Tool/naip fetcher (#16)

* Add initial NAIP fetcher

* Swap to Element84's EarthSearch API for NAIP STAC search and download

* clip to bounds of aoi

* Swap to Element84's EarthSearch API for NAIP STAC search and download

* rename bands and remove dask chunking

* Add DS_Store to .gitignore

* restrict date range for naip test

* Adjust timerange for tests

* Add xarray to pyproj

* Reduce aoi size

* revert test to use tmp path

* Update return types for tool to ensure state gets updated

* Update unit test for compatibility with Command output from tool

* Save image bytes directly to graph state for summarizer

* add safeguard against large image sizes

* remove print statement

* Fix stac.load to work with MCP API by manually inserting band data into the  extension

* Remove deleted file

* Add comment explaining workaround

---------

Co-authored-by: lillythomas <lillyelizathomas@gmail.com>
Co-authored-by: Daniel Wiesmann <yellowcap@users.noreply.github.com>

src/geo_assistant/agent/state.py

@@ -8,7 +8,7 @@ from pydantic import Field
 class GeoAssistantState(AgentState):
     place: NotRequired[Feature | None] = None
     search_area: NotRequired[Feature | None] = None
-    naip_png_path: NotRequired[str | None] = Field(
+    naip_img_bytes: NotRequired[bytes | None] = Field(
         default=None,
-        description="Path to the saved NAIP RGB PNG image",
+        description="Bytes of the saved NAIP RGB PNG image",
     )

src/geo_assistant/tools/naip.py

@@ -1,6 +1,6 @@
 # tools/naip_mpc_tools.py
 from concurrent.futures import ThreadPoolExecutor
-from pathlib import Path
+from io import BytesIO
 from typing import Annotated, Any
 
 import dotenv
@@ -12,12 +12,13 @@ from langchain_core.tools import tool
 from langchain_core.tools.base import InjectedToolCallId
 from langgraph.types import Command
 from odc.stac import stac_load
+from pystac.extensions.raster import RasterBand
 from pystac_client import Client
 
 dotenv.load_dotenv()
 
-# PC_STAC_URL = "https://planetarycomputer.microsoft.com/api/stac/v1"
-E84_STAC_URL = "https://earth-search.aws.element84.com/v1"
+DATA_URL = "https://planetarycomputer.microsoft.com/api/stac/v1"
+# DATA_URL = "https://earth-search.aws.element84.com/v1"
 
 
 @tool("fetch_naip_img")
@@ -39,7 +40,7 @@ async def fetch_naip_img(
 
     """
     # --- 1. STAC search on Element84's EarthSearch API ---
-    catalog = Client.open(E84_STAC_URL)
+    catalog = Client.open(DATA_URL)
 
     search = catalog.search(
         collections=["naip"],
@@ -48,6 +49,16 @@ async def fetch_naip_img(
     )
 
     items = list(search.items())
+
+    # This is a hack to add raster extension info to the items, since
+    # the Planetary Computer STAC API adds the band information using the
+    # eo:bands extension, but odc.stac expects the raster:bands extension.
+    for item in items:
+        item.assets["image"].ext.add("raster")
+        item.assets["image"].ext.raster.bands = [
+            RasterBand.create() for _ in ("red", "green", "blue", "nir")
+        ]
+
     if len(items) == 0:
         return Command(
             update={
@@ -61,18 +72,20 @@ async def fetch_naip_img(
             },
         )
 
-        # --- 2. Load as xarray cube with odc.stac ---
-        # NAIP in MPC: 4-band multi-band asset (R,G,B,NIR) in one asset named "image".
-        # odc.stac exposes these as measurements 'red','green','blue','nir' for this collection
+    # --- 2. Load as xarray cube with odc.stac ---
+    # NAIP in MPC: 4-band multi-band asset (R,G,B,NIR) in one asset named "image".
+    # odc.stac exposes these as measurements 'red','green','blue','nir' for this collection
 
     with ThreadPoolExecutor(max_workers=5) as executor:
         ds: xr.Dataset = stac_load(
             items,
-            bands=["Red", "Green", "Blue"],  # use only RGB
+            bands=["red", "green", "blue"],  # use only RGB
             geopolygon=aoi_geojson,
             resolution=1.0,  # NAIP native ~1 m
             executor=executor,
+            crs=items[0].properties["proj:code"],
         )
+
     if ds.dims.get("time", 0) == 0:
         return Command(
             update={
@@ -82,16 +95,33 @@ async def fetch_naip_img(
                         tool_call_id=tool_call_id,
                     ),
                 ],
-                "naip_png_path": None,
+                "naip_img_bytes": None,
+            },
+        )
+
+    # Enforce max output size based on dataset sizes (y, x)
+    sizes = dict(ds.sizes)
+    h = int(sizes.get("y", 0))
+    w = int(sizes.get("x", 0))
+    if h > 512 or w > 512:
+        return Command(
+            update={
+                "messages": [
+                    ToolMessage(
+                        content=f"NAIP RGB image {w}x{h} exceeds 512x512 limit. Skipping image output.",
+                        tool_call_id=tool_call_id,
+                    ),
+                ],
+                "naip_img_bytes": None,
             },
         )
 
