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()));
+    }
+}

StarterNG/Application/Abstractions/IRandomSource.cs

@@ -0,0 +1,15 @@
+namespace StarterNG.Application.Abstractions;
+
+/// <summary>
+/// Port over randomness. Scenery weather deliberately varies between runs (fog
+/// distance, overcast presets, texture randomiser); routing it through a port
+/// keeps those rules assertable instead of flaky.
+/// </summary>
+public interface IRandomSource
+{
+    /// <summary>Inclusive lower bound, exclusive upper bound.</summary>
+    int Next(int minInclusive, int maxExclusive);
+
+    /// <summary>Uniform value in [0, 1).</summary>
+    double NextDouble();
+}

StarterNG/Application/Abstractions/ISceneryRepository.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Collections.Generic;
+using StarterNG.Domain.Sceneries;
+
+namespace StarterNG.Application.Abstractions;
+
+/// <summary>How far a scenery sweep has got, for the splash screen.</summary>
+public readonly record struct SceneryLoadProgress(int Loaded, int Total, string FileName);
+
+/// <summary>
+/// Reads the scenarios of an installation. The only route from a .scn on disk to
+/// a <see cref="Scenery"/>; nothing else constructs one from a path.
+/// </summary>
+public interface ISceneryRepository
+{
+    /// <summary>
+    /// Every scenario in the installation, in no particular order. Files that
+    /// fail to parse are logged and skipped rather than failing the load.
+    /// </summary>
+    IReadOnlyList<Scenery> LoadAll(IProgress<SceneryLoadProgress>? progress = null);
+
+    /// <summary>Reloads a single scenario; null when it is gone or unreadable.</summary>
+    Scenery? Load(string path);
+}

StarterNG/Application/AppServices.cs

@@ -1,6 +1,7 @@
 using System;
 using StarterNG.Application.Abstractions;
 using StarterNG.Infrastructure.Adapters;
+using StarterNG.Infrastructure.Sceneries;
 using StarterNG.Services;
 
 namespace StarterNG.Application;
@@ -33,8 +34,11 @@ public sealed class AppServices
 
         var log = new FileDiagnosticsLog(files, clock, paths);
         Log = log;
+        Random = new SystemRandomSource();
         Processes = new SystemProcessLauncher(log);
         Localization = new LocalizationService(log);
+        Sceneries = new SceneryRepository(files, paths, log, new SceneryParser(clock, Random));
+        SceneryImages = new SceneryImageLocator(files);
     }
 
     /// <summary>
@@ -66,6 +70,12 @@ public sealed class AppServices
 
     public IProcessLauncher Processes { get; }
 
+    public IRandomSource Random { get; }
+
+    public ISceneryRepository Sceneries { get; }
+
+    public SceneryImageLocator SceneryImages { get; }
+
     /// <summary>
     /// Exposed as the concrete service rather than <see cref="ILocalizedStrings"/>
     /// because the XAML binds to it as a change-notifying source; code should take

StarterNG/Classes/AppState.cs

@@ -1,4 +1,5 @@
-using System;
+using System;
+using StarterNG.Domain.Sceneries;
 
 namespace StarterNG.Classes;
 

StarterNG/Classes/GameData.cs

@@ -4,6 +4,9 @@ using System.IO;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
+using StarterNG.Application;
+using StarterNG.Application.Abstractions;
+using StarterNG.Domain.Sceneries;
 
 namespace StarterNG.Classes;
 
@@ -26,17 +29,12 @@ public sealed class GameData
     public bool Loaded { get; private set; }
 
     public void Load(IProgress<LoadStatus>? progress = null,
-                     string sceneryDir = "scenery/",
                      string miniDir = "textures/mini/",
                      string dynamicRoot = "dynamic")
     {
         if (Loaded)
             return;
 
-        var scnFiles = EnumerateScenery(sceneryDir);
-        int total = Math.Max(1, scnFiles.Count);
-        int done = 0;
-
         progress?.Report(new LoadStatus(0, LoadPhase.Vehicles, "textures.txt"));
         int vehicles = Vehicles.LoadFromTexturesTxt(dynamicRoot);
         if (vehicles == 0)
@@ -46,61 +44,19 @@ public sealed class GameData
             () => VehicleDatabase.PreloadMiniIndex(miniDir),
             () => Physics.PreloadIndex());
 
