# Unit - Simple unit class for measurement values
# Created per slot_fixes.yaml migration for: collection_size
# Creation date: 2026-01-19
#
# Rule compliance:
# - Rule 38: Slot centralization with semantic URIs
# - Rule 39: RiC-O temporal naming conventions
# - Rule 53: Generic reusable slots
#
# Note: For complex unit definitions, use MeasureUnit class instead.
# This class is for simple, label-based unit specifications.

id: https://nde.nl/ontology/hc/classes/Unit
name: Unit
title: Unit

prefixes:
  linkml: https://w3id.org/linkml/
  hc: https://nde.nl/ontology/hc/
  qudt: http://qudt.org/schema/qudt/
  schema: http://schema.org/

imports:
  - linkml:types
  - ../slots/has_or_had_label

default_range: string
default_prefix: hc

classes:
  Unit:
    description: >-
      A simple unit of measurement for quantities.
      
      **PURPOSE**:
      Lightweight unit class for cases where a simple label suffices.
      For complex unit definitions with conversion factors, symbols,
      and dimensional analysis, use MeasureUnit class instead.
      
      **COMMON UNITS FOR HERITAGE COLLECTIONS**:
      
      | Unit | Description | Example Usage |
      |------|-------------|---------------|
      | item | Individual objects | "500 items" |
      | species | Biological species | "200 species" |
      | specimen | Individual specimens | "10,000 specimens" |
      | volume | Books/bound volumes | "50,000 volumes" |
      | linear_meter | Archival extent | "500 linear meters" |
      | hectare | Site area | "32 hectares" |
      | square_meter | Floor area | "10,000 m²" |
      
      **QUDT ALIGNMENT**:
      Maps to `qudt:Unit` for semantic interoperability.
      
      **RELATIONSHIP TO MeasureUnit**:
      Unit is a simplified alternative to MeasureUnit. Use Unit when:
      - Only a text label is needed
      - No conversion factors required
      - Simple quantity expressions
      
      Use MeasureUnit when:
      - Need unit symbols and codes
      - Require dimensional analysis
      - Complex unit conversions needed
      
    class_uri: qudt:Unit
    
    exact_mappings:
      - qudt:Unit
    
    close_mappings:
      - schema:unitCode
      - schema:unitText
    
    slots:
      - has_or_had_label
    
    attributes:
      unit_value:
        range: string
        description: >-
          The unit identifier or label (e.g., "item", "species", "hectare").
        examples:
          - value: "item"
            description: Countable objects
          - value: "species"
            description: Biological species count
          - value: "linear_meter"
            description: Archival extent measurement
          - value: "hectare"
            description: Land area
      
      unit_uri:
        range: uriorcurie
        description: >-
          Optional URI for the unit in a standard vocabulary (QUDT, OM).
        examples:
          - value: "qudt:NUM"
            description: QUDT number/count unit
          - value: "om:hectare"
            description: OM hectare unit
    
    annotations:
      custodian_types: '["*"]'
      custodian_types_rationale: >-
        Units apply to all heritage custodian types for measurement.
      custodian_types_primary: "*"
      specificity_score: 0.2
      specificity_rationale: >-
        Very low specificity - fundamental measurement concept.
    
    examples:
      - value: |
          Unit:
            unit_value: "item"
            has_or_had_label:
              - label_text: "Items"
        description: Simple item count unit.
      
      - value: |
          Unit:
            unit_value: "species"
            has_or_had_label:
              - label_text: "Species"
            unit_uri: "dwc:individualCount"
        description: Biological species count unit.
      
      - value: |
          Unit:
            unit_value: "linear_meter"
            has_or_had_label:
              - label_text: "Linear Meters"
            unit_uri: "qudt:M"
        description: Archival extent unit.
    
    comments:
      - Created from slot_fixes.yaml migration (2026-01-19)
      - Lightweight alternative to MeasureUnit class
      - Use with has_or_had_unit slot
      - For collection_size migration - default unit is "item"