Asset-identity model + merge-by-identity

src/ros2_medkit_gateway/CMakeLists.txt

@@ -642,6 +642,10 @@ if(BUILD_TESTING)
   ament_add_gtest(test_merge_pipeline test/test_merge_pipeline.cpp)
   target_link_libraries(test_merge_pipeline gateway_ros2)
 
+  # Add asset-identity model + merge tests
+  ament_add_gtest(test_asset_identity test/test_asset_identity.cpp)
+  target_link_libraries(test_asset_identity gateway_ros2)
+
   # Add capability builder tests
   ament_add_gtest(test_capability_builder test/test_capability_builder.cpp)
   target_link_libraries(test_capability_builder gateway_ros2)

src/ros2_medkit_gateway/README.md

@@ -1544,6 +1544,63 @@ Runtime mode mapping:
 /standalone_node                -> Component: <hostname>, App: standalone_node
 ```
 
+### Asset Identity (nameplate) and merge-by-identity
+
+Each Component can carry an **asset identity**: the stable nameplate of the physical
+or logical asset it represents (an ECU, PLC, drive, sensor), separate from its runtime
+ROS 2 footprint. The model lives in `core/discovery/models/asset_identity.hpp`.
+
+Typed fields (queryable, AAS-mappable) plus a generic `extra` key-value map for
+vendor-specific attributes we do not model up front:
+
+| Field | JSON key | AAS Nameplate (IDTA 02006) |
+|-------|----------|----------------------------|
+| `manufacturer` | `manufacturer` | ManufacturerName |
+| `model` (order code) | `model` | ManufacturerProductDesignation |
+| `serial_number` | `serialNumber` | SerialNumber |
+| `hardware_revision` | `hardwareRevision` | HardwareVersion |
+| `firmware_version` | `firmwareVersion` | FirmwareVersion |
+| `software_version` | `softwareVersion` | SoftwareVersion |
+| `network_endpoint` | `networkEndpoint` | Asset Interface Description (AID) endpoint |
+| `role` | `role` | functional role (BoM/usage context) |
+| `extra` | `extra` | additional Nameplate properties |
+
+The whole block maps to an Asset Administration Shell later without rework: the asset
+itself is the shell (`Component.id` as localId), this block is the **Nameplate** submodel,
+the Component hierarchy is the **BoM** submodel, and `network_endpoint` is an **AID** entry.
+
+Identity is emitted under `x-medkit.identity` only when populated, so identity-less
+components keep their existing JSON unchanged.
+
+**Why typed fields and a map?** Typed fields are the common, queryable, standard-mappable
+attributes; the `extra` map is the escape hatch for vendor keys (rack/slot, MAC, asset tag)
+that do not warrant a schema change. Both merge with the same rules.
+
+**Merge-by-identity with provenance.** A single asset is usually described by several
+sources (a hand-authored manifest, a live protocol device-info read, runtime discovery).
+`merge_identity()` (`core/discovery/identity_merge.hpp`) combines them field by field and
+records **per-field provenance** (which source set each field) under `_provenance`.
+
+- **Precedence** is config-driven (`IdentityMergeConfig::source_precedence`, highest first)
+  and is deliberately **decoupled from the structural `MergePolicy`**: a manifest can be the
+  authoritative *structure* source while a live protocol read is the authoritative *identity*
+  source. Authority is ranked on each contributing entity's canonical `Component.source` tag
+  ("manifest", "plugin", "runtime", "node", "config", or a protocol-class tag a provider sets
+  such as "opcua"), **not** the free-form discovery-layer name. Default order: protocol
+  device-info (`opcua`, `s7`, `ethernet_ip`, `modbus`, `ads`, `profinet`, and the generic
+  `plugin`) > `manifest` > `config` > runtime sources. A higher-authority source overrides a
+  field; lower-authority sources only fill gaps; unknown sources rank lowest. Empty values never
+  overwrite.
+
+Components are correlated for merging by `Component.id`; identity is merged whenever two
+sources contribute the same Component id (in the discovery pipeline, and gap-filled across
+peer aggregation).
+
+The pipeline calls `merge_identity` inside the `IDENTITY` field group for Components, seeding
+provenance with the base (highest-priority) layer's source tag. Configure via
+`MergePipeline::set_identity_merge_config()`; precedence entries must equal the canonical
+`Component.source` values you expect at runtime.
+
 ## Demo Nodes
 
 The package includes demo automotive nodes for testing:

src/ros2_medkit_gateway/include/ros2_medkit_gateway/core/discovery/identity_merge.hpp

@@ -0,0 +1,172 @@
+// Copyright 2026 bburda
+//
+// 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.
+
+#pragma once
+
+#include "ros2_medkit_gateway/core/discovery/models/asset_identity.hpp"
+
+#include <array>
+#include <cstddef>
+#include <string>
+#include <utility>
+#include <vector>
+
+namespace ros2_medkit_gateway {
+namespace discovery {
+
+/**
+ * @brief Configuration for identity merging.
+ *
+ * `source_precedence` ranks identity authority from highest to lowest. Entries are
+ * matched against a source's canonical identifier - the contributing entity's
+ * `Component.source` field ("manifest", "plugin", "runtime", "node", "heuristic",
+ * "config", or a protocol-class tag a provider sets such as "opcua"/"s7"), NOT the
+ * free-form discovery-layer / plugin name. A source not in the list ranks lowest: it
+ * can still fill empty fields but never overrides a known source.
+ *
+ * Identity authority is deliberately decoupled from the structural merge policy: a
+ * manifest may be the authoritative *structure* source while a live protocol read is
+ * the authoritative *identity* source.
+ *
+ * Default precedence (highest first): a live protocol device-info read (a `plugin`
+ * source, or a protocol-specific source tag) beats the hand-authored `manifest`,
+ * which beats whatever runtime discovery guessed. The protocol-specific tags lead the
