refactor: separate provider capability policy

backend/tests/test_provider_router.py

@@ -1,14 +1,21 @@
-"""Provider router 测试 - failover 和配置加载。"""
-
-from unittest.mock import AsyncMock, MagicMock, patch
+"""Provider router 测试 - failover 和配置加载。"""
+
+from types import SimpleNamespace
+from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
 
 from app.services.adapters import AdapterConfig
-from app.services.adapters.text.models import StoryOutput
+from app.services.adapters.text.models import StoryOutput
+from app.services.provider_policy import (
+    DEFAULT_PROVIDERS,
+    RoutingStrategy,
+    get_provider_names_from_settings,
+    list_capability_policies,
+)
 
 
-class TestProviderFailover:
+class TestProviderFailover:
     """Provider failover 测试。"""
 
     @pytest.mark.asyncio
@@ -126,7 +133,7 @@ class TestProviderFailover:
                     )
 
     @pytest.mark.asyncio
-    async def test_default_provider_skips_fk_backed_metrics(self):
+    async def test_default_provider_skips_fk_backed_metrics(self):
         """环境变量/default provider 没有 providers 表记录，不写带外键的指标表。"""
         from app.services import provider_router
 
@@ -187,7 +194,91 @@ class TestProviderFailover:
         mock_record_call.assert_not_called()
         mock_record_call_result.assert_not_called()
         mock_record_cost.assert_awaited_once()
-        assert mock_record_cost.await_args.kwargs["provider_id"] is None
+        assert mock_record_cost.await_args.kwargs["provider_id"] is None
+
+    @pytest.mark.asyncio
+    async def test_storybook_round_robin_strategy_is_supported(self):
+        """所有能力都应能使用 routing policy，storybook 不能漏掉轮询计数器。"""
+        from app.services import provider_router
+        from app.services.adapters.storybook.primary import Storybook
+
+        mock_storybook = Storybook(
+            title="轮询绘本",
+            main_character="小星",
+            art_style="温暖水彩",
+            pages=[],
+            cover_prompt="cover",
+        )
+
+        class MockAdapter:
+            estimated_cost = 0.0
+
+            def __init__(self, config):
+                self.config = config
+
+            async def execute(self, **kwargs):
+                return mock_storybook
+
+        with patch.object(
+            provider_router,
+            "_get_providers_with_config",
+            new_callable=AsyncMock,
+        ) as mock_providers:
+            mock_providers.return_value = [
+                ("storybook_primary", AdapterConfig(api_key=""), None),
+            ]
+
+            with patch.object(provider_router.AdapterRegistry, "get", return_value=MockAdapter):
+                result = await provider_router.generate_storybook(
+                    keywords="测试",
+                    strategy=RoutingStrategy.ROUND_ROBIN,
+                )
+
+        assert result == mock_storybook
+
+
+class TestProviderPolicy:
+    """Provider capability / routing policy boundary tests."""
+
+    def test_policy_lists_all_capabilities(self):
+        policies = list_capability_policies()
+        capabilities = {item["capability"] for item in policies}
+
+        assert capabilities == {"text", "image", "tts", "storybook"}
+        assert DEFAULT_PROVIDERS["storybook"] == ["storybook_primary"]
+
+    def test_demo_provider_only_added_to_supported_capabilities(self):
+        settings = SimpleNamespace(
+            text_providers=["gemini"],
+            image_providers=["cqtai"],
+            tts_providers=["edge_tts"],
+            storybook_providers=["storybook_primary"],
+            enable_demo_providers=True,
+        )
+
+        assert get_provider_names_from_settings("text", settings) == ["demo", "gemini"]
+        assert get_provider_names_from_settings("image", settings) == ["demo", "cqtai"]
+        assert get_provider_names_from_settings("storybook", settings) == [
+            "demo",
+            "storybook_primary",
+        ]
+        assert get_provider_names_from_settings("tts", settings) == ["edge_tts"]
+
+    def test_policy_defaults_when_settings_lists_are_empty(self):
+        settings = SimpleNamespace(
+            text_providers=[],
+            image_providers=[],
+            tts_providers=[],
+            storybook_providers=[],
+            enable_demo_providers=False,
+        )
+
+        assert get_provider_names_from_settings("text", settings) == ["gemini", "openai"]
+        assert get_provider_names_from_settings("tts", settings) == [
+            "minimax",
+            "elevenlabs",
+            "edge_tts",
+        ]
 
 
 class TestProviderConfigFromDB:
@@ -215,10 +306,10 @@ class TestProviderConfigFromDB:
         assert config.timeout_ms == 30000
         assert config.max_retries == 5
 
-    def test_build_config_fallback_to_settings(self):
-        """Provider 无 api_key 时回退到 settings。"""
-        from app.services.provider_router import _build_config_from_provider
-
+    def test_build_config_fallback_to_settings(self):
+        """Provider 无 api_key 时回退到 settings。"""
+        from app.services.provider_router import _build_config_from_provider
+
         mock_provider = MagicMock()
         mock_provider.adapter = "text_primary"
         mock_provider.api_key = None
@@ -234,8 +325,33 @@ class TestProviderConfigFromDB:
             mock_settings.text_model = "gemini-2.0-flash"
 
             config = _build_config_from_provider(mock_provider)
-
-            assert config.api_key == "settings-api-key"
+
+            assert config.api_key == "settings-api-key"
+
+    def test_build_config_uses_direct_config_ref_name(self):
+        """config_ref 可以直接使用 settings 字段名，便于后台配置。"""
+        from app.services.provider_router import _build_config_from_provider
+
+        mock_provider = MagicMock()
+        mock_provider.adapter = "antigravity"
+        mock_provider.api_key = None
+        mock_provider.api_base = None
+        mock_provider.model = None
+        mock_provider.timeout_ms = None
+        mock_provider.max_retries = None
+        mock_provider.config_ref = "antigravity_api_key"
+        mock_provider.config_json = {}
+
+        with patch("app.services.provider_router.settings") as mock_settings:
+            mock_settings.antigravity_api_key = "antigravity-key"
+            mock_settings.antigravity_api_base = "https://antigravity.example"
+            mock_settings.antigravity_model = "gemini-3-pro-image"
+
+            config = _build_config_from_provider(mock_provider)
+
+            assert config.api_key == "antigravity-key"
+            assert config.api_base == "https://antigravity.example"
+            assert config.model == "gemini-3-pro-image"
 
 
 class TestProviderCacheStartup: