import { AxiosError } from 'axios';
import { IMessageActivity, IMessageActivityInput, ITypingActivity, ITypingActivityInput, SentActivity, TextFormat } from '@microsoft/teams.api';
import { IEventEmitter } from '@microsoft/teams.common';
/**
 * @deprecated Teams no longer supports stopping a stream.
 */
export declare class StreamCancelledError extends Error {
    constructor(message?: string);
}
/**
 * Base class for terminal streaming errors that should not be retried.
 */
export declare class TerminalStreamError extends Error {
    constructor(message?: string);
}
/**
 * Raised when the service reports that streaming exceeded ten minutes from the
 * first informative or content chunk.
 * A buffered Plan completion cannot use the ordinary PUT fallback. Resolve it
 * explicitly through Plan.complete() rather than retrying the same stream close.
 */
export declare class StreamTimedOutError extends TerminalStreamError {
    constructor(message?: string);
}
/**
 * Raised when streaming is not allowed for this user or bot.
 */
export declare class StreamNotAllowedError extends TerminalStreamError {
    constructor(message?: string);
}
/**
 * Raised for HTTP 409 PlanConflict streaming failures without retrying.
 * Preserves the original HTTP request, response, and cause.
 * This is a service lifecycle conflict, not a timeout; resolve the Plan state
 * explicitly instead of retrying the same stream close.
 *
 * @experimental This API is in preview and may change in the future.
 * Diagnostic: ExperimentalTeamsPlan
 */
export declare class PlanConflictStreamError extends AxiosError {
    /** @param error The original HTTP 409 PlanConflict failure. */
    constructor(error: AxiosError);
}
/**
 * the minimum events a streamer
 * should support
 */
export interface IStreamerEvents {
    /**
     * emitted for each chunk sent
     */
    readonly chunk: SentActivity;
    /**
     * emitted once on stream close
     */
    readonly close: SentActivity;
}
/**
 * component that can send streamed chunks of an activity
 */
export interface IStreamer {
    readonly events: Omit<IEventEmitter<IStreamerEvents>, 'emit'>;
    /**
     * @deprecated Teams no longer supports stopping a stream. HttpStream always returns false.
     */
    readonly canceled: boolean;
    /**
     * whether the current streamed message has been finalized.
     *
     * Closing is idempotent until the next emit or update. Emitting or
     * updating after close starts a new streamed message using the same
     * stream instance.
     */
    readonly closed: boolean;
    /**
     * emit an activity chunk
     * @param activity the activity to send
     */
    /**
     * @deprecated Use {@link IMessageActivityInput} or {@link ITypingActivityInput} instead.
     */
    emit(activity: IMessageActivity | ITypingActivity): void;
    emit(activity: IMessageActivityInput | ITypingActivityInput | string): void;
    /**
     * send status updates before emitting (ex. "Thinking...")
     * @param text the status text to send
     * @param textFormat format of `text` (ex. `'extendedmarkdown'`); omit or pass `null`
     * to use the Teams default (`'markdown'`)
     */
    update(text: string, textFormat?: TextFormat | null): void;
    /**
     * Discard accumulated streamed text and any pending text deltas, so the
     * final message sent by `close()` doesn't include them. Useful when a
     * mid-turn decision (e.g. a tool call producing a card) means the
     * buffered text should not appear in the final activity. Typing chunks
     * already shipped to Teams are not undone, but the final message updates
     * the same activity to reflect the cleared state.
     */
    clearText(): void;
    /**
     * Finalize the current streamed message.
     *
     * Closing is idempotent until the next emit or update. Emitting or
     * updating after close starts a new streamed message using the same
     * stream instance.
     */
    close(): SentActivity | undefined | Promise<SentActivity | undefined>;
}