/*
 * file.h - Header file for file analysis tools.
 * Author: Michael Rywalt
 * Operating System Concepts
 */

#ifndef _FILE_H_
#define _FILE_H_

/* Necessary includes. */
#include <ext2fs/ext2fs.h>
#include <stdlib.h>
#include <stdio.h>

/* Useful definitions. */
#define BOOL int
#define TRUE  1
#define FALSE 0

/* Create types associated with the ext2 filesystem. */
typedef struct ext2_super_block tsSuperBlock;
typedef struct ext2_group_desc  tsGroupDescriptor;
typedef struct ext2_inode tsInode;
typedef struct ext2_dir_entry_2 tsDirEntry;

/* Functions prototypes and exports. */

/* Loads filesystem into memory. */
tsSuperBlock *LoadFileSystem(char *szFileName);

/* Frees memory allocated from LoadFileSystem. */
void FreeFileSystem(tsSuperBlock *pFileSystem);

/* Gets the filesystem block size. */
int  GetFSBlockSize(const tsSuperBlock *pSuperBlock);

/* Convert a block number into a block pointer. */
void *BlockNumToPointer(int iBlockNum, const void *pFileSystem);

/* Find the start of the Inode table. */
tsInode *FindInodeTableStart(const void *pFileSystem);

/* Gets the next Inode in the Inode table. */
tsInode *GetNextInode(const tsInode *pInode, void *pFileSystem);

/* Gets an Inode by its number. */
tsInode *GetInode(int iInodeNum, void *pFileSystem);

/* Verifies that this is an EXT2 filesystem. */
BOOL VerifyFSMagicNumber(tsSuperBlock *pSuperBlock);

/* Gets the datablock for an Inode. */
void *GetDataBlock(const tsInode *pInode, const void *pFileSystem);

/* Prints the directory listing. */
void PrintDirectoryListing(const tsInode *pInode, const void *pFileSystem);

/* Print a file type from a directory listing. */
void PrintFileType(const tsDirEntry *pDirEntry);

/* Gets the start of the group descriptors block. */
tsGroupDescriptor *FindGroupDescriptorStart(const void *pFileSystem);

/* Gets an inode by directory entry name. */
tsInode *GetMatchingInode(char *szName, tsInode *pCurDirInode, void *pFileSystem);

/* Creates a hard link to a in that directory. */
BOOL InsertHardLink(char *szFileSysName, char *szLinkName, tsInode *pInode, void *pFileSystem);

/* Saves the filesystem allocated by LoadFileSystem back to disk. */
BOOL SaveModifiedFileSystemData(char *szFileName, void *pData, int iLengthToWrite);

/* Returns the size of a file. */
int GetFileSize(char *szFileName);

#endif /* _FILE_H_ */