feat: upgrade student vocabulary learning flow

apps/taro/src/services/learning.ts

@@ -161,6 +161,8 @@ export interface VocabularyWord {
   difficulty?: string | null;
   status?: string;
   dueLevel?: string;
+  favoritedAt?: string | null;
+  note?: string | null;
 }
 
 export async function createPracticeSession(body: {
@@ -281,6 +283,12 @@ export async function toggleWordFavorite(wordId: string, favorite: boolean) {
   });
 }
 
+export async function loadFavoriteWords(unitId?: string, limit = 500) {
+  return apiRequest<{ items?: VocabularyWord[] }>('/api/learning/vocabulary/favorites', {
+    query: { unitId, limit },
+  });
+}
+
 export async function loadVocabularyStats(unitId?: string) {
   return apiRequest<{ item?: Record<string, unknown> }>('/api/learning/vocabulary/stats', { query: { unitId } });
 }

apps/taro/src/services/pronunciation.ts

@@ -0,0 +1,97 @@
+import Taro from '@tarojs/taro';
+
+export type AccentType = 'us' | 'uk';
+
+const YOUDAO_TYPE: Record<AccentType, number> = {
+  us: 1,
+  uk: 2,
+};
+
+let currentAudio: HTMLAudioElement | null = null;
+let currentInnerAudio: Taro.InnerAudioContext | null = null;
+
+function pronunciationUrl(word: string, accent: AccentType) {
+  return `https://dict.youdao.com/dictvoice?audio=${encodeURIComponent(word)}&type=${YOUDAO_TYPE[accent] || 1}`;
+}
+
+function stopCurrentAudio() {
+  try {
+    if (currentAudio) {
+      currentAudio.pause();
+      currentAudio.src = '';
+      currentAudio = null;
+    }
+  } catch (_error) {
+    // ignore playback cleanup errors
+  }
+  try {
+    if (currentInnerAudio) {
+      currentInnerAudio.stop();
+      currentInnerAudio.destroy();
+      currentInnerAudio = null;
+    }
+  } catch (_error) {
+    // ignore playback cleanup errors
+  }
+  try {
+    if (typeof window !== 'undefined' && 'speechSynthesis' in window) {
+      window.speechSynthesis.cancel();
+    }
+  } catch (_error) {
+    // ignore unsupported runtime
+  }
+}
+
+function fallbackSpeech(word: string, accent: AccentType) {
+  if (typeof window === 'undefined' || !('speechSynthesis' in window)) return false;
+  try {
+    const utterance = new SpeechSynthesisUtterance(word);
+    utterance.lang = accent === 'uk' ? 'en-GB' : 'en-US';
+    utterance.rate = 0.86;
+    window.speechSynthesis.speak(utterance);
+    return true;
+  } catch (_error) {
+    return false;
+  }
+}
+
+export async function playWordPronunciation(word: string, accent: AccentType = 'us') {
+  const text = word.trim();
+  if (!text) return;
+  stopCurrentAudio();
+
+  const url = pronunciationUrl(text, accent);
+
+  if (process.env.TARO_ENV === 'h5' && typeof Audio !== 'undefined') {
+    try {
+      const audio = new Audio(url);
+      audio.preload = 'auto';
+      currentAudio = audio;
+      audio.onerror = () => {
+        currentAudio = null;
+        fallbackSpeech(text, accent);
+      };
+      await audio.play();
+      return;
+    } catch (_error) {
+      if (fallbackSpeech(text, accent)) return;
+    }
+  }
+
+  try {
+    const audio = Taro.createInnerAudioContext();
+    currentInnerAudio = audio;
+    audio.src = url;
+    audio.autoplay = true;
+    audio.onEnded(() => {
+      if (currentInnerAudio === audio) currentInnerAudio = null;
+      audio.destroy();
+    });
+    audio.onError(() => {
+      if (currentInnerAudio === audio) currentInnerAudio = null;
+      audio.destroy();
+    });
+  } catch (_error) {
+    Taro.showToast({ title: '当前环境暂不支持发音', icon: 'none' });
+  }
+}