import type { IEvent } from './IEvent.ts';
import type { IEventSet } from './IEventSet.ts';
import type { ICommand } from './ICommand.ts';
import type { Identifier } from './Identifier.ts';
export interface ISaga {
    /**
     * Apply a historical event to restore saga state.
     */
    mutate(event: IEvent): unknown | Promise<unknown>;
    /**
     * Process an incoming event.
     *
     * @returns Commands produced by the saga in response to the event
     */
    handle(event: IEvent): ReadonlyArray<ICommand> | Promise<ReadonlyArray<ICommand>>;
}
export type ISagaConstructorParams = {
    id: Identifier;
    /** @deprecated Past events will be passed to the `mutate` method */
    events?: IEventSet;
};
export type ISagaFactory = (options: ISagaConstructorParams) => ISaga;
export interface ISagaConstructor {
    new (options: ISagaConstructorParams): ISaga;
    /**
     * Override to provide a stable saga descriptor used as a key in `message.sagaOrigins`.
     * Defaults to the Saga class name.
     */
    readonly sagaDescriptor?: string;
    /**
     * Optional list of event types that trigger new saga start.
     *
     * When not defined, saga start is inferred by the absence of `message.sagaOrigins[sagaDescriptor]`.
     */
    readonly startsWith?: string[];
    /** List of events being handled by Saga */
    readonly handles: string[];
}