import { XPEvent } from '../events';
import { FlagValue } from '../scenario/types';
import { ConditionTrace } from '../scenario/trace';
/** Why a matched trigger did not fire (undefined when it fired). */
export type SkipReason = 'once' | 'max' | 'when';
/** One trigger's outcome for a single event. */
export interface TriggerReport {
    /** Trigger id, or its index as a string. */
    id: string;
    index: number;
    on: string | string[];
    /** Did the event type match the trigger's `on`? */
    matchedOn: boolean;
    /** Present when `matchedOn` and the once/max budget allowed evaluation. */
    when?: ConditionTrace;
    fired: boolean;
    skip?: SkipReason;
    /** Times this trigger has fired so far. */
    fireCount: number;
}
/** A flag mutation attributed to the trigger that caused it. */
export interface FlagChange {
    flag: string;
    value: FlagValue;
    /** The firing trigger's id/index. */
    by: string;
}
/** The ScenarioRunner's full report for one processed event. */
export interface EvalReport {
    /** Monotonic sequence number within this instance. */
    seq: number;
    event: XPEvent;
    triggers: TriggerReport[];
    /** Flags snapshot after the event was processed. */
    flags: Record<string, FlagValue>;
    /** Flags changed while processing this event, with attribution. */
    changes: FlagChange[];
}
type Listener = (report: EvalReport) => void;
/** Publish a report to everyone listening on `prefix`. Never throws. */
export declare const publishTrace: (prefix: string, report: EvalReport) => void;
/**
 * Whether anyone is listening on `prefix`. The ScenarioRunner guards its extra
 * trace-building on this so a production build with no panel pays nothing.
 */
export declare const hasTraceListeners: (prefix: string) => boolean;
/** Subscribe to reports on `prefix`; returns an unsubscribe function. */
export declare const subscribeTrace: (prefix: string, fn: Listener) => (() => void);
export {};