module an-telemetry {
    yang-version "1.1";
    namespace "urn:an:yang:an-telemetry";

    prefix "an-telemetry";

    import an-inet-types {
        prefix an-inet;
    }
    import an-telemetry-types {
        prefix an-telemetry-types;
    }

    description
        "Data model which creates the configuration for the telemetry
         systems and functions on the device.

         This file is modified from openconfig-telemetry.yang, the original author of openconfig-telemetry.yang is OpenConfig,
         OpenConfig holds the copyright of the original work. openconfig-telemetry.yang is licensed under the Apache License 2.0,
         For details, please refer to https://www.openconfig.net/ and https://github.com/openconfig/public/blob/master/LICENSE";

    revision "2020-09-22";

    grouping telemetry-top {
        description
            "Top level grouping for telemetry configuration and operational
             state data";

        container telemetry-system {
            description
                "Top level configuration and state for the
                 device's telemetry system.";

            container sensor-groups {
                description
                    "Top level container for sensor-groups.";

                list sensor-group {
                    key "sensor-group-id";
                    description
                        "List of telemetry sensory groups on the local
                         system, where a sensor grouping represents a resuable
                         grouping of multiple paths and exclude filters.";

                    leaf sensor-group-id {
                        type leafref {
                            path "../config/sensor-group-id";
                        }
                        description
                            "Reference to the name or identifier of the
                             sensor grouping";
                    }

                    container config {
                        description
                            "Configuration parameters relating to the
                             telemetry sensor grouping";
                        uses telemetry-sensor-group-config;
                    }

                    container state {
                        config false;
                        description
                            "State information relating to the telemetry
                             sensor group";
                        uses telemetry-sensor-group-config;
                    }

                    container sensor-paths {
                        description
                            "Top level container to hold a set of sensor
                             paths grouped together";

                        list sensor-path {
                            key "path";
                            description
                                "List of paths in the model which together
                                 comprise a sensor grouping. Filters for each path
                                 to exclude items are also provided.";

                            leaf path {
                                type leafref {
                                    path "../config/path";
                                }
                                description
                                    "Reference to the path of interest";
                            }

                            container config {
                                description
                                    "Configuration parameters to configure a set
                                     of data model paths as a sensor grouping";
                                uses telemetry-sensor-path-config;
                            }

                            container state {
                                config false;
                                description
                                    "Configuration parameters to configure a set
                                     of data model paths as a sensor grouping";
                                uses telemetry-sensor-path-config;
                            }
                        }
                    }
                }
            }

                container destination-groups {
                    description
                        "Top level container for destination group configuration
                         and state.";

                    list destination-group {
                        key "group-id";
                        description
                            "List of destination-groups. Destination groups allow the
                             reuse of common telemetry destinations across the
                             telemetry configuration. An operator references a
                             set of destinations via the configurable
                             destination-group-identifier.

                             A destination group may contain one or more telemetry
                             destinations";

                        leaf group-id {
                            type leafref {
                                path "../config/group-id";
                            }
                            description
                                "Unique identifier for the destination group";
                        }

                        container config {
                            description
                                "Top level config container for destination groups";
                            leaf group-id {
                                type string;
                                description
                                    "Unique identifier for the destination group";
                            }
                        }

                        container state {
                            config false;
                            description
                                "Top level state container for destination groups";

                            leaf group-id {
                                type string;
                                description
                                    "Unique identifier for destination group";
                            }
                        }

                        container destinations {
                            description
                                "The destination container lists the destination
                                 information such as IP address and port of the
                                 telemetry messages from the network element.";
                            list destination {
                                key "destination-address destination-port";
                                description
                                    "List of telemetry stream destinations";

                                leaf destination-address {
                                    type leafref {
                                        path "../config/destination-address";
                                    }
                                    description
                                        "Reference to the destination address of the
                                         telemetry stream";
                                }

                                leaf destination-port {
                                    type leafref {
                                        path "../config/destination-port";
                                    }
                                    description
                                        "Reference to the port number of the stream
                                         destination";
                                }

                                container config {
                                    description
                                        "Configuration parameters relating to
                                         telemetry destinations";
                                    uses telemetry-stream-destination-config;
                                }

