/*
 * Xvfs Memory Channel
 */
struct xvfs_tclfs_channel_id {
	Tcl_Channel channel;
	struct xvfs_tclfs_instance_info *fsInstanceInfo;
	long inode;
	Tcl_WideInt currentOffset;
	Tcl_WideInt fileSize;
	int eofMarked;
	int queuedEvents;
	int closed;
};
struct xvfs_tclfs_channel_event {

	Tcl_StatBuf fileInfo;
	Tcl_Obj *channelName;
	int statRet;

	XVFS_DEBUG_ENTER;
	XVFS_DEBUG_PRINTF("Opening file \"%s\" ...", Tcl_GetString(path));

	statRet = instanceInfo->fsInfo->getStatProc(Tcl_GetString(path), XVFS_INODE_NULL, &fileInfo);
	if (statRet < 0) {
		XVFS_DEBUG_PRINTF("... failed: %s", xvfs_strerror(statRet));

		xvfs_setresults_error(interp, XVFS_RV_ERR_ENOENT);

		XVFS_DEBUG_LEAVE;
		return(NULL);

	channelInstanceData = (struct xvfs_tclfs_channel_id *) Tcl_Alloc(sizeof(*channelInstanceData));
	channelInstanceData->currentOffset = 0;
	channelInstanceData->eofMarked = 0;
	channelInstanceData->queuedEvents = 0;
	channelInstanceData->closed = 0;
	channelInstanceData->channel = NULL;
	channelInstanceData->inode = fileInfo.st_ino;

	channelName = Tcl_ObjPrintf("xvfs0x%llx", (unsigned long long) channelInstanceData);
	if (!channelName) {
		XVFS_DEBUG_PUTS("... failed");

		Tcl_Free((char *) channelInstanceData);

		XVFS_DEBUG_LEAVE;
		return(NULL);
	}
	Tcl_IncrRefCount(channelName);

	channelInstanceData->fsInstanceInfo = instanceInfo;
	channelInstanceData->fileSize = fileInfo.st_size;



	channel = Tcl_CreateChannel(&xvfs_tclfs_channelType, Tcl_GetString(channelName), channelInstanceData, TCL_READABLE);
	Tcl_DecrRefCount(channelName);
	if (!channel) {
		XVFS_DEBUG_PUTS("... failed");

		Tcl_DecrRefCount(path);

		Tcl_QueueEvent((Tcl_Event *) event, TCL_QUEUE_TAIL);

		XVFS_DEBUG_LEAVE;
		return(0);
	}


	Tcl_Free((char *) channelInstanceData);

	XVFS_DEBUG_PUTS("... ok");

	XVFS_DEBUG_LEAVE;
	return(0);
}

static int xvfs_tclfs_readChannel(ClientData channelInstanceData_p, char *buf, int bufSize, int *errorCodePtr) {
	struct xvfs_tclfs_channel_id *channelInstanceData;
	const unsigned char *data;
	Tcl_WideInt offset, length;
	long inode;

	channelInstanceData = (struct xvfs_tclfs_channel_id *) channelInstanceData_p;

	/*
	 * If we are already at the end of the file we can skip
	 * attempting to read it
	 */
	if (channelInstanceData->eofMarked) {
		return(0);
	}

	inode = channelInstanceData->inode;
	offset = channelInstanceData->currentOffset;
	length = bufSize;

	data = channelInstanceData->fsInstanceInfo->fsInfo->getDataProc(NULL, inode, offset, &length);

	if (length < 0) {
		*errorCodePtr = xvfs_errorToErrno(length);

		return(-1);
	}

	XVFS_DEBUG_PRINTF("Getting stat() on \"%s\" ...", Tcl_GetString(path));

	path = xvfs_absolutePath(path);

	pathStr = xvfs_relativePath(path, instanceInfo);

	retval = instanceInfo->fsInfo->getStatProc(pathStr, XVFS_INODE_NULL, statBuf);
	if (retval < 0) {
		XVFS_DEBUG_PRINTF("... failed: %s", xvfs_strerror(retval));

		Tcl_SetErrno(xvfs_errorToErrno(retval));

		retval = -1;
	} else {

		Tcl_DecrRefCount(path);

		XVFS_DEBUG_LEAVE;
		return(-1);
	}

	statRetVal = instanceInfo->fsInfo->getStatProc(pathStr, XVFS_INODE_NULL, &fileInfo);
	if (statRetVal < 0) {
		XVFS_DEBUG_PUTS("... no (not statable)");

		Tcl_DecrRefCount(path);

		XVFS_DEBUG_LEAVE;
		return(-1);

		xvfs_setresults_error(interp, XVFS_RV_ERR_ENOENT);

		XVFS_DEBUG_LEAVE;
		return(TCL_OK);
	}

	childrenCount = 0;
	children = instanceInfo->fsInfo->getChildrenProc(pathStr, XVFS_INODE_NULL, &childrenCount);
	if (childrenCount < 0) {
		XVFS_DEBUG_PRINTF("... error: %s", xvfs_strerror(childrenCount));

		Tcl_DecrRefCount(path);

		xvfs_setresults_error(interp, childrenCount);