/*
** w_wad.cpp
**
**---------------------------------------------------------------------------
** Copyright 1998-2009 Randy Heit
** Copyright 2005-2009 Christoph Oelckers
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1. Redistributions of source code must retain the above copyright
**    notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
**    notice, this list of conditions and the following disclaimer in the
**    documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
**    derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**---------------------------------------------------------------------------
**
**
*/


// HEADER FILES ------------------------------------------------------------

#include <stdlib.h>
#include <ctype.h>
#include <string.h>

#include "doomtype.h"
#include "m_argv.h"
#include "cmdlib.h"
#include "c_dispatch.h"
#include "w_wad.h"
#include "m_crc32.h"
#include "v_text.h"
#include "gi.h"
#include "resourcefiles/resourcefile.h"
#include "md5.h"
#include "doomstat.h"
#include "vm.h"

// MACROS ------------------------------------------------------------------

#define NULL_INDEX		(0xffffffff)

//
// WADFILE I/O related stuff.
//

union LumpShortName
{
	char		String[9];

	uint32_t		dword;			// These are for accessing the first 4 or 8 chars of
	uint64_t		qword;			// Name as a unit without breaking strict aliasing rules
};


struct FileSystem::LumpRecord
{
	FResourceLump *lump;
	FTexture* linkedTexture;
	LumpShortName shortName;
	FString		longName;
	int			wadnum;
	int			Namespace;
	int			resourceId;

	void SetFromLump(int filenum, FResourceLump* lmp)
	{
		lump = lmp;
		wadnum = filenum;
		linkedTexture = nullptr;

		if (lump->Flags & LUMPF_SHORTNAME)
		{
			uppercopy(shortName.String, lump->getName());
			shortName.String[8] = 0;
			longName = "";
			Namespace = lump->GetNamespace();
			resourceId = 0;

			if (gameinfo.gametype == GAME_Strife && gameinfo.flags & GI_SHAREWARE && filenum == fileSystem.GetIwadNum())
			{
				if (shortName.String[0] == 'V' &&
					shortName.String[1] == 'O' &&
					shortName.String[2] == 'C')
				{
					int j;

					for (j = 3; j < 8; ++j)
					{
						if (shortName.String[j] != 0 && !isdigit(shortName.String[j]))
							break;
					}
					if (j == 8)
					{
						Namespace = ns_strifevoices;
					}
				}
			}

		}
		else if ((lump->Flags & LUMPF_EMBEDDED) || !lump->getName() || !*lump->getName())
		{
			shortName.qword = 0;
			longName = "";
			Namespace = ns_hidden;
			resourceId = 0;
		}
		else
		{
			longName = lump->getName();
			resourceId = lump->GetIndexNum();

			// Map some directories to WAD namespaces.
			// Note that some of these namespaces don't exist in WADS.
			// CheckNumForName will handle any request for these namespaces accordingly.
			Namespace = !strncmp(longName.GetChars(), "flats/", 6) ? ns_flats :
				!strncmp(longName.GetChars(), "textures/", 9) ? ns_newtextures :
				!strncmp(longName.GetChars(), "hires/", 6) ? ns_hires :
				!strncmp(longName.GetChars(), "sprites/", 8) ? ns_sprites :
				!strncmp(longName.GetChars(), "voxels/", 7) ? ns_voxels :
				!strncmp(longName.GetChars(), "colormaps/", 10) ? ns_colormaps :
				!strncmp(longName.GetChars(), "acs/", 4) ? ns_acslibrary :
				!strncmp(longName.GetChars(), "voices/", 7) ? ns_strifevoices :
				!strncmp(longName.GetChars(), "patches/", 8) ? ns_patches :
				!strncmp(longName.GetChars(), "graphics/", 9) ? ns_graphics :
				!strncmp(longName.GetChars(), "sounds/", 7) ? ns_sounds :
				!strncmp(longName.GetChars(), "music/", 6) ? ns_music :
				!strchr(longName.GetChars(), '/') ? ns_global :
				ns_hidden;

			if (Namespace == ns_hidden) shortName.qword = 0;
			else
			{
				long slash = longName.LastIndexOf('/');
				FString base = (slash >= 0) ? longName.Mid(slash + 1) : longName;
				auto dot = base.LastIndexOf('.');
				if (dot >= 0) base.Truncate(dot);
				uppercopy(shortName.String, base);
				shortName.String[8] = 0;

				// Since '\' can't be used as a file name's part inside a ZIP
				// we have to work around this for sprites because it is a valid
				// frame character.
				if (Namespace == ns_sprites || Namespace == ns_voxels || Namespace == ns_hires)
				{
					char* c;

					while ((c = (char*)memchr(shortName.String, '^', 8)))
					{
						*c = '\\';
					}
				}
			}
		}
	}
};

// EXTERNAL FUNCTION PROTOTYPES --------------------------------------------
extern bool nospriterename;

// PUBLIC FUNCTION PROTOTYPES ----------------------------------------------

// PRIVATE FUNCTION PROTOTYPES ---------------------------------------------

static void PrintLastError ();

// PUBLIC DATA DEFINITIONS -------------------------------------------------

FileSystem fileSystem;

// PRIVATE DATA DEFINITIONS ------------------------------------------------

// CODE --------------------------------------------------------------------

void md5Update(FileReader& file, MD5Context &md5, unsigned len)
{
	uint8_t readbuf[8192];
	unsigned t;

	while (len > 0)
	{
		t = std::min<unsigned>(len, sizeof(readbuf));
		len -= t;
		t = (long)file.Read(readbuf, t);
		md5.Update(readbuf, t);
	}
}


//==========================================================================
//
// uppercoppy
//
// [RH] Copy up to 8 chars, upper-casing them in the process
//==========================================================================

void uppercopy (char *to, const char *from)
{
	int i;

	for (i = 0; i < 8 && from[i]; i++)
		to[i] = toupper (from[i]);
	for (; i < 8; i++)
		to[i] = 0;
}

FileSystem::FileSystem ()
{
}

FileSystem::~FileSystem ()
{
	DeleteAll();
}

void FileSystem::DeleteAll ()
{
	LumpInfo.Clear();
	NumLumps = 0;

	// we must count backward to ensure that embedded WADs are deleted before
	// the ones that contain their data.
	for (int i = Files.Size() - 1; i >= 0; --i)
	{
		delete Files[i];
	}
	Files.Clear();
}

//==========================================================================
//
// W_InitMultipleFiles
//
// Pass a null terminated list of files to use. All files are optional,
// but at least one file must be found. Lump names can appear multiple
// times. The name searcher looks backwards, so a later file can
// override an earlier one.
//
//==========================================================================

void FileSystem::InitSingleFile(const char* filename, bool quiet)
{
	TArray<FString> filenames;
	TArray<FString> deletes;
	filenames.Push(filename);
	InitMultipleFiles(filenames, deletes, true);
}

void FileSystem::InitMultipleFiles (TArray<FString> &filenames, const TArray<FString> &deletelumps, bool quiet, LumpFilterInfo* filter)
{
	int numfiles;

