import type { SpeechClip, VoiceInfo } from "@rakazo/adapter-kit";
import { GERMAN_VOICE_PRESETS } from "@rakazo/core";
import { readVoiceAudio, readVoiceJson, requireOk, voiceDeadline } from "./voice-http.js";

/** The Piper model behind each German voice; Kokoro has no German voices of its own. */
export const PIPER_MODELS: Record<string, string> = {
  dm_thorsten: "de_DE-thorsten-high",
  df_kerstin: "de_DE-kerstin-low",
  df_eva: "de_DE-eva_k-x_low",
  df_ramona: "de_DE-ramona-low",
  dm_karlsson: "de_DE-karlsson-low",
};

/** Piper runs only where configured, so a server without it skips the request entirely. */
export function piperBaseUrl(): string | undefined {
  const raw = process.env.PIPER_BASE_URL?.trim();
  return raw ? raw.replace(/\/+$/, "") : undefined;
}

export function piperUnreachable(): string {
  return "Deutsche Stimme nicht erreichbar. Prüfe, ob der Piper-Server läuft.";
}

/** The German voices whose Piper model the server has downloaded. */
export async function listPiperVoices(signal: AbortSignal): Promise<VoiceInfo[]> {
  const baseUrl = piperBaseUrl();
  if (!baseUrl) return [];
  try {
    const res = await fetch(`${baseUrl}/voices`, { signal: voiceDeadline(signal, 20_000) });
    if (!res.ok) return [];
    const body = await readVoiceJson(res, { requireValid: true });
    const models = new Set(body && typeof body === "object" ? Object.keys(body) : []);
    return GERMAN_VOICE_PRESETS.filter((voice) => {
      const model = PIPER_MODELS[voice.id];
      return model !== undefined && models.has(model);
    });
  } catch {
    return [];
  }
}

/** Speaks through Piper when the voice is one of its models, otherwise returns undefined. */
export async function synthesizePiper(
  voiceId: string | undefined,
  text: string,
  signal: AbortSignal,
): Promise<SpeechClip | undefined> {
  const model = voiceId ? PIPER_MODELS[voiceId] : undefined;
  if (!model) return undefined;
  const baseUrl = piperBaseUrl();
  if (!baseUrl) throw new Error(piperUnreachable());
  let res: Response;
  try {
    res = await fetch(`${baseUrl}/synthesize`, {
      method: "POST",
      headers: { "content-type": "application/json" },
      body: JSON.stringify({ text, voice: model }),
      signal,
    });
  } catch {
    throw new Error(piperUnreachable());
  }
  await requireOk(res, "Local voice", "speaking");
  return { bytes: await readVoiceAudio(res, signal), mimeType: "audio/wav" };
}