+ * list so that a provider which sets a concrete `Component.source` (e.g. "opcua") is
+ * honoured; the generic "plugin" tag covers the common case where the plugin layer
+ * stamps every plugin entity with source="plugin".
+ */
+struct IdentityMergeConfig {
+  std::vector<std::string> source_precedence{"opcua",    "s7",     "ethernet_ip", "modbus", "ads",
+                                             "profinet", "plugin", "manifest",    "config", "runtime",
+                                             "node",     "topic",  "heuristic"};
+};
+
+/**
+ * @brief Rank of a source: lower number = higher authority. Unknown sources rank
+ * just below every listed source (all unknowns share the same lowest rank).
+ */
+inline size_t source_rank(const std::string & source, const IdentityMergeConfig & config) {
+  for (size_t i = 0; i < config.source_precedence.size(); ++i) {
+    if (config.source_precedence[i] == source) {
+      return i;
+    }
+  }
+  return config.source_precedence.size();
+}
+
+namespace detail {
+
+/// All typed identity fields as (provenance-key, member-pointer) pairs.
+inline const std::array<std::pair<const char *, std::string AssetIdentity::*>, 8> & identity_fields() {
+  static const std::array<std::pair<const char *, std::string AssetIdentity::*>, 8> fields{{
+      {"manufacturer", &AssetIdentity::manufacturer},
+      {"model", &AssetIdentity::model},
+      {"serial_number", &AssetIdentity::serial_number},
+      {"hardware_revision", &AssetIdentity::hardware_revision},
+      {"firmware_version", &AssetIdentity::firmware_version},
+      {"software_version", &AssetIdentity::software_version},
+      {"network_endpoint", &AssetIdentity::network_endpoint},
+      {"role", &AssetIdentity::role},
+  }};
+  return fields;
+}
+
+/// Decide whether an incoming value should overwrite the current field value.
+/// @param field_set     Whether the target field already holds a value.
+/// @param current_owner Source that owns the current value ("" if unstamped/unknown).
+inline bool incoming_wins(bool field_set, const std::string & current_owner, const std::string & incoming_source,
+                          const IdentityMergeConfig & config) {
+  if (!field_set) {
+    return true;  // field unset -> fill it
+  }
+  // Unstamped existing value -> treat its owner as the lowest authority.
+  const size_t current_rank =
+      current_owner.empty() ? config.source_precedence.size() : source_rank(current_owner, config);
+  // Strictly higher authority (lower rank) wins; ties keep the existing value.
+  return source_rank(incoming_source, config) < current_rank;
+}
+
+}  // namespace detail
+
+/**
+ * @brief Stamp provenance for every populated typed field / extra of `identity`
+ *        to `source`, unless that field already has a provenance entry.
+ *
+ * Used to seed provenance for the first (base) source before merging others.
+ * A no-op when `source` is empty: an unknown owner is the implicit default, so
+ * stamping it would only add `_provenance` entries with empty values.
+ */
+inline void stamp_identity_provenance(AssetIdentity & identity, const std::string & source) {
+  if (source.empty()) {
+    return;
+  }
+  for (const auto & [prov_key, member] : detail::identity_fields()) {
+    if (!(identity.*member).empty() && identity.provenance.find(prov_key) == identity.provenance.end()) {
+      identity.provenance[prov_key] = source;
+    }
+  }
+  for (const auto & [key, value] : identity.extra) {
+    const std::string prov_key = "extra." + key;
+    if (!value.empty() && identity.provenance.find(prov_key) == identity.provenance.end()) {
+      identity.provenance[prov_key] = source;
+    }
+  }
+}
+
+/**
+ * @brief Merge `source` identity (tagged `source_name`) into `target` in place.
+ *
+ * For each field: if the target field is unset, take the incoming value; otherwise
+ * the incoming value wins only if `source_name` has strictly higher authority than
+ * the source currently owning the field (per `config.source_precedence`). Provenance
+ * is updated whenever a value is written. Empty incoming values never overwrite.
+ *
+ * `target` should have had ::stamp_identity_provenance called on it (directly or via
+ * a previous merge) so existing fields carry provenance; otherwise existing fields
+ * are treated as owned by an unknown (lowest authority) source.
+ */
+inline void merge_identity(AssetIdentity & target, const AssetIdentity & source, const std::string & source_name,
+                           const IdentityMergeConfig & config) {
+  for (const auto & [prov_key, member] : detail::identity_fields()) {
+    const std::string & incoming = source.*member;
+    if (incoming.empty()) {
+      continue;
+    }
+    auto prov_it = target.provenance.find(prov_key);
+    const std::string current_owner = prov_it != target.provenance.end() ? prov_it->second : std::string{};
+    const bool target_set = !(target.*member).empty();
+    if (detail::incoming_wins(target_set, current_owner, source_name, config)) {
+      target.*member = incoming;
+      target.provenance[prov_key] = source_name;
+    }
+  }
+
+  for (const auto & [key, value] : source.extra) {
+    if (value.empty()) {
+      continue;
+    }
+    const std::string prov_key = "extra." + key;
+    auto prov_it = target.provenance.find(prov_key);
+    const std::string current_owner = prov_it != target.provenance.end() ? prov_it->second : std::string{};
+    auto extra_it = target.extra.find(key);
+    const bool target_set = extra_it != target.extra.end() && !extra_it->second.empty();
+    if (detail::incoming_wins(target_set, current_owner, source_name, config)) {
+      target.extra[key] = value;
+      target.provenance[prov_key] = source_name;
+    }
+  }
+}
+
+}  // namespace discovery
+}  // namespace ros2_medkit_gateway