import { STTProvider, SpeechError } from './types.js';
interface _SpeechRecognitionAlternative {
    readonly transcript: string;
    readonly confidence: number;
}
interface _SpeechRecognitionResult {
    readonly isFinal: boolean;
    readonly length: number;
    [index: number]: _SpeechRecognitionAlternative;
}
interface _SpeechRecognitionResultList {
    readonly length: number;
    [index: number]: _SpeechRecognitionResult;
}
interface _SpeechRecognitionResultEvent {
    readonly resultIndex: number;
    readonly results: _SpeechRecognitionResultList;
}
interface _SpeechRecognitionErrorEvent {
    readonly error: string;
    readonly message?: string;
}
interface _SpeechRecognitionInstance {
    lang: string;
    interimResults: boolean;
    continuous: boolean;
    maxAlternatives: number;
    onresult: ((_: _SpeechRecognitionResultEvent) => void) | null;
    onerror: ((_: _SpeechRecognitionErrorEvent) => void) | null;
    onend: (() => void) | null;
    start(): void;
    stop(): void;
}
interface _SpeechRecognitionConstructor {
    new (): _SpeechRecognitionInstance;
}
declare global {
    interface Window {
        SpeechRecognition?: _SpeechRecognitionConstructor;
        webkitSpeechRecognition?: _SpeechRecognitionConstructor;
    }
}
export interface WebSpeechSTTOptions {
    /** BCP-47 language code, e.g. 'en-US'. Defaults to browser UI lang */
    lang?: string;
    /** Whether to return interim (non-final) results. Default: true */
    interimResults?: boolean;
    /** Whether recognition continues after the first final result. Default: true */
    continuous?: boolean;
    /** Maximum number of alternative transcripts per result. Default: 1 */
    maxAlternatives?: number;
}
export declare class WebSpeechSTTProvider implements STTProvider {
    readonly isSupported: boolean;
    readonly continuous: boolean;
    private _recognition;
    private _options;
    private _transcriptCbs;
    private _finalCbs;
    private _endCbs;
    private _errorCbs;
    constructor(options?: WebSpeechSTTOptions);
    onTranscript(cb: (transcript: string, confidence: number) => void): void;
    onFinalTranscript(cb: (transcript: string, confidence: number) => void): void;
    onEnd(cb: () => void): void;
    onError(cb: (err: SpeechError) => void): void;
    start(): void;
    stop(): void;
    private _teardown;
    private _emitError;
}
export {};