// * This file is part of the COLOBOT source code
// * Copyright (C) 2001-2008, Daniel ROUX & EPSITEC SA, www.epsitec.ch
// *
// * This program 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 3 of the License, or
// * (at your option) any later version.
// *
// * This program 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 this program. If not, see  http://www.gnu.org/licenses/.

// metafile.cpp

#define STRICT
#define D3D_OVERLOADS

#include <windows.h>
#include <stdio.h>

#include "language.h"
#include "metafile.h"




#if _FULL | _NET
static unsigned char table_codec[23] =
{
	0x85, 0x91, 0x73, 0xcf, 0xa2, 0xbb, 0xf4, 0x77,
	0x58, 0x39, 0x37, 0xfd, 0x2a, 0xcc, 0x5f, 0x55,
	0x96, 0x90, 0x07, 0xcd, 0x11, 0x88, 0x21,
};

void Codec(void* buffer, int len, int start)
{
	unsigned char *b = (unsigned char*)buffer;
	int		i;

	for ( i=0 ; i<len ; i++ )
	{
		b[i] ^= table_codec[(start++)%23];
	}
}
#endif

#if _SCHOOL
#if _CEEBOTDEMO
static unsigned char table_codec[136] =
{
	0x76, 0x76, 0x76, 0x76, 0x76, 0x76, 0x76, 0x76,
	0x76, 0x76, 0x76, 0x76, 0x76, 0x76, 0x76, 0x76,
	0x76, 0x76, 0x76, 0x76, 0x76, 0x76, 0x76, 0x76,
	0x76, 0x76, 0x76, 0x76, 0x76, 0x76, 0x76, 0x76,
	0x76, 0x76, 0x76, 0x76, 0x76, 0x76, 0x76, 0x76,
	0x76, 0x76, 0x76, 0x76, 0x76, 0x76, 0x76, 0x76,
	0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
	0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
	0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
	0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
	0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
	0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
	0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
	0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
	0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
	0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
	0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5, 0xa5,
};

void Codec(void* buffer, int len, int start)
{
	unsigned char *b = (unsigned char*)buffer;
	int		i;

	for ( i=0 ; i<len ; i++ )
	{
		b[i] ^= table_codec[(start++)%136];
	}
}
#else
static unsigned char table_codec[29] =
{
	0x72, 0x91, 0x37, 0xdf, 0xa1, 0xcc, 0xf5, 0x67,
	0x53, 0x40, 0xd3, 0xed, 0x3a, 0xbb, 0x5e, 0x43,
	0x67, 0x9a, 0x0c, 0xed, 0x33, 0x77, 0x2f, 0xf2,
	0xe3, 0x42, 0x11, 0x5e, 0xc2,
};

void Codec(void* buffer, int len, int start)
{
	unsigned char *b = (unsigned char*)buffer;
	int		i;

	for ( i=0 ; i<len ; i++ )
	{
		b[i] ^= table_codec[(start++)%29];
	}
}
#endif
#endif

#if _DEMO
static unsigned char table_codec[27] =
{
	0x85, 0x91, 0x77, 0xcf, 0xa3, 0xbb, 0xf4, 0x77,
	0x58, 0x39, 0x37, 0xfd, 0x2a, 0xcc, 0x7f, 0x55,
	0x96, 0x80, 0x07, 0xcd, 0x11, 0x88, 0x21, 0x44,
	0x17, 0xee, 0xf0,
};

void Codec(void* buffer, int len, int start)
{
	unsigned char *b = (unsigned char*)buffer;
	int		i;

	for ( i=0 ; i<len ; i++ )
	{
		b[i] ^= table_codec[(start++)%27];
	}
}
#endif



// Object's constructor.

CMetaFile::CMetaFile()
{
	int		i;

	for ( i=0 ; i<METAMAX ; i++ )
	{
		m_list[i].stream  = 0;
		m_list[i].headers = 0;
	}

	m_bMeta  = FALSE;
	m_bOpen  = FALSE;
	m_start  = 0;
	m_pos    = 0;
	m_len    = 0;
	m_stream = 0;
}

// Object's destructor.

CMetaFile::~CMetaFile()
{
	MetaClose();
}


// Test if a file exists.