     # --- 3. Build an RGB composite from the cube ---
     # For the PNG, we'll just use the first time slice (you can swap in “latest”
     # or a temporal reduction if you prefer).
-    red = ds["Red"].isel(time=0)
-    green = ds["Green"].isel(time=0)
-    blue = ds["Blue"].isel(time=0)
+    red = ds["red"].isel(time=0)
+    green = ds["green"].isel(time=0)
+    blue = ds["blue"].isel(time=0)
 
     # Stack into (y, x, 3) array
     rgb = xr.concat([red, green, blue], dim="band")  # (band, y, x)
@@ -110,18 +140,19 @@ async def fetch_naip_img(
 
     # --- 4. Save PNG ---
 
-    out_path = Path("naip_rgb.png")
-    out_path.parent.mkdir(parents=True, exist_ok=True)
-    plt.imsave(out_path.as_posix(), arr_uint8)
+    buf = BytesIO()
+    plt.imsave(buf, arr_uint8, format="png")
+    buf.seek(0)
+    img_bytes = buf.getvalue()
 
     return Command(
         update={
             "messages": [
                 ToolMessage(
-                    content=f"NAIP RGB image saved to {out_path.as_posix()}",
+                    content="NAIP RGB image fetched and encoded as PNG bytes.",
                     tool_call_id=tool_call_id,
                 ),
             ],
-            "naip_png_path": out_path.as_posix(),
+            "naip_img_bytes": img_bytes,
         },
     )

tests/tools/test_naip.py

@@ -1,4 +1,4 @@
-from pathlib import Path
+from types import NoneType
 
 import pytest
 from langchain_core.tools.base import ToolCall
@@ -8,8 +8,7 @@ from geo_assistant.tools.naip import fetch_naip_img
 
 
 @pytest.mark.asyncio
-@pytest.mark.xfail
-async def test_fetch_naip(tmp_path):
+async def test_fetch_naip():
     """
     Integration test: hit MPC STAC for NAIP around Union Market (DC),
     load imagery via odc-stac, and save an RGB PNG.
@@ -22,38 +21,67 @@ async def test_fetch_naip(tmp_path):
     # Union Market coordinates from GeoNames: 38.90789, -76.99831
     #   N 38°54'28"  W 76°59'54"
     # We'll use a small neighborhood AOI around that point.
-    # :contentReference[oaicite:0]{index=0}
     lat = 38.90789
     lon = -76.99831
 
-    # ~0.01 degrees (~1.1 km) buffer in each direction
+    # ~0.0001 degrees buffer in each direction
     aoi = box(lon - 0.0001, lat - 0.0001, lon + 0.0001, lat + 0.0001)
     aoi_geojson = mapping(aoi)
 
-    out_png = tmp_path / "naip_test_img.png"
-
     tool_call = ToolCall(
         name="fetch_naip_img",
         args={
             "aoi_geojson": aoi_geojson,
             "start_date": "2021-01-01",
             "end_date": "2021-12-31",
-            "out_png_path": str(out_png),
-            "resolution": 1.0,
         },
         type="tool_call",
         id="test_tool_call_id",
     )
 
     # Call the actual tool - no STAC / odc-stac mocking
-    result = await fetch_naip_img.ainvoke(tool_call["args"])
+    result = await fetch_naip_img.ainvoke(tool_call)
+    assert "naip_img_bytes" in result.update
+    assert result.update["naip_img_bytes"] is not None, "Expected PNG bytes in result"
+    assert isinstance(result.update["naip_img_bytes"], bytes)
+    assert len(result.update["naip_img_bytes"]) > 1, "Expected non-empty PNG bytes"
 
-    # Basic sanity checks on result
-    assert result["stac_item_count"] > 0, "Expected at least one NAIP item"
-    assert "time" in result["dataset_dims"]
-    assert result["dataset_dims"]["time"] >= 1
 
-    # PNG should have been written to disk
-    png_path = Path(result["png_path"])
-    assert png_path == out_png
-    assert png_path.is_file(), f"PNG was not created at {png_path}"
+@pytest.mark.asyncio
+async def test_fetch_naip_too_large():
+    """
+    Integration test: request a larger AOI that should produce an image
+    exceeding the 512x512 pixel limit. The tool should return no image
+    bytes and include a message indicating it skipped output due to size.
+
+    NOTE: This test requires:
+      - Internet access (to reach Planetary Computer STAC + blobs)
+      - Planetary Computer / NAIP service to be up
+    """
+
+    # Union Market coordinates from GeoNames: 38.90789, -76.99831
+    #   N 38°54'28"  W 76°59'54"
+    # We'll use a small neighborhood AOI around that point.
+    lat = 38.90789
+    lon = -76.99831
+
+    # ~0.003 degrees buffer in each direction
+    aoi = box(lon - 0.003, lat - 0.003, lon + 0.003, lat + 0.003)
+    aoi_geojson = mapping(aoi)
+
+    tool_call = ToolCall(
+        name="fetch_naip_img",
+        args={
+            "aoi_geojson": aoi_geojson,
+            "start_date": "2021-01-01",
+            "end_date": "2021-12-31",
+        },
+        type="tool_call",
+        id="test_tool_call_id",
+    )
+
+    # Call the actual tool - no STAC / odc-stac mocking
+    result = await fetch_naip_img.ainvoke(tool_call)
+    assert "naip_img_bytes" in result.update
+    assert result.update["naip_img_bytes"] is None, "Expected no PNG bytes in result"
+    assert isinstance(result.update["naip_img_bytes"], NoneType)