feat: add project-scoped operations

app/api/v1/endpoints/timeseries/scada.py

@@ -4,6 +4,7 @@ from datetime import datetime
 from psycopg import AsyncConnection
 from pydantic import BaseModel, Field, field_validator
 
+from app.domain.schemas.scada import ScadaLatestReadingsResponse
 from app.infra.db.postgresql.scada import ScadaInfoRepository
 from app.infra.db.timescaledb.repositories.scada import ScadaRepository
 from .dependencies import get_postgres_connection, get_timescale_connection
@@ -96,6 +97,54 @@ async def get_scada_by_ids_time_range(
     )
 
 
+@router.get(
+    "/timeseries/scada-readings/latest",
+    response_model=ScadaLatestReadingsResponse,
+    summary="获取SCADA设备最新数据",
+)
+async def get_latest_scada_readings(
+    limit: int = Query(100, ge=1, le=500, description="返回设备数上限"),
+    offset: int = Query(0, ge=0, description="设备目录偏移量"),
+    conn: AsyncConnection = Depends(get_timescale_connection),
+    postgres_conn: AsyncConnection = Depends(get_postgres_connection),
+) -> ScadaLatestReadingsResponse:
+    """Read one latest persisted row per project device without applying a time window."""
+    devices = await ScadaInfoRepository.get_scadas(postgres_conn)
+    selected_devices = devices[offset : offset + limit]
+    latest_by_device = await ScadaRepository.get_latest_scada_readings(
+        conn,
+        [device["device_id"] for device in selected_devices],
+    )
+
+    items = []
+    for device in selected_devices:
+        reading = latest_by_device.get(device["device_id"])
+        items.append(
+            {
+                "device_id": device["device_id"],
+                "device_type": device["device_type"],
+                "measurement_unit": device["measurement_unit"],
+                "transmission_mode": device["transmission_mode"],
+                "transmission_frequency": device["transmission_frequency"],
+                "observed_at": reading["time"] if reading else None,
+                "monitored_value": reading["monitored_value"] if reading else None,
+                "cleaned_value": reading["cleaned_value"] if reading else None,
+            }
+        )
+
+    observed_times = [item["observed_at"] for item in items if item["observed_at"] is not None]
+    return ScadaLatestReadingsResponse.model_validate(
+        {
+            "items": items,
+            "total": len(devices),
+            "limit": limit,
+            "offset": offset,
+            "observed_count": len(observed_times),
+            "latest_observed_at": max(observed_times) if observed_times else None,
+        }
+    )
+
+
 @router.get(
     "/timeseries/scada-readings/fields", summary="按设备ID、字段和时间范围查询SCADA数据"
 )