// Client for the torch stage worker (~/dockers/torch-worker) — speaker diarization and the
// "is this a conversation?" probe. The worker is deliberately dumb: it answers acoustic
// questions about audio it is handed and holds no policy. Deciding what to do with a verdict
// happens in index.ts.
//
// Every call passes `timeout: false`: a full diarization runs at roughly half realtime on CPU,
// so an hour-long recording legitimately holds this connection for tens of minutes. The 255s
// lessons of 2026-08-24 are not getting relearned here.

type BunRequestInit = RequestInit & { timeout?: boolean | number };

export type SpeakerTurn = { start: number; end: number; speaker: string };

export type ProbeVerdict = 'solo' | 'conversation' | 'unsure';

export type ProbeResult = {
  duration: number;
  analyzed: { start: number; end: number; whole_file: boolean };
  speakers_found: number;
  overlap_ratio: number;
  verdict: ProbeVerdict;
  /** Complete diarization when the probe covered the whole file — reuse it, skip /diarize. */
  turns: SpeakerTurn[] | null;
};

export type DiarizeResult = {
  duration: number;
  speakers: string[];
  turns: SpeakerTurn[];
};

async function post<T>(url: string, form: FormData): Promise<T> {
  const res = await fetch(url, { method: 'POST', body: form, timeout: false } as BunRequestInit);
  if (!res.ok) {
    const detail = await res.text().catch(() => '');
    throw new Error(`worker ${res.status}: ${detail.slice(0, 300)}`);
  }
  return (await res.json()) as T;
}

export async function probeAudio(file: File | Blob, workerUrl: string): Promise<ProbeResult> {
  const form = new FormData();
  form.append('file', file);
  return post<ProbeResult>(`${workerUrl.replace(/\/+$/, '')}/probe`, form);
}

export async function diarizeAudio(file: File | Blob, workerUrl: string): Promise<DiarizeResult> {
  const form = new FormData();
  form.append('file', file);
  return post<DiarizeResult>(`${workerUrl.replace(/\/+$/, '')}/diarize`, form);
}

export type WorkerProbe = { ok: true } | { ok: false; error: string };

/** Reachability check for PUT /config validation and /_health, mirroring probeWhisper. */
export async function probeWorker(workerUrl: string): Promise<WorkerProbe> {
  const controller = new AbortController();
  const timer = setTimeout(() => controller.abort(), 5000);
  try {
    const res = await fetch(`${workerUrl.replace(/\/+$/, '')}/health`, { signal: controller.signal });
    if (!res.ok) return { ok: false, error: `worker answered ${res.status}` };
    return { ok: true };
  } catch (err) {
    return { ok: false, error: err instanceof Error ? err.message : 'could not reach the worker' };
  } finally {
    clearTimeout(timer);
  }
}