#include <kernel/fs/smemfs.h>
#include <kernel/util/atomic.h>

/* smemfs_find_first_child() - Find the fist file in the (folder) inode (sync) */
void *smemfs_USB2_find_first_child(void *inode)
{
	extern struct smemfs_USB2_superblock smemfs_USB2_superblock;
	uint16_t folder_id;
	void *child_inode;

	// Check error.
	if (inode == NULL)
		return (NULL);

	// Start atomic operation
	atomic_start();

	// Check root inode
	if (inode == smemfs_USB2_superblock.sector_table)
	{
		folder_id = CASIO_SMEM_ROOT_ID;
	} else {
		// Check inode validity
		if (((struct casio_smem_header_s *)inode)->info != CASIO_SMEM_HEADER_INFO_EXIST ||
			((struct casio_smem_header_s *)inode)->type != CASIO_SMEM_HEADER_TYPE_DIRECTORY)
		{
			atomic_stop();
			return (NULL);
		}

		// Get directory ID
		folder_id = ((struct casio_smem_header_s *)inode)->id;
	}

	// Return the first child of the file.
	child_inode = smemfs_USB2_walk(inode, smemfs_USB2_superblock.inode_table,
					folder_id, WALK_FLAG_ID_CHECK_PARENT);

	// Stop atomic operation
	atomic_stop();
	return (child_inode);
}