-        var sceneryLock = new object();
-        var doneCount = done;
-        Parallel.ForEach(scnFiles, new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount },
-            file =>
-            {
-                try
-                {
-                    var scenery = new Scenery(file);
-                    lock (sceneryLock)
-                    {
-                        Sceneries.Add(scenery);
-                        doneCount++;
-                        progress?.Report(new LoadStatus((double)doneCount / total, LoadPhase.Sceneries,
-                            Path.GetFileName(file)));
-                    }
-                }
-                catch (Exception ex)
-                {
-                    StarterNG.Infrastructure.Diagnostics.Log($"scenery/{Path.GetFileName(file)}", ex);
-                }
-            });
-        done = doneCount;
+        var sceneryProgress = progress is null
+            ? null
+            : new Progress<SceneryLoadProgress>(step => progress.Report(
+                new LoadStatus((double)step.Loaded / step.Total, LoadPhase.Sceneries, step.FileName)));
+        ReloadSceneries(sceneryProgress);
 
         progress?.Report(new LoadStatus(1.0, LoadPhase.Done, null));
         Loaded = true;
     }
 
-    public void ReloadSceneries(string sceneryDir = "scenery/")
+    public void ReloadSceneries(IProgress<SceneryLoadProgress>? progress = null)
     {
         Sceneries.Clear();
-        var scnFiles = EnumerateScenery(sceneryDir);
-        var sceneryLock = new object();
-        Parallel.ForEach(scnFiles, new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount },
-            file =>
-            {
-                try
-                {
-                    var scenery = new Scenery(file);
-                    lock (sceneryLock)
-                        Sceneries.Add(scenery);
-                }
-                catch (Exception ex)
-                {
-                    StarterNG.Infrastructure.Diagnostics.Log($"scenery/{Path.GetFileName(file)}", ex);
-                }
-            });
-    }
-
-    private static List<string> EnumerateScenery(string sceneryDir)
-    {
-        if (!Directory.Exists(sceneryDir))
-            return new List<string>();
-
-        return Directory.GetFiles(sceneryDir, "*.scn")
-            .Where(p => !Path.GetFileName(p).StartsWith("$"))
-            .ToList();
+        Sceneries.AddRange(AppServices.Current.Sceneries.LoadAll(progress));
     }
 }

