/*
 *
 *   Copyright 2018 CTTC
 *   Copyright 2018 Telefonica Investigacion y Desarrollo S.A.U.
 *
 *   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.
 *
 *
 */

module nst {
  //header information
  yang-version 1;
  namespace "urn:etsi:osm:yang:nst";
  prefix "nst";

  import nsd-base{
    prefix "nsd-base";
  }

  import nsd {
    prefix "nsd";
  }

  import instantiation-parameters {
    prefix "instantiation-parameters";
  }

  import ietf-inet-types {
    prefix "inet";
  }

  //revision history
  revision 2018-08-20 {
    description "Initial version";
  }

  //typedef definitions
  typedef connection-points {
    description "";
    type string;
  }

  typedef network-slice-type {
    type enumeration {
      enum eMBB {
        description "enhanced Mobile Broadband slice";
      }
      enum URLLC {
        description "Ultra Reliable Low Latency Communications slice";
      }
      enum mMTC {
        description "massive Machine Type Communications slice";
      }
    }
  }

  typedef resource-type {
    type enumeration {
      enum delay-critical-GBR {
        description "delay critical guaranted bit rate";
      }
      enum GBR {
        description "guaranted bit rate";
      }
      enum non-GBR {
        description "NON guaranted bit rate";
      }
    }
  }

  grouping nsvld {
    description "List of NetSlice Subnet Virtual Link Descriptors.";

    uses nsd-base:vld-common;

    list nss-connection-point-ref {
      description
          "A list of references to connection points.";
      key "nss-ref nsd-connection-point-ref";

      leaf nss-ref {
        description "Reference to nsd";
        type leafref {
          path "/nst:nst/nst:netslice-subnet/nst:id";
        }
      }

      leaf nsd-connection-point-ref {
        description "A reference to a connection point name";
        type leafref {
          path "/nsd:nsd-catalog/nsd:nsd/nsd:connection-point/nsd:name";
        }
      }

      leaf ip-address {
        description "IP address of the connection point";
        type inet:ip-address;
      }

    }
  } // nsvld

  grouping snssai {
    description "";
    leaf slice-service-type {
      description "Network slice service type ";
      type network-slice-type;
      mandatory true;
    }
    leaf slice-differentiator {
      description "Network slice differentiator";
      type string;
    }
  } // snssai

  grouping five-qi {
    leaf id{
      description "Quality of service identifier";
      type uint16;
      mandatory true;
    }
    leaf resource-type {
      description "Quality of service resource type";
      type resource-type;
    }
    leaf priority-level {
      description "Priority level of the service";
      type uint16;
    }
    leaf packet-delay-budget {
      description "Packet delay budget in miliseconds (ms)";
      type uint16;
    }
    leaf packet-error-rate {
      description "Packet error rate (PER) given in powers of ten";
      type uint16;
    }
    leaf default-max-data-burst {
      description "Maximum data burst given in bytes (B)";
      type uint16;
    }
  }

  grouping netslice-subnet {
    leaf id {
      description "Identifier or name for the netslice-subnet in NST scope.";
      mandatory true;
      type string {
        length 1..63;
      }
    }
    leaf description {
      description "Description of the NSD.";
      type string;
    }
    leaf is-shared-nss {
      description "NSS is shared between NS";
      type boolean;
      default false;
    }
    leaf nsd-ref {
      description "Reference to catalog NSD";
      mandatory true;
      type leafref{
          path "/nsd:nsd-catalog/nsd:nsd/nsd:id";
      }
    }
    container instantiation-parameters {
      uses instantiation-parameters:ns_params;
    }

  }

  grouping slice-connection-points {
    description "List for external connection points. Each NS has one or more external connection
                points. As the name implies that external connection points are used for connecting
                the NS to other NS or to external networks. Each NS exposes these connection points 
                to the orchestrator. The orchestrator can construct network service chains by 
                connecting the connection points between different NS.";

    uses nsd-base:nsd-connection-point-common;

    choice connection {
      description "Logical connection of the CP to a NSVLD or to a NSD CP";
      case netslice-vld-ref {
        leaf netslice-vld-id-ref {
          description "ID reference to a NSVLD in the NS";
          type leafref {
            path "../../netslice-vld/id";
          }

        }
      }
      case nsd-connection-point-ref {
        leaf nsd-id-ref {
          description "A reference to a nsd.";
          type leafref {
            path "/nsd:nsd-catalog/nsd:nsd/nsd:id";
          }
        }
        leaf nsd-connection-point-ref {
          description "";
          type leafref {
            path "/nsd:nsd-catalog/nsd:nsd/nsd:connection-point/nsd:name";
           }
        }
      }
    }
  }

  grouping rsp {

    uses nsd-base:rsp-common;

    list nsd-connection-point-ref {
      description
        "A list of references to connection points.";
      key "nsd-ref";

      leaf nsd-ref {
        description "Reference to member-vnf within constituent-vnfds";
        type leafref {
          path "/nsd:nsd-catalog/nsd:nsd/nsd:id";
        }
      }
      leaf order {
        type uint8;
        description
          "A number that denotes the order of a NSD in a chain";
      }
      leaf nsd-connection-point-ref {    
        type leafref {
          path "/nsd:nsd-catalog/nsd:nsd/nsd:connection-point/nsd:name";
         }
      }
    }  
  }

  grouping classifier {
    uses nsd-base:classifier-common;

    leaf nsd-ref {
      type leafref {
          path "/nsd:nsd-catalog/nsd:nsd/nsd:id";
      }
    }

    leaf nsd-connection-point-ref {

      type leafref {
        path "/nsd:nsd-catalog/nsd:nsd/nsd:connection-point/nsd:name";
       }
    }
  }

  grouping netslicefgd {

    uses nsd-base:fgd-common;

    list rsp {
      description
        "List of Rendered Service Paths (RSP).";
      key "id";
      uses rsp;
    } 

    list classifier {
      description
          "List of classifier rules.";
      key "id";
      uses classifier;
    } 
  }
  grouping network-slice{
    leaf id {
      mandatory true;
      type string;
    }

    leaf name {
      type string;
      mandatory true;
    }

    container SNSSAI-identifier {
      uses snssai;
    }
    container quality-of-service {
      uses five-qi;
    }
    list netslice-subnet {//list with multiple network service elements
      key "id";
      uses netslice-subnet;
    }
    list netslice-connection-point {
      key "name";
      uses slice-connection-points;
    }
    list netslice-vld {
      key "id";
      uses nsvld;
    }
    list netslicefgd {
      key "id";
      uses netslicefgd;
    }
  }

  //containers definitions
  list nst {
    key "id";
    uses network-slice;
  }
}