import { RetryManager } from '../../core/RetryManager';
import { RetryPlugin } from '../../types';
/**
 * Configuration options for the Circuit Breaker behavior.
 */
export interface CircuitBreakerOptions {
    /**
     * Number of consecutive failures required to trip the circuit.
     * Once this threshold is exceeded, the circuit transitions from `CLOSED` to `OPEN`.
     */
    failureThreshold: number;
    /**
     * Duration (in milliseconds) the circuit remains in the `OPEN` state
     * before allowing a test request in the `HALF_OPEN` state.
     */
    openTimeout: number;
    /**
     * Maximum number of test requests allowed in `HALF_OPEN` state
     * before deciding to either reset (back to `CLOSED`) or trip again to `OPEN`.
     */
    halfOpenMax: number;
}
/**
 * CircuitBreakerPlugin
 *
 * This plugin implements the Circuit Breaker pattern by temporarily stopping retries if a service
 * appears to be down. When too many consecutive failures occur, the circuit "trips" (opens) and all
 * incoming requests are immediately rejected (fail-fast). After a cool-down period, the circuit transitions
 * to a half-open state and allows a limited number of test requests. A successful test resets the circuit,
 * while a failure reopens it.
 *
 * @implements {RetryPlugin}
 */
export declare class CircuitBreakerPlugin implements RetryPlugin {
    readonly name = "CircuitBreakerPlugin";
    readonly version = "1.0.0";
    private _options;
    private _state;
    private _failureCount;
    private _halfOpenCount;
    private _nextAttempt;
    private _requestInterceptorId?;
    private _responseInterceptorId?;
    private _manager;
    static STATES: {
        CLOSED: string;
        OPEN: string;
        HALF_OPEN: string;
    };
    /**
     * Creates an instance of CircuitBreakerPlugin.
     * @param {Partial<CircuitBreakerOptions>} [options] - Configuration options.
     *   - failureThreshold: Number of consecutive failures to trip the circuit (default: 5).
     *   - openTimeout: Time (in ms) the circuit remains open before transitioning to half-open (default: 30000).
     *   - halfOpenMax: Maximum number of test requests allowed in the half-open state (default: 1).
     */
    constructor(options?: Partial<CircuitBreakerOptions>);
    /**
     * Initializes the plugin by setting up request and response interceptors.
     * Called when the plugin is attached.
     *
     * @param {RetryManager} manager - The RetryManager instance.
     */
    initialize(manager: RetryManager): void;
    /**
     * Called before the plugin is removed.
     * Ejects the interceptors.
     *
     * @param {RetryManager} manager - The RetryManager instance.
     */
    onBeforeDestroyed(manager: RetryManager): void;
    /**
     * Trips the circuit by transitioning it to OPEN state.
     * Sets the next attempt time based on the openTimeout option.
     */
    private _trip;
    /**
     * Resets the circuit by transitioning it back to CLOSED state.
     */
    private _reset;
    /**
     * Transitions the circuit to HALF_OPEN state, allowing test requests.
     */
    private _transitionToHalfOpen;
}