import type { Config } from '../config/schema.js';
export type ProductLanguage = 'en' | 'zh';
export type VoiceLanguageMode = 'auto' | 'manual';
export interface VoiceLanguageProfile {
    language: ProductLanguage;
    sttLanguage: 'auto' | 'en';
    edgeLanguage: 'en-US' | 'zh-CN';
    edgeVoice: 'en-US-MichelleNeural' | 'zh-CN-XiaoxiaoNeural';
}
export declare function resolveVoiceLanguageProfile(language: ProductLanguage): VoiceLanguageProfile;
export declare function inferProductLanguageFromEnvironment(): ProductLanguage;
/**
 * Install safe product defaults while preserving every explicit on/off choice.
 * Older configs with a persisted language or Edge voice are treated as manual.
 */
export declare function initializeVoiceDefaults(config: Config, language?: ProductLanguage): boolean;
/** Apply product language only to providers whose language mapping is known. */
export declare function applyAutomaticVoiceLanguage(config: Config, language: ProductLanguage): boolean;
/** Start the model download without delaying gateway readiness. */
export declare function prepareConfiguredLocalVoiceModel(config: Config): void;