fixed a bug

android/sample-app/src/main/java/cn/learningpad/oraltrainer/sample/CourseCatalogController.kt

@@ -128,7 +128,7 @@ internal class CourseCatalogController(
                     return
                 }
                 host.onStatus("句子边界加载失败：${error.message.orEmpty()}")
-                host.onSentencePlaceholder("暂无句子边界", video.title)
+                host.onSentencePlaceholder("暂无句子边界", "")
             }
         })
     }

android/sample-app/src/main/java/cn/learningpad/oraltrainer/sample/MainActivity.kt

@@ -214,7 +214,7 @@ class MainActivity : Activity() {
                     bindings.statusText.text =
                         "句子边界获取失败，使用默认快退/快进：${error.message.orEmpty()}"
                     bindings.sentenceMetaText.text = "暂无句子边界"
-                    bindings.sentenceText.text = item.title
+                    bindings.sentenceText.text = ""
                 }
             }
         })
@@ -372,7 +372,7 @@ class MainActivity : Activity() {
         if (!bindings.hasPlayerChrome) return
         if (sentence == null) {
             bindings.sentenceMetaText.text = "暂无句子边界"
-            bindings.sentenceText.text = bindings.lessonTitleText.text
+            bindings.sentenceText.text = ""
             bindings.explainSentenceButton?.isEnabled = false
             return
         }

ios/OralTrainer/Views/FullscreenPlayerView.swift

@@ -171,10 +171,10 @@ struct FullscreenPlayerView: View {
         case .loading(let isLocal):
             return isLocal ? "正在匹配服务端句子边界" : (controller.currentItem?.title ?? "加载中")
         case .failed:
-            return controller.currentItem?.title ?? "未选择课程"
+            return ""
         case .idle, .loaded:
             guard let sentence = controller.currentSentence else {
-                return controller.currentItem?.title ?? "未选择课程"
+                return ""
             }
             if let text = sentence.text, !text.isEmpty {
                 return text

ios/OralTrainer/Views/PlayerSectionView.swift

@@ -189,10 +189,10 @@ struct PlayerSectionView: View {
             }
             return controller.currentItem?.title ?? "加载中"
         case .failed:
-            return controller.currentItem?.title ?? "未选择课程"
+            return ""
         case .idle, .loaded:
             guard let sentence = controller.currentSentence else {
-                return controller.currentItem?.title ?? "未选择课程"
+                return ""
             }
             if let text = sentence.text, !text.isEmpty {
                 return text

sentence_api/.env.example

@@ -17,7 +17,8 @@ MOSS_MAX_NEW_TOKENS=65536
 # 每句结束时间向后顺延的毫秒数，避免句子末尾发音被切掉；按需在 200-500 之间调整
 MOSS_END_PADDING_MS=300
 
-# AI sentence explanation (OpenAI-compatible chat completions endpoint).
+# AI sentence explanation (OpenAI-compatible chat endpoint). A base URL ending
+# in /v1 is also accepted and will automatically use /v1/chat/completions.
 # The URL and key stay on the server; mobile clients only send the sentence text.
 AI_API_URL=https://api.example.com/v1/chat/completions
 AI_API_KEY=replace-with-your-ai-api-key

sentence_api/README.md

@@ -68,7 +68,9 @@ requests use `X-Client-Key` when `CLIENT_API_KEY` is configured.
 
 ## AI Sentence Explanation
 
-Configure an OpenAI-compatible chat-completions endpoint in `sentence_api/.env`:
+Configure an OpenAI-compatible chat-completions endpoint in `sentence_api/.env`.
+A base URL ending in `/v1` is also accepted and is resolved to
+`/v1/chat/completions`:
 
 ```dotenv
 AI_API_URL=https://api.example.com/v1/chat/completions

sentence_api/ai_tutor.py

@@ -2,6 +2,7 @@
 
 from dataclasses import dataclass
 import logging
+from urllib.parse import urlsplit
 
 import requests
 
@@ -24,6 +25,19 @@ class AITutor:
     def available(self) -> bool:
         return bool(self.endpoint and self.model)
 
+    @property
+    def request_url(self) -> str:
+        """Resolve either a full chat URL or an OpenAI-compatible base URL."""
+        parsed = urlsplit(self.endpoint)
+        path = parsed.path.rstrip("/")
+        if parsed.query or path.endswith("/chat/completions"):
+            return self.endpoint
+        if path.endswith("/v1") or path.endswith("/v1/openai"):
+            return self.endpoint + "/chat/completions"
+        if not path:
+            return self.endpoint + "/v1/chat/completions"
+        return self.endpoint
+
     def explain(
         self,
         sentence_text: str,
@@ -51,7 +65,7 @@ class AITutor:
             headers["Authorization"] = f"Bearer {self.api_key}"
         try:
             response = requests.post(
-                self.endpoint,
+                self.request_url,
                 headers=headers,
                 json={
                     "model": self.model,
@@ -67,7 +81,7 @@ class AITutor:
         except requests.RequestException as exc:
             logger.exception(
                 "AI explanation request failed: endpoint=%s model=%s",
-                self.endpoint,
+                self.request_url,
                 self.model,
             )
             raise AITutorError("AI service request failed.") from exc
@@ -76,7 +90,7 @@ class AITutor:
             logger.warning(
                 "AI explanation returned HTTP %s: endpoint=%s model=%s body=%s",
                 response.status_code,
-                self.endpoint,
+                self.request_url,
                 self.model,
                 response.text[:1000],
             )
@@ -87,14 +101,14 @@ class AITutor:
         except (KeyError, IndexError, TypeError, ValueError) as exc:
             logger.warning(
                 "AI explanation returned an unexpected body: endpoint=%s body=%s",
-                self.endpoint,
+                self.request_url,
                 response.text[:1000],
             )
             raise AITutorError("AI service returned an unexpected response.") from exc
         if not isinstance(explanation, str) or not explanation.strip():
             logger.warning(
                 "AI explanation returned empty content: endpoint=%s body=%s",
-                self.endpoint,
+                self.request_url,
                 response.text[:1000],
             )
             raise AITutorError("AI service returned an empty explanation.")

sentence_api/tests/test_ai_tutor.py

@@ -47,6 +47,21 @@ def test_ai_tutor_parses_chat_completion(monkeypatch):
     assert timeout == 1.5
 
 
+def test_ai_tutor_resolves_openai_compatible_base_url(monkeypatch):
+    endpoints = []
+
+    def fake_post(endpoint, **kwargs):
+        endpoints.append(endpoint)
+        return FakeResponse(body={"choices": [{"message": {"content": "ok"}}]})
+
+    monkeypatch.setattr("sentence_api.ai_tutor.requests.post", fake_post)
+    tutor = AITutor("https://ai.test:8080/v1", "secret", "test-model", 1)
+
+    assert tutor.explain("Hello.") == "ok"
+    assert endpoints == ["https://ai.test:8080/v1/chat/completions"]
+    assert tutor.request_url == "https://ai.test:8080/v1/chat/completions"
+
+
 def test_ai_tutor_rejects_unexpected_response(monkeypatch):
     monkeypatch.setattr(
         "sentence_api.ai_tutor.requests.post",