import { ref, watch } from 'vue';

function storageKey(pageKey: string) {
  return `oms.operation.voiceBroadcast.${pageKey}`;
}

function pickChineseVoice(): SpeechSynthesisVoice | undefined {
  const voices = window.speechSynthesis?.getVoices?.() ?? [];
  return (
    voices.find((v) => v.lang === 'zh-CN') ||
    voices.find((v) => v.lang.startsWith('zh')) ||
    voices[0]
  );
}

/**
 * 操作扫描页语音播报（Web Speech API）。
 */
export function useOperationVoiceBroadcast(pageKey: string) {
  const voiceEnabled = ref(true);

  try {
    const stored = localStorage.getItem(storageKey(pageKey));
    if (stored != null) voiceEnabled.value = stored === '1';
  } catch {
    /* ignore */
  }

  watch(voiceEnabled, (v) => {
    try {
      localStorage.setItem(storageKey(pageKey), v ? '1' : '0');
    } catch {
      /* ignore */
    }
    if (!v) {
      window.speechSynthesis?.cancel?.();
    }
  });

  if (typeof window !== 'undefined' && window.speechSynthesis) {
    window.speechSynthesis.onvoiceschanged = () => {
      pickChineseVoice();
    };
  }

  function speak(text: string) {
    const content = text?.trim();
    if (!voiceEnabled.value || !content || typeof window === 'undefined') return;
    if (!('speechSynthesis' in window)) return;

    window.speechSynthesis.cancel();
    const utterance = new SpeechSynthesisUtterance(content);
    utterance.lang = 'zh-CN';
    utterance.rate = 1.05;
    utterance.pitch = 1;
    const voice = pickChineseVoice();
    if (voice) utterance.voice = voice;
    window.speechSynthesis.speak(utterance);
  }

  function stopSpeak() {
    window.speechSynthesis?.cancel?.();
  }

  return { voiceEnabled, speak, stopSpeak };
}