const version = document.querySelector('#frontend-version')?.textContent || 'dev';
const workerUrl = `/tts/piper-wasm-v1/piper-worker.js?v=${encodeURIComponent(version)}`;
let worker;
let requestId = 0;
const pending = new Map();

function getWorker() {
  if (worker) return worker;
  // ONNX Runtime resolves its WASM loader relative to the worker module URL.
  // Keep the worker as ESM so import.meta.url remains available at runtime.
  worker = new Worker(workerUrl, {type: 'module'});
  worker.onmessage = event => {
    const message = event.data || {};
    const request = pending.get(message.id);
    if (!request) return;
    if (message.type === 'progress') {
      request.onProgress?.(message.progress);
    } else {
      pending.delete(message.id);
      if (message.type === 'audio') {
        request.resolve(new Blob([message.audio], {type: 'audio/x-wav'}));
      } else {
        const error = new Error(message.error || 'Piper-arbetaren misslyckades.');
        request.reject(error);
        // TtsSession keeps a singleton even when ONNX initialization fails.
        // Discard the whole worker so a player retry starts with a clean ONNX
        // module and does not reuse a poisoned WASM initialization.
        for (const queued of pending.values()) queued.reject(error);
        pending.clear();
        worker?.terminate();
        worker = null;
      }
    }
  };
  worker.onerror = event => {
    const details = [event.message, event.filename && `${event.filename}:${event.lineno || 0}:${event.colno || 0}`]
      .filter(Boolean)
      .join(' — ');
    const error = new Error(details
      ? `Piper-arbetaren kunde inte startas: ${details}`
      : 'Piper-arbetaren kunde inte startas.');
    for (const request of pending.values()) request.reject(error);
    pending.clear();
    worker?.terminate();
    worker = null;
  };
  worker.onmessageerror = () => {
    const error = new Error('Piper-arbetaren skickade ett oläsbart svar.');
    for (const request of pending.values()) request.reject(error);
    pending.clear();
    worker?.terminate();
    worker = null;
  };
  return worker;
}

window.GamePiper = {
  voiceId: 'sv_SE-nst-medium',
  synthesize(text, onProgress) {
    return new Promise((resolve, reject) => {
      const id = ++requestId;
      pending.set(id, {resolve, reject, onProgress});
      try { getWorker().postMessage({id, text: String(text)}); }
      catch (error) { pending.delete(id); reject(error); }
    });
  },
};