                                container state {
                                    config false;
                                    description
                                        "State information associated with
                                         telemetry destinations";
                                    uses telemetry-stream-destination-config;
                                }
                            }
                        }
                    }
                }

            container subscriptions {
                description
                    "This container holds information for both persistent
                     and dynamic telemetry subscriptions.";

                container persistent-subscriptions {
                    description
                        "This container holds information relating to persistent
                         telemetry subscriptions. A persistent telemetry
                         subscription is configued locally on the device through
                         configuration, and is persistent across device restarts or
                         other redundancy changes.";

                    list persistent-subscription {
                        key "name";
                        description
                            "List of telemetry subscriptions. A telemetry
                             subscription consists of a set of collection
                             destinations, stream attributes, and associated paths to
                             state information in the model (sensor data)";

                        leaf name {
                            type leafref {
                                path "../config/name";
                            }
                            description
                                "Reference to the identifier of the subscription
                                 itself. The id will be the handle to refer to the
                                 subscription once created";
                        }

                        container config {
                            description
                                "Config parameters relating to the telemetry
                                 subscriptions on the local device";

                            uses telemetry-subscription-name-config;
                            uses telemetry-local-source-address-config;
                            uses telemetry-qos-marking-config;
                            uses telemetry-stream-protocol-config;
                            uses telemetry-stream-encoding-config;
                        }

                        container state {
                            config false;
                            description
                                "State parameters relating to the telemetry
                                 subscriptions on the local device";

                            uses telemetry-subscription-name-config;
                            uses telemetry-subscription-config;
                            uses telemetry-subscription-state;
                            uses telemetry-local-source-address-config;
                            uses telemetry-qos-marking-config;
                            uses telemetry-stream-protocol-config;
                            uses telemetry-stream-encoding-config;
                        }

                        container sensor-profiles {
                            description
                                "A sensor profile is a set of sensor groups or
                                 individual sensor paths which are associated with a
                                 telemetry subscription. This is the source of the
                                 telemetry data for the subscription to send to the
                                 defined collectors.";
                            list sensor-profile {
                                key "sensor-group";
                                description
                                    "List of telemetry sensor groups used
                                     in the subscription";

                                leaf sensor-group {
                                    type leafref {
                                        path "../config/sensor-group";
                                    }
                                    description
                                        "Reference to the telemetry sensor group name";
                                }

                                container config {
                                    description
                                        "Configuration parameters related to the sensor
                                         profile for a subscription";
                                    uses telemetry-sensor-profile-config;
                                }

                                container state {
                                    config false;
                                    description
                                        "State information relating to the sensor profile
                                         for a subscription";
                                    uses telemetry-sensor-profile-config;
                                }
                            }
                        }

                        container destination-groups {
                            description
                                "A subscription may specify destination addresses.
                                 If the subscription supplies destination addresses,
                                 the network element will be the initiator of the
                                 telemetry streaming, sending it to the destination(s)
                                 specified.

                                 If the destination set is omitted, the subscription
                                 preconfigures certain elements such as paths and
                                 sample intervals under a specified subscription ID.
                                 In this case, the network element will NOT initiate an
                                 outbound connection for telemetry, but will wait for
                                 an inbound connection from a network management
                                 system.

                                 It is expected that the network management system
                                 connecting to the network element will reference
                                 the preconfigured subscription ID when initiating
                                 a subscription.";

                            list destination-group {
                                key "group-id";
                                description
                                    "Identifier of the previously defined destination
                                     group";

                                leaf group-id {
                                    type leafref {
                                        path "../config/group-id";
                                    }
                                    description
                                        "The destination group id references a configured
                                         group of destinations for the telemetry stream.";
                                }

                                container config {
                                    description
                                    "Configuration parameters related to telemetry
                                     destinations.";

                                    leaf group-id {
                                        type leafref {
                                            path "../../../../../../../destination-groups"
                                                + "/destination-group/group-id";
                                        }
                                        description
                                            "The destination group id references a reusable
                                             group of destination addresses and ports for
                                             the telemetry stream.";
                                    }
                                }

                                container state {
                                    config false;
                                    description
                                    "State information related to telemetry
                                     destinations";

