import { type CombatantId, type DomainError, type DomainEvent, isDomainError, toggleConcentration, } from "@initiative/domain"; import type { EncounterStore } from "./ports.js"; export function toggleConcentrationUseCase( store: EncounterStore, combatantId: CombatantId, ): DomainEvent[] | DomainError { const encounter = store.get(); const result = toggleConcentration(encounter, combatantId); if (isDomainError(result)) { return result; } store.save(result.encounter); return result.events; }