StarterNG/Classes/Scenery.cs

@@ -1,541 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Text;
-using System.Text.RegularExpressions;
-using StarterNG.Domain;
-
-namespace StarterNG.Classes;
-
-public sealed class SceneryAttachment
-{
-    public string FilePath = "";
-    public string Label = "";
-}
-
-public sealed class SceneryInclude
-{
-    public string FilePath = "";
-    public string Desc = "";
-    public int Kind;
-    public bool Selected;
-}
-
-public class Scenery
-{
-    public List<string> Lines;
-    public List<Trainset> Trainsets;
-    public List<SceneryAttachment> Attachments = new();
-    public List<SceneryInclude> Includes = new();
-
-    public List<string> LooseVehicleNames = new();
-
-    public List<Dynamic> LooseVehicles = new();
-
-    public List<string> Faults = new();
-    public string Group;
-    public string Path;
-
-    public string Name;
-    public string Description;
-    public string ImageName;
-
-    public bool Archival;
-
-    public string Time = "10:30";
-    public string ScenarioTimeOverride = "10:30";
-    public int Day = 0;
-    public double Temperature = 15;
-    public int FogStart = 10;
-    public int FogEnd = 2000;
-
-    public const int FogMin = 10;
-    public const int FogMax = 10000;
-    public double Overcast = 0;
-    public bool OvercastRandom;
-
-    public bool HasWeather;
-
-    public bool WeatherDirty;
-
-    private string _origTime = "10:30";
-    private string _origOverride = "10:30";
-    private int _origDay;
-    private double _origTemperature = 15;
-    private int _origFogEnd = 2000;
-    private double _origOvercast;
-    private bool _origOvercastRandom;
-
-    private readonly string _template;
-
-    public string DisplayName
-    {
-        get
-        {
-            return System.IO.Path.GetFileNameWithoutExtension(Path);
-        }
-    }
-
-    public string LocalizedDescription =>
-        string.IsNullOrEmpty(Description) ? "" :
-        string.Join("\n", Description.Split('\n').Select(SceneryI18n.T));
-
-    private string _imagePath;
-    private bool _imagePathResolved;
-
-    public Scenery(string path)
-    {
-        this.Path = path;
-        Trainsets = new List<Trainset>();
-        if (!File.Exists(path))
-            throw new FileNotFoundException(path);
-        var encoding = Encoding.GetEncoding(1250);
-        string content = File.ReadAllText(path, encoding);
-
-        this.Group = MatchDirective(content, "l");
-        this.Name = MatchDirective(content, "n");
-
-        this.Description = MatchAllDirectives(content, "d");
-        this.ImageName = MatchDirective(content, "i");
-
-        this.Archival = MatchDirective(content, "a") != null;
-
-        ParseWeather(content);
-        SnapshotWeather();
-
-        ParseAttachments(content);
-        content = ParseAndStripOptionalIncludes(content);
-
-        List<string> trainsetEntries = new  List<string>();
-        Regex regex = new Regex(
-            @"trainset\b[\s\S]*?\bendtrainset\b",
-            RegexOptions.IgnoreCase
-        );
-        int idx = 0;
-        content = regex.Replace(content, match =>
-        {
-            trainsetEntries.Add(match.Value);
-            return $"{{{{{idx++}}}}}";
-        });
-        content = ExtractLooseVehicles(content);
-        _template = content;
-
-        foreach (string trainsetEntry in trainsetEntries)
-        {
-            var ts = new Trainset(trainsetEntry);
-            Trainsets.Add(ts);
-            if (!ts.Parsed)
-                Faults.Add($"# trainset parse fault: {ts.Name} ({ts.Track})");
-        }
-    }
-
-    private string ExtractLooseVehicles(string content)
-    {
-        LooseVehicles.Clear();
-        LooseVehicleNames.Clear();
-        var inv = System.Globalization.CultureInfo.InvariantCulture;
-
-        return Regex.Replace(
-            content,
-            @"(?is)\bnode\s+(\S+)\s+(\S+)\s+(\S+)\s+dynamic\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)((?:\s+(?!enddynamic)\S+)*)\s*enddynamic\b",
-            m =>
-            {
-                string name = m.Groups[3].Value;
-                if (name.StartsWith("{{", StringComparison.Ordinal))
-                    return m.Value;
-                try
-                {
-                    var d = new Dynamic
-                    {
-                        RangeMax = float.Parse(m.Groups[1].Value, inv),
-                        RangeMin = float.Parse(m.Groups[2].Value, inv),
-                        Name = name,
-                        DataFolder = m.Groups[4].Value,
