import { ReadiumSpeechPlaybackEngine } from '../engine';
import { ReadiumSpeechPlaybackEvent, ReadiumSpeechPlaybackState } from '../navigator';
import { ReadiumSpeechUtterance } from '../utterance';
import { ReadiumSpeechVoice } from '../voices/types';
import { SpeechServerFormatOptions } from './selectFormat';
export interface SpeechServerEndpoints {
    voices: string;
    synthesize: string;
    service: string;
}
export interface SpeechServerEngineOptions {
    endpoints: SpeechServerEndpoints;
    fetch?: typeof fetch;
    prefetchWindow?: number;
    readyBufferChars?: number;
    overLengthText?: "split" | "error";
    format?: SpeechServerFormatOptions;
    timeoutMs?: number;
}
export declare class SpeechServerEngine implements ReadiumSpeechPlaybackEngine {
    private endpoints;
    private fetchImpl;
    private currentVoice;
    private voices;
    private serviceInfo;
    private serviceInfoPromise;
    private currentUtterances;
    private currentUtteranceIndex;
    private playbackState;
    private readonly events;
    private speakInContentLanguage;
    private speakGeneration;
    private loadGeneration;
    private readonly prefetchWindow;
    private readonly readyBufferChars;
    private readonly overLengthText;
    private readonly timeoutMs;
    private readonly formatOptions;
    private readonly canPlayType;
    private prefetchCache;
    private prefetchChainTail;
    private activeControllers;
    private liveControllers;
    private isSpeakingInternal;
    private restartPending;
    private audioContext;
    private masterGain;
    private scheduledChunks;
    private boundaryRafHandle;
    private rate;
    private pitch;
    private volume;
    constructor(options: SpeechServerEngineOptions);
    setAvailableVoices(voices: ReadiumSpeechVoice[]): void;
    private fetchNetwork;
    loadUtterances(contents: ReadiumSpeechUtterance[], startIndex?: number): void;
    private bufferUntilReady;
    private indexCoveringChars;
    setVoice(voice: ReadiumSpeechVoice | string): void;
    getCurrentVoice(): ReadiumSpeechVoice | null;
    getAvailableVoices(): Promise<ReadiumSpeechVoice[]>;
    private getServiceInfo;
    private fetchServiceInfo;
    setSpeakInContentLanguage(enabled: boolean): void;
    getSpeakInContentLanguage(): boolean;
    speak(utteranceIndex?: number): void;
    private synthesizeAndPlay;
    private resolveSynthesisStream;
    private fillPrefetchWindow;
    private queuePrefetch;
    private clearPrefetchCache;
    private abortLiveControllers;
    private synthesizeStream;
    private synthesizeChunk;
    private ensureAudioContext;
    private awaitWithStallDeadline;
    private scheduleChunksStreaming;
    private handleUtteranceEnded;
    private startBoundaryPolling;
    private stopBoundaryPolling;
    private checkBoundaries;
    private stopAudio;
    pause(): void;
    resume(): void;
    stop(): void;
    setRate(rate: number): void;
    getRate(): number;
    setPitch(pitch: number): void;
    getPitch(): number;
    setVolume(volume: number): void;
    getVolume(): number;
    private scheduleRestartIfSpeaking;
    getState(): ReadiumSpeechPlaybackState;
    getCurrentUtteranceIndex(): number;
    setCurrentUtteranceIndex(index: number, onComplete?: (success: boolean) => void): void;
    getUtteranceCount(): number;
    on(event: ReadiumSpeechPlaybackEvent["type"], callback: (event: ReadiumSpeechPlaybackEvent) => void): () => void;
    private emitEvent;
    private setState;
    destroy(): Promise<void>;
}