BOOL CMetaFile::IsExist(char *metaname, char *filename)
{
	FILE*	file;
	int		index, i;

	if ( metaname[0] == 0 )
	{
		file = fopen(filename, "rb");
		if ( file == NULL )  return FALSE;
		fclose(file);
		return TRUE;
	}
	else
	{
		index = MetaOpen(metaname);
		if ( index == -1 )  return 1;

		for ( i=0 ; i<m_list[index].total ; i++ )
		{
			if ( strcmp(m_list[index].headers[i].name, filename) == 0 )
			{
				return TRUE;
			}
		}
		return FALSE;
	}
}

// Opens a file. If metaname is empty, it normally opens a file.

int CMetaFile::Open(char *metaname, char *filename)
{
	int		index, i;

	if ( m_bOpen )  // file already open?
	{
		Close();
	}

	if ( metaname[0] == 0 )
	{
		m_stream = fopen(filename, "rb");
		if ( m_stream == 0 )  return 1;
		m_bOpen = TRUE;
		m_bMeta = FALSE;
		return 0;
	}
	else
	{
		index = MetaOpen(metaname);
		if ( index == -1 )  return 1;

		for ( i=0 ; i<m_list[index].total ; i++ )
		{
			if ( strcmp(m_list[index].headers[i].name, filename) == 0 )
			{
				m_stream = m_list[index].stream;
				m_start  = m_list[index].headers[i].start;
				m_len    = m_list[index].headers[i].len;
				m_bOpen = TRUE;
				m_bMeta = TRUE;
				Seek(0);
				return 0;
			}
		}
		return 1;
	}
}

// Returns the length of a file.

int CMetaFile::RetLength()
{
	int		len;

	if ( !m_bOpen )  return 0;

	if ( m_bMeta )
	{
		len = m_len;
	}
	else
	{
		fseek(m_stream, 0, SEEK_END);
		len = ftell(m_stream);
		fseek(m_stream, 0, SEEK_SET);
	}
	return len;
}

// Positioning in the file, relative to the beginning.

int CMetaFile::Seek(int offset)
{
	if ( !m_bOpen )  return 1;

	if ( m_bMeta )
	{
		m_pos = m_start+offset;
		return fseek(m_stream, m_start+offset, SEEK_SET);
	}
	else
	{
		return fseek(m_stream, offset, SEEK_SET);
	}
}

// Reads bytes number.

int CMetaFile::Read(void *buffer, int size)
{
	int		err;

	if ( !m_bOpen )  return 1;

	if ( m_bMeta )
	{
		err = fread(buffer, size, 1, m_stream);
		Codec(buffer, size, m_pos);
		m_pos += size;
		return err;
	}
	else
	{
		return fread(buffer, size, 1, m_stream);
	}
}

// Reads a byte.

int CMetaFile::GetByte()
{
	BYTE	b;

	if ( !m_bOpen )  return 1;

	b = getc(m_stream);
	if ( m_bMeta )
	{
		Codec(&b, 1, m_pos);
		m_pos += 1;
	}
	return b;
}

// Reads 2 bytes.

int CMetaFile::GetWord()
{
	WORD	w;

	if ( !m_bOpen )  return 1;

	w = getc(m_stream);
	if ( m_bMeta )
	{
		Codec(&w, 2, m_pos);
		m_pos += 2;
	}
	return w;
}

// Closes the file.

int CMetaFile::Close()
{
	if ( !m_bOpen )  return 1;

	if ( !m_bMeta )
	{
		fclose(m_stream);
	}
	m_bOpen = FALSE;
	m_stream = 0;

	return 0;
}


// Opens a metafile. Returns the index or -1.

int CMetaFile::MetaOpen(char *metaname)
{
	int		i, j, offset;

	i = MetaSearch(metaname);
	if ( i != -1 )  return i;

	for ( i=0 ; i<METAMAX ; i++ )
	{
		if ( m_list[i].stream == 0 )
		{
			m_list[i].stream = fopen(metaname, "rb");
			if ( m_list[i].stream == 0 )  return -1;

			strcpy(m_list[i].name, metaname);  // memorized the name

			fread(&m_list[i].total, sizeof(int), 1, m_list[i].stream);
			m_list[i].headers = (MetaHeader*)malloc(sizeof(MetaHeader)*m_list[i].total);

			offset = 4;
			for ( j=0 ; j<m_list[i].total ; j++ )
			{
				fread(&m_list[i].headers[j], sizeof(MetaHeader), 1, m_list[i].stream);
				Codec(&m_list[i].headers[j], sizeof(MetaHeader), offset);
				offset += sizeof(MetaHeader);
			}
			return i;
		}
	}

	return -1;
}

// Seeks if the metafile is already open. Returns the index or -1.

int CMetaFile::MetaSearch(char *metaname)
{
	int		i;

	for ( i=0 ; i<METAMAX ; i++ )
	{
		if ( m_list[i].stream != 0 )
		{
			if ( strcmp(m_list[i].name, metaname) == 0 )  return i;
		}
	}

	return -1;
}

// Closes all metafiles.

int CMetaFile::MetaClose()
{
	int		i;

	if ( m_stream != 0 )
	{
		fclose(m_stream);
		m_stream = 0;
	}

	for ( i=0 ; i<METAMAX ; i++ )
	{
		if ( m_list[i].stream != 0 )
		{
			free(m_list[i].headers);
			m_list[i].headers = 0;

			fclose(m_list[i].stream);
			m_list[i].stream = 0;
		}
	}

	return 0;
}