	// open all the files, load headers, and count lumps
	DeleteAll();
	numfiles = 0;

	for(unsigned i=0;i<filenames.Size(); i++)
	{
		int baselump = NumLumps;
		AddFile (filenames[i], nullptr, quiet, filter);
		
		if (i == (unsigned)MaxIwadIndex) MoveLumpsInFolder("after_iwad/");
		FStringf path("filter/%s", Files.Last()->GetHash().GetChars());
		MoveLumpsInFolder(path);
	}
	
	NumLumps = LumpInfo.Size();
	if (NumLumps == 0)
	{
		if (!quiet) I_FatalError("W_InitMultipleFiles: no files found");
		else return;
	}
	RenameNerve();
	RenameSprites(deletelumps);
	FixMacHexen();

	// [RH] Set up hash table
	Hashes.Resize(6 * NumLumps);
	FirstLumpIndex = &Hashes[0];
	NextLumpIndex = &Hashes[NumLumps];
	FirstLumpIndex_FullName = &Hashes[NumLumps*2];
	NextLumpIndex_FullName = &Hashes[NumLumps*3];
	FirstLumpIndex_NoExt = &Hashes[NumLumps*4];
	NextLumpIndex_NoExt = &Hashes[NumLumps*5];
	InitHashChains ();
	LumpInfo.ShrinkToFit();
	Files.ShrinkToFit();
}

//-----------------------------------------------------------------------
//
// Adds an external file to the lump list but not to the hash chains
// It's just a simple means to assign a lump number to some file so that
// the texture manager can read from it.
//
//-----------------------------------------------------------------------

int FileSystem::AddExternalFile(const char *filename)
{
	FResourceLump *lump = new FExternalLump(filename);

	FileSystem::LumpRecord *lumprec = &LumpInfo[LumpInfo.Reserve(1)];
	lumprec->SetFromLump(-1, lump);
	return LumpInfo.Size()-1;	// later
}

//==========================================================================
//
// W_AddFile
//
// Files with a .wad extension are wadlink files with multiple lumps,
// other files are single lumps with the base filename for the lump name.
//
// [RH] Removed reload hack
//==========================================================================

void FileSystem::AddFile (const char *filename, FileReader *wadr, bool quiet, LumpFilterInfo* filter)
{
	int startlump;
	bool isdir = false;
	FileReader wadreader;

	if (wadr == nullptr)
	{
		// Does this exist? If so, is it a directory?
		if (!DirEntryExists(filename, &isdir))
		{
			if (!quiet)
			{
				Printf(TEXTCOLOR_RED "%s: File or Directory not found\n", filename);
				PrintLastError();
			}
			return;
		}

		if (!isdir)
		{
			if (!wadreader.OpenFile(filename))
			{ // Didn't find file
				if (!quiet)
				{
					Printf(TEXTCOLOR_RED "%s: File not found\n", filename);
					PrintLastError();
				}
				return;
			}
		}
	}
	else wadreader = std::move(*wadr);

	if (!batchrun && !quiet) Printf (" adding %s", filename);
	startlump = NumLumps;

	FResourceFile *resfile;
	
	if (!isdir)
		resfile = FResourceFile::OpenResourceFile(filename, wadreader, quiet, false, filter);
	else
		resfile = FResourceFile::OpenDirectory(filename, quiet, filter);

	if (resfile != NULL)
	{
		if (!quiet && !batchrun) Printf(", %d lumps\n", resfile->LumpCount());

		uint32_t lumpstart = LumpInfo.Size();

		resfile->SetFirstLump(lumpstart);
		for (uint32_t i=0; i < resfile->LumpCount(); i++)
		{
			FResourceLump *lump = resfile->GetLump(i);
			FileSystem::LumpRecord *lump_p = &LumpInfo[LumpInfo.Reserve(1)];
			lump_p->SetFromLump(Files.Size(), lump);
		}

		Files.Push(resfile);

		for (uint32_t i=0; i < resfile->LumpCount(); i++)
		{
			FResourceLump *lump = resfile->GetLump(i);
			if (lump->Flags & LUMPF_EMBEDDED)
			{
				FString path;
				path.Format("%s:%s", filename, lump->getName());
				auto embedded = lump->NewReader();
				AddFile(path, &embedded, quiet, filter);
			}
		}

		if (hashfile && !quiet)
		{
			uint8_t cksum[16];
			char cksumout[33];
			memset(cksumout, 0, sizeof(cksumout));

			if (wadreader.isOpen())
			{
				MD5Context md5;
				wadreader.Seek(0, FileReader::SeekSet);
				md5Update(wadreader, md5, (unsigned)wadreader.GetLength());
				md5.Final(cksum);

				for (size_t j = 0; j < sizeof(cksum); ++j)
				{
					sprintf(cksumout + (j * 2), "%02X", cksum[j]);
				}

				fprintf(hashfile, "file: %s, hash: %s, size: %d\n", filename, cksumout, (int)wadreader.GetLength());
			}

			else
				fprintf(hashfile, "file: %s, Directory structure\n", filename);

			for (uint32_t i = 0; i < resfile->LumpCount(); i++)
			{
				FResourceLump *lump = resfile->GetLump(i);

				if (!(lump->Flags & LUMPF_EMBEDDED))
				{
					MD5Context md5;
					auto reader = lump->NewReader();
					md5Update(reader, md5, lump->LumpSize);
					md5.Final(cksum);

					for (size_t j = 0; j < sizeof(cksum); ++j)
					{
						sprintf(cksumout + (j * 2), "%02X", cksum[j]);
					}

					fprintf(hashfile, "file: %s, lump: %s, hash: %s, size: %d\n", filename, lump->getName(), cksumout, lump->LumpSize);
				}
			}
		}
		return;
	}
}

//==========================================================================
//
// W_CheckIfWadLoaded
//
// Returns true if the specified wad is loaded, false otherwise.
// If a fully-qualified path is specified, then the wad must match exactly.
// Otherwise, any wad with that name will work, whatever its path.
// Returns the wads index if found, or -1 if not.
//
//==========================================================================

int FileSystem::CheckIfWadLoaded (const char *name)
{
	unsigned int i;

	if (strrchr (name, '/') != NULL)
	{
		for (i = 0; i < Files.Size(); ++i)
		{
			if (stricmp (GetWadFullName (i), name) == 0)
			{
				return i;
			}
		}
	}
	else
	{
		for (i = 0; i < Files.Size(); ++i)
		{
			if (stricmp (GetWadName (i), name) == 0)
			{
				return i;
			}
		}
	}
	return -1;
}

//==========================================================================
//
// W_NumLumps
//
//==========================================================================

DEFINE_ACTION_FUNCTION(_Wads, GetNumLumps)
{
	PARAM_PROLOGUE;
	ACTION_RETURN_INT(fileSystem.GetNumLumps());
}

