module ietf-coreconf {
  yang-version 1.1;

  namespace "urn:ietf:params:xml:ns:yang:ietf-coreconf";
  prefix coreconf;

  import ietf-datastores {
    prefix ds;
    reference
      "RFC 8342: Network Management Datastore Architecture (NMDA)";
  }

  import ietf-restconf {
    prefix rc;
    description
      "This import statement is required to access
       the yang-data extension defined in RFC 8040.";
    reference "RFC 8040: RESTCONF Protocol";
  }

  organization
    "IETF Core Working Group";

  contact
    "WG Web:   <https://datatracker.ietf.org/wg/core/>
     WG List:  <mailto:core@ietf.org>

     Michel Veillette
     <mailto:michel.veillette@trilliantinc.com>

     Alexander Pelov
     <mailto:alexander.pelov@imt-atlantique.fr>

     Peter van der Stok
     <mailto:stokcons@kpnmail.nl>

     Andy Bierman
     <mailto:andy@yumaworks.com>";

  description
    "This module contains the different definitions required
     by the CORECONF protocol.

     Copyright (c) 2024 IETF Trust and the persons identified as
     authors of the code.  All rights reserved.

     Redistribution and use in source and binary forms, with or
     without modification, is permitted pursuant to, and subject
     to the license terms contained in, the Revised BSD License
     set forth in Section 4.c of the IETF Trust's Legal Provisions
     Relating to IETF Documents
     (https://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC XXXX;
     see the RFC itself for full legal notices.";

  revision 2024-03-04 {
     description
      "Initial revision.";
    reference
      "[I-D.ietf-core-comi] CoAP Management Interface";
  }

  identity unified {
    base ds:datastore;
    description
      "Identifier of the unified configuration and operational
       state datastore.";
  }

  identity error-tag {
    description
      "Base identity for error-tag.";
  }

  identity operation-failed {
    base error-tag;
    description
      "Returned by the CORECONF server when the operation request
       can't be processed successfully.";
  }

  identity invalid-value {
    base error-tag;
    description
      "Returned by the CORECONF server when the CORECONF client tries
       to update or create a leaf with a value encoded using an
       invalid CBOR datatype or if the 'range', 'length',
       'pattern' or 'require-instance' constrain is not
       fulfilled.";
  }
  identity missing-element {
    base error-tag;
    description
      "Returned by the CORECONF server when the operation requested
       by a CORECONF client fails to comply with the 'mandatory'
       constraint defined. The 'mandatory' constraint is
       enforced for leafs and choices, unless the node or any of
       its ancestors have a 'when' condition or 'if-feature'
       expression that evaluates to 'false'.";
  }

  identity unknown-element {
    base error-tag;
    description
      "Returned by the CORECONF server when the CORECONF client tries
       to access a data node of a YANG module not supported, of a
       data node associated with an 'if-feature' expression
       evaluated to 'false' or to a 'when' condition evaluated
       to 'false'.";
  }

  identity bad-element {
    base error-tag;
    description
      "Returned by the CORECONF server when the CORECONF client tries
       to create data nodes for more than one case in a choice.";
  }

  identity data-missing {
    base error-tag;
    description
      "Returned by the CORECONF server when a data node required to
       accept the request is not present.";
  }

  identity error {
    base error-tag;
    description
      "Returned by the CORECONF server when an unspecified error has
      occurred.";
  }

  identity error-app-tag {
    description
      "Base identity for error-app-tag.";
  }

  identity malformed-message {
    base error-app-tag;
    description
      "Returned by the CORECONF server when the payload received
       from the CORECONF client don't contain a well-formed CBOR
       content as defined in [RFC8949] or don't
       comply with the CBOR structure defined within this
       document.";
  }

  identity data-not-unique {
    base error-app-tag;
    description
      "Returned by the CORECONF server when the validation of the
       'unique' constraint of a list or leaf-list fails.";
  }

  identity too-many-elements {
    base error-app-tag;
    description
      "Returned by the CORECONF server when the validation of the
       'max-elements' constraint of a list or leaf-list fails.";
  }

  identity too-few-elements {
    base error-app-tag;
    description
      "Returned by the CORECONF server when the validation of the
       'min-elements' constraint of a list or leaf-list fails.";
  }

  identity must-violation {
    base error-app-tag;
    description
      "Returned by the CORECONF server when the restrictions
       imposed by a 'must' statement are violated.";
  }

  identity duplicate {
    base error-app-tag;
    description
      "Returned by the CORECONF server when a client tries to create
       a duplicate list or leaf-list entry.";
  }

  identity invalid-datatype {
    base error-app-tag;
    description
      "Returned by the CORECONF server when CBOR encoding is
       incorect or when the value encoded is incompatible with
       the YANG Built-In type. (e.g., value greater than 127
       for an int8, undefined enumeration).";
  }

  identity not-in-range {
    base error-app-tag;
    description
      "Returned by the CORECONF server when the validation of the
       'range' property fails.";
  }

  identity invalid-length {
    base error-app-tag;
    description
      "Returned by the CORECONF server when the validation of the
       'length' property fails.";
  }

  identity pattern-test-failed {
    base error-app-tag;
    description
      "Returned by the CORECONF server when the validation of the
       'pattern' property fails.";
  }

  identity missing-key {
    base error-app-tag;
    description
      "Returned by the CORECONF server to further qualify a
       missing-element error. This error is returned when the
       CORECONF client tries to create a list instance, without all
       the 'key' specified or when the CORECONF client tries to
       delete a leaf listed as a 'key'.";
  }

  identity missing-input-parameter {
    base error-app-tag;
    description
      "Returned by the CORECONF server when the input parameters
       of a RPC or action are incomplete.";
  }

  identity instance-required {
    base error-app-tag;
    description
      "Returned by the CORECONF server when a leaf of type
       'instance-identifier' or 'leafref' marked with
       require-instance set to 'true' refers to an instance
       that does not exist.";
  }

  identity missing-choice {
    base error-app-tag;
    description
      "Returned by the CORECONF server when no nodes exist in a
       mandatory choice.";
  }

  rc:yang-data coreconf-error {
    container error {
      description
        "Optional payload of a 4.00 Bad Request CoAP error.";

      leaf error-tag {
        type identityref {
          base error-tag;
        }
        mandatory true;
        description
          "The enumerated error-tag.";
      }

      leaf error-app-tag {
        type identityref {
          base error-app-tag;
        }
        description
          "The application-specific error-tag.";
      }

      leaf error-data-node {
        type instance-identifier;
        description
          "When the error reported is caused by a specific data node,
           this leaf identifies the data node in error.";
      }

      leaf error-message {
        type string;
        description
          "A message describing the error.";
      }
    }
  }
}