Enforce unique enemy engagements per scene

internal/modules/dnd/validate/enemyevents/engagements/validator.go

@@ -0,0 +1,85 @@
+// Package engagements prevents duplicate enemy engagements within one scene.
+package engagements
+
+import (
+	"context"
+	"fmt"
+
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/pipeline"
+	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd"
+	enemyeventmodel "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/enemyevents"
+	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/shared/diagnostics"
+	enemyeventshape "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/validate/enemyevents/shape"
+)
+
+const (
+	Key        = "extract/dnd/enemy-events/engagements"
+	ReasonCode = "duplicate_enemy_engagement"
+	policy     = "dnd.enemy_events.validator.engagements.v1"
+)
+
+type Options struct{}
+type Validator struct{}
+
+var _ contracts.TypedValidator[dnd.EnemyEventList] = (*Validator)(nil)
+var _ pipeline.CheckpointFingerprintProvider = (*Validator)(nil)
+
+func New(Options) *Validator      { return &Validator{} }
+func (v *Validator) Name() string { return Key }
+func (v *Validator) ExecutionClass() contracts.ExecutionClass {
+	return contracts.ExecutionClassDeterministic
+}
+func (v *Validator) CheckpointFingerprints() []pipeline.CheckpointFingerprint {
+	return []pipeline.CheckpointFingerprint{{Name: "policy", Value: policy}}
+}
+
+func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationRequest[dnd.EnemyEventList]) (contracts.ValidationResult, error) {
+	if enemyeventshape.Validate(req.Value) != nil {
+		return contracts.ValidationResult{Approved: true}, nil
+	}
+	seen := make(map[string]struct{})
+	for _, event := range req.Value.Events {
+		if event.Kind != dnd.EnemyEventKindEngaged {
+			continue
+		}
+		identity := enemyeventmodel.ComparisonKey(event.Name)
+		if identity == "" {
+			continue
+		}
+		if _, found := seen[identity]; found {
+			return contracts.ValidationResult{
+				Approved:   false,
+				ReasonCode: ReasonCode,
+				Message: diagnostics.Aggregate("duplicate enemy engagement", []string{
+					fmt.Sprintf("subject %s has more than one engagement in one combat scene", diagnostics.Quote(event.Name)),
+				}),
+			}, nil
+		}
+		seen[identity] = struct{}{}
+	}
+	return contracts.ValidationResult{Approved: true}, nil
+}
+
+func Spec() pipeline.ValidatorSpec {
+	return pipeline.ValidatorSpec{Key: Key, ExecutionClass: contracts.ExecutionClassDeterministic}
+}
+
+func Register(registry *pipeline.ValidatorRegistry) error {
+	return pipeline.RegisterTypedValidatorBuilder(registry, dnd.EnemyEventListKind, Spec(), validateOptions, func(request pipeline.BuildRequest) (contracts.TypedValidator[dnd.EnemyEventList], error) {
+		options, err := DecodeOptions(request.Options)
+		if err != nil {
+			return nil, err
+		}
+		return New(options), nil
+	})
+}
+
+func DecodeOptions(options map[string]any) (Options, error) {
+	if err := pipeline.RejectUnknownOptions(options); err != nil {
+		return Options{}, err
+	}
+	return Options{}, nil
+}
+
+func validateOptions(options map[string]any) error { _, err := DecodeOptions(options); return err }

internal/modules/dnd/validate/enemyevents/engagements/validator_test.go

@@ -0,0 +1,70 @@
+package engagements
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"gitea.maximumdirect.net/eric/notarius/internal/core/source"
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/pipeline"
+	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd"
+)
+
+func TestValidatorEnforcesOneEngagementPerSubject(t *testing.T) {
+	for _, test := range []struct {
+		name     string
+		value    dnd.EnemyEventList
+		approved bool
+	}{
+		{name: "empty", value: dnd.EnemyEventList{Events: []dnd.EnemyEvent{}}, approved: true},
+		{name: "one engagement", value: events(event("Ashfang", dnd.EnemyEventKindEngaged, 1)), approved: true},
+		{name: "same subject different evidence", value: events(event("Ashfang", dnd.EnemyEventKindEngaged, 1), event("Ashfang", dnd.EnemyEventKindEngaged, 2))},
+		{name: "whitespace and case variant", value: events(event("Ashfang", dnd.EnemyEventKindEngaged, 1), event("  ASHFANG  ", dnd.EnemyEventKindEngaged, 2))},
+		{name: "different subjects", value: events(event("Ashfang", dnd.EnemyEventKindEngaged, 1), event("Briar", dnd.EnemyEventKindEngaged, 2)), approved: true},
+		{name: "different kinds", value: events(event("Ashfang", dnd.EnemyEventKindEngaged, 1), event("Ashfang", dnd.EnemyEventKindFled, 2)), approved: true},
+		{name: "malformed shape", value: dnd.EnemyEventList{Events: []dnd.EnemyEvent{{Name: "Ashfang"}, {Name: "Ashfang", Kind: dnd.EnemyEventKindEngaged, SourceRefs: refs(2)}}}, approved: true},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.EnemyEventList]{Value: test.value})
+			if err != nil || result.Approved != test.approved {
+				t.Fatalf("Validate() = %#v, %v; want approved=%t", result, err, test.approved)
+			}
+			if !test.approved && result.ReasonCode != ReasonCode {
+				t.Fatalf("reason code = %q, want %q", result.ReasonCode, ReasonCode)
+			}
+		})
+	}
+	for _, unitID := range []int{1, 2} {
+		result, err := New(Options{}).Validate(context.Background(), contracts.TypedValidationRequest[dnd.EnemyEventList]{Value: events(event("Ashfang", dnd.EnemyEventKindEngaged, unitID))})
+		if err != nil || !result.Approved {
+			t.Fatalf("separate scene validation = %#v, %v; want approved", result, err)
+		}
+	}
+}
+
+func TestValidatorRegistersStrictOptionsAndPolicy(t *testing.T) {
+	registry := pipeline.NewValidatorRegistry()
+	if err := Register(registry); err != nil {
+		t.Fatal(err)
+	}
+	if Spec().Key != Key || Spec().ExecutionClass != contracts.ExecutionClassDeterministic {
+		t.Fatalf("Spec() = %#v", Spec())
+	}
+	if got := New(Options{}).CheckpointFingerprints(); len(got) != 1 || got[0].Name != "policy" || got[0].Value != policy {
+		t.Fatalf("CheckpointFingerprints() = %#v", got)
+	}
+	if _, err := DecodeOptions(map[string]any{"unexpected": true}); err == nil || !strings.Contains(err.Error(), "unknown option") {
+		t.Fatalf("DecodeOptions() error = %v, want strict option rejection", err)
+	}
+}
+
+func events(values ...dnd.EnemyEvent) dnd.EnemyEventList { return dnd.EnemyEventList{Events: values} }
+
+func event(name string, kind dnd.EnemyEventKind, unitID int) dnd.EnemyEvent {
+	return dnd.EnemyEvent{Name: name, Kind: kind, SourceRefs: refs(unitID)}
+}
+
+func refs(unitID int) []source.SourceRef {
+	return []source.SourceRef{{SourceID: "session", StartUnitID: unitID, EndUnitID: unitID}}
+}