/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. 
 *
 *    Copyright 2015-2018 (c) Julius Pfrommer, Fraunhofer IOSB
 *    Copyright 2015 (c) Oleksiy Vasylyev
 *    Copyright 2016 (c) Sten Grüner
 *    Copyright 2017-2018 (c) Thomas Stalder
 *    Copyright 2016-2017 (c) Florian Palm
 *    Copyright 2017 (c) Frank Meerkötter
 *    Copyright 2017 (c) Stefan Profanter, fortiss GmbH
 */

#include "ua_client_highlevel.h"
#include "ua_client_internal.h"
#include "ua_util.h"

#ifdef UA_ENABLE_SUBSCRIPTIONS /* conditional compilation */

UA_StatusCode
UA_Client_Subscriptions_new(UA_Client *client, UA_SubscriptionSettings settings,
                            UA_UInt32 *newSubscriptionId) {
    UA_CreateSubscriptionRequest request;
    UA_CreateSubscriptionRequest_init(&request);
    request.requestedPublishingInterval = settings.requestedPublishingInterval;
    request.requestedLifetimeCount = settings.requestedLifetimeCount;
    request.requestedMaxKeepAliveCount = settings.requestedMaxKeepAliveCount;
    request.maxNotificationsPerPublish = settings.maxNotificationsPerPublish;
    request.publishingEnabled = settings.publishingEnabled;
    request.priority = settings.priority;

    UA_CreateSubscriptionResponse response = UA_Client_Service_createSubscription(client, request);
    UA_StatusCode retval = response.responseHeader.serviceResult;
    if(retval != UA_STATUSCODE_GOOD) {
        UA_CreateSubscriptionResponse_deleteMembers(&response);
        return retval;
    }

    UA_Client_Subscription *newSub = (UA_Client_Subscription *)UA_malloc(sizeof(UA_Client_Subscription));
    if(!newSub) {
        UA_CreateSubscriptionResponse_deleteMembers(&response);
        return UA_STATUSCODE_BADOUTOFMEMORY;
    }

    LIST_INIT(&newSub->monitoredItems);
    newSub->lifeTime = response.revisedLifetimeCount;
    newSub->keepAliveCount = response.revisedMaxKeepAliveCount;
    newSub->publishingInterval = response.revisedPublishingInterval;
    newSub->subscriptionID = response.subscriptionId;
    newSub->notificationsPerPublish = request.maxNotificationsPerPublish;
    newSub->priority = request.priority;
    LIST_INSERT_HEAD(&client->subscriptions, newSub, listEntry);

    if(newSubscriptionId)
        *newSubscriptionId = newSub->subscriptionID;

    UA_CreateSubscriptionResponse_deleteMembers(&response);
    return UA_STATUSCODE_GOOD;
}

static UA_Client_Subscription *findSubscription(const UA_Client *client, UA_UInt32 subscriptionId)
{
    UA_Client_Subscription *sub = NULL;
    LIST_FOREACH(sub, &client->subscriptions, listEntry) {
        if(sub->subscriptionID == subscriptionId)
            break;
    }
    return sub;
}

/* remove the subscription remotely */
UA_StatusCode
UA_Client_Subscriptions_remove(UA_Client *client, UA_UInt32 subscriptionId) {
    UA_Client_Subscription *sub = findSubscription(client, subscriptionId);
    if(!sub)
        return UA_STATUSCODE_BADSUBSCRIPTIONIDINVALID;

    UA_StatusCode retval = UA_STATUSCODE_GOOD;
    UA_Client_MonitoredItem *mon, *tmpmon;
    LIST_FOREACH_SAFE(mon, &sub->monitoredItems, listEntry, tmpmon) {
        retval =
            UA_Client_Subscriptions_removeMonitoredItem(client, sub->subscriptionID,
                                                        mon->monitoredItemId);
        if(retval != UA_STATUSCODE_GOOD)
            return retval;
    }

