Make Scenery a domain aggregate with no I/O

Parsing and loading move to Infrastructure/Sceneries. Weather becomes a value
object owning the "does this differ from the file" rule.

StarterNG.Tests/Fakes/StubRandom.cs

@@ -0,0 +1,22 @@
+using StarterNG.Application.Abstractions;
+
+namespace StarterNG.Tests.Fakes;
+
+/// <summary>
+/// Randomness pinned to the low end of every range, so weather that varies in
+/// production is deterministic in tests.
+/// </summary>
+public sealed class StubRandom : IRandomSource
+{
+    private readonly int _fixedValue;
+
+    public StubRandom(int fixedValue = 0)
+    {
+        _fixedValue = fixedValue;
+    }
+
+    public int Next(int minInclusive, int maxExclusive) =>
+        Math.Clamp(minInclusive + _fixedValue, minInclusive, Math.Max(minInclusive, maxExclusive - 1));
+
+    public double NextDouble() => 0.0;
+}

StarterNG.Tests/SceneryExportTests.cs

@@ -0,0 +1,146 @@
+using StarterNG.Infrastructure.Sceneries;
+using StarterNG.Tests.Fakes;
+
+namespace StarterNG.Tests;
+
+public class SceneryExportTests
+{
+    private static SceneryParser Parser() =>
+        new(new FixedClock(new DateTime(2026, 1, 1, 12, 0, 0)), new StubRandom());
+
+    [Fact]
+    public void An_untouched_scenery_exports_its_trainsets_back_verbatim()
+    {
+        const string scn = """
+            //$n Test
+            trainset pociag tor_1 10 0
+            node -1 -1 ep07-001 dynamic PKP/EP07 ep07 ep07.mmd 0 headdriver 0
+            endtrainset
+            FirstInit
+            """;
+        var scenery = Parser().Parse("scenery/x.scn", scn);
+
+        string exported = scenery.BuildExportContent(skipDecorTrainsets: false, new StubRandom());
+
+        Assert.DoesNotContain("{{0}}", exported);
+        Assert.Contains("trainset pociag tor_1", exported);
+        Assert.Contains("endtrainset", exported);
+    }
+
+    [Fact]
+    public void Selected_optional_includes_are_written_back_before_FirstInit()
+    {
+        const string scn = """
+            include zima.inc end //$optional 1, Zima
+            x
+            endoptional
+            FirstInit
+            """;
+        var scenery = Parser().Parse("scenery/x.scn", scn);
+
+        string exported = scenery.BuildExportContent(skipDecorTrainsets: false, new StubRandom());
+
+        Assert.Contains("include zima.inc end", exported);
+        Assert.True(exported.IndexOf("include zima.inc", StringComparison.Ordinal) <
+                    exported.IndexOf("FirstInit", StringComparison.Ordinal));
+    }
+
+    [Fact]
+    public void A_deselected_optional_include_stays_out()
+    {
+        const string scn = """
+            include zima.inc end //$optional 1, Zima
+            x
+            endoptional
+            FirstInit
+            """;
+        var scenery = Parser().Parse("scenery/x.scn", scn);
+        scenery.Includes[0].Selected = false;
+
+        string exported = scenery.BuildExportContent(skipDecorTrainsets: false, new StubRandom());
+
+        Assert.DoesNotContain("include zima.inc", exported);