-                        SkinFile = Dynamic.StripSkinExtension(m.Groups[5].Value),
-                        MmdFile = m.Groups[6].Value,
-                        PathName = m.Groups[7].Value,
-                        Offset = float.Parse(m.Groups[8].Value, inv),
-                        DriverType = m.Groups[9].Value.ToLowerInvariant() switch
-                        {
-                            "headdriver" => eDriverType.Headdriver,
-                            "reardriver" => eDriverType.Reardriver,
-                            "passenger" => eDriverType.Passenger,
-                            _ => eDriverType.Nobody
-                        },
-                        HasVelocity = true,
-                        Velocity = float.Parse(m.Groups[10].Value, inv)
-                    };
-                    var trailing = m.Groups[11].Value
-                        .Split((char[]?)null, StringSplitOptions.RemoveEmptyEntries)
-                        .ToList();
-                    d.ReadTrailing(trailing);
-                    LooseVehicles.Add(d);
-                    LooseVehicleNames.Add(d.Name);
-                    return "\n";
-                }
-                catch
-                {
-                    Faults.Add($"# loose dynamic parse fault: {name}");
-                    LooseVehicleNames.Add(name);
-                    return m.Value;
-                }
-            });
-    }
-
-    public string BuildExportContent(bool skipDecorTrainsets = false)
-    {
-        string result = _template;
-
-        if (WeatherDirty)
-            result = RewriteWeather(result);
-
-        result = InjectIncludes(result);
-
-        for (int i = 0; i < Trainsets.Count; i++)
-        {
-            string entry = skipDecorTrainsets && Trainsets[i].Decor
-                ? string.Empty
-                : Trainsets[i].ToSceneryEntry();
-            result = result.Replace("{{" + i + "}}", entry);
-        }
-
-        if (LooseVehicles.Count > 0)
-            result = AppendLooseVehicles(result);
-
-        return result;
-    }
-
-    private string AppendLooseVehicles(string text)
-    {
-        var sb = new StringBuilder();
-        foreach (var v in LooseVehicles)
-            sb.Append(v.ToLooseNode());
-        if (sb.Length == 0) return text;
-
-        var fi = Regex.Match(text, @"\bFirstInit\b", RegexOptions.IgnoreCase);
-        if (fi.Success)
-            return text[..fi.Index] + sb + text[fi.Index..];
-        return text + sb;
-    }
-
-    private void ParseAttachments(string content)
-    {
-        Attachments.Clear();
-        foreach (Match m in Regex.Matches(content, @"^//\$f\b[ \t]*([^\r\n]*)", RegexOptions.Multiline))
-        {
-            string rest = m.Groups[1].Value.Trim();
-            if (rest.Length == 0) continue;
-            string[] parts = rest.Split((char[]?)null, StringSplitOptions.RemoveEmptyEntries);
-
-            if (parts.Length >= 3 && parts[0].Length <= 2)
-                Attachments.Add(new SceneryAttachment
-                {
-                    FilePath = parts[1],
-                    Label = string.Join(" ", parts.Skip(2))
-                });
-            else if (parts.Length >= 2)
-                Attachments.Add(new SceneryAttachment
-                {
-                    FilePath = parts[0],
-                    Label = string.Join(" ", parts.Skip(1))
-                });
-            else
-                Attachments.Add(new SceneryAttachment
-                {
-                    FilePath = parts[0],
-                    Label = System.IO.Path.GetFileName(parts[0])
-                });
-        }
-    }
-
-    private string ParseAndStripOptionalIncludes(string content)
-    {
-        Includes.Clear();
-
-        if (content.IndexOf("$optional", StringComparison.OrdinalIgnoreCase) < 0)
-            return content;
-
-        return Regex.Replace(
-            content,
-            @"include\s+(\S+(?:\s+\S+)*?)\s+end\s*//[^\r\n]*\$optional([^\r\n]*)\r?\n([\s\S]*?)endoptional\b",
-            m =>
-            {
-                string incPath = Regex.Replace(m.Groups[1].Value.Trim(), @"\s+", " ");
-                string raw = m.Groups[2].Value.Trim().TrimStart(',', ' ');
-                string[] par = raw.Split(new[] { ',', '|', ';' },
-                    StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
-
-                int kind = 1;
-                string desc = incPath;
-                if (par.Length >= 1 && int.TryParse(par[0], out int k))
-                    kind = k;
