Add drag-to-trash exhibit disposal

src/boardDomain.ts

@@ -178,6 +178,29 @@ export function relationPosition(state: CaseState, relation: WidgetRelation) {
   }
 }
 
+export function discardExhibit(state: CaseState, exhibitId: string): CaseState {
+  if (!state.evidence.some(exhibit => exhibit.id === exhibitId)) return state
+  return {
+    ...state,
+    evidence: state.evidence
+      .filter(exhibit => exhibit.id !== exhibitId)
+      .map(exhibit => ({
+        ...exhibit,
+        containedDocumentIds: exhibit.containedDocumentIds?.filter(id => id !== exhibitId),
+        supportingEvidenceIds: exhibit.supportingEvidenceIds?.filter(id => id !== exhibitId),
+        relatedEvidenceIds: exhibit.relatedEvidenceIds?.filter(id => id !== exhibitId),
+      })),
+    relations: state.relations.filter(relation => relation.fromWidgetId !== exhibitId && relation.toWidgetId !== exhibitId),
+    connections: state.connections.filter(connection => connection.fromEvidenceId !== exhibitId && connection.toEvidenceId !== exhibitId),
+    brief: {
+      ...state.brief,
+      concepts: state.brief.concepts.map(concept => concept.resolvedPartyExhibitId === exhibitId
+        ? { ...concept, resolvedPartyExhibitId: undefined }
+        : concept),
+    },
+  }
+}
+
 export function normalizeCase(state: CaseState): CaseState {
   const relations = Array.isArray(state.relations)
     ? state.relations