+    }
+
+    [Fact]
+    public void A_kind_two_include_is_written_only_without_a_companion_timetable()
+    {
+        const string scn = """
+            include rozklad.inc end //$optional 2, Rozkład
+            x
+            endoptional
+            FirstInit
+            """;
+        var scenery = Parser().Parse("scenery/x.scn", scn);
+
+        scenery.HasCompanionTimetable = false;
+        Assert.Contains("include rozklad.inc",
+                        scenery.BuildExportContent(skipDecorTrainsets: false, new StubRandom()));
+
+        scenery.HasCompanionTimetable = true;
+        Assert.DoesNotContain("include rozklad.inc",
+                              scenery.BuildExportContent(skipDecorTrainsets: false, new StubRandom()));
+    }
+
+    [Fact]
+    public void Edited_weather_replaces_the_authored_config_block()
+    {
+        const string scn = """
+            config
+            movelight 100
+            scenario.weather.temperature 5
+            eventlauncher.range 200
+            endconfig
+            atmo 0 0 0 10 2000 0 0 0 0 endatmo
+            time 8:30 0 0 endtime
+            FirstInit
+            """;
+        var scenery = Parser().Parse("scenery/x.scn", scn);
+
+        scenery.Weather.Day = 200;
+        scenery.Weather.Temperature = 25;
+        scenery.Weather.Dirty = true;
+
+        string exported = scenery.BuildExportContent(skipDecorTrainsets: false, new StubRandom());
+
+        Assert.Contains("movelight 200", exported);
+        Assert.Contains("scenario.weather.temperature 25", exported);
+        Assert.DoesNotContain("movelight 100", exported);
+        // Config the scenery author wrote and the starter does not manage survives.
+        Assert.Contains("eventlauncher.range 200", exported);
+    }
+
+    [Fact]
+    public void Decor_trainsets_can_be_dropped_from_the_export()
+    {
+        const string scn = """
+            //$n Test
+            trainset ai_1 tor_1 10 0 //$decor
+            node -1 -1 ai-1 dynamic PKP/EP07 ep07 ep07.mmd 0 nobody 0
+            endtrainset
+            FirstInit
+            """;
+        var scenery = Parser().Parse("scenery/x.scn", scn);
+
+        Assert.True(scenery.Trainsets[0].Decor);
+        Assert.DoesNotContain("trainset ai_1",
+                              scenery.BuildExportContent(skipDecorTrainsets: true, new StubRandom()));
+        Assert.Contains("trainset ai_1",
+                        scenery.BuildExportContent(skipDecorTrainsets: false, new StubRandom()));
+    }
+
+    [Fact]
+    public void Loose_vehicles_are_appended_as_nodes_again()
+    {
+        const string scn = """
+            node -1 -1 wagon_1 dynamic PKP/111A 111a 111a.mmd none 0 nobody 0 enddynamic
+            FirstInit
+            """;
+        var scenery = Parser().Parse("scenery/x.scn", scn);
+
+        string exported = scenery.BuildExportContent(skipDecorTrainsets: false, new StubRandom());
+
+        Assert.Contains("wagon_1", exported);
+        Assert.Contains("enddynamic", exported);
+    }
+}

