import type { TextToSpeech } from "./types.js";

/** Creates a non-blocking browser speech-synthesis adapter when supported. */
export function createTextToSpeech(): TextToSpeech {
  const isSupported =
    "speechSynthesis" in window && "SpeechSynthesisUtterance" in window;

  return {
    isSupported,
    cancel() {
      if (isSupported) window.speechSynthesis.cancel();
    },
    speak(text: string) {
      if (!isSupported || text.trim().length === 0) return;
      // Cancel the previous utterance so repeated controls cannot build an
      // inaccessible queue of stale answers.
      window.speechSynthesis.cancel();
      const utterance = new SpeechSynthesisUtterance(text);
      utterance.lang = document.documentElement.lang || "it-IT";
      window.speechSynthesis.speak(utterance);
    },
  };
}