@prefix sh:      <http://www.w3.org/ns/shacl#> .
@prefix xsd:     <http://www.w3.org/2001/XMLSchema#> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix rdfs:    <http://www.w3.org/2000/01/rdf-schema#> .
@prefix prov:    <http://www.w3.org/ns/prov#> .
@prefix ess:     <https://schema.bra0.org/essence-kernel#> .
@prefix evo:     <https://schema.bra0.org/evidence-os#> .

#
# SHACL shapes — Requirement instance validator
# Single RequirementInstanceShape targeting prov:Entity instances that
# declare ess:advancesAlpha ess:Requirements. Acceptance semantics are
# carried by OMG Essence alpha-state transitions on the requirement entity.
# Target selector: SPARQL (W3C SHACL §5.3) — SHACL Core does not combine
# sh:targetClass with additional triple constraints natively.
#

<> dcterms:license <https://creativecommons.org/licenses/by-sa/4.0/> .

#######################################################################
# evo:RequirementInstanceShape
# Target: prov:Entity instances carrying ess:advancesAlpha ess:Requirements
# Replaces the v0.1.0 evo:UserStoryShape. Acceptance criteria are modelled
# as Essence alpha-state transitions on the requirement entity (Acceptable
# -> Addressed -> Fulfilled); no dedicated AC shape is required.
#######################################################################

evo:RequirementInstanceShape
    a sh:NodeShape ;
    rdfs:label "Requirement-instance shape"@en ;
    rdfs:comment "Validates structural integrity of requirement instances. A requirement is any node carrying ess:advancesAlpha ess:Requirements (OMG Essence 2.0 alpha; the parent type prov:Entity is entailed by the ess:advancesAlpha range once the kernel is loaded, so the shape targets the predicate use directly). Every requirement MUST carry a human-readable label, a stable identifier for cross-connector traceability, advance the Requirements alpha, and carry a provenance attribution. Acceptance semantics are expressed as alpha-state transitions on this entity, not as a separate shape."@en ;
    sh:targetSubjectsOf ess:advancesAlpha ;
    sh:property [
        sh:path rdfs:label ;
        sh:datatype xsd:string ;
        sh:minCount 1 ; sh:maxCount 1 ;
        sh:message "A requirement instance MUST declare exactly one rdfs:label (human-readable narrative — INVEST story text, plain-language requirement, etc.)."@en ;
    ] ,
    [
        sh:path dcterms:identifier ;
        sh:datatype xsd:string ;
        sh:minCount 1 ; sh:maxCount 1 ;
        sh:message "A requirement instance MUST carry dcterms:identifier (connector-sourced stable ID, e.g. Jira key, ticket number)."@en ;
    ] ,
    [
        sh:path ess:advancesAlpha ;
        sh:hasValue ess:Requirements ;
        sh:minCount 1 ;
        sh:message "A requirement instance MUST advance the ess:Requirements alpha (OMG Essence 2.0 bridge). Current alpha state is carried on the corresponding advancement activity via ess:currentAlphaState."@en ;
    ] ,
    [
        sh:path prov:wasAttributedTo ;
        sh:nodeKind sh:IRI ;
        sh:minCount 1 ;
        sh:message "A requirement instance MUST carry prov:wasAttributedTo (author / product-owner agent IRI) — PROV-O provenance."@en ;
    ] .