Add transport policy config

ampbrowser/plan.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 from dataclasses import dataclass
 
+from .config import AppConfig, default_config
 from .routing import Route, route_url
 from .transports import TransportStatus, inspect_transport
 
@@ -13,15 +14,43 @@ class BrowsePlan:
     action: str
     requires_consent: bool = False
     prompt: str = ""
+    policy_mode: str = "adopt-or-prompt-manage"
 
 
-def plan_url(raw_url: str) -> BrowsePlan:
+def plan_url(raw_url: str, *, config: AppConfig | None = None) -> BrowsePlan:
+    config = config or default_config()
     route = route_url(raw_url)
     status = inspect_transport(route.transport)
+    policy_mode = config.transport_mode(route.transport)
+
+    if policy_mode == "disabled":
+        return BrowsePlan(
+            route=route,
+            status=status,
+            action=f"blocked by policy: {route.transport} disabled",
+            policy_mode=policy_mode,
+        )
     if route.transport in {"clearnet", "unknown"}:
-        return BrowsePlan(route=route, status=status, action="open with clearnet profile")
+        return BrowsePlan(
+            route=route,
+            status=status,
+            action="open with clearnet profile",
+            policy_mode=policy_mode,
+        )
     if status and status.adoptable:
-        return BrowsePlan(route=route, status=status, action="adopt existing transport")
+        return BrowsePlan(
+            route=route,
+            status=status,
+            action="adopt existing transport",
+            policy_mode=policy_mode,
+        )
+    if policy_mode == "adopt":
+        return BrowsePlan(
+            route=route,
+            status=status,
+            action=f"blocked by policy: {route.transport} mode is adopt",
+            policy_mode=policy_mode,
+        )
     if status and status.manage_supported:
         action = "prompt to start managed transport"
         prompt = (
@@ -40,5 +69,11 @@ def plan_url(raw_url: str) -> BrowsePlan:
             action=action,
             requires_consent=True,
             prompt=prompt,
+            policy_mode=policy_mode,
         )
-    return BrowsePlan(route=route, status=status, action="blocked until adapter is configured")
+    return BrowsePlan(
+        route=route,
+        status=status,
+        action="blocked until adapter is configured",
+        policy_mode=policy_mode,
+    )