-                if (par.Length >= 2)
-                    desc = par[1];
-
-                Includes.Add(new SceneryInclude
-                {
-                    FilePath = incPath,
-                    Desc = desc,
-                    Kind = kind,
-                    Selected = kind == 1
-                });
-                return " ";
-            },
-            RegexOptions.IgnoreCase);
-    }
-
-    private string InjectIncludes(string text)
-    {
-        if (Includes.Count == 0)
-            return text;
-
-        var sb = new StringBuilder();
-        string sbt = System.IO.Path.ChangeExtension(Path, ".sbt");
-        bool hasSbt = File.Exists(sbt);
-
-        foreach (var inc in Includes)
-        {
-            if (inc.Kind == 2)
-            {
-                if (!hasSbt)
-                    sb.Append("include ").Append(inc.FilePath).Append(" end\r\n");
-                continue;
-            }
-            if (inc.Selected)
-                sb.Append("include ").Append(inc.FilePath).Append(" end\r\n");
-        }
-
-        if (sb.Length == 0)
-            return text;
-
-        var fi = Regex.Match(text, @"\bFirstInit\b", RegexOptions.IgnoreCase);
-        if (fi.Success)
-            return text[..fi.Index] + sb + text[fi.Index..];
-        return sb + text;
-    }
-
-    private void ParseWeather(string content)
-    {
-
-        var time = Regex.Match(content, @"(?im)^\s*time\s+(\d{1,2})[:.](\d{2})\b");
-        if (time.Success)
-        {
-            Time = $"{time.Groups[1].Value.PadLeft(2, '0')}:{time.Groups[2].Value}";
-            ScenarioTimeOverride = Time;
-        }
-
-        var ovr = Regex.Match(content, @"(?i)scenario\.time\.override\s+(\d{1,2})[:.](\d{2})");
-        if (ovr.Success)
-        {
-            ScenarioTimeOverride = $"{ovr.Groups[1].Value.PadLeft(2, '0')}:{ovr.Groups[2].Value}";
-            HasWeather = true;
-        }
-        else if (!time.Success)
-        {
-
-            var now = System.DateTime.Now;
-            ScenarioTimeOverride = $"{now.Hour:D2}:{now.Minute:D2}";
-        }
-
-        var move = Regex.Match(content, @"(?im)\bmovelight\s+(-?\d+)");
-        if (move.Success && int.TryParse(move.Groups[1].Value, out int day))
-        {
-            Day = day;
-            HasWeather = true;
-        }
-
-        var temp = Regex.Match(content, @"(?i)scenario\.weather\.temperature\s+(-?\d+(?:\.\d+)?)");
-        if (temp.Success &&
-            double.TryParse(temp.Groups[1].Value, System.Globalization.NumberStyles.Float,
-                System.Globalization.CultureInfo.InvariantCulture, out double t))
-        {
-            Temperature = t;
-            HasWeather = true;
-        }
-
-        var atmo = Regex.Match(content, @"(?is)\batmo\b(.*?)\bendatmo\b");
-        if (atmo.Success)
-        {
-            var nums = Regex.Matches(atmo.Groups[1].Value, @"-?\d+(?:\.\d+)?")
-                .Select(m => m.Value).ToList();
-            if (nums.Count >= 5 &&
-                int.TryParse(nums[3], out int fogStart) &&
-                int.TryParse(nums[4], out int fogEnd))
-            {
-                FogStart = Math.Clamp(fogStart, FogMin, FogMax);
-                fogEnd = Math.Clamp(fogEnd, FogStart, FogMax);
-                FogEnd = fogEnd > FogStart
-                    ? Random.Shared.Next(FogStart, fogEnd + 1)
-                    : fogEnd;
-                HasWeather = true;
-            }
-            if (nums.Count >= 6 &&
-                double.TryParse(nums[^1], System.Globalization.NumberStyles.Float,
-                    System.Globalization.CultureInfo.InvariantCulture, out double oc))
-                Overcast = oc;
-        }
-    }
-
-    private void SnapshotWeather()
-    {
-        _origTime = Time;
-        _origOverride = ScenarioTimeOverride;
-        _origDay = Day;
-        _origTemperature = Temperature;
-        _origFogEnd = FogEnd;
-        _origOvercast = Overcast;
-        _origOvercastRandom = OvercastRandom;
-    }
-
-    public bool WeatherChanged =>
-        Day != _origDay ||
-        ScenarioTimeOverride != _origOverride ||
-        Math.Abs(Temperature - _origTemperature) > 0.001 ||
-        FogEnd != _origFogEnd ||
-        OvercastRandom != _origOvercastRandom ||
-        (!OvercastRandom && Math.Abs(Overcast - _origOvercast) > 0.001);
-
-    public void RestoreWeather()
-    {
-        Time = _origTime;
-        ScenarioTimeOverride = _origOverride;
-        Day = _origDay;
-        Temperature = _origTemperature;
-        FogEnd = _origFogEnd;
-        Overcast = _origOvercast;