    /* remove the subscription remotely */
    UA_DeleteSubscriptionsRequest request;
    UA_DeleteSubscriptionsRequest_init(&request);
    request.subscriptionIdsSize = 1;
    request.subscriptionIds = &sub->subscriptionID;
    UA_DeleteSubscriptionsResponse response = UA_Client_Service_deleteSubscriptions(client, request);
    retval = response.responseHeader.serviceResult;
    if(retval == UA_STATUSCODE_GOOD && response.resultsSize > 0)
        retval = response.results[0];
    UA_DeleteSubscriptionsResponse_deleteMembers(&response);

    if(retval != UA_STATUSCODE_GOOD && retval != UA_STATUSCODE_BADSUBSCRIPTIONIDINVALID) {
        UA_LOG_INFO(client->config.logger, UA_LOGCATEGORY_CLIENT,
                    "Could not remove subscription %u with error code %s",
                    sub->subscriptionID, UA_StatusCode_name(retval));
        return retval;
    }

    UA_Client_Subscriptions_forceDelete(client, sub);
    return UA_STATUSCODE_GOOD;
}

void
UA_Client_Subscriptions_forceDelete(UA_Client *client,
                                    UA_Client_Subscription *sub) {
    UA_Client_MonitoredItem *mon, *mon_tmp;
    LIST_FOREACH_SAFE(mon, &sub->monitoredItems, listEntry, mon_tmp) {
        UA_NodeId_deleteMembers(&mon->monitoredNodeId);
        LIST_REMOVE(mon, listEntry);
        UA_free(mon);
    }
    LIST_REMOVE(sub, listEntry);
    UA_free(sub);
}

static UA_StatusCode
addMonitoredItems(UA_Client *client, const UA_UInt32 subscriptionId,
                  UA_MonitoredItemCreateRequest *items, size_t itemsSize,
                  void **hfs, void **hfContexts, UA_StatusCode *itemResults,
                  UA_UInt32 *newMonitoredItemIds, UA_Boolean isEventMonitoredItem) {
    UA_Client_Subscription *sub = findSubscription(client, subscriptionId);
    if(!sub)
        return UA_STATUSCODE_BADSUBSCRIPTIONIDINVALID;

    UA_CreateMonitoredItemsRequest request;
    UA_CreateMonitoredItemsRequest_init(&request);
    UA_CreateMonitoredItemsResponse response;
    UA_CreateMonitoredItemsResponse_init(&response);

    /* Create the handlers */
    UA_StatusCode retval = UA_STATUSCODE_GOOD;
    UA_Client_MonitoredItem **mis = (UA_Client_MonitoredItem**)
        UA_alloca(sizeof(void*) * itemsSize);
    memset(mis, 0, sizeof(void*) * itemsSize);
    for(size_t i = 0; i < itemsSize; i++) {
        mis[i] = (UA_Client_MonitoredItem*)UA_malloc(sizeof(UA_Client_MonitoredItem));
        if(!mis[i]) {
            retval = UA_STATUSCODE_BADOUTOFMEMORY;
            goto cleanup;
        }
    }

    /* Set the clientHandle */
    for(size_t i = 0; i < itemsSize; i++)
        items[i].requestedParameters.clientHandle = ++(client->monitoredItemHandles);

    /* Initialize the request */
    request.subscriptionId = subscriptionId;
    request.itemsToCreate = items;
    request.itemsToCreateSize = itemsSize;

    /* Send the request */
    response = UA_Client_Service_createMonitoredItems(client, request);

    /* Remove for _deleteMembers */
    request.itemsToCreate = NULL;
    request.itemsToCreateSize = 0;

    retval = response.responseHeader.serviceResult;
    if(retval != UA_STATUSCODE_GOOD)
        goto cleanup;

    if(response.resultsSize != itemsSize) {
        retval = UA_STATUSCODE_BADINTERNALERROR;
        goto cleanup;
    }

    for(size_t i = 0; i < itemsSize; i++) {
        UA_MonitoredItemCreateResult *result = &response.results[i];
        UA_Client_MonitoredItem *newMon = mis[i];

        itemResults[i] = result->statusCode;
        if(result->statusCode != UA_STATUSCODE_GOOD) {
            UA_free(newMon);
            continue;
        }

