module openconfig-telemetry {

  yang-version "1";

  // namespace
  namespace "http://openconfig.net/yang/telemetry";

  prefix "oc-telemetry";

  // import some basic types
  import openconfig-inet-types { prefix oc-inet; }
  import openconfig-extensions { prefix oc-ext; }
  import openconfig-telemetry-types { prefix oc-telemetry-types; }

  // meta
  organization "OpenConfig working group";

  contact
    "OpenConfig working group www.openconfig.net";

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

  oc-ext:openconfig-version "0.4.0";

  revision "2017-02-20" {
    description
      "Fixes for YANG 1.0 compliance, add types module";
    reference "0.4.0";
  }

  revision "2016-04-05" {
    description
      "OpenConfig public release";
    reference "0.2.0";
  }

  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 {
          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 subscription {
            key "subscription-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 subscription-name {
              type leafref {
                path "../config/subscription-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 {
          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 subscription {
            key "subscription-id";
            config false;
            description
              "List representation of telemetry subscriptions that
              are configured via an inline RPC, otherwise known
              as dynamic telemetry subscriptions.";

            leaf subscription-id {
              type leafref {
                path "../state/subscription-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 oc-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 subscription-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 subscription-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 oc-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 oc-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 oc-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
        "Time in milliseconds between the device's sample of a
         telemetry data source. For example, setting this to 100
         would require the local device to collect the telemetry
         data every 100 milliseconds. There can be latency or jitter
         in transmitting the data, but the sample must occur at
         the specified interval.

         The timestamp must reflect the actual time when the data
         was sampled, not simply the previous sample timestamp +
         sample-interval.

         If sample-interval is set to 0, the telemetry sensor
         becomes event based. The sensor must then emit data upon
         every change of the underlying data source.";
    }
  }

  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";
      }
      // This may not be needed. Decide on removal.
      leaf sensor-exclude-filter {
        type string;
        description
          "The exclude filter allows certain values of state to be
          filtered out of the telemetry stream";
      }
    }
  }


  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 oc-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

}