//==========================================================================
//
// W_CheckNumForName
//
// Returns -1 if name not found. The version with a third parameter will
// look exclusively in the specified wad for the lump.
//
// [RH] Changed to use hash lookup ala BOOM instead of a linear search
// and namespace parameter
//==========================================================================

int FileSystem::CheckNumForName (const char *name, int space)
{
	union
	{
		char uname[8];
		uint64_t qname;
	};
	uint32_t i;

	if (name == NULL)
	{
		return -1;
	}

	// Let's not search for names that are longer than 8 characters and contain path separators
	// They are almost certainly full path names passed to this function.
	if (strlen(name) > 8 && strpbrk(name, "/."))
	{
		return -1;
	}

	uppercopy (uname, name);
	i = FirstLumpIndex[LumpNameHash (uname) % NumLumps];

	while (i != NULL_INDEX)
	{

		if (LumpInfo[i].shortName.qword == qname)
		{
			auto &lump = LumpInfo[i];
			if (lump.Namespace == space) break;
			// If the lump is from one of the special namespaces exclusive to Zips
			// the check has to be done differently:
			// If we find a lump with this name in the global namespace that does not come
			// from a Zip return that. WADs don't know these namespaces and single lumps must
			// work as well.
			if (space > ns_specialzipdirectory && lump.Namespace == ns_global && 
				!(lump.lump->Flags & LUMPF_FULLPATH)) break;
		}
		i = NextLumpIndex[i];
	}

	return i != NULL_INDEX ? i : -1;
}

int FileSystem::CheckNumForName (const char *name, int space, int wadnum, bool exact)
{
	union
	{
		char uname[8];
		uint64_t qname;
	};
	uint32_t i;

	if (wadnum < 0)
	{
		return CheckNumForName (name, space);
	}

	uppercopy (uname, name);
	i = FirstLumpIndex[LumpNameHash (uname) % NumLumps];

	// If exact is true if will only find lumps in the same WAD, otherwise
	// also those in earlier WADs.

	while (i != NULL_INDEX &&
		(LumpInfo[i].shortName.qword != qname || LumpInfo[i].Namespace != space ||
		 (exact? (LumpInfo[i].wadnum != wadnum) : (LumpInfo[i].wadnum > wadnum)) ))
	{
		i = NextLumpIndex[i];
	}

	return i != NULL_INDEX ? i : -1;
}

DEFINE_ACTION_FUNCTION(_Wads, CheckNumForName)
{
	PARAM_PROLOGUE;
	PARAM_STRING(name);
	PARAM_INT(ns);
	PARAM_INT(wadnum);
	PARAM_BOOL(exact);
	ACTION_RETURN_INT(fileSystem.CheckNumForName(name, ns, wadnum, exact));
}
//==========================================================================
//
// W_GetNumForName
//
// Calls W_CheckNumForName, but bombs out if not found.
//
//==========================================================================

int FileSystem::GetNumForName (const char *name, int space)
{
	int	i;

	i = CheckNumForName (name, space);

	if (i == -1)
		I_Error ("GetNumForName: %s not found!", name);

	return i;
}


//==========================================================================
//
// W_CheckNumForFullName
//
// Same as above but looks for a fully qualified name from a .zip
// These don't care about namespaces though because those are part
// of the path.
//
//==========================================================================

int FileSystem::CheckNumForFullName (const char *name, bool trynormal, int namespc, bool ignoreext)
{
	uint32_t i;

	if (name == NULL)
	{
		return -1;
	}
	uint32_t *fli = ignoreext ? FirstLumpIndex_NoExt : FirstLumpIndex_FullName;
	uint32_t *nli = ignoreext ? NextLumpIndex_NoExt : NextLumpIndex_FullName;
	auto len = strlen(name);

	for (i = fli[MakeKey(name) % NumLumps]; i != NULL_INDEX; i = nli[i])
	{
		if (strnicmp(name, LumpInfo[i].longName, len)) continue;
		if (LumpInfo[i].longName[len] == 0) break;	// this is a full match
		if (ignoreext && LumpInfo[i].longName[len] == '.') 
		{
			// is this the last '.' in the last path element, indicating that the remaining part of the name is only an extension?
			if (strpbrk(LumpInfo[i].longName.GetChars() + len + 1, "./") == nullptr) break;	
		}
	}

	if (i != NULL_INDEX) return i;

	if (trynormal && strlen(name) <= 8 && !strpbrk(name, "./"))
	{
		return CheckNumForName(name, namespc);
	}
	return -1;
}

DEFINE_ACTION_FUNCTION(_Wads, CheckNumForFullName)
{
	PARAM_PROLOGUE;
	PARAM_STRING(name);
	ACTION_RETURN_INT(fileSystem.CheckNumForFullName(name));
}

int FileSystem::CheckNumForFullName (const char *name, int wadnum)
{
	uint32_t i;

	if (wadnum < 0)
	{
		return CheckNumForFullName (name);
	}

	i = FirstLumpIndex_FullName[MakeKey (name) % NumLumps];

	while (i != NULL_INDEX && 
		(stricmp(name, LumpInfo[i].longName) || LumpInfo[i].wadnum != wadnum))
	{
		i = NextLumpIndex_FullName[i];
	}

	return i != NULL_INDEX ? i : -1;
}

//==========================================================================
//
// W_GetNumForFullName
//
// Calls W_CheckNumForFullName, but bombs out if not found.
//
//==========================================================================

int FileSystem::GetNumForFullName (const char *name)
{
	int	i;

	i = CheckNumForFullName (name);

	if (i == -1)
		I_Error ("GetNumForFullName: %s not found!", name);

	return i;
}

//==========================================================================
//
// link a texture with a given lump
//
//==========================================================================

void FileSystem::SetLinkedTexture(int lump, FTexture *tex)
{
	if ((size_t)lump < NumLumps)
	{
		LumpInfo[lump].linkedTexture = tex;
	}
}

//==========================================================================
//
// retrieve linked texture
//
//==========================================================================

FTexture *FileSystem::GetLinkedTexture(int lump)
{
	if ((size_t)lump < NumLumps)
	{
		return LumpInfo[lump].linkedTexture;
	}
	return NULL;
}

