feat(host-protocol): long poll assignments

tests/test_host_agent_internal_api.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from datetime import UTC, datetime
+from datetime import timedelta
 
 from fastapi import FastAPI
 from fastapi.testclient import TestClient
@@ -9,6 +10,7 @@ from cloud.auth import BearerCredential, ConfiguredBearerAuthProvider
 from cloud.config import CloudConfig
 from cloud.internal_api.api import create_internal_router
 from cloud.pool import DevicePool, PooledDevice
+from cloud.scheduler import ScheduledTask, TaskConstraints
 from cloud.store import CloudStore
 
 
@@ -136,3 +138,69 @@ def test_host_token_cannot_submit_heartbeat_for_another_host(tmp_path) -> None:
 
     assert response.status_code == 403
     assert pool.store.get_host("host-b") is None
+
+
+def test_long_poll_claim_returns_at_most_one_owned_assignment(tmp_path) -> None:
+    client, pool = _build_client(tmp_path)
+    now = datetime.now(UTC)
+    pool.store.upsert_host("host-a", address=None, last_seen_at=now)
+    pool.store.replace_host_devices(
+        "host-a",
+        [
+            PooledDevice(
+                device_id="claim-device",
+                host_id="host-a",
+                driver_type="wda",
+                status="idle",
+                synced_at=now,
+            )
+        ],
+    )
+    pool.store.enqueue_task(
+        ScheduledTask(
+            id="claim-task",
+            goal="open settings",
+            workflow_definition_id=None,
+            constraints=TaskConstraints(),
+            created_at=now,
+        )
+    )
+    pool.store.assign_task(
+        task_id="claim-task",
+        host_id="host-a",
+        device_id="claim-device",
+        lease_id="claim-lease",
+        lease_expires_at=now + timedelta(minutes=1),
+        now=now,
+    )
+
+    first = client.post(
+        "/internal/v1/hosts/host-a/assignments/claim",
+        headers={"Authorization": "Bearer token-a"},
+        json={"host_id": "host-a", "timeout_seconds": 0},
+    )
+    second = client.post(
+        "/internal/v1/hosts/host-a/assignments/claim",
+        headers={"Authorization": "Bearer token-a"},
+        json={"host_id": "host-a", "timeout_seconds": 0},
+    )
+
+    assert first.status_code == 200
+    assignment = first.json()["assignment"]
+    assert assignment["task_id"] == "claim-task"
+    assert assignment["lease_id"] == "claim-lease"
+    assert second.status_code == 200
+    assert second.json() == {"assignment": None, "timed_out": True}
+
+
+def test_empty_long_poll_timeout_is_normal_response(tmp_path) -> None:
+    client, _ = _build_client(tmp_path)
+
+    response = client.post(
+        "/internal/v1/hosts/host-a/assignments/claim",
+        headers={"Authorization": "Bearer token-a"},
+        json={"host_id": "host-a", "timeout_seconds": 0},
+    )
+
+    assert response.status_code == 200
+    assert response.json() == {"assignment": None, "timed_out": True}