#ifndef _NUCLEUS_VFS_H
#define _NUCLEUS_VFS_H

#include <stddef.h>
#include <sys/dirent.h>
#include <sys/limits.h>
#include <sys/types.h>
#include <nucleus/memory.h>
#include <nucleus/object.h>
#include <nucleus/types.h>

typedef Inode *(*mount_callback_t)(FSType *, int, const char *, void *);

/* Structure for a Super Block */
struct SuperBlock {
	Object obj;
	FSType *type;
	SuperOps *ops;
	Inode *root;
	ObjectList *inodes; /* List of cached inodes */
	File *back;
	void *data;
};
struct SuperOps {
	Inode *(*alloc_inode)(SuperBlock *);
	int (*write_inode)(Inode *);
	void (*delete_inode)(Inode *);
};

/* Structure for an Inode */
struct Inode {
	Object obj;
	ino_t ino;
	uid_t uid;
	gid_t gid;
	mode_t mode;
	nlink_t nlink;
	size_t size;
	dev_t dev;
	InodeOps *ops;
	FileOps *fileOps;
	SuperBlock *super;
	ObjectList *dirEntries;
	ObjectList *pages;
};
struct InodeOps {
	int (*create)(Inode *, DirEntry *, mode_t);
	Inode *(*lookup)(Inode *, const char *);
	int (*mkdir)(Inode *, DirEntry *, mode_t);
	int (*rmdir)(Inode *, DirEntry *);
	int (*mknod)(Inode *, DirEntry *, mode_t, dev_t);
	int (*rename)(Inode *, DirEntry *, Inode *, DirEntry *);
};

/* Structure for a Directory Entry */
struct DirEntry {
	Object obj;
	Inode *inode, *mnt;
	uint32_t hash;
	char name[NAME_MAX];
	SuperBlock *super;
};

/* Structure for an open File */
struct File {
	Object obj;
	Inode *inode;
	int flags;
	off_t pos;
	FileOps *ops;
	ObjectList *path;
};
struct FileOps {
	size_t (*read)(File *, char *, size_t, off_t);
	size_t (*write)(File *, char *, size_t, off_t);
	int (*open)(File *);
	int (*ioctl)(File *, unsigned long, uintptr_t);
	int (*readdir)(File *, struct dirent *, off_t);
	void (*mmap)(File *, void *, size_t, off_t);
};

extern ObjectType fstypeType;
extern ObjectType fsType;
extern ObjectType filesType;
extern ObjectType superBlockType;
extern ObjectType inodeType;
extern ObjectType dirEntryType;
extern ObjectType fileType;

void init_vfs(void);
File *create_anonymous_file(void);
void register_fstype(const char *name,	mount_callback_t mount);
Inode *lookup(const char *path, ObjectList *newcustody);

/* Super Block functions */
Inode *super_alloc_inode(SuperBlock *sb);
Inode *super_find_inode(SuperBlock *sb, ino_t ino);
/* Inode functions */
int permission(Inode *inode, int mask);
int inode_create(Inode *inode, DirEntry *entry, mode_t mode);
DirEntry *inode_lookup(Inode *inode, const char *name);
int inode_mkdir(Inode *inode, DirEntry *entry, mode_t mode);
int inode_rmdir(Inode *inode, DirEntry *entry);
int inode_mknod(Inode *inode, DirEntry *entry, mode_t mode, dev_t dev);
/* Directory Entry functions */
DirEntry *find_direntry(ObjectList *list, const char *name);
/* File functions */
int file_open(File *file);
size_t file_read(File *file, char *buf, size_t count);
size_t file_write(File *file, char *buf, size_t count);
int file_ioctl(File *file, unsigned long request, uintptr_t arpg);
int file_readdir(File *file, struct dirent *dent, off_t index);
void file_mmap(File *file, void *addr, size_t len, off_t offset);
/* Files namespace functions */
File *get_file_by_fd(int fd);
int allocate_fd(void);
void install_fd(int fd, File *file);

#endif