//==========================================================================
//
// W_LumpLength
//
// Returns the buffer size needed to load the given lump.
//
//==========================================================================

int FileSystem::LumpLength (int lump) const
{
	if ((size_t)lump >= NumLumps)
	{
		I_Error ("W_LumpLength: %i >= NumLumps",lump);
	}

	return LumpInfo[lump].lump->LumpSize;
}

//==========================================================================
//
// GetLumpOffset
//
// Returns the offset from the beginning of the file to the lump.
// Returns -1 if the lump is compressed or can't be read directly
//
//==========================================================================

int FileSystem::GetLumpOffset (int lump)
{
	if ((size_t)lump >= NumLumps)
	{
		I_Error ("GetLumpOffset: %i >= NumLumps",lump);
	}

	return LumpInfo[lump].lump->GetFileOffset();
}

//==========================================================================
//
// GetLumpOffset
//
//==========================================================================

int FileSystem::GetLumpFlags (int lump)
{
	if ((size_t)lump >= NumLumps)
	{
		return 0;
	}

	return LumpInfo[lump].lump->Flags;
}

//==========================================================================
//
// W_LumpNameHash
//
// NOTE: s should already be uppercase, in contrast to the BOOM version.
//
// Hash function used for lump names.
// Must be mod'ed with table size.
// Can be used for any 8-character names.
//
//==========================================================================

uint32_t FileSystem::LumpNameHash (const char *s)
{
	const uint32_t *table = GetCRCTable ();;
	uint32_t hash = 0xffffffff;
	int i;

	for (i = 8; i > 0 && *s; --i, ++s)
	{
		hash = CRC1 (hash, *s, table);
	}
	return hash ^ 0xffffffff;
}

//==========================================================================
//
// W_InitHashChains
//
// Prepares the lumpinfos for hashing.
// (Hey! This looks suspiciously like something from Boom! :-)
//
//==========================================================================

void FileSystem::InitHashChains (void)
{
	unsigned int i, j;

	// Mark all buckets as empty
	memset (FirstLumpIndex, 255, NumLumps*sizeof(FirstLumpIndex[0]));
	memset (NextLumpIndex, 255, NumLumps*sizeof(NextLumpIndex[0]));
	memset (FirstLumpIndex_FullName, 255, NumLumps*sizeof(FirstLumpIndex_FullName[0]));
	memset (NextLumpIndex_FullName, 255, NumLumps*sizeof(NextLumpIndex_FullName[0]));
	memset(FirstLumpIndex_NoExt, 255, NumLumps * sizeof(FirstLumpIndex_NoExt[0]));
	memset(NextLumpIndex_NoExt, 255, NumLumps * sizeof(NextLumpIndex_NoExt[0]));

	// Now set up the chains
	for (i = 0; i < (unsigned)NumLumps; i++)
	{
		j = LumpNameHash (LumpInfo[i].shortName.String) % NumLumps;
		NextLumpIndex[i] = FirstLumpIndex[j];
		FirstLumpIndex[j] = i;

		// Do the same for the full paths
		if (LumpInfo[i].longName.IsNotEmpty())
		{
			j = MakeKey(LumpInfo[i].longName) % NumLumps;
			NextLumpIndex_FullName[i] = FirstLumpIndex_FullName[j];
			FirstLumpIndex_FullName[j] = i;

			FString nameNoExt = LumpInfo[i].longName;
			auto dot = nameNoExt.LastIndexOf('.');
			auto slash = nameNoExt.LastIndexOf('/');
			if (dot > slash) nameNoExt.Truncate(dot);

			j = MakeKey(nameNoExt) % NumLumps;
			NextLumpIndex_NoExt[i] = FirstLumpIndex_NoExt[j];
			FirstLumpIndex_NoExt[j] = i;

		}
	}
}

//==========================================================================
//
// RenameSprites
//
// Renames sprites in IWADs so that unique actors can have unique sprites,
// making it possible to import any actor from any game into any other
// game without jumping through hoops to resolve duplicate sprite names.
// You just need to know what the sprite's new name is.
//
//==========================================================================

void FileSystem::RenameSprites (const TArray<FString> &deletelumps)
{
	bool renameAll;
	bool MNTRZfound = false;
	const char *altbigfont = gameinfo.gametype == GAME_Strife? "SBIGFONT" : (gameinfo.gametype & GAME_Raven)? "HBIGFONT" : "DBIGFONT";

	static const uint32_t HereticRenames[] =
	{ MAKE_ID('H','E','A','D'), MAKE_ID('L','I','C','H'),		// Ironlich
	};

	static const uint32_t HexenRenames[] =
	{ MAKE_ID('B','A','R','L'), MAKE_ID('Z','B','A','R'),		// ZBarrel
	  MAKE_ID('A','R','M','1'), MAKE_ID('A','R','_','1'),		// MeshArmor
	  MAKE_ID('A','R','M','2'), MAKE_ID('A','R','_','2'),		// FalconShield
	  MAKE_ID('A','R','M','3'), MAKE_ID('A','R','_','3'),		// PlatinumHelm
	  MAKE_ID('A','R','M','4'), MAKE_ID('A','R','_','4'),		// AmuletOfWarding
	  MAKE_ID('S','U','I','T'), MAKE_ID('Z','S','U','I'),		// ZSuitOfArmor and ZArmorChunk
	  MAKE_ID('T','R','E','1'), MAKE_ID('Z','T','R','E'),		// ZTree and ZTreeDead
	  MAKE_ID('T','R','E','2'), MAKE_ID('T','R','E','S'),		// ZTreeSwamp150
	  MAKE_ID('C','A','N','D'), MAKE_ID('B','C','A','N'),		// ZBlueCandle
	  MAKE_ID('R','O','C','K'), MAKE_ID('R','O','K','K'),		// rocks and dirt in a_debris.cpp
	  MAKE_ID('W','A','T','R'), MAKE_ID('H','W','A','T'),		// Strife also has WATR
	  MAKE_ID('G','I','B','S'), MAKE_ID('P','O','L','5'),		// RealGibs
	  MAKE_ID('E','G','G','M'), MAKE_ID('P','R','K','M'),		// PorkFX
	  MAKE_ID('I','N','V','U'), MAKE_ID('D','E','F','N'),		// Icon of the Defender
	};

	static const uint32_t StrifeRenames[] =
	{ MAKE_ID('M','I','S','L'), MAKE_ID('S','M','I','S'),		// lots of places
	  MAKE_ID('A','R','M','1'), MAKE_ID('A','R','M','3'),		// MetalArmor
	  MAKE_ID('A','R','M','2'), MAKE_ID('A','R','M','4'),		// LeatherArmor
	  MAKE_ID('P','M','A','P'), MAKE_ID('S','M','A','P'),		// StrifeMap
	  MAKE_ID('T','L','M','P'), MAKE_ID('T','E','C','H'),		// TechLampSilver and TechLampBrass
	  MAKE_ID('T','R','E','1'), MAKE_ID('T','R','E','T'),		// TreeStub
	  MAKE_ID('B','A','R','1'), MAKE_ID('B','A','R','C'),		// BarricadeColumn
	  MAKE_ID('S','H','T','2'), MAKE_ID('M','P','U','F'),		// MaulerPuff
	  MAKE_ID('B','A','R','L'), MAKE_ID('B','B','A','R'),		// StrifeBurningBarrel
	  MAKE_ID('T','R','C','H'), MAKE_ID('T','R','H','L'),		// SmallTorchLit
	  MAKE_ID('S','H','R','D'), MAKE_ID('S','H','A','R'),		// glass shards
	  MAKE_ID('B','L','S','T'), MAKE_ID('M','A','U','L'),		// Mauler
	  MAKE_ID('L','O','G','G'), MAKE_ID('L','O','G','W'),		// StickInWater
	  MAKE_ID('V','A','S','E'), MAKE_ID('V','A','Z','E'),		// Pot and Pitcher
	  MAKE_ID('C','N','D','L'), MAKE_ID('K','N','D','L'),		// Candle
	  MAKE_ID('P','O','T','1'), MAKE_ID('M','P','O','T'),		// MetalPot
	  MAKE_ID('S','P','I','D'), MAKE_ID('S','T','L','K'),		// Stalker
	};