StarterNG.Tests/SceneryParserTests.cs

@@ -0,0 +1,154 @@
+using StarterNG.Infrastructure.Sceneries;
+using StarterNG.Tests.Fakes;
+
+namespace StarterNG.Tests;
+
+public class SceneryParserTests
+{
+    private static SceneryParser Parser(DateTime? now = null) =>
+        new(new FixedClock(now ?? new DateTime(2026, 5, 4, 9, 15, 0)), new StubRandom());
+
+    [Fact]
+    public void Directives_become_the_scenery_headline()
+    {
+        const string scn = """
+            //$l Śląsk
+            //$n Osobowy do Katowic
+            //$d Pierwszy opis
+            //$d drugi wiersz
+            //$i images/kato.jpg
+            """;
+
+        var scenery = Parser().Parse("scenery/kato.scn", scn);
+
+        Assert.Equal("Śląsk", scenery.Group);
+        Assert.Equal("Osobowy do Katowic", scenery.Name);
+        Assert.Equal("Pierwszy opis\ndrugi wiersz", scenery.Description);
+        Assert.Equal("images/kato.jpg", scenery.ImageName);
+        Assert.False(scenery.Archival);
+        Assert.Equal("kato", scenery.DisplayName);
+    }
+
+    [Fact]
+    public void The_a_directive_marks_a_scenery_archival()
+    {
+        var scenery = Parser().Parse("scenery/old.scn", "//$a\n//$n Stary\n");
+
+        Assert.True(scenery.Archival);
+    }
+
+    [Fact]
+    public void Attachments_take_a_label_from_the_rest_of_the_line()
+    {
+        const string scn = """
+            //$f 01 doc/rozklad.pdf Rozkład jazdy
+            //$f doc/mapa.png Mapa
+            //$f doc/notes.txt
+            """;
+
+        var scenery = Parser().Parse("scenery/x.scn", scn);
+
+        Assert.Collection(scenery.Attachments,
+            first =>
+            {
+                Assert.Equal("doc/rozklad.pdf", first.FilePath);
+                Assert.Equal("Rozkład jazdy", first.Label);
+            },
+            second =>
+            {
+                Assert.Equal("doc/mapa.png", second.FilePath);
+                Assert.Equal("Mapa", second.Label);
+            },
+            third =>
+            {
+                Assert.Equal("doc/notes.txt", third.FilePath);
+                Assert.Equal("notes.txt", third.Label);
+            });
+    }
+
+    [Fact]
+    public void Optional_includes_are_lifted_out_of_the_template()
+    {
+        const string scn = """
+            include zima.inc end //$optional 1, Sceneria zimowa
+            some content
+            endoptional
+            FirstInit
+            """;
+
+        var scenery = Parser().Parse("scenery/x.scn", scn);
+
+        var include = Assert.Single(scenery.Includes);
+        Assert.Equal("zima.inc", include.FilePath);
+        Assert.Equal("Sceneria zimowa", include.Desc);
+        Assert.Equal(1, include.Kind);
+        Assert.True(include.Selected);
+        Assert.DoesNotContain("zima.inc", scenery.Template);
+    }
+
+    [Fact]
+    public void Includes_of_kind_two_are_off_until_export_decides()
+    {
+        const string scn = """
+            include rozklad.inc end //$optional 2, Rozkład wbudowany
+            x
+            endoptional
+            """;
+
+        var include = Assert.Single(Parser().Parse("scenery/x.scn", scn).Includes);
+
+        Assert.Equal(2, include.Kind);
+        Assert.False(include.Selected);
+    }
+
+    [Fact]
+    public void Trainsets_are_parsed_and_replaced_by_placeholders()
+    {
+        const string scn = """
+            //$n Test
+            trainset pociag tor_1 10 0
+            node -1 -1 ep07-001 dynamic PKP/EP07 ep07 ep07.mmd 0 headdriver 0
+            endtrainset
+            FirstInit
+            """;
+
+        var scenery = Parser().Parse("scenery/x.scn", scn);
+
+        var trainset = Assert.Single(scenery.Trainsets);
+        Assert.True(trainset.Parsed);
+        Assert.Equal("pociag", trainset.Name);
+        Assert.Equal("tor_1", trainset.Track);
+        Assert.Contains("{{0}}", scenery.Template);
+        Assert.DoesNotContain("endtrainset", scenery.Template);
+    }
+
+    [Fact]
+    public void Vehicles_outside_a_trainset_are_collected_as_loose()
+    {
+        const string scn = """
+            node -1 -1 wagon_1 dynamic PKP/111A 111a 111a.mmd none 0 nobody 0 enddynamic
+            FirstInit
+            """;
+
+        var scenery = Parser().Parse("scenery/x.scn", scn);
+
+        var vehicle = Assert.Single(scenery.LooseVehicles);
+        Assert.Equal("wagon_1", vehicle.Name);
+        Assert.Equal("PKP/111A", vehicle.DataFolder);
+        Assert.Equal(new[] { "wagon_1" }, scenery.LooseVehicleNames);
+        Assert.DoesNotContain("enddynamic", scenery.Template);
+    }
+
+    [Fact]
+    public void A_malformed_loose_vehicle_is_reported_and_left_in_place()
+    {
+        const string scn = "node x -1 wagon_1 dynamic PKP/111A 111a 111a.mmd none 0 nobody 0 enddynamic\n";
+
+        var scenery = Parser().Parse("scenery/x.scn", scn);
+
+        Assert.Empty(scenery.LooseVehicles);
+        Assert.Equal(new[] { "wagon_1" }, scenery.LooseVehicleNames);
+        Assert.Contains(scenery.Faults, fault => fault.Contains("wagon_1"));
+        Assert.Contains("enddynamic", scenery.Template);
+    }
+}