-        OvercastRandom = _origOvercastRandom;
-        WeatherDirty = true;
-    }
-
-    private static readonly double[] OvercastPresets = { -1.5, 0, 0.3, 0.7, 1, 1.1, 1.5 };
-
-    private double EffectiveOvercast() =>
-        OvercastRandom ? OvercastPresets[Random.Shared.Next(OvercastPresets.Length)] : Overcast;
-
-    private string RewriteWeather(string text)
-    {
-        try
-        {
-
-            string s = text;
-
-            string carried = CarriedConfigLines(s);
-
-            s = Regex.Replace(s, @"(?is)\bconfig\b.*?\bendconfig\b", " ");
-            s = Regex.Replace(s, @"(?is)\btime\b\s+\d[^\r\n]*?\bendtime\b", " ");
-            s = Regex.Replace(s, @"(?is)\batmo\b.*?\bendatmo\b", " ");
-            s = Regex.Replace(s, @"(?im)^[ \t]*movelight\s+\S+", " ");
-            s = Regex.Replace(s, @"(?i)scenario\.weather\.temperature\s+\S+", " ");
-            s = Regex.Replace(s, @"(?i)scenario\.time\.override\s+\S+", " ");
-
-            var inv = System.Globalization.CultureInfo.InvariantCulture;
-
-            string config =
-                "config\r\n" +
-                $"movelight {Day}\r\n" +
-                $"scenario.weather.temperature {Temperature.ToString(inv)}\r\n" +
-                $"scenario.time.override {DelphiHourMinute(ScenarioTimeOverride)}\r\n" +
-                carried +
-                "endconfig\r\n" +
-                $"atmo 0 0 0 {FogEnd} {FogEnd} 0 0 0 {EffectiveOvercast().ToString(inv)} endatmo\r\n" +
-                $"time {DelphiHourMinute(Time)} 0 0 endtime\r\n";
-
-            return config + s;
-        }
-        catch
-        {
-            return text;
-        }
-    }
-
-    private static string DelphiHourMinute(string hhmm)
-    {
-        int colon = hhmm.IndexOf(':');
-        if (colon <= 0) return hhmm;
-        return hhmm[..colon].TrimStart('0') is { Length: > 0 } h
-            ? h + hhmm[colon..]
-            : "0" + hhmm[colon..];
-    }
-
-    private static readonly Regex ManagedConfigLine = new(
-        @"^\s*(movelight|scenario\.weather\.temperature|scenario\.time\.override)\b",
-        RegexOptions.IgnoreCase | RegexOptions.Compiled);
-
-    private static string CarriedConfigLines(string text)
-    {
-        var block = Regex.Match(text, @"(?is)\bconfig\b(.*?)\bendconfig\b");
-        if (!block.Success)
-            return "";
-
-        var sb = new StringBuilder();
-        foreach (string raw in block.Groups[1].Value.Split('\n'))
-        {
-            string line = raw.TrimEnd('\r').Trim();
-            if (line.Length == 0 || ManagedConfigLine.IsMatch(line))
-                continue;
-            sb.Append(line).Append("\r\n");
-        }
-        return sb.ToString();
-    }
-
-    private static string MatchAllDirectives(string content, string letter)
-    {
-        var matches = Regex.Matches(
-            content,
-            @"^//\$" + letter + @"\b[ \t]*([^\r\n]*)",
-            RegexOptions.Multiline
-        );
-        if (matches.Count == 0)
-            return null;
-        return string.Join("\n", matches.Select(m => m.Groups[1].Value.TrimEnd()));
-    }
-
-    private static string MatchDirective(string content, string letter)
-    {
-        var match = Regex.Match(
-            content,
-            @"^//\$" + letter + @"\b[ \t]*([^\r\n]*)",
-            RegexOptions.Multiline
-        );
-        return match.Success ? match.Groups[1].Value.Trim() : null;
-    }
-
-    public string ImagePath
-    {
-        get
-        {
-            if (_imagePathResolved)
-                return _imagePath;
-            _imagePathResolved = true;
-            _imagePath = ResolveImagePath();
-            return _imagePath;
-        }
-    }
-
-    private string ResolveImagePath()
-    {
-        if (string.IsNullOrWhiteSpace(ImageName))
-            return null;
-
-        string name = ImageName.Replace('\\', '/').Trim();
-        string scnDir = System.IO.Path.GetDirectoryName(Path) ?? ".";
-        string root = System.IO.Path.GetDirectoryName(scnDir) ?? ".";
-
-        var candidates = new List<string>
-        {
-            name,
-            System.IO.Path.Combine(root, name),
-            System.IO.Path.Combine(scnDir, name),
-            System.IO.Path.Combine(scnDir, "images", name),
-            System.IO.Path.Combine(root, "scenery", "images", name),
-        };
-
-        foreach (string candidate in candidates)
-        {
-            if (File.Exists(candidate))
-                return candidate;
-        }
-        return null;
-    }
-}

