init repo

app/middleware/chain.py

@@ -0,0 +1,35 @@
+"""Middleware chain — runs ordered middlewares before/after graph execution."""
+
+from __future__ import annotations
+
+import logging
+
+from app.graph.state import ReportState
+from .base import Middleware
+
+logger = logging.getLogger(__name__)
+
+
+class MiddlewareChain:
+    """Ordered list of middlewares. before() runs in order, after() runs in reverse."""
+
+    def __init__(self, middlewares: list[Middleware] | None = None):
+        self.middlewares = middlewares or []
+
+    def add(self, mw: Middleware) -> "MiddlewareChain":
+        self.middlewares.append(mw)
+        return self
+
+    async def before(self, state: ReportState) -> ReportState:
+        for mw in self.middlewares:
+            if mw.enabled:
+                logger.debug(f"[middleware:before] {mw.name}")
+                state = await mw.before(state)
+        return state
+
+    async def after(self, state: ReportState) -> ReportState:
+        for mw in reversed(self.middlewares):
+            if mw.enabled:
+                logger.debug(f"[middleware:after] {mw.name}")
+                state = await mw.after(state)
+        return state