        /* Set the internal representation */
        newMon->monitoringMode = UA_MONITORINGMODE_REPORTING;
        UA_NodeId_copy(&items[i].itemToMonitor.nodeId, &newMon->monitoredNodeId);
        newMon->attributeID = items[i].itemToMonitor.attributeId;
        newMon->clientHandle = items[i].requestedParameters.clientHandle;
        newMon->samplingInterval = result->revisedSamplingInterval;
        newMon->queueSize = result->revisedQueueSize;
        newMon->discardOldest = items[i].requestedParameters.discardOldest;
        newMon->monitoredItemId = response.results[i].monitoredItemId;
        newMon->isEventMonitoredItem = isEventMonitoredItem;
        /* eventHandler is at the same position in the union */
        newMon->handler.dataChangeHandler = (UA_MonitoredItemHandlingFunction)(uintptr_t)hfs[i];
        newMon->handlerContext = hfContexts[i];

        LIST_INSERT_HEAD(&sub->monitoredItems, newMon, listEntry);
        newMonitoredItemIds[i] = newMon->monitoredItemId;
        UA_LOG_DEBUG(client->config.logger, UA_LOGCATEGORY_CLIENT,
                     "Created a monitored item with client handle %u",
                     newMon->clientHandle);
    }

 cleanup:
    if(retval != UA_STATUSCODE_GOOD) {
        for(size_t i = 0; i < itemsSize; i++)
            UA_free(mis[i]);
    }
    UA_CreateMonitoredItemsRequest_deleteMembers(&request);
    UA_CreateMonitoredItemsResponse_deleteMembers(&response);
    return retval;
}


UA_StatusCode
UA_Client_Subscriptions_addMonitoredItems(UA_Client *client, const UA_UInt32 subscriptionId,
                                          UA_MonitoredItemCreateRequest *items, size_t itemsSize,
                                          UA_MonitoredItemHandlingFunction *hfs,
                                          void **hfContexts, UA_StatusCode *itemResults,
                                          UA_UInt32 *newMonitoredItemIds) {
    return addMonitoredItems(client, subscriptionId, items, itemsSize, (void**)hfs,
                             hfContexts, itemResults, newMonitoredItemIds, false);
}

UA_StatusCode UA_EXPORT
UA_Client_Subscriptions_addMonitoredItem(UA_Client *client, UA_UInt32 subscriptionId,
                                         UA_NodeId nodeId, UA_UInt32 attributeID,
                                         UA_MonitoredItemHandlingFunction hf, void *hfContext,
                                         UA_UInt32 *newMonitoredItemId, UA_Double samplingInterval) {
    UA_MonitoredItemCreateRequest item;
    UA_MonitoredItemCreateRequest_init(&item);
    item.itemToMonitor.nodeId = nodeId;
    item.itemToMonitor.attributeId = attributeID;
    item.monitoringMode = UA_MONITORINGMODE_REPORTING;
    item.requestedParameters.samplingInterval = samplingInterval;
    item.requestedParameters.discardOldest = true;
    item.requestedParameters.queueSize = 1;

    UA_StatusCode retval_item = UA_STATUSCODE_GOOD;
    UA_StatusCode retval = addMonitoredItems(client, subscriptionId, &item, 1,
                                             (void**)(uintptr_t)&hf, &hfContext,
                                             &retval_item, newMonitoredItemId, false);
    return retval | retval_item;
}


UA_StatusCode
UA_Client_Subscriptions_addMonitoredEvents(UA_Client *client, const UA_UInt32 subscriptionId,
                                           UA_MonitoredItemCreateRequest *items, size_t itemsSize,
                                           UA_MonitoredEventHandlingFunction *hfs,
                                           void **hfContexts, UA_StatusCode *itemResults,
                                           UA_UInt32 *newMonitoredItemIds) {
    return addMonitoredItems(client, subscriptionId, items, itemsSize, (void**)hfs,
                             hfContexts, itemResults, newMonitoredItemIds, true);
}

UA_StatusCode
UA_Client_Subscriptions_addMonitoredEvent(UA_Client *client, UA_UInt32 subscriptionId,
                                          const UA_NodeId nodeId, UA_UInt32 attributeID,
                                          const UA_SimpleAttributeOperand *selectClauses,
                                          size_t selectClausesSize,
                                          const UA_ContentFilterElement *whereClauses,
                                          size_t whereClausesSize,
                                          const UA_MonitoredEventHandlingFunction hf,
                                          void *hfContext, UA_UInt32 *newMonitoredItemId) {
    UA_MonitoredItemCreateRequest item;
    UA_MonitoredItemCreateRequest_init(&item);
    item.itemToMonitor.nodeId = nodeId;
    item.itemToMonitor.attributeId = attributeID;
    item.monitoringMode = UA_MONITORINGMODE_REPORTING;
    item.requestedParameters.samplingInterval = 0;
    item.requestedParameters.discardOldest = false;

