Common YANG extensions

module o-ran-smo-teiv-common-yang-extensions {

  yang-version 1.1;
  namespace "urn:o-ran:smo-teiv-common-yang-extensions";
  prefix or-teiv-yext;

  organization "ORAN";
  contact "The Authors";
  description
  "Topology and Inventory YANG extensions model

  This model contains extensions to the YANG language that topology and
  inventory models will use to define and annotate types and relationships.

  Copyright (C) 2024 Ericsson
  Modifications Copyright (C) 2024 OpenInfra Foundation Europe

  Licensed under the Apache License, Version 2.0 (the \"License\");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

  http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an \"AS IS\" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

  SPDX-License-Identifier: Apache-2.0";

  revision "2024-05-02" {
    description "Initial revision.";
    or-teiv-yext:label 0.3.0;
  }

  extension biDirectionalTopologyRelationship {

    description
      "Defines a bi-directional relationship in the topology.

       A bi-directional-association (BDA) is a relationship comprising of an
       A-side and a B-side. The A-side is considered the originating side of
       the relationship; the B-side is considered the terminating side of the
       relationship. The order of A-side and B-side is of importance and MUST
       NOT be changed once defined.

       Both A-side and B-side are defined on a type, and are given a role. A
       type may have multiple originating and/or terminating sides of a
       relationship, all distinguished by role name.

       The statement MUST only be a substatement of the 'module' statement.
       Multiple 'bi-directional-topology-relationship' statements are allowed
       per parent statement.

       Substatements to the 'bi-directional-topology-relationship' define the
       A-side and the B-side, respectively, and optionally properties of the
       relationship. Data nodes of types 'leaf' and 'leaf-list' are used for
       this purpose. One of the data nodes MUST be annotated with the 'a-side'
       extension; another data node MUST be annotated with the 'b-side'
       extension. Other data nodes define properties of the relationship.

       The argument is the name of the relationship. The relationship name is
       scoped to the namespace of the declaring module and MUST be unique
       within the scope.";

    argument relationshipName;
  }

  extension aSide {
    description
      "Defines the A-side of a relationship.

       The statement MUST only be a substatement of a 'leaf' or 'leaf-list'
       statement, which itself must be a substatement of the
       'uni-directional-topology-relationship' statement.

       The data type of the parent 'leaf' or 'leaf-list' MUST be
       'instance-identifier'. Constraints MAY be used as part of the parent
       'leaf' or 'leaf-list' to enforce cardinality.

       The identifier of the parent 'leaf' or 'leaf-list' is used as name of
       the role of the A-side of the relationship. The name of the role is
       scoped to the type on which the A-side is defined and MUST be unique
       within the scope.

       While the parent 'leaf' or 'leaf-list' does not result in a property of
       the relationship, it is RECOMMENDED to avoid using the name of an
       existing type property as role name to avoid potential ambiguities
       between properties of a type, and roles of a relationship on the type.

       The argument is the name of the type on which the A-side resides. If the
       type is declared in another module, the type must be prefixed, and a
       corresponding 'import' statement be used to declare the prefix.";

    argument aSideType;
  }

  extension bSide {
    description "Defines the B-side of a relationship.

       The statement MUST only be a substatement of a 'leaf' or 'leaf-list'
       statement, which itself must be a substatement of the
       'uni-directional-topology-relationship' statement.

       The data type of the parent 'leaf' or 'leaf-list' MUST be
       'instance-identifier'. Constraints MAY be used as part of the parent
       'leaf' or 'leaf-list' to enforce cardinality.

       The identifier of the parent 'leaf' or 'leaf-list' is used as name of
       the role of the B-side of the relationship. The name of the role is
       scoped to the type on which the B-side is defined and MUST be unique
       within the scope.

       While the parent 'leaf' or 'leaf-list' does not result in a property of
       the relationship, it is RECOMMENDED to avoid using the name of an
       existing type property as role name to avoid potential ambiguities
       between properties of a type, and roles of a relationship on the type.

       The argument is the name of the type on which the B-side resides. If the
       type is declared in another module, the type must be prefixed, and a
       corresponding 'import' statement be used to declare the prefix.";

    argument bSideType;
  }

  extension domain {
    description "Keyword used to carry domain information.";
    argument domainName;
  }

  extension label {
    description "The label can be used to give modules and submodules a semantic version, in addition to their revision.

      The format of the label is 'x.y.z' - expressed as pattern, it is [0-9]+\\.[0-9]+\\.[0-9]+

      The statement MUST only be a substatement of the revision statement.  Zero or one revision label statements
      per parent statement are allowed.

      Revision labels MUST be unique amongst all revisions of a module or submodule.";
      argument semversion;
  }
}