defmodule Microwaveprop.Propagation.DailyOutlookTest do
  use Microwaveprop.DataCase, async: false

  alias Microwaveprop.Propagation
  alias Microwaveprop.Propagation.ScoreCache

  setup do
    ScoreCache.clear()
    on_exit(fn -> ScoreCache.clear() end)
    :ok
  end

  describe "daily_outlook_at/3" do
    test "returns an empty list when no scores have been written" do
      assert Propagation.daily_outlook_at(32.9, -97.0, days: 3) == []
    end

    test "groups scores by UTC date and picks the peak per day" do
      # Use a lat on the grid: snap(32.9) = 32.875 (step 0.125). Write at
      # the snapped coords so point_forecast's internal snap-to-grid finds
      # the scores on disk.
      lat = 32.875
      lon = -97.0
      band = 10_000

      # Day A: 5Z @ 40, 17Z @ 80 → peak 80
      # Day B: 5Z @ 60 → peak 60
      day_a_1 = ~U[2026-04-20 05:00:00Z]
      day_a_2 = ~U[2026-04-20 17:00:00Z]
      day_b_1 = ~U[2026-04-21 05:00:00Z]

      Propagation.replace_scores(
        [%{lat: lat, lon: lon, valid_time: day_a_1, band_mhz: band, score: 40, factors: nil}],
        day_a_1
      )

      Propagation.replace_scores(
        [%{lat: lat, lon: lon, valid_time: day_a_2, band_mhz: band, score: 80, factors: nil}],
        day_a_2
      )

      Propagation.replace_scores(
        [%{lat: lat, lon: lon, valid_time: day_b_1, band_mhz: band, score: 60, factors: nil}],
        day_b_1
      )

      outlook = Propagation.daily_outlook_at(lat, lon, band_mhz: band, days: 30)

      # The helper returns entries in ascending date order.
      assert length(outlook) >= 2

      day_a = Enum.find(outlook, &(&1.date == ~D[2026-04-20]))
      day_b = Enum.find(outlook, &(&1.date == ~D[2026-04-21]))

      assert day_a.peak_score == 80
      assert day_b.peak_score == 60
    end
  end
end