/**
 * SherpaOnnx WebAssembly TTS Client
 *
 * Enhanced version with multi-model support for browser environments.
 * Supports dynamic loading of Kokoro, Matcha, and VITS models.
 *
 * BACKWARD COMPATIBILITY: Maintains full compatibility with existing API.
 * New multi-model features are opt-in via constructor options.
 */
import { AbstractTTSClient } from "../core/abstract-tts";
import type { SpeakOptions, TTSCredentials, UnifiedVoice, WordBoundaryCallback } from "../types";
export type ModelType = "kokoro" | "matcha" | "vits" | "mms";
export interface ModelConfig {
    id: string;
    type: ModelType;
    name: string;
    language: string;
    gender: string;
    sampleRate: number;
    url?: string;
    compressed?: boolean;
    files: {
        model: string;
        tokens: string;
        voices?: string;
        vocoder?: string;
        dataDir?: string;
    };
    size: number;
}
export interface ModelFiles {
    model: ArrayBuffer;
    tokens: ArrayBuffer;
    voices?: ArrayBuffer;
    vocoder?: ArrayBuffer;
    dataDir?: ArrayBuffer;
}
export interface LoadedModel {
    config: ModelConfig;
    handle: number;
    loaded: boolean;
    lastUsed: number;
}
export interface EnhancedWasmOptions {
    enableMultiModel?: boolean;
    maxCachedModels?: number;
    modelsMirrorBaseUrl?: string;
}
declare global {
    interface Window {
        SherpaOnnx?: any;
    }
}
/**
 * Extended options for SherpaOnnxWasm TTS
 */
export interface SherpaOnnxWasmTTSOptions extends SpeakOptions {
    format?: "wav";
}
/**
 * Enhanced SherpaOnnx WebAssembly TTS Client
 *
 * Supports both legacy single-model mode and new multi-model mode.
 * Maintains full backward compatibility with existing API.
 */
export declare class SherpaOnnxWasmTTSClient extends AbstractTTSClient {
    private wasmModule;
    private tts;
    private wasmPath;
    private wasmLoaded;
    private wasmBaseUrl?;
    private mergedModelsUrl?;
    private modelsMirrorUrl?;
    private enhancedOptions;
    private modelRepository?;
    private modelManager?;
    private currentVoiceId?;
    private currentVoiceConfig?;
    /**
     * Create a new SherpaOnnx WebAssembly TTS client
     * @param credentials Optional credentials object
     * @param enhancedOptions Optional enhanced options for multi-model support
     */
    constructor(credentials?: TTSCredentials, enhancedOptions?: EnhancedWasmOptions);
    /**
     * Get the list of required credential types for this engine
     * @returns Array of required credential field names
     */
    protected getRequiredCredentials(): string[];
    /**
     * Check if the credentials are valid
     * @returns Promise resolving to true if credentials are valid
     */
    checkCredentials(): Promise<boolean>;
    /**
     * Get available voices
     * @returns Promise resolving to an array of unified voice objects
     */
    protected _getVoices(): Promise<UnifiedVoice[]>;
    /**
     * Initialize the WebAssembly module
     * @param wasmUrl URL to the WebAssembly file
     * @returns Promise resolving when the module is initialized
     */
    initializeWasm(wasmUrl: string): Promise<void>;
    /**
     * Synthesize text to speech and return the audio as a byte array
     * @param text Text to synthesize
     * @param options Options for synthesis
     * @returns Promise resolving to a byte array of audio data
     */
    synthToBytes(text: string, _options?: SpeakOptions): Promise<Uint8Array>;
    /**
     * Convert audio samples to the requested format
     * @param samples Float32Array of audio samples
     * @returns Uint8Array of audio data in the requested format
     */
    private _convertAudioFormat;
    /**
     * Check if SherpaOnnx is properly initialized
     * @returns Object with initialization status and details
     */
    getInitializationStatus(): {
        isInitialized: boolean;
        wasmLoaded: boolean;
        wasmModule: boolean;
        createOfflineTts: boolean;
        issues: string[];
    };
    /**
     * Get detailed error message for initialization issues
     * @returns Detailed error message with troubleshooting steps
     */
    private getInitializationErrorMessage;
    /**
     * Synthesize text to speech and stream the audio
     * @param text Text to synthesize
     * @param onAudioBuffer Callback for audio buffers
     * @param onStart Callback for when synthesis starts
     * @param onEnd Callback for when synthesis ends
     * @param onWord Callback for word boundary events
     * @param options Options for synthesis
     * @returns Promise resolving when synthesis is complete
     */
    synthToStream(text: string, onAudioBuffer: (audioBuffer: Uint8Array) => void, onStart?: () => void, onEnd?: () => void, onWord?: WordBoundaryCallback, options?: SpeakOptions): Promise<void>;
    /**
     * Synthesize text to speech and save to a file
     * @param text Text to synthesize
     * @param filename Filename to save as
     * @param format Audio format (mp3 or wav)
     * @param options Options for synthesis
     * @returns Promise resolving when synthesis is complete
     */
    synthToFile(text: string, filename: string, format?: "wav", // Override base class to only allow 'wav'
    options?: SherpaOnnxWasmTTSOptions): Promise<void>;
    /**
     * Get a property value
     * @param property Property name
     * @returns Property value
     */
    getProperty(property: string): any;
    /**
     * Set a property value
     * @param property Property name
     * @param value Property value
     */
    setProperty(property: string, value: any): void;
    /**
     * Build the OfflineTts configuration object expected by sherpa-onnx-tts.js.
     * Uses the currently selected voice metadata to decide which model block
     * (vits/kokoro/matcha) to populate and which auxiliary files to reference.
     */
    private buildOfflineTtsConfig;
    /**
     * Set the voice to use for synthesis
     * Enhanced with multi-model support while maintaining backward compatibility
     * @param voiceId Voice ID to use
     */
    setVoice(voiceId: string): Promise<void>;
    /**
     * Clean up resources
     * Enhanced to handle multi-model cleanup
     */
    dispose(): void;
    /**
     * Synthesize text to a byte stream
     * @param text Text to synthesize
     * @param options Options for synthesis
     * @returns Promise resolving to an object containing the audio stream and an empty word boundaries array
     */
    synthToBytestream(text: string, options?: SpeakOptions): Promise<{
        audioStream: ReadableStream<Uint8Array>;
        wordBoundaries: Array<{
            text: string;
            offset: number;
            duration: number;
        }>;
    }>;
}