// vfs.h
// Author: Josh Holtrop
// Date: 08/22/04
// Modified: 12/21/04

#ifndef __HOS_VFS_H__
#define __HOS_VFS_H__ __HOS_VFS_H__

#include "hos_defines.h"
#include "fs/devices.h"

#define FS_EXT2 1
#define VFS_MAX_FS 10

#define VFS_FT_UNKNOWN	0
#define VFS_FT_FILE	1
#define VFS_FT_DIR	2
#define VFS_FT_CHAR	3
#define VFS_FT_BLOCK	4
#define VFS_FT_FIFO	5
#define VFS_FT_SOCK	6
#define VFS_FT_SYMLINK	7

#define VFS_PERMS_OX		0x0001
#define VFS_PERMS_OW		0x0002
#define VFS_PERMS_OR		0x0004
#define VFS_PERMS_GX		0x0008
#define VFS_PERMS_GW		0x0010
#define VFS_PERMS_GR		0x0020
#define VFS_PERMS_UX		0x0040
#define VFS_PERMS_UW		0x0080
#define VFS_PERMS_UR		0x0100
#define VFS_PERMS_STICKY	0x0200
#define VFS_PERMS_SGID		0x0400
#define VFS_PERMS_SUID		0x0800

#define EOF 1000000

/* Structure to hold information about a mount point */
typedef struct
{
	int refs;
	void *super;
	int fs;
	major_t major;
	minor_t minor;
} vfs_mount_t;

/* This structure represents a node of the "VFS Mount Tree" */
struct vfs_node_s
{
	char chr;				// the character we are at
	vfs_mount_t *mount;			// is there a mount at this character?
	struct vfs_node_s *up;			// the parent
	struct vfs_node_s *next;		// the next sibling
	struct vfs_node_s *down;		// subtree for submounts
};

typedef struct vfs_node_s vfs_node_t;

/* This structure is generated when a path is matched. For example, if /dev is mounted on
	device (4,2) and '/dev/yoda' is looked up, the structure returned would be
	{4, 2, 4} and then the lookup could continue on device (4,2) with 4 characters stripped
	off the front of the initial path (ex '/yoda') */
typedef struct
{
	vfs_mount_t	*mount;
	int	length;
} vfs_mount_match_t;

typedef struct
{
	u16_t	type;			// file type, of VFS_FILE_TYPE_*
	u32_t	size;
	u32_t	inode;
	u16_t	permissions;
	u16_t	uid;
	u16_t	gid;
	u32_t	atime;
	u32_t	mtime;
	u32_t	ctime;
	u16_t	links;
	u32_t	dev;
} vfs_stat_t;

typedef struct
{
	vfs_mount_t *mount;
	void *fs_data;
} vfs_open_file_t;

typedef struct
{
	char name[257];
} vfs_dir_entry_t;

/* Every filesystem must provide pointers to its respective functions in a structure like this */
typedef struct
{
	void	*(*mount_super)(major_t major, minor_t minor);
	int	(*umount_super)(vfs_mount_t *mount);
	int	(*stat)(vfs_mount_t *mount, char *file, vfs_stat_t *stat);

	int	(*open_dir)(vfs_mount_t *mount, char *file, vfs_open_file_t *dir);
	int	(*read_dir)(vfs_mount_t *mount, vfs_open_file_t *dir, vfs_dir_entry_t *dentry);
	int	(*close_dir)(vfs_mount_t *mount, vfs_open_file_t *dir);

	int	(*open_file)(vfs_mount_t *mount, char *file, vfs_open_file_t *open_file);
	int	(*read_file)(vfs_mount_t *mount, vfs_open_file_t *open_file);
	int	(*close_file)(vfs_mount_t *mount, vfs_open_file_t *open_file);

	int	(*open_block_file)(vfs_mount_t *mount, char *file, vfs_open_file_t *open_file);
	int	(*read_block_file)(vfs_mount_t *mount, vfs_open_file_t *open_file, void *buffer);
	int	(*block_file_seek)(vfs_mount_t *mount, vfs_open_file_t *open_file, u32_t block_number);
	int	(*close_block_file)(vfs_mount_t *mount, vfs_open_file_t *open_file);

} vfs_fs_t;


int	vfs_init();
int	vfs_mount(major_t maj, minor_t min, int fsType, char *mountPoint);
int	vfs_register_fs(int fsn, vfs_fs_t *fs);
int	vfs_add_mount(vfs_mount_t *mnt, char *mountPoint);
vfs_mount_t *vfs_find_mount(char *mountPoint);
vfs_mount_match_t vfs_get_rel_path(char *path);
int	vfs_umount(char *mountPoint);
int	vfs_retire_node(vfs_node_t *node);

int	vfs_stat(char *file, vfs_stat_t *stat);

vfs_open_file_t *vfs_open_dir(char *file);
int	vfs_read_dir(vfs_open_file_t *open_dir, vfs_dir_entry_t *dentry);
int	vfs_close_dir(vfs_open_file_t *open_dir);

vfs_open_file_t *vfs_open_block_file(char *file);
int	vfs_read_block_file(vfs_open_file_t *open_file, void *buffer);
int	vfs_block_file_seek(vfs_open_file_t *open_file, u32_t block_number);
int	vfs_close_block_file(vfs_open_file_t *open_file);


// DEBUG routines
void	vfs_dump_tree();
void	vfs_dump_node(vfs_node_t *node, int level);


#endif