StarterNG.Tests/SceneryRepositoryTests.cs

@@ -0,0 +1,101 @@
+using System.Text;
+using StarterNG.Infrastructure.Adapters;
+using StarterNG.Infrastructure.Sceneries;
+using StarterNG.Tests.Fakes;
+
+namespace StarterNG.Tests;
+
+public class SceneryRepositoryTests
+{
+    private static SceneryRepository Build(InMemoryFileSystem files, out FileDiagnosticsLog log)
+    {
+        var paths = new GamePaths("game");
+        var clock = new FixedClock(new DateTime(2026, 1, 1));
+        log = new FileDiagnosticsLog(files, clock, paths);
+        return new SceneryRepository(files, paths, log, new SceneryParser(clock, new StubRandom()));
+    }
+
+    [Fact]
+    public void Every_scn_in_the_scenery_folder_is_loaded()
+    {
+        var files = new InMemoryFileSystem()
+            .WithFile(Path.Combine("game", "scenery", "kato.scn"), "//$n Katowice")
+            .WithFile(Path.Combine("game", "scenery", "gdansk.scn"), "//$n Gdańsk");
+
+        var loaded = Build(files, out _).LoadAll();
+
+        Assert.Equal(2, loaded.Count);
+        Assert.Contains(loaded, scenery => scenery.Name == "Katowice");
+    }
+
+    [Fact]
+    public void Authoring_scratch_files_and_other_extensions_are_skipped()
+    {
+        var files = new InMemoryFileSystem()
+            .WithFile(Path.Combine("game", "scenery", "$wip.scn"), "//$n Robocza")
+            .WithFile(Path.Combine("game", "scenery", "kato.inc"), "//$n Include")
+            .WithFile(Path.Combine("game", "scenery", "kato.scn"), "//$n Katowice");
+
+        var loaded = Build(files, out _).LoadAll();
+
+        Assert.Equal("Katowice", Assert.Single(loaded).Name);
+    }
+
+    [Fact]
+    public void A_companion_sbt_is_noticed_when_the_scenery_is_loaded()
+    {
+        var files = new InMemoryFileSystem()
+            .WithFile(Path.Combine("game", "scenery", "kato.scn"), "//$n Katowice")
+            .WithFile(Path.Combine("game", "scenery", "kato.sbt"), "timetable");
+
+        var scenery = Assert.Single(Build(files, out _).LoadAll());
+
+        Assert.True(scenery.HasCompanionTimetable);
+    }
+
+    [Fact]
+    public void A_missing_scenery_loads_as_null_rather_than_throwing()
+    {
+        Assert.Null(Build(new InMemoryFileSystem(), out _).Load(Path.Combine("game", "scenery", "gone.scn")));
+    }
+
+    [Fact]
+    public void Progress_is_reported_once_per_file()
+    {
+        var files = new InMemoryFileSystem()
+            .WithFile(Path.Combine("game", "scenery", "a.scn"), "//$n A")
+            .WithFile(Path.Combine("game", "scenery", "b.scn"), "//$n B");
+        var steps = new List<int>();
+
+        Build(files, out _).LoadAll(new Progress<StarterNG.Application.Abstractions.SceneryLoadProgress>(
+            step => { lock (steps) steps.Add(step.Loaded); }));
+
+        // Progress<T> posts asynchronously; give it a moment to drain.
+        SpinWait.SpinUntil(() => { lock (steps) return steps.Count == 2; }, TimeSpan.FromSeconds(2));
+        lock (steps)
+            Assert.Equal(new[] { 1, 2 }, steps.OrderBy(value => value));
+    }
+
+    [Fact]
+    public void The_preview_image_is_found_next_to_the_scenery()
+    {
+        var files = new InMemoryFileSystem()
+            .WithFile(Path.Combine("game", "scenery", "kato.scn"), "//$i kato.jpg")
+            .WithFile(Path.Combine("game", "scenery", "images", "kato.jpg"), "binary");
+        var scenery = Assert.Single(Build(files, out _).LoadAll());
+
+        string? image = new SceneryImageLocator(files).Resolve(scenery);
+
+        Assert.Equal(Path.Combine("game", "scenery", "images", "kato.jpg"), image);
+    }
+
+    [Fact]
+    public void A_scenery_without_an_image_directive_resolves_to_nothing()
+    {
+        var files = new InMemoryFileSystem()
+            .WithFile(Path.Combine("game", "scenery", "kato.scn"), "//$n Katowice");
+        var scenery = Assert.Single(Build(files, out _).LoadAll());
+
+        Assert.Null(new SceneryImageLocator(files).Resolve(scenery));
+    }
+}

