defmodule Microwaveprop.Weather.HrrrNativeClientTest do
  use ExUnit.Case, async: true

  alias Microwaveprop.Weather.HrrrClient
  alias Microwaveprop.Weather.HrrrNativeClient

  describe "hrrr_native_url/3" do
    test "builds the wrfnatf00 URL for a given date and hour" do
      url = HrrrNativeClient.hrrr_native_url(~D[2026-04-09], 12)

      assert url ==
               "https://noaa-hrrr-bdp-pds.s3.amazonaws.com/hrrr.20260409/conus/hrrr.t12z.wrfnatf00.grib2"
    end

    test "pads single-digit hours" do
      url = HrrrNativeClient.hrrr_native_url(~D[2026-04-09], 6)
      assert url =~ "hrrr.t06z."
    end

    test "supports non-zero forecast hours" do
      url = HrrrNativeClient.hrrr_native_url(~D[2026-04-09], 12, 3)
      assert url =~ "wrfnatf03.grib2"
    end
  end

  describe "native_messages/0" do
    test "lists 350 messages (7 vars × 50 levels)" do
      messages = HrrrNativeClient.native_messages()
      assert length(messages) == 350
    end

    test "every level appears with every essential variable" do
      messages = HrrrNativeClient.native_messages()

      # Pick level 5 — should have all 7 vars
      level5 = Enum.filter(messages, fn %{level: l} -> l == "5 hybrid level" end)
      vars = level5 |> Enum.map(& &1.var) |> Enum.sort()

      assert vars == ~w(HGT PRES SPFH TKE TMP UGRD VGRD)
    end

    test "covers levels 1 through 50" do
      levels =
        HrrrNativeClient.native_messages()
        |> Enum.map(& &1.level)
        |> Enum.uniq()
        |> Enum.map(fn level_str ->
          [digits, _] = String.split(level_str, " ", parts: 2)
          String.to_integer(digits)
        end)
        |> Enum.sort()

      assert levels == Enum.to_list(1..50)
    end
  end

  describe "build_native_profile/1" do
    test "assembles arrays in level order and caches surface scalars" do
      parsed = %{
        "HGT:1 hybrid level" => 8.0,
        "TMP:1 hybrid level" => 295.0,
        "SPFH:1 hybrid level" => 0.010,
        "PRES:1 hybrid level" => 101_000.0,
        "UGRD:1 hybrid level" => 2.0,
        "VGRD:1 hybrid level" => 1.0,
        "TKE:1 hybrid level" => 0.5,
        "HGT:2 hybrid level" => 25.0,
        "TMP:2 hybrid level" => 293.0,
        "SPFH:2 hybrid level" => 0.008,
        "PRES:2 hybrid level" => 99_800.0,
        "UGRD:2 hybrid level" => 3.0,
        "VGRD:2 hybrid level" => 1.5,
        "TKE:2 hybrid level" => 0.3,
        "TMP:surface" => 295.5,
        "SPFH:2 m above ground" => 0.011,
        "PRES:surface" => 101_325.0
      }

      profile = HrrrNativeClient.build_native_profile(parsed)

      assert profile.level_count == 2
      assert profile.heights_m == [8.0, 25.0]
      assert profile.temp_k == [295.0, 293.0]
      assert profile.spfh == [0.010, 0.008]
      assert profile.u_wind_ms == [2.0, 3.0]
      assert profile.surface_temp_k == 295.5
      assert profile.surface_spfh == 0.011
      assert profile.surface_pressure_pa == 101_325.0
    end

    test "skips levels missing either HGT or TMP" do
      parsed = %{
        "HGT:1 hybrid level" => 8.0,
        "TMP:1 hybrid level" => 295.0,
        # level 2 has HGT but no TMP → skipped
        "HGT:2 hybrid level" => 25.0,
        "SPFH:2 hybrid level" => 0.008
      }

      profile = HrrrNativeClient.build_native_profile(parsed)
      assert profile.level_count == 1
      assert profile.heights_m == [8.0]
    end

    test "orders levels by ascending height, not by hybrid level number" do
      # Pathological: level 2 happens to be lower than level 1 (terrain).
      parsed = %{
        "HGT:1 hybrid level" => 50.0,
        "TMP:1 hybrid level" => 290.0,
        "HGT:2 hybrid level" => 30.0,
        "TMP:2 hybrid level" => 292.0
      }

      profile = HrrrNativeClient.build_native_profile(parsed)
      assert profile.heights_m == [30.0, 50.0]
      assert profile.temp_k == [292.0, 290.0]
    end

