import { MsgHdrs } from '@nats-io/nats-core';
import { ActorRefFrom } from 'xstate';
import { type AuthConfig } from '../actions/types';
export interface NatsCredentials {
    auth?: AuthConfig;
    requestHeaders?: MsgHdrs;
    /** Epoch milliseconds after which these credentials must not be used. Use the earliest expiry. */
    expiresAt?: number;
}
export interface NatsCredentialAdapter {
    load: () => Promise<NatsCredentials>;
    refresh?: (current: NatsCredentials) => Promise<NatsCredentials>;
}
export interface NatsCredentialConfig {
    adapter: NatsCredentialAdapter;
    /** Refresh this long before expiry. Defaults to 60 seconds. */
    refreshBeforeExpiryMs?: number;
    /** Maximum duration of one adapter load or refresh. Defaults to 30 seconds. */
    operationTimeoutMs?: number;
    /** Called when credentials expire or cannot be loaded/refreshed. */
    onUnavailable?: (error: Error) => void;
    /** Emit sanitized credential lifecycle debug logs. */
    diagnostics?: boolean;
}
type CredentialResult = {
    ok: true;
    credentials: NatsCredentials;
} | {
    ok: false;
    error: Error;
};
type Waiter = (result: CredentialResult) => void;
export interface CredentialContext {
    config: NatsCredentialConfig;
    current?: NatsCredentials;
    waiters: Waiter[];
    error?: Error;
}
export declare const credentialMachine: import("xstate").StateMachine<CredentialContext, {
    type: 'CREDENTIALS.GET';
    reply: Waiter;
} | {
    type: 'CREDENTIALS.RELOAD';
}, {
    [x: string]: import("xstate").ActorRefFromLogic<import("xstate").PromiseActorLogic<NatsCredentials, NatsCredentialConfig, import("xstate").EventObject> | import("xstate").PromiseActorLogic<NatsCredentials, {
        config: NatsCredentialConfig;
        current: NatsCredentials;
    }, import("xstate").EventObject>> | undefined;
}, {
    src: "load";
    logic: import("xstate").PromiseActorLogic<NatsCredentials, NatsCredentialConfig, import("xstate").EventObject>;
    id: string | undefined;
} | {
    src: "refresh";
    logic: import("xstate").PromiseActorLogic<NatsCredentials, {
        config: NatsCredentialConfig;
        current: NatsCredentials;
    }, import("xstate").EventObject>;
    id: string | undefined;
}, {
    type: "acceptCredentials";
    params: import("xstate").NonReducibleUnknown;
} | {
    type: "markExpired";
    params: import("xstate").NonReducibleUnknown;
} | {
    type: "notifyUnavailable";
    params: unknown;
} | {
    type: "queue";
    params: import("xstate").NonReducibleUnknown;
} | {
    type: "rejectWaiters";
    params: import("xstate").NonReducibleUnknown;
} | {
    type: "replyReady";
    params: unknown;
} | {
    type: "storeCredentials";
    params: import("xstate").NonReducibleUnknown;
}, {
    type: "canRefresh";
    params: unknown;
} | {
    type: "hasExpiry";
    params: unknown;
} | {
    type: "isExpired";
    params: unknown;
} | {
    type: "outputExpired";
    params: unknown;
} | {
    type: "outputShouldRefresh";
    params: unknown;
} | {
    type: "shouldRefreshNow";
    params: unknown;
}, "credentialDeadline", "expired" | "failed" | "loading" | "ready" | "refreshing", string, NatsCredentialConfig, import("xstate").NonReducibleUnknown, import("xstate").EventObject, import("xstate").MetaObject, {
    id: "credentials";
    states: {
        readonly loading: {};
        readonly ready: {};
        readonly refreshing: {};
        readonly expired: {};
        readonly failed: {};
    };
}, import("xstate").MetaObject>;
export type CredentialActor = ActorRefFrom<typeof credentialMachine>;
export declare function getCredentials(actor: CredentialActor): Promise<NatsCredentials>;
export {};
//# sourceMappingURL=credentials.d.ts.map