StarterNG.Tests/SceneryWeatherTests.cs

@@ -0,0 +1,87 @@
+using StarterNG.Domain.Sceneries;
+using StarterNG.Infrastructure.Sceneries;
+using StarterNG.Tests.Fakes;
+
+namespace StarterNG.Tests;
+
+public class SceneryWeatherTests
+{
+    private static SceneryParser Parser(DateTime now) => new(new FixedClock(now), new StubRandom());
+
+    [Fact]
+    public void Authored_weather_is_read_from_the_config_block()
+    {
+        const string scn = """
+            config
+            movelight 172
+            scenario.weather.temperature 21.5
+            scenario.time.override 6:05
+            endconfig
+            atmo 0 0 0 50 900 0 0 0 0.7 endatmo
+            time 8:30 0 0 endtime
+            """;
+
+        var weather = Parser(new DateTime(2026, 1, 1)).Parse("scenery/x.scn", scn).Weather;
+
+        Assert.True(weather.IsAuthored);
+        Assert.Equal(172, weather.Day);
+        Assert.Equal(21.5, weather.Temperature);
+        Assert.Equal("06:05", weather.ScenarioTimeOverride);
+        Assert.Equal("08:30", weather.Time);
+        Assert.Equal(50, weather.FogStart);
+        Assert.Equal(0.7, weather.Overcast);
+    }
+
+    [Fact]
+    public void A_scenery_without_a_time_starts_at_the_players_clock()
+    {
+        var weather = Parser(new DateTime(2026, 5, 4, 17, 42, 0)).Parse("scenery/x.scn", "//$n Test").Weather;
+
+        Assert.Equal("17:42", weather.ScenarioTimeOverride);
+        Assert.False(weather.IsAuthored);
+    }
+
+    [Fact]
+    public void Freshly_parsed_weather_counts_as_unchanged()
+    {
+        var weather = Parser(new DateTime(2026, 1, 1)).Parse("scenery/x.scn", "movelight 100\n").Weather;
+
+        Assert.False(weather.Changed);
+    }
+
+    [Fact]
+    public void Editing_then_restoring_returns_to_the_authored_values()
+    {
+        var weather = Parser(new DateTime(2026, 1, 1)).Parse("scenery/x.scn", "movelight 100\n").Weather;
+
+        weather.Day = 5;
+        weather.Temperature = -12;
+        Assert.True(weather.Changed);
+
+        weather.Restore();
+
+        Assert.False(weather.Changed);
+        Assert.Equal(100, weather.Day);
+        Assert.True(weather.Dirty);
+    }
+
+    [Fact]
+    public void A_fog_range_is_clamped_into_the_supported_span()
+    {
+        var weather = new SceneryWeather();
+
+        weather.SetFogRange(start: 1, end: 999999, random: new StubRandom());
+
+        Assert.Equal(SceneryWeather.FogMin, weather.FogStart);
+        Assert.InRange(weather.FogEnd, SceneryWeather.FogMin, SceneryWeather.FogMax);
+    }
+
+    [Fact]
+    public void Random_overcast_draws_from_the_presets_rather_than_the_stored_value()
+    {
+        var weather = new SceneryWeather { Overcast = 0.42, OvercastRandom = true };
+
+        Assert.Equal(-1.5, weather.EffectiveOvercast(new StubRandom()));
+        Assert.Equal(0.42, new SceneryWeather { Overcast = 0.42 }.EffectiveOvercast(new StubRandom()));
+    }
+}