#include <string.h>
#include <errno.h>
#include <nucleus/vfs.h>
#include "ext2fs.h"

size_t ext2fs_read(File *file, char *buf, size_t size, off_t offset);
int ext2fs_readdir(File *file, struct dirent *dent, off_t index);
int ext2fs_open(File *file);

FileOps ext2fsFileOps = {
	.read = ext2fs_read,
	.readdir = ext2fs_readdir,
	.open = ext2fs_open,
};

/* Read an ext2fs file */
size_t
ext2fs_read(File *file, char *buf, size_t size, off_t offset)
{
	SuperBlock *sb = file->inode->super;
	struct Ext2Inode inode;
	uint16_t min, indent = offset % PAGE_SIZE;
	size_t count = 0, i = offset / PAGE_SIZE;
	uint32_t blk;
	char ebuf[PAGE_SIZE];
	ext2fs_read_inode(sb, file->inode->ino, &inode);
	if (offset > inode.lsize)
		return 0;
	if (size + offset > inode.lsize)
		size = inode.lsize - offset;
	while (size) {
		min = (size > PAGE_SIZE) ? PAGE_SIZE : size;
		blk = ext2fs_get_data_addr(sb, &inode, i);
		ext2fs_read_block(sb, blk, ebuf);
		memcpy(buf + count, ebuf + indent, min);
		size -= min;
		count += min;
		indent = 0;
		i++;
	}
	return count;
}

/* Read an ext2fs directory entry */
int
ext2fs_readdir(File *file, struct dirent *dent, off_t index)
{
	char buf[PAGE_SIZE];
	uint32_t block, blk = 0;
	struct Ext2DirEntry *de;
	struct Ext2Inode inode;
	SuperBlock *sb = file->inode->super;
	ext2fs_read_inode(sb, file->inode->ino, &inode);
	for (blk = 0; blk < 0xFFFF; blk++) {
		block = ext2fs_get_data_addr(sb, &inode, blk);
		if (!block)
			return -ENOENT;
		ext2fs_read_block(sb, block, buf);
		for (de = (struct Ext2DirEntry *) buf;
		     index && de < (struct Ext2DirEntry *) (buf + PAGE_SIZE);
		     de = (void *) de + de->size, index--);
		if (de >= (struct Ext2DirEntry *) (buf + PAGE_SIZE))
			return -ENOENT;
		if (!index)
			break;
	}
	if (!de->ino)
		return -ENOENT;
	dent->d_ino = de->ino;
	dent->d_type = de->type;
	dent->d_namelen = de->namelen + 1;
	strncpy(dent->d_name, de->name, de->size);
	return 0;
}

/* Open an ext2fs file */
int
ext2fs_open(File *file)
{
	return 0;
}