    UA_EventFilter *evFilter = UA_EventFilter_new();
    if(!evFilter)
        return UA_STATUSCODE_BADOUTOFMEMORY;
    UA_EventFilter_init(evFilter);
    evFilter->selectClausesSize = selectClausesSize;
    evFilter->selectClauses = (UA_SimpleAttributeOperand*)(uintptr_t)selectClauses;
    evFilter->whereClause.elementsSize = whereClausesSize;
    evFilter->whereClause.elements = (UA_ContentFilterElement*)(uintptr_t)whereClauses;

    item.requestedParameters.filter.encoding = UA_EXTENSIONOBJECT_DECODED_NODELETE;
    item.requestedParameters.filter.content.decoded.type = &UA_TYPES[UA_TYPES_EVENTFILTER];
    item.requestedParameters.filter.content.decoded.data = evFilter;
    UA_StatusCode retval_item = UA_STATUSCODE_GOOD;
    UA_StatusCode retval = addMonitoredItems(client, subscriptionId, &item, 1,
                                             (void**)(uintptr_t)&hf, &hfContext,
                                             &retval_item, newMonitoredItemId, true);
    UA_free(evFilter);
    return retval | retval_item;
}

UA_StatusCode
UA_Client_Subscriptions_removeMonitoredItems(UA_Client *client, UA_UInt32 subscriptionId,
                                            UA_UInt32 *monitoredItemId, size_t itemsSize,
                                            UA_StatusCode *itemResults) {
    UA_Client_Subscription *sub = findSubscription(client, subscriptionId);
    if(!sub)
        return UA_STATUSCODE_BADSUBSCRIPTIONIDINVALID;

    /* remove the monitoreditem remotely */
    UA_DeleteMonitoredItemsRequest request;
    UA_DeleteMonitoredItemsRequest_init(&request);
    request.subscriptionId = sub->subscriptionID;
    request.monitoredItemIdsSize = itemsSize;
    request.monitoredItemIds = monitoredItemId;
    UA_DeleteMonitoredItemsResponse response = UA_Client_Service_deleteMonitoredItems(client, request);

    UA_StatusCode retval = response.responseHeader.serviceResult;
    if(retval != UA_STATUSCODE_GOOD)
        goto cleanup;

    if(response.resultsSize != itemsSize) {
        retval = UA_STATUSCODE_BADINTERNALERROR;
        goto cleanup;
    }

    for(size_t i = 0; i < itemsSize; i++) {
        itemResults[i] = response.results[i];
        if(response.results[i] != UA_STATUSCODE_GOOD &&
           response.results[i] != UA_STATUSCODE_BADMONITOREDITEMIDINVALID) {
            UA_LOG_INFO(client->config.logger, UA_LOGCATEGORY_CLIENT,
                        "Could not remove monitoreditem %u with error code %s",
                        monitoredItemId[i], UA_StatusCode_name(response.results[i]));
            continue;
        }
        UA_Client_MonitoredItem *mon;
        LIST_FOREACH(mon, &sub->monitoredItems, listEntry) {
            if(mon->monitoredItemId == monitoredItemId[i]) {
                LIST_REMOVE(mon, listEntry);
                UA_NodeId_deleteMembers(&mon->monitoredNodeId);
                UA_free(mon);
                break;
            }
        }
    }

 cleanup:
    /* Remove for _deleteMembers */
    request.monitoredItemIdsSize = 0;
    request.monitoredItemIds = NULL;

    UA_DeleteMonitoredItemsRequest_deleteMembers(&request);
    UA_DeleteMonitoredItemsResponse_deleteMembers(&response);

    return retval;
}

UA_StatusCode
UA_Client_Subscriptions_removeMonitoredItem(UA_Client *client, UA_UInt32 subscriptionId,
                                            UA_UInt32 monitoredItemId) {
    UA_StatusCode retval_item = UA_STATUSCODE_GOOD;
    UA_StatusCode retval = UA_Client_Subscriptions_removeMonitoredItems(client, subscriptionId,
                                                                        &monitoredItemId, 1,
                                                                        &retval_item);
    return retval | retval_item;
}

static void
UA_Client_processPublishResponse(UA_Client *client, UA_PublishRequest *request,
                                 UA_PublishResponse *response) {
    if(response->responseHeader.serviceResult != UA_STATUSCODE_GOOD)
        return;

