/*
** file_rff.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.
**---------------------------------------------------------------------------
**
**
*/

#include "resourcefile.h"
#include "cmdlib.h"
#include "templates.h"
#include "v_text.h"
#include "w_wad.h"

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

struct RFFInfo
{
	// Should be "RFF\x18"
	DWORD		Magic;
	DWORD		Version;
	DWORD		DirOfs;
	DWORD		NumLumps;
};

struct RFFLump
{
	BYTE		IDontKnow[16];
	DWORD		FilePos;
	DWORD		Size;
	BYTE		IStillDontKnow[8];
	BYTE		Flags;
	char		Extension[3];
	char		Name[8+4];		// 4 bytes that I don't know what they are for
};

//==========================================================================
//
// Blood RFF lump (uncompressed lump with encryption)
//
//==========================================================================

struct FRFFLump : public FUncompressedLump
{
	virtual FileReader *GetReader();
	virtual int FillCache();
};

//==========================================================================
//
// BloodCrypt
//
//==========================================================================

void BloodCrypt (void *data, int key, int len)
{
	int p = (BYTE)key, i;

	for (i = 0; i < len; ++i)
	{
		((BYTE *)data)[i] ^= (unsigned char)(p+(i>>1));
	}
}


//==========================================================================
//
// Blood RFF file
//
//==========================================================================

class FRFFFile : public FResourceFile
{
	FRFFLump *Lumps;

public:
	FRFFFile(const char * filename, FileReader *file);
	virtual ~FRFFFile();
	virtual bool Open();
	virtual FResourceLump *GetLump(int no) { return ((unsigned)no < NumLumps)? &Lumps[no] : NULL; }
};


//==========================================================================
//
// Initializes a Blood RFF file
//
//==========================================================================

FRFFFile::FRFFFile(const char *filename, FileReader *file)
: FResourceFile(filename, file)
{
	Lumps = NULL;
}

//==========================================================================
//
// Initializes a Blood RFF file
//
//==========================================================================

bool FRFFFile::Open()
{
	RFFLump *lumps;
	RFFInfo header;

	Reader->Read(&header, sizeof(header));

	NumLumps = LittleLong(header.NumLumps);
	header.DirOfs = LittleLong(header.DirOfs);
	lumps = new RFFLump[header.NumLumps];
	Reader->Seek (header.DirOfs, SEEK_SET);
	Reader->Read (lumps, header.NumLumps * sizeof(RFFLump));
	BloodCrypt (lumps, header.DirOfs, header.NumLumps * sizeof(RFFLump));

	Lumps = new FRFFLump[NumLumps];

	Printf(", %d lumps\n", NumLumps);
	for (DWORD i = 0; i < NumLumps; ++i)
	{
		if (lumps[i].Extension[0] == 'S' && lumps[i].Extension[1] == 'F' &&
			lumps[i].Extension[2] == 'X')
		{
			Lumps[i].Namespace = ns_bloodsfx;
		}
		else if (lumps[i].Extension[0] == 'R' && lumps[i].Extension[1] == 'A' &&
			lumps[i].Extension[2] == 'W')
		{
			Lumps[i].Namespace = ns_bloodraw;
		}
		else
		{
			Lumps[i].Namespace = ns_global;
		}

		Lumps[i].Position = LittleLong(lumps[i].FilePos);
		Lumps[i].LumpSize = LittleLong(lumps[i].Size);
		Lumps[i].Owner = this;
		if (lumps[i].Flags & 0x10) Lumps[i].Flags |= LUMPF_BLOODCRYPT;

		// Rearrange the name and extension in a part of the lump record
		// that I don't have any use for in order to cnstruct the fullname.
		lumps[i].Name[8] = '\0';
		strcpy ((char *)lumps[i].IDontKnow, lumps[i].Name);
		strcat ((char *)lumps[i].IDontKnow, ".");
		strcat ((char *)lumps[i].IDontKnow, lumps[i].Extension);
		Lumps[i].LumpNameSetup((char *)lumps[i].IDontKnow);
	}
	delete[] lumps;
	return true;
}

FRFFFile::~FRFFFile()
{
	if (Lumps != NULL) delete [] Lumps;
}


//==========================================================================
//
// Get reader (only returns non-NULL if not encrypted)
//
//==========================================================================

FileReader *FRFFLump::GetReader()
{
	// Don't return the reader if this lump is encrypted
	// In that case always force caching of the lump
	if (!(Flags & LUMPF_BLOODCRYPT)) return FUncompressedLump::GetReader();
	else return NULL;	
}

//==========================================================================
//
// Fills the lump cache and performs decryption
//
//==========================================================================

int FRFFLump::FillCache()
{
	int res = FUncompressedLump::FillCache();

	if (Flags & LUMPF_BLOODCRYPT)
	{
		int cryptlen = MIN<int> (LumpSize, 256);
		BYTE *data = (BYTE *)Cache;
		
		for (int i = 0; i < cryptlen; ++i)
		{
			data[i] ^= i >> 1;
		}
	}
	return res;
}


//==========================================================================
//
// File open
//
//==========================================================================

FResourceFile *CheckRFF(const char *filename, FileReader *file)
{
	char head[4];

	if (file->GetLength() >= 16)
	{
		file->Seek(0, SEEK_SET);
		file->Read(&head, 4);
		file->Seek(0, SEEK_SET);
		if (!memcmp(head, "RFF\x1a", 4))
		{
			FResourceFile *rf = new FRFFFile(filename, file);
			if (rf->Open()) return rf;
			delete rf;
		}
	}
	return NULL;
}