	const uint32_t *renames;
	int numrenames;

	switch (gameinfo.gametype)
	{
	case GAME_Doom:
	default:
		// Doom's sprites don't get renamed.
		renames = nullptr;
		numrenames = 0;
		break;

	case GAME_Heretic:
		renames = HereticRenames;
		numrenames = sizeof(HereticRenames)/8;
		break;

	case GAME_Hexen:
		renames = HexenRenames;
		numrenames = sizeof(HexenRenames)/8;
		break;

	case GAME_Strife:
		renames = StrifeRenames;
		numrenames = sizeof(StrifeRenames)/8;
		break;
	}


	for (uint32_t i=0; i< LumpInfo.Size(); i++)
	{
		// check for full Minotaur animations. If this is not found
		// some frames need to be renamed.
		if (LumpInfo[i].Namespace == ns_sprites)
		{
			if (LumpInfo[i].shortName.dword == MAKE_ID('M', 'N', 'T', 'R') && LumpInfo[i].shortName.String[4] == 'Z' )
			{
				MNTRZfound = true;
				break;
			}
		}
	}

	renameAll = !!Args->CheckParm ("-oldsprites") || nospriterename;
	
	for (uint32_t i = 0; i < LumpInfo.Size(); i++)
	{
		if (LumpInfo[i].Namespace == ns_sprites)
		{
			// Only sprites in the IWAD normally get renamed
			if (renameAll || LumpInfo[i].wadnum == GetIwadNum())
			{
				for (int j = 0; j < numrenames; ++j)
				{
					if (LumpInfo[i].shortName.dword == renames[j*2])
					{
						LumpInfo[i].shortName.dword = renames[j*2+1];
					}
				}
				if (gameinfo.gametype == GAME_Hexen)
				{
					if (CheckLumpName(i, "ARTIINVU"))
					{
						LumpInfo[i].shortName.String[4] = 'D'; LumpInfo[i].shortName.String[5] = 'E';
						LumpInfo[i].shortName.String[6] = 'F'; LumpInfo[i].shortName.String[7] = 'N';
					}
				}
			}

			if (!MNTRZfound)
			{
				if (LumpInfo[i].shortName.dword == MAKE_ID('M', 'N', 'T', 'R'))
				{
					for (size_t fi : {4, 6})
					{
						if (LumpInfo[i].shortName.String[fi] >= 'F' && LumpInfo[i].shortName.String[fi] <= 'K')
						{
							LumpInfo[i].shortName.String[fi] += 'U' - 'F';
						}
					}
				}
			}
			
			// When not playing Doom rename all BLOD sprites to BLUD so that
			// the same blood states can be used everywhere
			if (!(gameinfo.gametype & GAME_DoomChex))
			{
				if (LumpInfo[i].shortName.dword == MAKE_ID('B', 'L', 'O', 'D'))
				{
					LumpInfo[i].shortName.dword = MAKE_ID('B', 'L', 'U', 'D');
				}
			}
		}
		else if (LumpInfo[i].Namespace == ns_global)
		{
			if (LumpInfo[i].wadnum >= GetIwadNum() && LumpInfo[i].wadnum <= GetMaxIwadNum() && deletelumps.Find(LumpInfo[i].shortName.String) < deletelumps.Size())
			{
				LumpInfo[i].shortName.String[0] = 0;	// Lump must be deleted from directory.
			}
			// Rename the game specific big font lumps so that the font manager does not have to do problematic special checks for them.
			else if (!strcmp(LumpInfo[i].shortName.String, altbigfont))
			{
				strcpy(LumpInfo[i].shortName.String, "BIGFONT");
			}
		}
	}
}

//==========================================================================
//
// RenameNerve
//
// Renames map headers and map name pictures in nerve.wad so as to load it
// alongside Doom II and offer both episodes without causing conflicts.
// MD5 checksum for NERVE.WAD: 967d5ae23daf45196212ae1b605da3b0 (3,819,855)
// MD5 checksum for Unity version of NERVE.WAD: 4214c47651b63ee2257b1c2490a518c9 (3,821,966)
//
//==========================================================================
void FileSystem::RenameNerve ()
{
	if (gameinfo.gametype != GAME_Doom)
		return;

	const int numnerveversions = 2;

	bool found = false;
	uint8_t cksum[16];
	static const uint8_t nerve[numnerveversions][16] = {
			{ 0x96, 0x7d, 0x5a, 0xe2, 0x3d, 0xaf, 0x45, 0x19,
				0x62, 0x12, 0xae, 0x1b, 0x60, 0x5d, 0xa3, 0xb0 },
			{ 0x42, 0x14, 0xc4, 0x76, 0x51, 0xb6, 0x3e, 0xe2,
				0x25, 0x7b, 0x1c, 0x24, 0x90, 0xa5, 0x18, 0xc9 }
		};
	size_t nervesize[numnerveversions] = { 3819855, 3821966 } ; // NERVE.WAD's file size
	int w = GetIwadNum();
	while (++w < GetNumWads())
	{
		auto fr = GetFileReader(w);
		int isizecheck = -1;
		if (fr == NULL)
		{
			continue;
		}
		for (int icheck = 0; icheck < numnerveversions; icheck++)
			if (fr->GetLength() == (long)nervesize[icheck])
				isizecheck = icheck;
		if (isizecheck == -1)
		{
			// Skip MD5 computation when there is a
			// cheaper way to know this is not the file
			continue;
		}
		fr->Seek(0, FileReader::SeekSet);
		MD5Context md5;
		md5Update(*fr, md5, (unsigned)fr->GetLength());
		md5.Final(cksum);
		if (memcmp(nerve[isizecheck], cksum, 16) == 0)
		{
			found = true;
			break;
		}
	}

	if (!found)
		return;

	for (int i = GetFirstLump(w); i <= GetLastLump(w); i++)
	{
		// Only rename the maps from NERVE.WAD
		assert(LumpInfo[i].wadnum == w);
		if (LumpInfo[i].shortName.dword == MAKE_ID('C', 'W', 'I', 'L'))
		{
			LumpInfo[i].shortName.String[0] = 'N';
		}
		else if (LumpInfo[i].shortName.dword == MAKE_ID('M', 'A', 'P', '0'))
		{
			LumpInfo[i].shortName.String[6] = LumpInfo[i].shortName.String[4];
			LumpInfo[i].shortName.String[5] = '0';
			LumpInfo[i].shortName.String[4] = 'L';
			LumpInfo[i].shortName.dword = MAKE_ID('L', 'E', 'V', 'E');
		}
	}
}

