import {
	adjustHp,
	type CombatantId,
	type DomainError,
	type DomainEvent,
	isDomainError,
} from "@initiative/domain";
import type { EncounterStore } from "./ports.js";

export function adjustHpUseCase(
	store: EncounterStore,
	combatantId: CombatantId,
	delta: number,
): DomainEvent[] | DomainError {
	const encounter = store.get();
	const result = adjustHp(encounter, combatantId, delta);

	if (isDomainError(result)) {
		return result;
	}

	store.save(result.encounter);
	return result.events;
}