*Create()), stream(new (std::nothrow) InFileStream(file))
		{
			Open();
		}

		Archive::Un7zip::~Un7zip()
		{
			Close();
		}

		void Archive::Un7zip::Open()
		{
			if (stream)
			{
				try
				{
					if (SUCCEEDED(archive.Open( stream, NULL, NULL )))
						return;
				}
				catch (...)
				{
				}

				delete stream;
			}

			archive.Release();

			throw ERR_OPEN;
		}

		void Archive::Un7zip::Close()
		{
			archive.Close();
			delete stream;
			archive.Release();
		}

		bool Archive::Un7zip::Build(Items& files)
		{
			UInt32 numFiles;

			if (SUCCEEDED(archive.GetNumberOfItems( &numFiles )) && numFiles)
			{
				files.reserve( numFiles );

				Path path;
				PROPVARIANT prop;

				for (uint i=0; i < numFiles; ++i)
				{
					prop.vt = VT_EMPTY;

					if (FAILED(archive.GetProperty( i, kpidSize, &prop )) || prop.vt != VT_UI8 || !prop.uhVal.LowPart || prop.uhVal.HighPart)
						continue;

					const uint size = prop.uhVal.LowPart;

					prop.vt = VT_EMPTY;

					if (FAILED(archive.GetProperty( i, kpidPath, &prop )) || prop.vt != VT_BSTR || prop.bstrVal == NULL)
						continue;

					path = prop.bstrVal;

					::VariantClear( reinterpret_cast<VARIANTARG*>(&prop) );

					if (path.Length())
						files.push_back( Item(this,path.Ptr(),size,i) );
				}
			}

			return false;
		}

		uint Archive::Un7zip::Extract(uint index,void* data,uint size)
		{
			NST_ASSERT( data );

			OutStream outStream( index, data, size );
			const UInt32 indices[1] = {index};

			if (SUCCEEDED(archive.Extract( indices, sizeof(array(indices)), 0, &outStream )) && outStream.Size() == size)
				return size;
			else
				return 0;
		}

		Archive::Archive()
		: codec(NULL)
		{
		}

		Archive::Archive(const File& file)
		: codec(NULL)
		{
			Open( &file, NULL, 0 );
		}

		Archive::Archive(const void* raw,uint size)
		: codec(NULL)
		{
			Open( NULL, raw, size );
		}

		Archive::~Archive()
		{
			Close();
		}

		bool Archive::Open(const File& file)
		{
			Close();
			return Open( &file, NULL, 0 );
		}

		bool Archive::Open(const void* raw,uint size)
		{
			Close();
			return Open( NULL, raw, size );
		}

		bool Archive::Open(const File* const file,const void* const raw,uint size)
		{
			try
			{
				if (raw)
				{
					if (size >= 4)
					{
						switch (FourCC<>::T(static_cast<const uchar*>(raw)))
						{
							case FILE_ID_ZIP:

								codec = new UnZip( raw, size );
								break;

							case FILE_ID_7Z:

								codec = new Un7zip( raw, size );
								break;
						}
					}
				}
				else switch (file->Peek32())
				{
					case FILE_ID_ZIP:

						codec = new UnZip( *file );
						break;

					case FILE_ID_7Z:

						codec = new Un7zip( *file );
						break;

					case FILE_ID_RAR:

						codec = new UnRar( file->GetName() );
						break;
				}

				return codec ? codec->Build( files ) : false;
			}
			catch (...)
			{
			}

			Close();

			return false;
		}

		void Archive::Close()
		{
			if (codec)
			{
				delete codec;
				codec = NULL;
			}

			files.clear();
		}

		inline Archive::Item::Item
		(
			Codec* const c,
			wcstring const n,
			const uint s,
			const uint i
		)
		:
		codec ( c ),
		name  ( n ),
		size  ( s ),
		index ( i )
		{}

		uint Archive::Item::Uncompress(void* const data) const
		{
			NST_ASSERT( data && codec && size );
			return codec->Extract( index, data, size );
		}

		uint Archive::Find(const GenericString name) const
		{
			for (uint i=0, n=files.size(); i < n; ++i)
			{
				if (files[i].GetName() == name)
					return i+1;
			}

			return NO_FILES;
		}

		uint Archive::UserSelect() const
		{
			if (files.empty())
			{
				return NO_FILES;
			}
			else if (files.size() == 1)
			{
				return FIRST_FILE;
			}
			else
			{
				std::vector<wcstring> names( files.size() );

				for (uint i=0, n=names.size(); i < n; ++i)
					names[i] = files[i].GetName().Ptr();

				return Window::User::Choose( IDS_CHOOSE_FILE, IDS_TEXT_ABORT, &names.front(), names.size() );
			}
		}

		uint Archive::UserSelect(const GenericString* const filter,const uint count) const
		{
			if (filter && count)
			{
				std::vector<wcstring> names;
				std::vector<uint> indices;

				for (Items::const_iterator it(files.begin()), end(files.end()); it != end; ++it)
				{
					const GenericString extension( it->GetName().Extension() );

					for (uint i=0; i < count; ++i)
					{
						if (filter[i] == extension)
						{
							indices.push_back( it - files.begin() );
							names.push_back( it->GetName().Ptr() );
							break;
						}
					}
				}

				if (names.empty())
				{
					return NO_FILES;
				}
				else if (names.size() == 1)
				{
					return indices.front() + 1;
				}
				else
				{
					return Window::User::Choose
					(
						IDS_CHOOSE_FILE,
						IDS_TEXT_ABORT,
						&names.front(),
						names.size(),
						&indices.front()
					);
				}
			}
			else
			{
				return UserSelect();
			}
		}
	}
}