    UA_Client_Subscription *sub = findSubscription(client, response->subscriptionId);
    if(!sub)
        return;

    /* Check if the server has acknowledged any of the sent ACKs */
    for(size_t i = 0; i < response->resultsSize && i < request->subscriptionAcknowledgementsSize; ++i) {
        /* remove also acks that are unknown to the server */
        if(response->results[i] != UA_STATUSCODE_GOOD &&
           response->results[i] != UA_STATUSCODE_BADSEQUENCENUMBERUNKNOWN)
            continue;

        /* Remove the ack from the list */
        UA_SubscriptionAcknowledgement *orig_ack = &request->subscriptionAcknowledgements[i];
        UA_Client_NotificationsAckNumber *ack;
        LIST_FOREACH(ack, &client->pendingNotificationsAcks, listEntry) {
            if(ack->subAck.subscriptionId == orig_ack->subscriptionId &&
               ack->subAck.sequenceNumber == orig_ack->sequenceNumber) {
                LIST_REMOVE(ack, listEntry);
                UA_free(ack);
                UA_assert(ack != LIST_FIRST(&client->pendingNotificationsAcks));
                break;
            }
        }
    }

    /* Process the notification messages */
    UA_NotificationMessage *msg = &response->notificationMessage;
    for(size_t k = 0; k < msg->notificationDataSize; ++k) {
        if(msg->notificationData[k].encoding != UA_EXTENSIONOBJECT_DECODED)
            continue;

        /* Handle DataChangeNotification */
        if(msg->notificationData[k].content.decoded.type == &UA_TYPES[UA_TYPES_DATACHANGENOTIFICATION]) {
            UA_DataChangeNotification *dataChangeNotification =
                (UA_DataChangeNotification *)msg->notificationData[k].content.decoded.data;
            for(size_t j = 0; j < dataChangeNotification->monitoredItemsSize; ++j) {
                UA_MonitoredItemNotification *mitemNot = &dataChangeNotification->monitoredItems[j];

                /* Find the MonitoredItem */
                UA_Client_MonitoredItem *mon;
                LIST_FOREACH(mon, &sub->monitoredItems, listEntry) {
                    if(mon->clientHandle == mitemNot->clientHandle)
                        break;
                }

                if(!mon) {
                    UA_LOG_DEBUG(client->config.logger, UA_LOGCATEGORY_CLIENT,
                                 "Could not process a notification with clienthandle %u on subscription %u",
                                 mitemNot->clientHandle, sub->subscriptionID);
                    continue;
                }

                if(mon->isEventMonitoredItem) {
                    UA_LOG_DEBUG(client->config.logger, UA_LOGCATEGORY_CLIENT,
                                 "MonitoredItem is configured for Events. But received a "
                                 "DataChangeNotification.");
                    continue;
                }

                mon->handler.dataChangeHandler(client, mon->monitoredItemId,
                                               &mitemNot->value, mon->handlerContext);
            }
            continue;
        }

        /* Handle EventNotification */
        if(msg->notificationData[k].content.decoded.type == &UA_TYPES[UA_TYPES_EVENTNOTIFICATIONLIST]) {
            UA_EventNotificationList *eventNotificationList =
                (UA_EventNotificationList *)msg->notificationData[k].content.decoded.data;
            for(size_t j = 0; j < eventNotificationList->eventsSize; ++j) {
                UA_EventFieldList *eventFieldList = &eventNotificationList->events[j];

