feat: persist story generation states and cache audio

backend/tests/conftest.py

@@ -1,4 +1,4 @@
-"""测试配置和 fixtures。"""
+"""Pytest fixtures for backend tests."""
 
 import os
 from collections.abc import AsyncGenerator
@@ -11,6 +11,7 @@ from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_asyn
 os.environ.setdefault("SECRET_KEY", "test-secret-key-for-testing")
 os.environ.setdefault("DATABASE_URL", "sqlite+aiosqlite:///:memory:")
 
+from app.core.config import settings
 from app.core.security import create_access_token
 from app.db.database import get_db
 from app.db.models import Base, Story, User
@@ -19,7 +20,8 @@ from app.main import app
 
 @pytest.fixture
 async def async_engine():
-    """创建内存数据库引擎。"""
+    """Create an in-memory database engine."""
+
     engine = create_async_engine("sqlite+aiosqlite:///:memory:", echo=False)
     async with engine.begin() as conn:
         await conn.run_sync(Base.metadata.create_all)
@@ -29,7 +31,8 @@ async def async_engine():
 
 @pytest.fixture
 async def db_session(async_engine) -> AsyncGenerator[AsyncSession, None]:
-    """创建数据库会话。"""
+    """Create a database session."""
+
     session_factory = async_sessionmaker(
         async_engine, class_=AsyncSession, expire_on_commit=False
     )
@@ -39,7 +42,8 @@ async def db_session(async_engine) -> AsyncGenerator[AsyncSession, None]:
 
 @pytest.fixture
 async def test_user(db_session: AsyncSession) -> User:
-    """创建测试用户。"""
+    """Create a test user."""
+
     user = User(
         id="github:12345",
         name="Test User",
@@ -54,13 +58,74 @@ async def test_user(db_session: AsyncSession) -> User:
 
 @pytest.fixture
 async def test_story(db_session: AsyncSession, test_user: User) -> Story:
-    """创建测试故事。"""
+    """Create a plain generated story."""
+
     story = Story(
         user_id=test_user.id,
         title="测试故事",
-        story_text="从前有一只小兔子...",
+        story_text="从前有一只小兔子。",
         cover_prompt="A cute rabbit in a forest",
         mode="generated",
+        generation_status="narrative_ready",
+        image_status="not_requested",
+        audio_status="not_requested",
+    )
+    db_session.add(story)
+    await db_session.commit()
+    await db_session.refresh(story)
+    return story
+
+
+@pytest.fixture
+async def storybook_story(db_session: AsyncSession, test_user: User) -> Story:
+    """Create a storybook-mode story."""
+
+    story = Story(
+        user_id=test_user.id,
+        title="森林绘本冒险",
+        story_text=None,
+        pages=[
+            {
+                "page_number": 1,
+                "text": "小兔子走进了会发光的森林。",
+                "image_prompt": "A glowing forest with a curious rabbit",
+                "image_url": "https://example.com/page-1.png",
+            },
+            {
+                "page_number": 2,
+                "text": "它遇见了一位会唱歌的萤火虫朋友。",
+                "image_prompt": "A rabbit meeting a singing firefly",
+                "image_url": None,
+            },
+        ],
+        cover_prompt="A magical forest storybook cover",
+        image_url="https://example.com/storybook-cover.png",
+        mode="storybook",
+        generation_status="degraded_completed",
+        image_status="failed",
+        audio_status="not_requested",
+        last_error="第 2 页插图生成失败",
+    )
+    db_session.add(story)
+    await db_session.commit()
+    await db_session.refresh(story)
+    return story
+
+
+@pytest.fixture
+async def degraded_story_with_text(db_session: AsyncSession, test_user: User) -> Story:
+    """Create a readable story whose image generation already failed."""
+
+    story = Story(
+        user_id=test_user.id,
+        title="部分完成的测试故事",
+        story_text="从前有一只小兔子继续冒险。",
+        cover_prompt="A rabbit under the moon",
+        mode="generated",
+        generation_status="degraded_completed",
+        image_status="failed",
+        audio_status="not_requested",
+        last_error="封面生成失败",
     )
     db_session.add(story)
     await db_session.commit()
@@ -70,13 +135,14 @@ async def test_story(db_session: AsyncSession, test_user: User) -> Story:
 
 @pytest.fixture
 def auth_token(test_user: User) -> str:
-    """生成测试用户的 JWT token。"""
+    """Create a JWT token for the test user."""
+
     return create_access_token({"sub": test_user.id})
 
 
 @pytest.fixture
 def client(db_session: AsyncSession) -> TestClient:
-    """创建测试客户端。"""
+    """Create a test client."""
 
     async def override_get_db():
         yield db_session
@@ -89,35 +155,45 @@ def client(db_session: AsyncSession) -> TestClient:
 
 @pytest.fixture
 def auth_client(client: TestClient, auth_token: str) -> TestClient:
-    """带认证的测试客户端。"""
+    """Create an authenticated test client."""
+
     client.cookies.set("access_token", auth_token)
     return client
 
 
 @pytest.fixture(autouse=True)
 def bypass_rate_limit():
-    """默认绕过限流，让非限流测试正常运行。"""
+    """Bypass rate limiting in most tests."""
+
     with patch("app.core.rate_limiter.get_redis", new_callable=AsyncMock) as mock_redis:
-        # 创建一个模拟的 Redis 客户端，所有操作返回安全默认值
         redis_instance = AsyncMock()
-        redis_instance.incr.return_value = 1  # 始终返回 1 (不触发限流)
+        redis_instance.incr.return_value = 1
         redis_instance.expire.return_value = True
-        redis_instance.get.return_value = None  # 无锁定记录
+        redis_instance.get.return_value = None
         redis_instance.ttl.return_value = 0
         redis_instance.delete.return_value = 1
         mock_redis.return_value = redis_instance
         yield redis_instance
 
 
+@pytest.fixture(autouse=True)
+def isolated_story_audio_cache(tmp_path, monkeypatch):
+    """Use an isolated directory for cached story audio files."""
+
+    monkeypatch.setattr(settings, "story_audio_cache_dir", str(tmp_path / "audio"))
+    yield
+
+
 @pytest.fixture
 def mock_text_provider():
-    """Mock 文本生成适配器 API 调用。"""
+    """Mock text generation."""
+
     from app.services.adapters.text.models import StoryOutput
 
     mock_result = StoryOutput(
         mode="generated",
         title="小兔子的冒险",
-        story_text="从前有一只小兔子...",
+        story_text="从前有一只小兔子。",
         cover_prompt_suggestion="A cute rabbit",
     )
 
@@ -128,7 +204,8 @@ def mock_text_provider():
 
 @pytest.fixture
 def mock_image_provider():
-    """Mock 图像生成。"""
+    """Mock image generation."""
+
     with patch("app.services.story_service.generate_image", new_callable=AsyncMock) as mock:
         mock.return_value = "https://example.com/image.png"
         yield mock
@@ -136,7 +213,8 @@ def mock_image_provider():
 
 @pytest.fixture
 def mock_tts_provider():
-    """Mock TTS。"""
+    """Mock text-to-speech generation."""
+
     with patch("app.services.provider_router.text_to_speech", new_callable=AsyncMock) as mock:
         mock.return_value = b"fake-audio-bytes"
         yield mock
@@ -144,7 +222,8 @@ def mock_tts_provider():
 
 @pytest.fixture
 def mock_all_providers(mock_text_provider, mock_image_provider, mock_tts_provider):
-    """Mock 所有 AI 供应商。"""
+    """Group all mocked providers."""
+
     return {
         "text_primary": mock_text_provider,
         "image_primary": mock_image_provider,