//==========================================================================
//
// FixMacHexen
//
// Discard all extra lumps in Mac version of Hexen IWAD (demo or full)
// to avoid any issues caused by names of these lumps, including:
//  * Wrong height of small font
//  * Broken life bar of mage class
//
//==========================================================================

void FileSystem::FixMacHexen()
{
	if (GAME_Hexen != gameinfo.gametype)
	{
		return;
	}

	FileReader *reader = GetFileReader(GetIwadNum());
	auto iwadSize = reader->GetLength();

	static const long DEMO_SIZE = 13596228;
	static const long BETA_SIZE = 13749984;
	static const long FULL_SIZE = 21078584;

	if (   DEMO_SIZE != iwadSize
		&& BETA_SIZE != iwadSize
		&& FULL_SIZE != iwadSize)
	{
		return;
	}

	reader->Seek(0, FileReader::SeekSet);

	uint8_t checksum[16];
	MD5Context md5;

	md5Update(*reader, md5, (unsigned)iwadSize);
	md5.Final(checksum);

	static const uint8_t HEXEN_DEMO_MD5[16] =
	{
		0x92, 0x5f, 0x9f, 0x50, 0x00, 0xe1, 0x7d, 0xc8,
		0x4b, 0x0a, 0x6a, 0x3b, 0xed, 0x3a, 0x6f, 0x31
	};

	static const uint8_t HEXEN_BETA_MD5[16] =
	{
		0x2a, 0xf1, 0xb2, 0x7c, 0xd1, 0x1f, 0xb1, 0x59,
		0xe6, 0x08, 0x47, 0x2a, 0x1b, 0x53, 0xe4, 0x0e
	};

	static const uint8_t HEXEN_FULL_MD5[16] =
	{
		0xb6, 0x81, 0x40, 0xa7, 0x96, 0xf6, 0xfd, 0x7f,
		0x3a, 0x5d, 0x32, 0x26, 0xa3, 0x2b, 0x93, 0xbe
	};

	const bool isBeta = 0 == memcmp(HEXEN_BETA_MD5, checksum, sizeof checksum);

	if (   !isBeta
		&& 0 != memcmp(HEXEN_DEMO_MD5, checksum, sizeof checksum)
		&& 0 != memcmp(HEXEN_FULL_MD5, checksum, sizeof checksum))
	{
		return;
	}

	static const int EXTRA_LUMPS = 299;

	// Hexen Beta is very similar to Demo but it has MAP41: Maze at the end of the WAD
	// So keep this map if it's present but discard all extra lumps

	const int lastLump = GetLastLump(GetIwadNum()) - (isBeta ? 12 : 0);
	assert(GetFirstLump(GetIwadNum()) + 299 < lastLump);

	for (int i = lastLump - EXTRA_LUMPS + 1; i <= lastLump; ++i)
	{
		LumpInfo[i].shortName.String[0] = '\0';
	}
}

//==========================================================================
//
// MoveLumpsInFolder
//
// Moves all content from the given subfolder of the internal
// resources to the current end of the directory.
// Used to allow modifying content in the base files, this is needed
// so that Hacx and Harmony can override some content that clashes
// with localization, and to inject modifying data into mods, in case
// this is needed for some compatibility requirement.
//
//==========================================================================

static FResourceLump placeholderLump;

void FileSystem::MoveLumpsInFolder(const char *path)
{
	auto len = strlen(path);
	auto wadnum = LumpInfo.Last().wadnum;
	
	unsigned i;
	for (i = 0; i < LumpInfo.Size(); i++)
	{
		auto& li = LumpInfo[i];
		if (li.wadnum >= GetIwadNum()) break;
		if (li.longName.Left(len).CompareNoCase(path) == 0)
		{
			LumpInfo.Push(li);
			li.lump = &placeholderLump;			// Make the old entry point to something empty. We cannot delete the lump record here because it'd require adjustment of all indices in the list.
			auto &ln = LumpInfo.Last();
			ln.lump->LumpNameSetup(ln.longName.Mid(len));
			ln.SetFromLump(wadnum, ln.lump);
		}
	}
}

//==========================================================================
//
// W_FindLump
//
// Find a named lump. Specifically allows duplicates for merging of e.g.
// SNDINFO lumps.
//
//==========================================================================

int FileSystem::FindLump (const char *name, int *lastlump, bool anyns)
{
	union
	{
		char name8[8];
		uint64_t qname;
	};
	LumpRecord *lump_p;

	uppercopy (name8, name);

	assert(lastlump != NULL && *lastlump >= 0);
	lump_p = &LumpInfo[*lastlump];
	while (lump_p < &LumpInfo[NumLumps])
	{
		if ((anyns || lump_p->Namespace == ns_global) && lump_p->shortName.qword == qname)
		{
			int lump = int(lump_p - &LumpInfo[0]);
			*lastlump = lump + 1;
			return lump;
		}
		lump_p++;
	}

	*lastlump = NumLumps;
	return -1;
}

DEFINE_ACTION_FUNCTION(_Wads, FindLump)
{
	PARAM_PROLOGUE;
	PARAM_STRING(name);
	PARAM_INT(startlump);
	PARAM_INT(ns);
	const bool isLumpValid = startlump >= 0 && startlump < fileSystem.GetNumLumps();
	ACTION_RETURN_INT(isLumpValid ? fileSystem.FindLump(name, &startlump, 0 != ns) : -1);
}

//==========================================================================
//
// W_FindLumpMulti
//
// Find a named lump. Specifically allows duplicates for merging of e.g.
// SNDINFO lumps. Returns everything having one of the passed names.
//
//==========================================================================

int FileSystem::FindLumpMulti (const char **names, int *lastlump, bool anyns, int *nameindex)
{
	LumpRecord *lump_p;

	assert(lastlump != NULL && *lastlump >= 0);
	lump_p = &LumpInfo[*lastlump];
	while (lump_p < &LumpInfo[NumLumps])
	{
		if (anyns || lump_p->Namespace == ns_global)
		{
			
			for(const char **name = names; *name != NULL; name++)
			{
				if (!strnicmp(*name, lump_p->shortName.String, 8))
				{
					int lump = int(lump_p - &LumpInfo[0]);
					*lastlump = lump + 1;
					if (nameindex != NULL) *nameindex = int(name - names);
					return lump;
				}
			}
		}
		lump_p++;
	}

