feat: add portfolio snapshot read layer

tests/application/test_snapshot_handler.py

@@ -0,0 +1,92 @@
+"""Snapshot RPC handler envelope path (REQ-028 AC-1/AC-2/AC-3)."""
+from __future__ import annotations
+
+from datetime import date
+
+from trex_core.application.messaging import RpcRequest
+from trex_core.application.messaging_handlers import make_snapshot_rpc_handler
+from trex_core.application.portfolio import (
+    DegradedReason,
+    InMemoryPauseStore,
+    PortfolioItem,
+    SnapshotStore,
+)
+from trex_core.domain.slot import SlotService
+from trex_core.domain.slot.in_memory_repository import InMemorySlotRepository
+
+DAY = date(2026, 6, 5)
+
+
+def _wire(items=None):
+    repo = InMemorySlotRepository()
+    svc = SlotService(repo)
+    svc.preallocate_daily_slots(DAY, 5)
+    store = SnapshotStore()
+    store.swap(items or [
+        PortfolioItem(portfolio_id="pf-A", symbol="005930",
+                      cash_balance=1_000_000, asset_quantity=0,
+                      active_strategy_id="target-value-v1",
+                      strategy_params={"k": 1}),
+    ])
+    pause = InMemoryPauseStore()
+    handler = make_snapshot_rpc_handler(
+        repo, svc,
+        snapshot_store=store, pause_store=pause, default_total_slots=5,
+    )
+    return store, pause, handler
+
+
+def test_envelope_shape_returned():
+    _, _, handler = _wire()
+    resp = handler(RpcRequest(
+        payload={"view": "all", "trading_date": DAY.isoformat()},
+        correlation_id="snap-1",
+    ))
+    body = resp.payload
+    assert set(body.keys()) == {"assets", "view", "available_slots", "degraded", "reason", "message"}
+    assert isinstance(body["assets"], list)
+    assert body["view"] == "all"
+    assert body["degraded"] is False
+    assert body["reason"] is None
+
+
+def test_envelope_strategy_key_filter():
+    _, _, handler = _wire([
+        PortfolioItem(portfolio_id="x", symbol="X", cash_balance=0, asset_quantity=0,
+                      active_strategy_id="alpha"),
+        PortfolioItem(portfolio_id="y", symbol="Y", cash_balance=0, asset_quantity=0,
+                      active_strategy_id="beta"),
+    ])
+    resp = handler(RpcRequest(
+        payload={"view": "all", "strategy_key": "alpha"}, correlation_id="snap-2",
+    ))
+    pids = {a["asset_id"] for a in resp.payload["assets"]}
+    assert pids == {"x"}
+
+
+def test_degraded_signal_does_not_leak_credentials():
+    store, _, handler = _wire()
+    store.set_degraded(
+        DegradedReason.PORTFOLIO_HUB_UNAVAILABLE,
+        "GET https://hub failed: 401 Bearer secret-token-abc",
+    )
+    resp = handler(RpcRequest(payload={"view": "all"}, correlation_id="snap-3"))
+    body = resp.payload
+    assert body["degraded"] is True
+    assert body["reason"] == "portfolio_hub_unavailable"
+    assert body["message"] is not None
+    assert "secret-token-abc" not in body["message"]
+
+
+def test_bat007_legacy_path_when_stores_unset():
+    """Make sure pre-BAT-008 callers still work (slots+capacity stub shape)."""
+    repo = InMemorySlotRepository()
+    svc = SlotService(repo)
+    svc.preallocate_daily_slots(DAY, 3)
+    handler = make_snapshot_rpc_handler(repo, svc)
+    resp = handler(RpcRequest(
+        payload={"view": "all", "trading_date": DAY.isoformat()}, correlation_id="legacy",
+    ))
+    body = resp.payload
+    assert "slots" in body and "capacity" in body
+    assert "assets" not in body