import { AbstractTTSClient } from "../core/abstract-tts.js";
import type { SpeakOptions, TTSCredentials, UnifiedVoice } from "../types.js";
/**
 * Extended options for Polly TTS
 */
export interface PollyTTSOptions extends SpeakOptions {
    format?: "mp3" | "wav" | "ogg";
    filePath?: string;
}
/**
 * AWS Polly TTS credentials
 */
export interface PollyTTSCredentials extends TTSCredentials {
    /**
     * AWS region
     */
    region: string;
    /**
     * AWS access key ID
     */
    accessKeyId: string;
    /**
     * AWS secret access key
     */
    secretAccessKey: string;
}
/**
 * AWS Polly TTS client
 */
export declare class PollyTTSClient extends AbstractTTSClient {
    /**
     * AWS Polly client
     */
    private client;
    private _pollyModule;
    /**
     * Cache of voice metadata for engine detection
     */
    private voiceCache;
    /**
     * Create a new AWS Polly TTS client
     * @param credentials AWS credentials
     */
    constructor(credentials: PollyTTSCredentials);
    /**
     * Get available voices from the provider
     * @returns Promise resolving to an array of voice objects
     */
    protected _getVoices(): Promise<any[]>;
    /**
     * Get available voices from the provider with caching
     * @returns Promise resolving to an array of unified voice objects
     */
    getVoices(): Promise<UnifiedVoice[]>;
    /**
     * Map AWS Polly voice objects to unified format
     * @param rawVoices Array of AWS Polly voice objects
     * @returns Promise resolving to an array of unified voice objects
     */
    protected _mapVoicesToUnified(rawVoices: any[]): Promise<UnifiedVoice[]>;
    /**
     * Get the appropriate engine for a voice based on supported engines
     * @param voiceId Voice ID to check
     * @returns The best engine to use for this voice
     */
    private getEngineForVoice;
    /**
     * Get SSML support level for a voice based on its engine type
     * @param voiceId Voice ID to check
     * @returns SSML support level: "full", "limited", or "none"
     */
    private getSSMLSupportLevel;
    /**
     * Prepare SSML for AWS Polly based on voice engine capabilities
     * @param text Text or SSML to prepare
     * @param options Synthesis options
     * @returns Promise resolving to prepared SSML or plain text
     */
    private prepareSSML;
    /**
     * Convert text to audio bytes
     * @param text Text or SSML to synthesize
     * @param options Synthesis options
     * @returns Promise resolving to audio bytes
     */
    synthToBytes(text: string, options?: PollyTTSOptions): Promise<Uint8Array>;
    /**
     * Synthesize text to a byte stream with word boundaries
     * @param text Text or SSML to synthesize
     * @param options Synthesis options
     * @returns Promise resolving to an object containing the audio stream and word boundaries
     */
    synthToBytestream(text: string, options?: PollyTTSOptions): Promise<{
        audioStream: ReadableStream<Uint8Array>;
        wordBoundaries: Array<{
            text: string;
            offset: number;
            duration: number;
        }>;
    }>;
    /**
     * Strip SSML tags from text
     * @param text Text with SSML tags
     * @returns Plain text without SSML tags
     */
    protected _stripSSML(text: string): string;
    /**
     * Add a WAV header to PCM audio data
     * This matches the Python implementation using wave.setparams((1, 2, 16000, 0, "NONE", "NONE"))
     * @param pcmData PCM audio data from AWS Polly (signed 16-bit, 1 channel, little-endian)
     * @param sampleRate Sample rate in Hz (default: 16000)
     * @returns PCM audio data with WAV header
     */
    private addWavHeader;
    /**
     * Get the list of required credential types for this engine
     * @returns Array of required credential field names
     */
    protected getRequiredCredentials(): string[];
    /**
     * Check if credentials are valid
     * @returns Promise resolving to true if credentials are valid
     */
    checkCredentials(): Promise<boolean>;
}