feat: add kill-switch control flow

trex_core/application/messaging_handlers.py

@@ -164,6 +164,7 @@ def make_snapshot_rpc_handler(
     pause_store: Optional[PauseStore] = None,
     default_total_slots: int = 10,
     watchdog_store: Optional[WatchdogStore] = None,
+    killswitch_store=None,
 ):
     """Build the RPC handler for `trex.snapshot.req` (REQ-028).
 
@@ -211,6 +212,7 @@ def make_snapshot_rpc_handler(
                 view=view,
                 strategy_key=strategy_key,
                 trading_date=day,
+                killswitch_store=killswitch_store,
             )
             return RpcResponse(payload=envelope.to_dict())
 
@@ -282,6 +284,78 @@ def _err(reason: str) -> RpcResponse:
     return RpcResponse(payload={"status": "error", "reason": reason})
 
 
+# ---- control RPC handler (REQ-043, BAT-012) ---------------------------------
+
+def make_control_rpc_handler(pause_store: PauseStore, *, kill_switch_service=None):
+    """RPC handler for `trex.control.req` — action discriminator dispatch (REQ-043).
+
+    Actions: `pause`/`resume`/`list` (REQ-032, delegated), `kill_switch` (REQ-045),
+    `resume_kill_switch` (REQ-046). Unknown actions return an error response.
+    """
+    pause_handler = make_pause_rpc_handler(pause_store)
+
+    def handler(req: RpcRequest) -> RpcResponse:
+        body = req.payload or {}
+        action = str(body.get("action") or "").lower()
+        if action == "kill_switch":
+            return _handle_kill_switch(body, kill_switch_service)
+        if action == "resume_kill_switch":
+            return _handle_resume_kill_switch(body, kill_switch_service)
+        if action in ("pause", "resume", "list"):
+            return pause_handler(req)
+        return _err(f"unknown_action:{action}")
+
+    return handler
+
+
+def _killswitch_scope(body: dict):
+    """Validate scope/portfolio_id. Returns (scope, pid) or (None, RpcResponse error)."""
+    scope = str(body.get("scope") or "").lower()
+    pid = _opt_str(body.get("portfolio_id"))
+    if scope not in ("portfolio", "global"):
+        return None, _err(f"bad_scope:{scope}")
+    if scope == "portfolio" and not pid:
+        return None, _err("portfolio_id_required")
+    return (scope, pid), None
+
+
+def _handle_kill_switch(body: dict, svc) -> RpcResponse:
+    """REQ-045: liquidate holding slots in scope + day-exclude."""
+    if svc is None:
+        return _err("kill_switch_unsupported")
+    parsed, err = _killswitch_scope(body)
+    if err is not None:
+        return err
+    scope, pid = parsed
+    actor = str(body.get("actor") or "operator")
+    try:
+        liquidated = svc.fire(scope=scope, portfolio_id=pid, actor=actor)
+    except Exception as exc:  # noqa: BLE001
+        return _err(f"kill_switch_failed:{exc.__class__.__name__}")
+    payload = {"status": "ok", "scope": scope, "liquidated": liquidated}
+    if pid:
+        payload["portfolio_id"] = pid
+    return RpcResponse(payload=payload)
+
+
+def _handle_resume_kill_switch(body: dict, svc) -> RpcResponse:
+    """REQ-046: clear the day-scoped exclusion (sold slots stay sold)."""
+    if svc is None:
+        return _err("resume_kill_switch_unsupported")
+    parsed, err = _killswitch_scope(body)
+    if err is not None:
+        return err
+    scope, pid = parsed
+    try:
+        svc.resume(scope=scope, portfolio_id=pid)
+    except Exception as exc:  # noqa: BLE001
+        return _err(f"resume_kill_switch_failed:{exc.__class__.__name__}")
+    payload = {"status": "ok", "scope": scope}
+    if pid:
+        payload["portfolio_id"] = pid
+    return RpcResponse(payload=payload)
+
+
 # ---- event payload builder --------------------------------------------------
 
 def slot_transition_event_payload(slot, *, event_type: str) -> dict: