defmodule Microwaveprop.Propagation.ProfilesFileTest do
  # async: false — tests mutate the global Application env to redirect
  # the scores dir to a private tmp tree.
  use ExUnit.Case, async: false

  alias Microwaveprop.Propagation.ProfilesFile

  setup do
    dir =
      Path.join(
        System.tmp_dir!(),
        "profiles_file_test_#{System.unique_integer([:positive])}"
      )

    File.mkdir_p!(dir)

    prev = Application.get_env(:microwaveprop, :propagation_scores_dir)
    Application.put_env(:microwaveprop, :propagation_scores_dir, dir)

    on_exit(fn ->
      File.rm_rf!(dir)

      if prev do
        Application.put_env(:microwaveprop, :propagation_scores_dir, prev)
      else
        Application.delete_env(:microwaveprop, :propagation_scores_dir)
      end
    end)

    %{dir: dir}
  end

  describe "path_for/1" do
    test "nests under base_dir/profiles/<iso>.etf.gz", %{dir: dir} do
      assert ProfilesFile.path_for(~U[2026-04-14 18:00:00Z]) ==
               Path.join([dir, "profiles", "2026-04-14T18:00:00Z.etf.gz"])
    end
  end

  describe "read/1" do
    test "returns the full grid_data map round-tripped through ETF" do
      valid_time = ~U[2026-04-14 18:00:00Z]

      grid_data = %{
        {32.75, -97.125} => %{surface_temp_c: 25.0, surface_dewpoint_c: 15.0},
        {33.0, -97.0} => %{surface_temp_c: 26.0}
      }

      ProfilesFile.write!(valid_time, grid_data)

      assert {:ok, round_tripped} = ProfilesFile.read(valid_time)
      assert round_tripped[{32.75, -97.125}][:surface_temp_c] == 25.0
      assert round_tripped[{33.0, -97.0}][:surface_temp_c] == 26.0
    end

    test "returns :enoent when no file exists" do
      assert ProfilesFile.read(~U[2026-04-14 18:00:00Z]) == {:error, :enoent}
    end

    test "round-trips the full production data shape including duct fields" do
      valid_time = ~U[2026-04-14 18:00:00Z]

      grid_data = %{
        {32.75, -97.125} => %{
          surface_temp_c: 25.0,
          surface_dewpoint_c: 15.0,
          surface_pressure_mb: 1013.25,
          hpbl_m: 750.0,
          pwat_mm: 32.5,
          run_time: ~U[2026-04-14 17:00:00Z],
          precip_mm: 0.0,
          wind_u: 3.2,
          wind_v: -1.7,
          cloud_cover_pct: 25.0,
          native_min_gradient: -78.4,
          best_duct_freq_ghz: 24.0,
          duct_count: 1,
          max_duct_thickness_m: 200.0,
          ducts: [
            %{base_m: 200.0, top_m: 400.0, thickness_m: 200.0, min_freq_ghz: 10.0}
          ],
          profile: [
            %{"pres" => 1000.0, "tmpc" => 25.0, "dwpc" => 15.0, "hght" => 50.0}
          ]
        }
      }

      ProfilesFile.write!(valid_time, grid_data)

      assert {:ok, round_tripped} = ProfilesFile.read(valid_time)

      point = round_tripped[{32.75, -97.125}]
      assert point[:surface_temp_c] == 25.0
      assert point[:run_time] == ~U[2026-04-14 17:00:00Z]
      assert [duct] = point[:ducts]
      assert duct[:base_m] == 200.0
      assert duct[:thickness_m] == 200.0
      assert duct[:min_freq_ghz] == 10.0
    end
  end

  describe "list_valid_times/0" do
    test "returns all persisted valid_times sorted ascending" do
      assert ProfilesFile.list_valid_times() == []

      for vt <- [~U[2026-04-14 18:00:00Z], ~U[2026-04-14 10:00:00Z], ~U[2026-04-14 14:00:00Z]] do
        ProfilesFile.write!(vt, %{{25.0, -125.0} => %{surface_temp_c: 1.0}})
      end

      assert ProfilesFile.list_valid_times() == [
               ~U[2026-04-14 10:00:00Z],
               ~U[2026-04-14 14:00:00Z],
               ~U[2026-04-14 18:00:00Z]
             ]
    end
  end

  describe "latest_valid_time/0" do
    test "returns the most recent persisted valid_time" do
      assert ProfilesFile.latest_valid_time() == nil

      for vt <- [~U[2026-04-14 10:00:00Z], ~U[2026-04-14 18:00:00Z], ~U[2026-04-14 14:00:00Z]] do
        ProfilesFile.write!(vt, %{{25.0, -125.0} => %{surface_temp_c: 1.0}})
      end

      assert ProfilesFile.latest_valid_time() == ~U[2026-04-14 18:00:00Z]
    end
  end

  describe "write!/2 + read_point/3" do
    test "round-trips a point and snaps lat/lon to the 0.125° grid" do
      valid_time = ~U[2026-04-14 18:00:00Z]

      grid_data = %{
        {32.75, -97.125} => %{surface_temp_c: 25.0, surface_dewpoint_c: 15.0, wind_u: 3.0, wind_v: -1.0},
        {25.0, -125.0} => %{surface_temp_c: 10.0}
      }

      ProfilesFile.write!(valid_time, grid_data)

      # Exact match
      assert %{surface_temp_c: 25.0, wind_u: 3.0} =
               ProfilesFile.read_point(valid_time, 32.75, -97.125)

      # Nudged within snap tolerance still resolves to the same cell
      assert %{surface_temp_c: 25.0} =
               ProfilesFile.read_point(valid_time, 32.7, -97.1)

      # A point with no stored profile returns nil
      assert ProfilesFile.read_point(valid_time, 40.0, -80.0) == nil
    end

    test "returns nil for a missing valid_time" do
      assert ProfilesFile.read_point(~U[2026-04-14 18:00:00Z], 32.75, -97.125) == nil
    end
  end

  describe "prune_older_than/1" do
    test "deletes files with valid_time strictly before the cutoff" do
      old = ~U[2026-04-14 10:00:00Z]
      keep = ~U[2026-04-14 18:00:00Z]

      ProfilesFile.write!(old, %{{25.0, -125.0} => %{surface_temp_c: 1.0}})
      ProfilesFile.write!(keep, %{{25.0, -125.0} => %{surface_temp_c: 2.0}})

      assert 1 == ProfilesFile.prune_older_than(~U[2026-04-14 12:00:00Z])
      assert ProfilesFile.read_point(old, 25.0, -125.0) == nil
      assert %{surface_temp_c: 2.0} = ProfilesFile.read_point(keep, 25.0, -125.0)
    end
  end

  describe "retain_window/2" do
    test "keeps only files whose valid_time is inside [run_time, run_time + max_fh * 3600]" do
      run_time = ~U[2026-04-14 18:00:00Z]

      inside_f00 = ~U[2026-04-14 18:00:00Z]
      inside_f10 = ~U[2026-04-15 04:00:00Z]
      after_window = ~U[2026-04-15 13:00:00Z]
      before_window = ~U[2026-04-14 10:00:00Z]

      for vt <- [inside_f00, inside_f10, after_window, before_window] do
        ProfilesFile.write!(vt, %{{25.0, -125.0} => %{surface_temp_c: 1.0}})
      end

      assert 2 == ProfilesFile.retain_window(run_time, 18)
      assert %{surface_temp_c: 1.0} = ProfilesFile.read_point(inside_f00, 25.0, -125.0)
      assert %{surface_temp_c: 1.0} = ProfilesFile.read_point(inside_f10, 25.0, -125.0)
      assert ProfilesFile.read_point(after_window, 25.0, -125.0) == nil
      assert ProfilesFile.read_point(before_window, 25.0, -125.0) == nil
    end
  end

  describe "MessagePack dual-format reader" do
    test "read/1 prefers .mp.gz over .etf.gz when both exist", %{dir: _dir} do
      vt = ~U[2026-04-19 14:00:00Z]

      # Elixir writes the legacy ETF path.
      ProfilesFile.write!(vt, %{{32.9, -97.0} => %{surface_temp_c: 1.0}})

      # Rust would land a .mp.gz sibling; simulate it.
      mp_body = %{
        "v" => 1,
        "valid_time" => "2026-04-19T14:00:00Z",
        "cells" => [
          %{"lat" => 32.9, "lon" => -97.0, "profile" => %{"surface_temp_c" => 2.0}}
        ]
      }

      mp_path = ProfilesFile.mp_path_for(vt)
      File.mkdir_p!(Path.dirname(mp_path))
      File.write!(mp_path, :zlib.gzip(Msgpax.pack!(mp_body, iodata: false)))

      # mp.gz wins.
      assert {:ok, grid} = ProfilesFile.read(vt)
      assert grid[{32.9, -97.0}] == %{surface_temp_c: 2.0}
    end

    test "read/1 atomizes whitelisted keys, leaves others as strings", %{dir: _dir} do
      vt = ~U[2026-04-19 14:00:00Z]

      mp_body = %{
        "v" => 1,
        "valid_time" => "2026-04-19T14:00:00Z",
        "cells" => [
          %{
            "lat" => 32.9,
            "lon" => -97.0,
            "profile" => %{
              "surface_temp_c" => 22.5,
              "duct_count" => 1,
              "ducts" => [
                %{"base_m" => 100, "top_m" => 200, "thickness_m" => 100, "m_deficit" => 12.3, "min_freq_ghz" => 15.2}
              ],
              "unknown_field" => "keep-as-string"
            }
          }
        ]
      }

      mp_path = ProfilesFile.mp_path_for(vt)
      File.mkdir_p!(Path.dirname(mp_path))
      File.write!(mp_path, :zlib.gzip(Msgpax.pack!(mp_body, iodata: false)))

      {:ok, grid} = ProfilesFile.read(vt)
      profile = grid[{32.9, -97.0}]

      assert profile[:surface_temp_c] == 22.5
      assert profile[:duct_count] == 1
      assert [duct] = profile[:ducts]
      assert duct[:base_m] == 100
      assert duct[:min_freq_ghz] == 15.2
      # Keys outside the whitelist stay strings so they can't crash a
      # later String.to_atom/1 bomb.
      assert profile["unknown_field"] == "keep-as-string"
    end

    test "read/1 returns :enoent when neither format exists", %{dir: _dir} do
      vt = ~U[2030-01-01 00:00:00Z]
      assert ProfilesFile.read(vt) == {:error, :enoent}
    end

    test "list_valid_times/0 dedupes when both formats share a timestamp", %{dir: _dir} do
      vt = ~U[2026-04-19 14:00:00Z]
      ProfilesFile.write!(vt, %{{32.9, -97.0} => %{surface_temp_c: 1.0}})

      mp_body = %{"v" => 1, "valid_time" => "2026-04-19T14:00:00Z", "cells" => []}
      mp_path = ProfilesFile.mp_path_for(vt)
      File.mkdir_p!(Path.dirname(mp_path))
      File.write!(mp_path, :zlib.gzip(Msgpax.pack!(mp_body, iodata: false)))

      assert ProfilesFile.list_valid_times() == [vt]
    end
  end
end