                                    leaf group-id {
                                        type leafref {
                                            path "../../../../../../../destination-groups"
                                                + "/destination-group/group-id";
                                        }
                                        description
                                            "The destination group id references a reusable
                                             group of destination addresses and ports for
                                             the telemetry stream.";
                                    }
                                }
                            }
                        }
                    }
                }

                container dynamic-subscriptions {
                    description
                        "This container holds information relating to dynamic
                         telemetry subscriptions. A dynamic subscription is
                         typically configured through an RPC channel, and does not
                         persist across device restarts, or if the RPC channel is
                         reset or otherwise torn down.";


                    list dynamic-subscription {
                        key "id";

                        config false;
                        description
                            "List representation of telemetry subscriptions that
                             are configured via an inline RPC, otherwise known
                             as dynamic telemetry subscriptions.";

                        leaf id {
                            type leafref {
                                path "../state/id";
                            }

                            description
                                "Reference to the identifier of the subscription
                                 itself. The id will be the handle to refer to the
                                 subscription once created";
                        }

                        container state {
                            config false;
                            description
                                "State information relating to dynamic telemetry
                                 subscriptions.";

                            uses telemetry-subscription-config;
                            uses telemetry-stream-destination-config;
                            uses telemetry-stream-frequency-config;
                            uses telemetry-heartbeat-config;
                            uses telemetry-suppress-redundant-config;
                            uses telemetry-qos-marking-config;
                            uses telemetry-stream-protocol-config;
                            uses telemetry-stream-encoding-config;
                        }

                        container sensor-paths {
                            description
                                "Top level container to hold a set of sensor
                                 paths grouped together";

                            list sensor-path {
                                key "path";
                                description
                                    "List of paths in the model which together
                                     comprise a sensor grouping. Filters for each path
                                     to exclude items are also provided.";

                                leaf path {
                                    type leafref {
                                        path "../state/path";
                                    }
                                    description
                                        "Reference to the path of interest";
                                }

                                container state {
                                    config false;
                                    description
                                        "State information for a dynamic subscription's
                                         paths of interest";
                                    uses telemetry-sensor-path-config;
                                }
                            }
                        }
                    }
                }
            }
        }
    }

    // identity statements

    // typedef statements

    // grouping statements

    grouping telemetry-sensor-path-config {
        description
            "Configuration parameters relating to the
             grouping of data model paths comprising a
             sensor grouping";
            leaf path {
                type string;
                description
                    "Path to a section of operational state of interest
                     (the sensor).";
            }

            leaf exclude-filter {
                type string;
                description
                    "Filter to exclude certain values out of the state
                     values";
                //May not be necessary. Could remove.
            }
    }

    grouping telemetry-heartbeat-config {
        description
            "Configuration parameters relating to the
             heartbeat of the telemetry subscription";
        leaf heartbeat-interval {
            type uint64;
            description
                "Maximum time interval in seconds that may pass
                 between updates from a device to a telemetry collector.
                 If this interval expires, but there is no updated data to
                 send (such as if suppress_updates has been configured), the
                 device must send a telemetry message to the collector.";
        }
    }

    grouping telemetry-suppress-redundant-config {
        description
            "Configuration parameters relating to suppression of
             redundant upstream updates";
        leaf suppress-redundant {
            type boolean;
            description
                "Boolean flag to control suppression of redundant
                 telemetry updates to the collector platform. If this flag is
                 set to TRUE, then the collector will only send an update at
                 the configured interval if a subscribed data value has
                 changed. Otherwise, the device will not send an update to
                 the collector until expiration of the heartbeat interval.";
        }
    }

    grouping telemetry-sensor-profile-config {
        description
            "Configuration parameters relating to the sensor groups
             used in the sensor profile";
        leaf sensor-group {
            type leafref {
                path "../../../../../../../sensor-groups/sensor-group"
                + "/config/sensor-group-id";
            }
            description
                "Reference to the sensor group which is used in the profile";
        }
        uses telemetry-stream-subscription-config;
    }

    grouping telemetry-stream-subscription-config {
        description
            "Configuration used when the sensor is a stream based sensor.";

        uses telemetry-stream-frequency-config;
        uses telemetry-heartbeat-config;
        uses telemetry-suppress-redundant-config;

