#include "vxBoot/fs/smemfs.h"

#include <gint/bfile.h>
#include <gint/gint.h>

#include <string.h>

/* internal struct */
struct __file_info {
	uint16_t pathname[256];
	void *buf;
	size_t count;
	off_t pos;
};

/* generate_abolute_path(): Generate abolute path

   This function will generate the absolute path of a file because Casio's open
   primitive doesn't handle cannonical path */
static void generate_absolute_path(uint16_t *pathname,
					struct smemfs_inode *inode, int *pos)
{
	if (inode == NULL) {
		memcpy(pathname, u"\\\\fls0", 12);
		*pos = 6;
		return;
	}

	generate_absolute_path(pathname, inode->parent, pos);

	pathname[(*pos)++] = '\\';
	for (int i = 0; inode->name[i] != '\0'; ) {
		pathname[*pos] = inode->name[i];
		*pos = *pos + 1;
		i = i + 1;
	}
	pathname[*pos] = '\0';
}

/* __smemfs_pread() : involved in Casio's world */
static void __smemfs_pread(struct __file_info *info, ssize_t *read)
{
	int handle;

	*read = -1;
	handle = BFile_Open(info->pathname, BFile_ReadOnly);
	if (handle >= 0) {
		*read = BFile_Read(handle, info->buf, info->count, info->pos);
		BFile_Close(handle);
	}
}

/* smemfs_read(): Read primitive */
ssize_t	smemfs_pread(struct smemfs_inode *inode,
					void *buf, size_t count, off_t pos)
{
	struct __file_info file_info = {
		.buf = buf,
		.count = count,
		.pos = pos
	};
	ssize_t read;
	int tmp;

	if (inode == NULL)
		return (-1);

	tmp = 0;
	generate_absolute_path(file_info.pathname, inode, &tmp);

	gint_world_switch(GINT_CALL(
		(void*)&__smemfs_pread,
		(void*)&file_info, &read
	));

	return (read);
}