evOo-local/apps/web/src/lib/onboarding-voices.ts

import type { VoiceInfo } from "@rakazo/contracts";
import { defaultVoiceForLocale, GERMAN_VOICE_PRESETS, voicesForLocale } from "@rakazo/core";

/** English presets when the local voice server is unreachable during onboarding. */
const ENGLISH_ONBOARDING_VOICES: VoiceInfo[] = [
  { id: "af_heart", label: "Heart", description: "warm" },
  { id: "af_bella", label: "Bella", description: "expressive" },
  { id: "af_sky", label: "Sky", description: "bright" },
  { id: "af_nova", label: "Nova", description: "energetic" },
  { id: "am_adam", label: "Adam", description: "clear" },
  { id: "am_michael", label: "Michael", description: "steady" },
];

const OFFLINE_CATALOG = [...GERMAN_VOICE_PRESETS, ...ENGLISH_ONBOARDING_VOICES];

const KOKORO_LANGUAGE_PREFIXES: Record<string, string> = {
  de: "d",
  en: "ab",
  es: "e",
  fr: "f",
  hi: "h",
  it: "i",
  ja: "j",
  pt: "p",
  zh: "z",
};

function listedVoicesSpeakLocale(listed: VoiceInfo[], locale: string): boolean {
  const language = locale.toLowerCase().split("-")[0] ?? "";
  const prefixes = KOKORO_LANGUAGE_PREFIXES[language];
  if (!prefixes) return listed.length > 0;
  return listed.some((voice) => {
    const prefix = /^([a-z])[fm]_/.exec(voice.id)?.[1];
    return Boolean(prefix && prefixes.includes(prefix));
  });
}

/** Locale-aware voice choices for onboarding when listing from the server fails. */
export function offlineOnboardingVoices(locale: string): VoiceInfo[] {
  return voicesForLocale(OFFLINE_CATALOG, locale).slice(0, 6);
}

/** Prefer server voices that speak the UI language; otherwise use offline presets. */
export function onboardingVoicesFromList(listed: VoiceInfo[], locale: string): VoiceInfo[] {
  if (listedVoicesSpeakLocale(listed, locale)) {
    return voicesForLocale(listed, locale).slice(0, 6);
  }
  return offlineOnboardingVoices(locale);
}

export function defaultOnboardingVoiceId(locale: string, voices: VoiceInfo[]): string {
  return defaultVoiceForLocale(voices, locale)?.id ?? "";
}