feat(ai_router): feedback_from_aider_events read-only hook (Phase 24 A8)

apps/api/src/services/ai_router.py

@@ -655,6 +655,50 @@ class AIRouter:
             },
         ]
 
+    async def feedback_from_aider_events(
+        self,
+        repo: str | None = None,
+        days: int = 7,
+    ) -> dict[str, float]:
+        """從 aider_events 聚合近 N 日 success rate per model。
+
+        Phase 24 ADR-052 延伸：AI 自主化 feedback loop。
+        目前為 read-only（未接入 route() 決策），等 USE_AIDER_FEEDBACK flag
+        + 7 天灰度驗證後才會調整 provider 權重。
+
+        Args:
+            repo: 若給定，只聚合該 repo 的 session；否則所有 repo。
+            days: 時間窗口（預設 7 天）。
+
+        Returns:
+            {model_name: success_rate_float} e.g. {"elephant-alpha": 0.85, "gemini-pro": 0.92}
+            空 dict 代表無資料或查詢失敗（caller 應降級為忽略）。
+        """
+        try:
+            from src.db.base import get_session_factory
+            from src.repositories.aider_event_repository import AiderEventRepository
+        except ImportError:
+            return {}
+
+        try:
+            sf = get_session_factory()
+            async with sf() as sess:
+                repo_obj = AiderEventRepository(sess)
+                stats = await repo_obj.model_stats_since(days=days)
+        except Exception:
+            logger.debug("ai_router_feedback_aggregation_failed")
+            return {}
+
+        out: dict[str, float] = {}
+        for row in stats:
+            if repo and row.get("repo") != repo:
+                continue
+            model = row.get("model")
+            if not model:
+                continue
+            out[model] = float(row.get("success_rate") or 0)
+        return out
+
 
 # =============================================================================
 # Phase 24 ADR-052: AI Provider Registry + Execution Layer

apps/api/tests/test_ai_router_feedback.py

@@ -0,0 +1,93 @@
+# apps/api/tests/test_ai_router_feedback.py | 2026-04-20 @ Asia/Taipei
+"""Task A8: AIRouter.feedback_from_aider_events read-only aggregation test."""
+import pytest
+from unittest.mock import AsyncMock, MagicMock
+from src.services.ai_router import AIRouter
+
+
+@pytest.mark.asyncio
+async def test_feedback_aggregates_by_model(monkeypatch):
+    stats = [
+        {"repo": "awoooi", "model": "elephant-alpha", "total": 10,
+         "errors": 2, "success_rate": 0.8},
+        {"repo": "awoooi", "model": "gemini-pro", "total": 5,
+         "errors": 0, "success_rate": 1.0},
+    ]
+
+    class FakeRepo:
+        def __init__(self, sess): pass
+        async def model_stats_since(self, days): return stats
+
+    class FakeSession:
+        async def __aenter__(self): return self
+        async def __aexit__(self, *a): return False
+
+    monkeypatch.setattr("src.services.ai_router.get_session_factory",
+                        lambda: (lambda: FakeSession()), raising=False)
+    monkeypatch.setattr("src.repositories.aider_event_repository.AiderEventRepository",
+                        FakeRepo)
+
+    r = AIRouter()
+    out = await r.feedback_from_aider_events(days=7)
+    assert out["elephant-alpha"] == 0.8
+    assert out["gemini-pro"] == 1.0
+
+
+@pytest.mark.asyncio
+async def test_feedback_filters_by_repo(monkeypatch):
+    stats = [
+        {"repo": "awoooi", "model": "elephant-alpha", "total": 5,
+         "errors": 1, "success_rate": 0.8},
+        {"repo": "other-repo", "model": "elephant-alpha", "total": 3,
+         "errors": 3, "success_rate": 0.0},
+    ]
+
+    class FakeRepo:
+        def __init__(self, sess): pass
+        async def model_stats_since(self, days): return stats
+
+    class FakeSession:
+        async def __aenter__(self): return self
+        async def __aexit__(self, *a): return False
+
+    monkeypatch.setattr("src.services.ai_router.get_session_factory",
+                        lambda: (lambda: FakeSession()), raising=False)
+    monkeypatch.setattr("src.repositories.aider_event_repository.AiderEventRepository",
+                        FakeRepo)
+
+    r = AIRouter()
+    out = await r.feedback_from_aider_events(repo="awoooi", days=7)
+    assert out == {"elephant-alpha": 0.8}   # other-repo 過濾掉
+
+
+@pytest.mark.asyncio
+async def test_feedback_returns_empty_on_db_failure(monkeypatch):
+    def fail_sf():
+        raise RuntimeError("DB unavailable")
+
+    monkeypatch.setattr("src.services.ai_router.get_session_factory",
+                        fail_sf, raising=False)
+
+    r = AIRouter()
+    out = await r.feedback_from_aider_events(days=7)
+    assert out == {}   # 降級為空 dict，caller 不該崩
+
+
+@pytest.mark.asyncio
+async def test_feedback_handles_empty_stats(monkeypatch):
+    class FakeRepo:
+        def __init__(self, sess): pass
+        async def model_stats_since(self, days): return []
+
+    class FakeSession:
+        async def __aenter__(self): return self
+        async def __aexit__(self, *a): return False
+
+    monkeypatch.setattr("src.services.ai_router.get_session_factory",
+                        lambda: (lambda: FakeSession()), raising=False)
+    monkeypatch.setattr("src.repositories.aider_event_repository.AiderEventRepository",
+                        FakeRepo)
+
+    r = AIRouter()
+    out = await r.feedback_from_aider_events()
+    assert out == {}