	*lastlump = NumLumps;
	return -1;
}

//==========================================================================
//
// W_CheckLumpName
//
//==========================================================================

bool FileSystem::CheckLumpName (int lump, const char *name)
{
	if ((size_t)lump >= NumLumps)
		return false;

	return !strnicmp (LumpInfo[lump].shortName.String, name, 8);
}

//==========================================================================
//
// W_GetLumpName
//
//==========================================================================

void FileSystem::GetLumpName (char *to, int lump) const
{
	if ((size_t)lump >= NumLumps)
		*to = 0;
	else
		uppercopy (to, LumpInfo[lump].shortName.String);
}

const char* FileSystem::GetLumpName(int lump) const
{
	if ((size_t)lump >= NumLumps)
		return nullptr;
	else
		return LumpInfo[lump].shortName.String;
}

void FileSystem::GetLumpName(FString &to, int lump) const
{
	if ((size_t)lump >= NumLumps)
		to = FString();
	else {
		to = LumpInfo[lump].shortName.String;
		to.ToUpper();
	}
}

DEFINE_ACTION_FUNCTION(_Wads, GetLumpName)
{
	PARAM_PROLOGUE;
	PARAM_INT(lump);
	FString lumpname;
	fileSystem.GetLumpName(lumpname, lump);
	ACTION_RETURN_STRING(lumpname);
}

//==========================================================================
//
// FileSystem :: GetLumpFullName
//
// Returns the lump's full name if it has one or its short name if not.
//
//==========================================================================

const char *FileSystem::GetLumpFullName (int lump, bool returnshort) const
{
	if ((size_t)lump >= NumLumps)
		return NULL;
	else if (LumpInfo[lump].longName.IsNotEmpty())
		return LumpInfo[lump].longName;
	else if (returnshort)
		return LumpInfo[lump].shortName.String;
	else return nullptr;
}

DEFINE_ACTION_FUNCTION(_Wads, GetLumpFullName)
{
	PARAM_PROLOGUE;
	PARAM_INT(lump);
	ACTION_RETURN_STRING(fileSystem.GetLumpFullName(lump));
}

//==========================================================================
//
// FileSystem :: GetLumpFullPath
//
// Returns the name of the lump's wad prefixed to the lump's full name.
//
//==========================================================================

FString FileSystem::GetLumpFullPath(int lump) const
{
	FString foo;

	if ((size_t) lump <  NumLumps)
	{
		foo << GetWadName(LumpInfo[lump].wadnum) << ':' << GetLumpFullName(lump);
	}
	return foo;
}

//==========================================================================
//
// GetLumpNamespace
//
//==========================================================================

int FileSystem::GetLumpNamespace (int lump) const
{
	if ((size_t)lump >= NumLumps)
		return ns_global;
	else
		return LumpInfo[lump].Namespace;
}

DEFINE_ACTION_FUNCTION(_Wads, GetLumpNamespace)
{
	PARAM_PROLOGUE;
	PARAM_INT(lump);
	ACTION_RETURN_INT(fileSystem.GetLumpNamespace(lump));
}

//==========================================================================
//
// FileSystem :: GetLumpIndexNum
//
// Returns the index number for this lump. This is *not* the lump's position
// in the lump directory, but rather a special value that RFF can associate
// with files. Other archive types will return 0, since they don't have it.
//
//==========================================================================

int FileSystem::GetLumpIndexNum(int lump) const
{
	if ((size_t)lump >= NumLumps)
		return 0;
	else
		return LumpInfo[lump].resourceId;
}

//==========================================================================
//
// W_GetLumpFile
//
//==========================================================================

int FileSystem::GetLumpFile (int lump) const
{
	if ((size_t)lump >= LumpInfo.Size())
		return -1;
	return LumpInfo[lump].wadnum;
}

//==========================================================================
//
// W_GetLumpFile
//
//==========================================================================

FResourceLump *FileSystem::GetLumpRecord(int lump) const
{
	if ((size_t)lump >= LumpInfo.Size())
		return nullptr;
	return LumpInfo[lump].lump;
}

//==========================================================================
//
// GetLumpsInFolder
// 
// Gets all lumps within a single folder in the hierarchy.
// If 'atomic' is set, it treats folders as atomic, i.e. only the
// content of the last found resource file having the given folder name gets used.
//
//==========================================================================

static int folderentrycmp(const void *a, const void *b)
{
	auto A = (FolderEntry*)a;
	auto B = (FolderEntry*)b;
	return strcmp(A->name, B->name);
}

unsigned FileSystem::GetLumpsInFolder(const char *inpath, TArray<FolderEntry> &result, bool atomic) const
{
	FString path = inpath;
	FixPathSeperator(path);
	path.ToLower();
	if (path[path.Len() - 1] != '/') path += '/';
	result.Clear();
	for (unsigned i = 0; i < LumpInfo.Size(); i++)
	{
		if (LumpInfo[i].longName.IndexOf(path) == 0)
		{
			// Only if it hasn't been replaced.
			if ((unsigned)fileSystem.CheckNumForFullName(LumpInfo[i].longName) == i)
			{
				result.Push({ LumpInfo[i].longName.GetChars(), i });
			}
		}
	}
	if (result.Size())
	{
		int maxfile = -1;
		if (atomic)
		{
			// Find the highest resource file having content in the given folder.
			for (auto & entry : result)
			{
				int thisfile = fileSystem.GetLumpFile(entry.lumpnum);
				if (thisfile > maxfile) maxfile = thisfile;
			}
			// Delete everything from older files.
			for (int i = result.Size() - 1; i >= 0; i--)
			{
				if (fileSystem.GetLumpFile(result[i].lumpnum) != maxfile) result.Delete(i);
			}
		}
		qsort(result.Data(), result.Size(), sizeof(FolderEntry), folderentrycmp);
	}
	return result.Size();
}

//==========================================================================
//
// W_ReadLump
//
// Loads the lump into the given buffer, which must be >= W_LumpLength().
//
//==========================================================================

void FileSystem::ReadLump (int lump, void *dest)
{
	auto lumpr = OpenLumpReader (lump);
	auto size = lumpr.GetLength ();
	auto numread = lumpr.Read (dest, size);

	if (numread != size)
	{
		I_Error ("W_ReadLump: only read %ld of %ld on lump %i\n",
			numread, size, lump);	
	}
}

//==========================================================================
//
// W_ReadLump
//
// Loads the lump into a TArray and returns it.
//
//==========================================================================

TArray<uint8_t> FileSystem::ReadLumpIntoArray(int lump, int pad)
{
	auto lumpr = OpenLumpReader(lump);
	auto size = lumpr.GetLength();
	TArray<uint8_t> data(size + pad, true);
	auto numread = lumpr.Read(data.Data(), size);

	if (numread != size)
	{
		I_Error("W_ReadLump: only read %ld of %ld on lump %i\n",
			numread, size, lump);
	}
	if (pad > 0) memset(&data[size], 0, pad);
	return data;
}

//==========================================================================
//
// ReadLump - variant 2
//
// Loads the lump into a newly created buffer and returns it.
//
//==========================================================================

FMemLump FileSystem::ReadLump (int lump)
{
	return FMemLump(FString(ELumpNum(lump)));
}

DEFINE_ACTION_FUNCTION(_Wads, ReadLump)
{
	PARAM_PROLOGUE;
	PARAM_INT(lump);
	const bool isLumpValid = lump >= 0 && lump < fileSystem.GetNumLumps();
	ACTION_RETURN_STRING(isLumpValid ? fileSystem.ReadLump(lump).GetString() : FString());
}

//==========================================================================
//
// OpenLumpReader
//
// uses a more abstract interface to allow for easier low level optimization later
//
//==========================================================================


FileReader FileSystem::OpenLumpReader(int lump)
{
	if ((unsigned)lump >= (unsigned)LumpInfo.Size())
	{
		I_Error("W_OpenLumpNum: %u >= NumLumps", lump);
	}

	auto rl = LumpInfo[lump].lump;
	auto rd = rl->GetReader();

	if (rl->RefCount == 0 && rd != nullptr && !rd->GetBuffer() && !(rl->Flags & LUMPF_COMPRESSED))
	{
		FileReader rdr;
		rdr.OpenFilePart(*rd, rl->GetFileOffset(), rl->LumpSize);
		return rdr;
	}
	return rl->NewReader();	// This always gets a reader to the cache
}

FileReader FileSystem::ReopenLumpReader(int lump, bool alwayscache)
{
	if ((unsigned)lump >= (unsigned)LumpInfo.Size())
	{
		I_Error("ReopenLumpReader: %u >= NumLumps", lump);
	}

	auto rl = LumpInfo[lump].lump;
	auto rd = rl->GetReader();

	if (rl->RefCount == 0 && rd != nullptr && !rd->GetBuffer() && !alwayscache && !(rl->Flags & LUMPF_COMPRESSED))
	{
		int fileno = fileSystem.GetLumpFile(lump);
		const char *filename = fileSystem.GetWadFullName(fileno);
		FileReader fr;
		if (fr.OpenFile(filename, rl->GetFileOffset(), rl->LumpSize))
		{
			return fr;
		}
	}
	return rl->NewReader();	// This always gets a reader to the cache
}

//==========================================================================
//
// GetFileReader
//
// Retrieves the File reader object to access the given WAD
// Careful: This is only useful for real WAD files!
//
//==========================================================================

FileReader *FileSystem::GetFileReader(int wadnum)
{
	if ((uint32_t)wadnum >= Files.Size())
	{
		return NULL;
	}

	return Files[wadnum]->GetReader();
}

//==========================================================================
//
// W_GetWadName
//
// Returns the name of the given wad.
//
//==========================================================================

const char *FileSystem::GetWadName (int wadnum) const
{
	const char *name, *slash;

	if ((uint32_t)wadnum >= Files.Size())
	{
		return NULL;
	}

	name = Files[wadnum]->FileName;
	slash = strrchr (name, '/');
	return slash != NULL ? slash+1 : name;
}

//==========================================================================
//
//
//==========================================================================

int FileSystem::GetFirstLump (int wadnum) const
{
	if ((uint32_t)wadnum >= Files.Size())
	{
		return 0;
	}

	return Files[wadnum]->GetFirstLump();
}

//==========================================================================
//
//
//==========================================================================

int FileSystem::GetLastLump (int wadnum) const
{
	if ((uint32_t)wadnum >= Files.Size())
	{
		return 0;
	}

	return Files[wadnum]->GetFirstLump() + Files[wadnum]->LumpCount() - 1;
}

//==========================================================================
//
//
//==========================================================================

int FileSystem::GetLumpCount (int wadnum) const
{
	if ((uint32_t)wadnum >= Files.Size())
	{
		return 0;
	}
	
	return Files[wadnum]->LumpCount();
}


//==========================================================================
//
// W_GetWadFullName
//
// Returns the name of the given wad, including any path
//
//==========================================================================

const char *FileSystem::GetWadFullName (int wadnum) const
{
	if ((unsigned int)wadnum >= Files.Size())
	{
		return nullptr;
	}

	return Files[wadnum]->FileName;
}


// FMemLump -----------------------------------------------------------------

FMemLump::FMemLump ()
{
}

FMemLump::FMemLump (const FMemLump &copy)
{
	Block = copy.Block;
}

FMemLump &FMemLump::operator = (const FMemLump &copy)
{
	Block = copy.Block;
	return *this;
}

FMemLump::FMemLump (const FString &source)
: Block (source)
{
}

FMemLump::~FMemLump ()
{
}

FString::FString (ELumpNum lumpnum)
{
	auto lumpr = fileSystem.OpenLumpReader ((int)lumpnum);
	auto size = lumpr.GetLength ();
	AllocBuffer (1 + size);
	auto numread = lumpr.Read (&Chars[0], size);
	Chars[size] = '\0';

	if (numread != size)
	{
		I_Error ("ConstructStringFromLump: Only read %ld of %ld bytes on lump %i (%s)\n",
			numread, size, lumpnum, fileSystem.GetLumpFullName((int)lumpnum));
	}
}

//==========================================================================
//
// PrintLastError
//
//==========================================================================

#ifdef _WIN32
//#define WIN32_LEAN_AND_MEAN
//#include <windows.h>

extern "C" {
__declspec(dllimport) unsigned long __stdcall FormatMessageA(
    unsigned long dwFlags,
    const void *lpSource,
    unsigned long dwMessageId,
    unsigned long dwLanguageId,
    char **lpBuffer,
    unsigned long nSize,
    va_list *Arguments
    );
__declspec(dllimport) void * __stdcall LocalFree (void *);
__declspec(dllimport) unsigned long __stdcall GetLastError ();
}

static void PrintLastError ()
{
	char *lpMsgBuf;
	FormatMessageA(0x1300 /*FORMAT_MESSAGE_ALLOCATE_BUFFER | 
							FORMAT_MESSAGE_FROM_SYSTEM | 
							FORMAT_MESSAGE_IGNORE_INSERTS*/,
		NULL,
		GetLastError(),
		1 << 10 /*MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT)*/, // Default language
		&lpMsgBuf,
		0,
		NULL 
	);
	Printf (TEXTCOLOR_RED "  %s\n", lpMsgBuf);
	// Free the buffer.
	LocalFree( lpMsgBuf );
}
#else
static void PrintLastError ()
{
	Printf (TEXTCOLOR_RED "  %s\n", strerror(errno));
}
#endif

#ifdef _DEBUG
//==========================================================================
//
// CCMD LumpNum
//
//==========================================================================

CCMD(lumpnum)
{
	for (int i = 1; i < argv.argc(); ++i)
	{
		Printf("%s: %d\n", argv[i], fileSystem.CheckNumForName(argv[i]));
	}
}

//==========================================================================
//
// CCMD LumpNumFull
//
//==========================================================================

CCMD(lumpnumfull)
{
	for (int i = 1; i < argv.argc(); ++i)
	{
		Printf("%s: %d\n", argv[i], fileSystem.CheckNumForFullName(argv[i]));
	}
}
#endif