import { RolloutConfig, EvaluationContext, Variant, VariantId } from './types';
import { HashFunction } from './hash-function';
/**
 * Result of rollout evaluation.
 */
export interface RolloutResult {
    /** Whether the user is included in the rollout */
    readonly included: boolean;
    /** The variant to serve */
    readonly variantId?: VariantId;
    /** The percentage bucket the user falls into */
    readonly bucket?: number;
    /** Current rollout percentage */
    readonly percentage?: number;
    /** Current stage (for staged rollouts) */
    readonly stage?: string;
    /** Current ring (for ring rollouts) */
    readonly ring?: string;
    /** Whether user is in canary group */
    readonly isCanary?: boolean;
    /** Experiment details */
    readonly experiment?: {
        readonly experimentId: string;
        readonly allocationPercentage: number;
    };
}
/**
 * Engine for evaluating percentage-based rollouts.
 */
export declare class PercentageRolloutEngine {
    private readonly hashFunction;
    private stickyBuckets;
    constructor(hashFunction?: HashFunction);
    /**
     * Evaluate a rollout configuration.
     */
    evaluate(rollout: RolloutConfig, context: EvaluationContext, flagKey: string, variants: readonly Variant[]): RolloutResult;
    /**
     * Set a sticky bucket for a user/flag combination.
     */
    setStickyBucket(flagKey: string, hashKey: string, bucket: number): void;
    /**
     * Clear sticky buckets.
     */
    clearStickyBuckets(): void;
    /**
     * Get the bucket for a user/flag combination.
     */
    getBucket(flagKey: string, hashKey: string, salt?: string): number;
    private evaluatePercentage;
    private evaluateScheduled;
    private getCurrentStage;
    private evaluateRing;
    private getRingPriority;
    private isInRing;
    private evaluateCanary;
    private evaluateExperiment;
    private getDefaultHashKey;
    private selectVariant;
}