                /* Find the MonitoredItem */
                UA_Client_MonitoredItem *mon;
                LIST_FOREACH(mon, &sub->monitoredItems, listEntry) {
                    if(mon->clientHandle == eventFieldList->clientHandle)
                        break;
                }

                if(!mon) {
                    UA_LOG_DEBUG(client->config.logger, UA_LOGCATEGORY_CLIENT,
                                 "Could not process a notification with clienthandle %u on subscription %u",
                                 eventFieldList->clientHandle, sub->subscriptionID);
                    continue;
                }

                if(!mon->isEventMonitoredItem) {
                    UA_LOG_DEBUG(client->config.logger, UA_LOGCATEGORY_CLIENT,
                                 "MonitoredItem is configured for DataChanges. But received a "
                                 "EventNotification.");
                    continue;
                }

                mon->handler.eventHandler(mon->monitoredItemId, eventFieldList->eventFieldsSize,
                                          eventFieldList->eventFields, mon->handlerContext);
            }
        }
    }

    /* Add to the list of pending acks */
    UA_Client_NotificationsAckNumber *tmpAck =
        (UA_Client_NotificationsAckNumber*)UA_malloc(sizeof(UA_Client_NotificationsAckNumber));
    if(!tmpAck) {
        UA_LOG_WARNING(client->config.logger, UA_LOGCATEGORY_CLIENT,
                       "Not enough memory to store the acknowledgement for a publish "
                       "message on subscription %u", sub->subscriptionID);
        return;
    }
    tmpAck->subAck.sequenceNumber = msg->sequenceNumber;
    tmpAck->subAck.subscriptionId = sub->subscriptionID;
    LIST_INSERT_HEAD(&client->pendingNotificationsAcks, tmpAck, listEntry);
}

UA_StatusCode
UA_Client_Subscriptions_manuallySendPublishRequest(UA_Client *client) {
    if(client->state < UA_CLIENTSTATE_SESSION)
        return UA_STATUSCODE_BADSERVERNOTCONNECTED;

    UA_StatusCode retval = UA_STATUSCODE_GOOD;

    UA_DateTime now = UA_DateTime_nowMonotonic();
    UA_DateTime maxDate = now + (UA_DateTime)(client->config.timeout * UA_DATETIME_MSEC);

    UA_Boolean moreNotifications = true;
    while(moreNotifications) {
        UA_PublishRequest request;
        UA_PublishRequest_init(&request);
        request.subscriptionAcknowledgementsSize = 0;

        UA_Client_NotificationsAckNumber *ack;
        LIST_FOREACH(ack, &client->pendingNotificationsAcks, listEntry)
            ++request.subscriptionAcknowledgementsSize;
        if(request.subscriptionAcknowledgementsSize > 0) {
            request.subscriptionAcknowledgements = (UA_SubscriptionAcknowledgement*)
                UA_malloc(sizeof(UA_SubscriptionAcknowledgement) * request.subscriptionAcknowledgementsSize);
            if(!request.subscriptionAcknowledgements)
                return UA_STATUSCODE_BADOUTOFMEMORY;
        }

        int i = 0;
        LIST_FOREACH(ack, &client->pendingNotificationsAcks, listEntry) {
            request.subscriptionAcknowledgements[i].sequenceNumber = ack->subAck.sequenceNumber;
            request.subscriptionAcknowledgements[i].subscriptionId = ack->subAck.subscriptionId;
            ++i;
        }

        UA_PublishResponse response = UA_Client_Service_publish(client, request);
        UA_Client_processPublishResponse(client, &request, &response);

        now = UA_DateTime_nowMonotonic();
        if(now > maxDate) {
            moreNotifications = UA_FALSE;
            retval = UA_STATUSCODE_GOODNONCRITICALTIMEOUT;
        } else {
            moreNotifications = response.moreNotifications;
        }

        UA_PublishResponse_deleteMembers(&response);
        UA_PublishRequest_deleteMembers(&request);
    }

    if(client->state < UA_CLIENTSTATE_SESSION)
        return UA_STATUSCODE_BADSERVERNOTCONNECTED;

    return retval;
}

void
UA_Client_Subscriptions_clean(UA_Client *client) {
    UA_Client_NotificationsAckNumber *n, *tmp;
    LIST_FOREACH_SAFE(n, &client->pendingNotificationsAcks, listEntry, tmp) {
        LIST_REMOVE(n, listEntry);
        UA_free(n);
    }

    UA_Client_Subscription *sub, *tmps;
    LIST_FOREACH_SAFE(sub, &client->subscriptions, listEntry, tmps)
        UA_Client_Subscriptions_forceDelete(client, sub); /* force local removal */
}

#endif /* UA_ENABLE_SUBSCRIPTIONS */