Index enemy event duplicate identities

internal/modules/dnd/enemyevents/enemyevents.go

@@ -3,6 +3,8 @@
 package enemyevents
 
 import (
+	"encoding/json"
+
 	"gitea.maximumdirect.net/eric/notarius/internal/core/source"
 	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd"
 	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/npcs/identity"
@@ -58,9 +60,49 @@ func SourceRefsEqual(order shared.SourceRefOrder, left, right []source.SourceRef
 // ExactEqual reports whether events have the same subject identity, kind, and
 // complete canonical evidence sequence.
 func ExactEqual(order shared.SourceRefOrder, left, right dnd.EnemyEvent) bool {
+	left.SourceRefs = order.Canonicalize(left.SourceRefs)
+	right.SourceRefs = order.Canonicalize(right.SourceRefs)
+	return CanonicalExactEqual(left, right)
+}
+
+type canonicalIdentity struct {
+	Subject    string             `json:"subject"`
+	Kind       dnd.EnemyEventKind `json:"kind"`
+	SourceRefs []source.SourceRef `json:"source_refs"`
+}
+
+// CanonicalIdentity returns the complete duplicate-lookup key for an event
+// whose source references are already canonical.
+func CanonicalIdentity(event dnd.EnemyEvent) string {
+	encoded, err := json.Marshal(canonicalIdentity{
+		Subject:    ComparisonKey(event.Name),
+		Kind:       event.Kind,
+		SourceRefs: event.SourceRefs,
+	})
+	if err != nil {
+		panic("encode enemy event identity")
+	}
+	return string(encoded)
+}
+
+// CanonicalExactEqual reports whether events have the same complete duplicate
+// identity without modifying or canonicalizing their source references.
+func CanonicalExactEqual(left, right dnd.EnemyEvent) bool {
 	return ComparisonKey(left.Name) == ComparisonKey(right.Name) &&
 		left.Kind == right.Kind &&
-		SourceRefsEqual(order, left.SourceRefs, right.SourceRefs)
+		canonicalSourceRefsEqual(left.SourceRefs, right.SourceRefs)
+}
+
+func canonicalSourceRefsEqual(left, right []source.SourceRef) bool {
+	if (left == nil) != (right == nil) || len(left) != len(right) {
+		return false
+	}
+	for index := range left {
+		if left[index] != right[index] {
+			return false
+		}
+	}
+	return true
 }
 
 // Less defines the canonical stable event order. Invalid source references