    test "falls back to lowest level for surface scalars when parsed has no surface entries" do
      parsed = %{
        "HGT:1 hybrid level" => 8.0,
        "TMP:1 hybrid level" => 295.0,
        "SPFH:1 hybrid level" => 0.010,
        "PRES:1 hybrid level" => 101_000.0
      }

      profile = HrrrNativeClient.build_native_profile(parsed)
      assert profile.surface_temp_k == 295.0
      assert profile.surface_spfh == 0.010
      assert profile.surface_pressure_pa == 101_000.0
    end
  end

  describe "essential_byte_ranges/1" do
    test "produces one range per essential message present in the idx" do
      # Minimal fake idx: level 1 TMP/SPFH/HGT with nothing else.
      idx_entries = [
        %{msg: 1, offset: 0, var: "TMP", level: "1 hybrid level"},
        %{msg: 2, offset: 1000, var: "SPFH", level: "1 hybrid level"},
        %{msg: 3, offset: 2000, var: "HGT", level: "1 hybrid level"},
        %{msg: 4, offset: 3000, var: "REFC", level: "entire atmosphere"}
      ]

      ranges = HrrrNativeClient.essential_byte_ranges(idx_entries)

      # Expect 3 ranges (the three essentials we actually have)
      assert length(ranges) == 3
      # Each range is {start, end} tuples, all integers
      Enum.each(ranges, fn {s, e} ->
        assert is_integer(s) and is_integer(e)
        assert s < e
      end)
    end

    test "delegates to HrrrClient.byte_ranges_for_messages/2" do
      # Just check the two stay in sync by computing the same ranges
      # two different ways.
      idx_entries = [
        %{msg: 1, offset: 0, var: "TMP", level: "1 hybrid level"},
        %{msg: 2, offset: 5000, var: "UGRD", level: "1 hybrid level"}
      ]

      assert HrrrNativeClient.essential_byte_ranges(idx_entries) ==
               HrrrClient.byte_ranges_for_messages(idx_entries, HrrrNativeClient.native_messages())
    end
  end

  describe "native_level_count/0 and native_variables/0" do
    test "native_level_count is 50 (full hybrid stack)" do
      assert HrrrNativeClient.native_level_count() == 50
    end

    test "native_variables lists exactly the 7 native-grid fields" do
      vars = HrrrNativeClient.native_variables()
      assert length(vars) == 7
      assert "TMP" in vars
      assert "SPFH" in vars
      assert "HGT" in vars
      assert "PRES" in vars
      assert "UGRD" in vars
      assert "VGRD" in vars
      assert "TKE" in vars
    end
  end

  describe "native_messages/0 shape" do
    test "emits one message per (level, variable) across the 50-level hybrid stack" do
      messages = HrrrNativeClient.native_messages()
      expected = HrrrNativeClient.native_level_count() * length(HrrrNativeClient.native_variables())
      assert length(messages) == expected

      # Every message carries a non-empty var and a hybrid-level string.
      Enum.each(messages, fn %{var: var, level: level} ->
        assert var in HrrrNativeClient.native_variables()
        assert level =~ ~r/\A\d+ hybrid level\z/
      end)
    end

    test "each (var, level) pair is unique" do
      messages = HrrrNativeClient.native_messages()
      unique = messages |> Enum.uniq_by(fn %{var: v, level: l} -> {v, l} end) |> length()
      assert unique == length(messages)
    end
  end

  describe "duct_messages/0 and duct_byte_ranges/1" do
    test "emits one message per (level, duct-var) across the 50-level stack (4 vars)" do
      messages = HrrrNativeClient.duct_messages()
      assert length(messages) == 50 * 4

      # Exactly the duct-detection variables — no UGRD/VGRD/TKE.
      vars = messages |> Enum.map(& &1.var) |> Enum.uniq() |> Enum.sort()
      assert vars == ["HGT", "PRES", "SPFH", "TMP"]
    end

    test "duct_byte_ranges/1 returns integer ranges for matching idx entries" do
      idx_entries = [
        %{msg: 1, offset: 0, var: "TMP", level: "1 hybrid level"},
        %{msg: 2, offset: 1000, var: "SPFH", level: "1 hybrid level"},
        %{msg: 3, offset: 2000, var: "UGRD", level: "1 hybrid level"},
        %{msg: 4, offset: 3000, var: "HGT", level: "1 hybrid level"}
      ]

      ranges = HrrrNativeClient.duct_byte_ranges(idx_entries)
      # UGRD is not in the duct set, so only 3 ranges should come back.
      assert length(ranges) == 3

      Enum.each(ranges, fn {s, e} ->
        assert is_integer(s) and is_integer(e)
        assert s < e
      end)
    end
  end
end