module event-aggregator {
    // FIXME: this module needs to be split up to concepts and API
    //        as the concepts are shared with the other model in this
    //        package.
    yang-version 1;
    namespace "urn:cisco:params:xml:ns:yang:messagebus:eventaggregator";
    prefix "eventaggregator";

    organization "Cisco Systems, Inc.";
    contact "Robert Gallas";

    description
        "Module implementing message but RPC.

        Copyright (c)2014 Cisco Systems, Inc. All rights reserved.

        This program and the accompanying materials are made available
        under the terms of the Eclipse Public License v1.0 which
        accompanies this distribution, and is available at
        http://www.eclipse.org/legal/epl-v10.html";

    revision "2014-12-02" {
        description "Initial revision";
    }

    typedef pattern {
        type string {
            length 1..max;
        }

        // FIXME: make this a regular expression
        description "A match pattern. Specifically this is a wildcard pattern.";
    }

    typedef notification-pattern {
        type pattern;
        description
            "Pattern for matching candidate notification types. This pattern is to be
            applied against the concatenation of the namespace of the module which
            defines that particular notification, followed by a single colon, and
            then followed by notification identifier, as supplied in the argument to
            the notification statement.";
    }

    typedef topic-id {
        type string {
            length 1..max;
        }
        description
            "A topic identifier. It uniquely defines a topic as seen by the the user
            of this model's RPCs";
    }

    // FIXME: we would really like to share instances here, but that requires some sort
    //        of sane reference counting. The reason for sharing is the data path part
    //        of notification delivery -- multiple creators of topics can still share
    //        a single data path.
    rpc create-topic {
        description
            "Create a new topic. A topic is an aggregation of several notification
            types from a set of nodes. Each successful invocation results in a unique
            topic being created. The caller is responsible for removing the topic
            once it is no longer needed.";

        input {
            leaf notification-pattern {
                type notification-pattern;
                mandatory true;
                description
                    "Pattern matching notification which should be forwarded into this
                    topic.";
            }

            leaf node-id-pattern {
                type pattern;
                mandatory true;
                description
                    "Pattern for matching candidate event source nodes when looking
                    for contributors to the topic. The pattern will be applied against
                    /network-topology/topology/node/node-id";
            }
        }

        output {
            leaf topic-id {
                type topic-id;
                mandatory true;
            }
        }
    }

    rpc destroy-topic {
        description
            "Destroy a topic. No further messages will be delivered to it.";

        input {
            leaf topic-id {
                type topic-id;
                mandatory true;
            }
        }
    }

    notification topic-notification {
        description
            "Notification of an event occuring on a particular node. This notification
            acts as an encapsulation for the event being delivered.";

        leaf topic-id {
            type topic-id;
            mandatory true;
            description
                "Topic to which this event is being delivered.";
        }

        leaf node-id {
            // FIXME: should be topology node ID
            type string;
            mandatory true;
            description
                "Node ID of the node which generated the event.";
        }

        anyxml payload {
            mandatory true;
            description
                "Encapsulated notification. The format is the XML representation of
                a notification according to RFC6020 section 7.14.2.";
        }
    }
}