    }

    grouping telemetry-qos-marking-config {
        description
            "Config parameters relating to the quality of service
             marking on device generated telemetry packets";

        leaf originated-qos-marking {
            type an-inet:dscp;
            description
                "DSCP marking of packets generated by the telemetry
                 subsystem on the network device.";
        }
    }


    grouping telemetry-sensor-group-config {
        description
            "Config parameters related to the sensor groups
             on the device";
        leaf sensor-group-id {
            type string;
            description
                "Name or identifier for the sensor group itself.
                 Will be referenced by other configuration specifying a
                 sensor group";
        }
    }

    grouping telemetry-subscription-config {
        description
            "Configuration parameters relating to the telemetry
             subscription";

        leaf id {
            type uint64;
            description
                "System generated identifer of the telemetry
                 subscription.";
        }
    }

    grouping telemetry-subscription-name-config {
        description
            "Configuration parameters relating to the configured
             name of the telemetry subscription. The name is a user
             configured string value which uniquely identifies the
             subscription in the configuration database.";

         leaf name {
             type string;
             description
                "User configured identifier of the telemetry
                 subscription. This value is used primarily for
                 subscriptions configured locally on the network
                 element.";
         }
    }

    grouping telemetry-subscription-state {
        description
            "State values for the telemetry subscription";
        //TODO add values
    }

    grouping telemetry-stream-protocol-config {
        description
            "Configuration parameters relating to the
             transport protocol carrying telemetry
             data.";

        leaf protocol {
            type identityref {
                base an-telemetry-types:STREAM_PROTOCOL;
            }
            description
                "Selection of the transport protocol for the telemetry
                 stream.";
        }
    }

    grouping telemetry-stream-encoding-config {
        description
            "Configuration parameters relating to the
             encoding of telemetry data to and from the
             network element. The encoding method controls
             specifically the wire format of the telemetry
             data, and also controls which RPC framework
             may be in use to exchange telemetry data.";

         leaf encoding {
             type identityref {
                 base an-telemetry-types:DATA_ENCODING_METHOD;
             }
             description
                "Selection of the specific encoding or RPC framework
                 for telemetry messages to and from the network element.";
         }
    }

    grouping telemetry-stream-destination-config {
        description
            "Configuration parameters for the stream destinations";
            leaf destination-address {
                type an-inet:ip-address;
                description
                    "IP address of the telemetry stream destination";
            }
            leaf destination-port {
                type uint16;
                description
                    "Protocol (udp or tcp) port number for the telemetry
                     stream destination";
            }
    }

    grouping telemetry-stream-frequency-config {
        description
            "Config parameters for the frequency of updates to
             the collector";
        leaf sample-interval {
            type uint64;
            description
                " The accuracy of the collected data reported by the device
to the collector";
        }
    }

    grouping telemetry-sensor-specification {
        description
            "Config related to creating telemetry sensor groups. A sensor
             group is a related set of sensor paths and/or filters to
             exclude items. A group is assigned a reusable identifer, so
             it can be used in multiple telemetry subscriptions.";
        list telemetry-sensor-group {
            key "telemetry-sensor-group-id";
            description
                "List of telemetry sensor groups";

            leaf telemetry-sensor-group-id {
                type string;
                description
                    "The sensor group identifer is a reusable handle which
                     identifies a single sensor group. It is referenced from
                     the subscription configuration.";
            }
            uses telemetry-sensor-paths;
        }
    }

    grouping telemetry-sensor-paths {
        description
            "This grouping contains these paths to leaves or containers
             in the data model which are the sources of telemetry
             information.";

        list telemetry-sensor-paths {
            key "telemetry-sensor-path";
            description
                "A list of sensor paths and exclude filters which comprise
                 a sensor grouping";

            leaf telemetry-sensor-path {
                type string;
                description
                    "The sensor path is a path to a portion of operational
                     state of interest in the data model";
            }
        }
    }


    grouping telemetry-local-source-address-config {
        description
            "Config relating to the local source address for telemetry
             messages";
        // TODO: Make this a reference to an interface.
        leaf local-source-address {
            type an-inet:ip-address;
            description
                "The IP address which will be the source of packets from
                 the device to a telemetry collector destination.";
        }
    }

    // data definition statements

    uses telemetry-top;

    // augment statements

    // rpc statements

    // notification statements
}