/**
 * @file header.c CPIO header
 * 
 * $Id: header.c,v 1.6 2003/01/01 06:22:32 chipx86 Exp $
 *
 * @Copyright (C) 1999-2003 The GNUpdate Project.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA  02111-1307, USA.
 */
#include <libcomprex/internal.h>
#include "cpio.h"

/* Return a 16-bit integer with the bytes swapped. */
#define __swabShort(i) ((((i) << 8) & 0xFF00) | (((i) >> 8) & 0x00FF))

#define __skipPadding(fp, modulo) \
	cxSeek(fp, ((modulo) - cxTell(fp) % (modulo)) % (modulo), SEEK_CUR);

static CxStatus
__readNewAsciiHeader(CxFP *fp, CxArchive *archive, char checkCrc)
{
	char buffer[112];
	CpioNewHeader header;
	CxDirectory *dir, *root;
	CxFile *file;
	char *dirName, *baseName;

	if (cxRead(buffer, 1, 104, fp) != 104)
		return CX_CORRUPT;

	buffer[104] = '\0';

	sscanf(buffer,
		   "%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx%8lx",
		   &header.inode, &header.mode, &header.uid, &header.gid,
		   &header.nlink, &header.mtime, &header.fileSize,
		   &header.devMajor, &header.devMinor, &header.rDevMajor,
		   &header.rDevMinor, &header.nameSize, &header.checksum);

	/* Read the filename. */
	header.filename = (char *)malloc(header.nameSize);

	if (cxRead(header.filename, 1, header.nameSize, fp) != header.nameSize)
	{
		free(header.filename);

		return CX_CORRUPT;
	}

	if (!strcmp(header.filename, CPIO_TRAILER))
	{
		free(header.filename);

		return CX_EOF;
	}

	/* Get the parts of the filename. */
	if (*header.filename == '.')
		cxSplitPath(header.filename + 1, &dirName, &baseName);
	else
		cxSplitPath(header.filename, &dirName, &baseName);

	/* Create the file. */
	file = cxNewFile();

#if 0
	if (*header.filename == '.' && header.filename[1] == '/')
		cxSetFilePath(file, header.filename + 1);
	else
		cxSetFilePath(file, header.filename);
#endif

	cxSetFileName(file, baseName);
	cxSetFileMode(file, (mode_t)header.mode);
	cxSetFileUid(file,  (uid_t)header.uid);
	cxSetFileGid(file,  (gid_t)header.gid);
	cxSetFileSize(file, (size_t)header.fileSize);
	cxSetFileDate(file, (time_t)header.mtime);

	cxSetFileCompressedSize(file, cxGetFileSize(file));

	archive->archiveSize += cxGetFileCompressedSize(file);

	root = cxGetArchiveRoot(archive);

	/* Get the directory. */
	if (dirName != NULL)
	{
		dir = cxGetDirectory(root, dirName);

		if (dir == NULL)
		{
			/* Create it. */
			dir = cxMkDir(root, dirName);
		}

		free(dirName);
	}
	else
		dir = root;

	/* Add the file. */
	cxDirAddFile(dir, file);

	/* Clean up. */
	free(header.filename);
	free(baseName);

	/* Skip the padding and data. */
	__skipPadding(fp, 4);

	/* Save this location: The start of the data. */
	file->moduleData = (void *)cxTell(fp);

	/* Go past the rest. */
	cxSeek(fp, cxGetFileSize(file), SEEK_CUR);
	__skipPadding(fp, 4);

	return CX_SUCCESS;
}

static CxStatus
__readOldAsciiHeader(CxFP *fp, CxArchive *archive)
{
	printf("Old ASCII header\n");

	return CX_NOT_SUPPORTED;
}

static CxStatus
__readBinaryHeader(CxFP *fp, CxArchive *archive)
{
	printf("Binary header\n");

	return CX_NOT_SUPPORTED;
}

CxStatus
cxCpioReadHeader(CxFP *fp, CxArchive *archive)
{
	char buffer[CPIO_MAGICS_LEN];
	size_t s;

	/* Read in 6 bytes, the size of the largest magic string. */
	s = cxRead(buffer, 1, CPIO_MAGICS_LEN, fp);

	if (s == 0)
		return CX_EOF;
	else if (s < 0)
		return CX_ERROR;
	else if (s < CPIO_MAGICS_LEN)
		return CX_CORRUPT;

	/* Find out what we've got here. */
	if (!strncmp(buffer, CPIO_MAGICS_ASCII, CPIO_MAGICS_LEN))
		return __readNewAsciiHeader(fp, archive, 0);
	else if (!strncmp(buffer, CPIO_MAGICS_CRC, CPIO_MAGICS_LEN))
		return __readNewAsciiHeader(fp, archive, 1);
	else if (!strncmp(buffer, CPIO_MAGICS_CHR, CPIO_MAGICS_LEN))
		return __readOldAsciiHeader(fp, archive);
	else if ((*((unsigned short *)buffer) == CPIO_MAGICN_BIN) ||
			 (*((unsigned short *)buffer) == __swabShort(CPIO_MAGICN_BIN)))
		return __readBinaryHeader(fp, archive);

	return CX_INVALID_FORMAT;
}