defmodule Microwaveprop.Rover.LinkMarginTest do
  use ExUnit.Case, async: true

  alias Microwaveprop.Rover.LinkMargin

  describe "score_to_db/1" do
    test "0 maps to -25.0 dB" do
      assert LinkMargin.score_to_db(0) == -25.0
    end

    test "50 maps to 0.0 dB" do
      assert LinkMargin.score_to_db(50) == 0.0
    end

    test "100 maps to 25.0 dB" do
      assert LinkMargin.score_to_db(100) == 25.0
    end

    test "nil maps to nil" do
      assert LinkMargin.score_to_db(nil) == nil
    end

    test "negative score maps below -25 dB" do
      assert LinkMargin.score_to_db(-10) == -30.0
    end

    test "score above 100 maps above 25 dB" do
      assert LinkMargin.score_to_db(120) == 35.0
    end
  end

  describe "link_margin_from_score/2" do
    test "score 80 in :ssb mode = 15.0 dB" do
      assert LinkMargin.link_margin_from_score(80, :ssb) == 15.0
    end

    test "score 50 in :cw mode = 18.0 dB (0 - (-18))" do
      assert LinkMargin.link_margin_from_score(50, :cw) == 18.0
    end

    test "nil score returns nil" do
      assert LinkMargin.link_margin_from_score(nil, :ssb) == nil
    end

    test "score 0 in :cw mode = -7.0 dB" do
      assert LinkMargin.link_margin_from_score(0, :cw) == -7.0
    end

    test "score 100 in :cw mode = 43.0 dB" do
      assert LinkMargin.link_margin_from_score(100, :cw) == 43.0
    end

    test "score 30 in :ssb mode gives negative margin" do
      margin = LinkMargin.link_margin_from_score(30, :ssb)
      assert margin < 0
    end

    test "score 50 in :q65_60a mode = 24.0 dB" do
      assert LinkMargin.link_margin_from_score(50, :q65_60a) == 24.0
    end
  end
end