prop/test/microwaveprop_web/controllers/weather_tile_controller_test.exs

defmodule MicrowavepropWeb.WeatherTileControllerTest do
  use MicrowavepropWeb.ConnCase, async: false

  alias Microwaveprop.Propagation.ProfilesFile
  alias Microwaveprop.Weather.GridCache
  alias Microwaveprop.Weather.ScalarFile

  setup do
    GridCache.clear()

    on_exit(fn ->
      GridCache.clear()
      ProfilesFile.prune_older_than(~U[2099-12-31 23:59:59Z])
    end)

    :ok
  end

  describe "GET /weather/cells" do
    test "returns 400 for missing or invalid params", %{conn: conn} do
      conn = get(conn, ~p"/weather/cells?time=not-a-time")
      assert json_response(conn, 400)
    end

    test "returns the binary cell pack with all default layers when ?layers is absent", %{conn: conn} do
      valid_time = ~U[2026-04-28 12:00:00Z]

      ProfilesFile.write!(valid_time, %{
        {33.0, -97.0} => %{
          surface_temp_c: 22.0,
          surface_dewpoint_c: 12.0,
          surface_pressure_mb: 1010.0,
          hpbl_m: 800.0,
          pwat_mm: 25.0,
          profile: []
        }
      })

      time = DateTime.to_iso8601(valid_time)

      conn =
        get(
          conn,
          ~p"/weather/cells?time=#{time}&south=32.5&north=33.5&west=-97.5&east=-96.5"
        )

      assert ["application/octet-stream"] = get_resp_header(conn, "content-type")
      body = response(conn, 200)
      assert <<"WCEL", 1::8, _cell_count::little-32, _layer_count::8, _rest::binary>> = body
    end

    test "with ?layers=foo,bar limits the binary pack to those layers", %{conn: conn} do
      valid_time = ~U[2026-04-28 12:00:00Z]

      ProfilesFile.write!(valid_time, %{
        {33.0, -97.0} => %{
          surface_temp_c: 22.0,
          surface_dewpoint_c: 12.0,
          surface_pressure_mb: 1010.0,
          hpbl_m: 800.0,
          pwat_mm: 25.0,
          profile: []
        },
        {33.125, -97.0} => %{
          surface_temp_c: 23.0,
          surface_dewpoint_c: 13.0,
          surface_pressure_mb: 1011.0,
          hpbl_m: 700.0,
          pwat_mm: 26.0,
          profile: []
        }
      })

      time = DateTime.to_iso8601(valid_time)

      conn =
        get(
          conn,
          ~p"/weather/cells?time=#{time}&south=32.0&north=34.0&west=-98.0&east=-96.0&layers=temperature,pwat"
        )

      assert ["application/octet-stream"] = get_resp_header(conn, "content-type")
      body = response(conn, 200)

      assert <<"WCEL", 1::8, cell_count::little-32, 2::8, rest::binary>> = body
      assert cell_count == 2

      # Two layer names: "temperature" (11), "pwat" (4).
      <<11::8, "temperature", 4::8, "pwat", padded_rest::binary>> = rest

      # Header so far: 4(magic) + 1 + 4 + 1 + (1+11) + (1+4) = 27 bytes. One
      # byte of zero padding aligns the f32 arrays to a 4-byte boundary.
      <<0::8, lats_and_more::binary>> = padded_rest

      <<lat1::little-float-32, lat2::little-float-32, _rest::binary>> = lats_and_more
      assert_in_delta lat1, 33.0, 0.001
      assert_in_delta lat2, 33.125, 0.001
    end

    test "returns an empty pack when no data exists for the valid_time", %{conn: conn} do
      valid_time = ~U[2099-04-28 12:00:00Z]
      time = DateTime.to_iso8601(valid_time)

      conn =
        get(
          conn,
          ~p"/weather/cells?time=#{time}&south=32.0&north=34.0&west=-98.0&east=-96.0"
        )

      assert ["application/octet-stream"] = get_resp_header(conn, "content-type")
      body = response(conn, 200)
      assert <<"WCEL", 1::8, 0::little-32, _layer_count::8, _rest::binary>> = body
    end

    test "with ?source=hrdps returns only HRDPS rows (skips HRRR scalars and ProfilesFile)", %{conn: conn} do
      valid_time = ~U[2026-04-28 12:00:00Z]

      # HRRR side: write a Texas row via the standard pipeline.
      ProfilesFile.write!(valid_time, %{
        {33.0, -97.0} => %{
          surface_temp_c: 22.0,
          surface_dewpoint_c: 12.0,
          surface_pressure_mb: 1010.0,
          hpbl_m: 800.0,
          pwat_mm: 25.0,
          profile: []
        }
      })

      # HRDPS side: hand-write a Canadian chunk into the HRDPS sibling dir.
      hrdps_dir = ScalarFile.dir_for_hrdps(valid_time)
      File.mkdir_p!(hrdps_dir)
      lat_band = (53.0 / 5) |> Float.floor() |> trunc()
      lon_band = (-60.0 / 5) |> Float.floor() |> trunc()
      path = Path.join(hrdps_dir, "#{lat_band}_#{lon_band}.mp.gz")

      payload =
        Msgpax.pack!(
          [
            %{
              "lat" => 53.0,
              "lon" => -60.0,
              "valid_time" => "2026-04-28T12:00:00Z",
              "temperature" => 8.0,
              "surface_rh" => 70.0
            }
          ],
          iodata: false
        )

      File.write!(path, :zlib.gzip(payload))

      time = DateTime.to_iso8601(valid_time)

      conn =
        get(
          conn,
          ~p"/weather/cells?time=#{time}&south=40.0&north=70.0&west=-150.0&east=-50.0&source=hrdps"
        )

      body = response(conn, 200)
      assert <<"WCEL", 1::8, cell_count::little-32, _rest::binary>> = body
      # Only the Canadian (53, -60) row — HRRR's (33, -97) is excluded.
      assert cell_count == 1

      File.rm_rf!(hrdps_dir)
    end
  end
end