StarterNG/Domain/Consist.cs

@@ -4,6 +4,7 @@ using System.Collections.Generic;
 using System.Linq;
 
 using StarterNG.Classes;
+using StarterNG.Domain.Sceneries;
 
 namespace StarterNG.Domain;
 

StarterNG/Domain/Sceneries/Scenery.cs

@@ -0,0 +1,183 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Text.RegularExpressions;
+using StarterNG.Application.Abstractions;
+using StarterNG.Classes;
+using StarterNG.Domain;
+
+namespace StarterNG.Domain.Sceneries;
+
+/// <summary>A file the scenery offers to open alongside it (map, manual, ...).</summary>
+public sealed class SceneryAttachment
+{
+    public string FilePath = "";
+    public string Label = "";
+}
+
+/// <summary>
+/// An <c>include</c> the scenery marks as optional, so the user can decide
+/// whether it ends up in the exported scenario.
+/// </summary>
+public sealed class SceneryInclude
+{
+    public string FilePath = "";
+    public string Desc = "";
+
+    /// <summary>1 = on by default, 2 = only when no companion timetable exists.</summary>
+    public int Kind;
+
+    public bool Selected;
+}
+
+/// <summary>
+/// A scenario the user can start: its consists, loose vehicles, optional
+/// includes and weather, plus the ability to render all of that back into a .scn
+/// the simulator can load.
+/// </summary>
+/// <remarks>
+/// The aggregate is pure: it never reads or writes files. Parsing lives in
+/// <c>Infrastructure.Sceneries.SceneryParser</c> and loading in
+/// <c>SceneryRepository</c>, which is what lets the export rules be tested from
+/// a string rather than an installation.
+///
+/// <see cref="Template"/> is the .scn text with every trainset replaced by a
+/// <c>{{index}}</c> placeholder and the optional includes stripped, so
+/// <see cref="BuildExportContent"/> only has to substitute rather than re-parse.
+/// </remarks>
+public sealed class Scenery
+{
+    public Scenery(string path, string template)
+    {
+        Path = path;
+        Template = template;
+    }
+
+    /// <summary>Path of the .scn this was parsed from; the aggregate's identity.</summary>
+    public string Path { get; }
+
+    /// <summary>The .scn body with trainset placeholders, used for export.</summary>
+    public string Template { get; }
+
+    /// <summary>True when a companion .sbt timetable sits next to the .scn.</summary>
+    public bool HasCompanionTimetable { get; set; }
+
+    public string? Group { get; set; }
+
+    public string? Name { get; set; }
+
+    public string? Description { get; set; }
+
+    public string? ImageName { get; set; }
+
+    /// <summary>Scenery kept for historical interest; hidden unless asked for.</summary>
+    public bool Archival { get; set; }
+
+    public List<Trainset> Trainsets { get; } = new();
+
+    public List<SceneryAttachment> Attachments { get; } = new();
+
+    public List<SceneryInclude> Includes { get; } = new();
+
+    /// <summary>Vehicles placed directly as nodes rather than inside a trainset.</summary>
+    public List<Dynamic> LooseVehicles { get; } = new();
+
+    /// <summary>
+    /// Names of every loose vehicle, including those whose node failed to parse
+    /// and therefore has no <see cref="Dynamic"/>.
+    /// </summary>
+    public List<string> LooseVehicleNames { get; } = new();
+
+    /// <summary>Parse problems worth showing on the scenario's fault list.</summary>
+    public List<string> Faults { get; } = new();
+
+    public SceneryWeather Weather { get; } = new();
+
+    public string DisplayName => System.IO.Path.GetFileNameWithoutExtension(Path);
+
+    public string LocalizedDescription =>
+        string.IsNullOrEmpty(Description)
+            ? ""
+            : string.Join("\n", Description.Split('\n').Select(SceneryI18n.T));
+
+    /// <summary>
+    /// Renders the scenario the simulator should load: the original file with the
+    /// user's consists, weather and optional includes applied.
+    /// </summary>
+    /// <param name="skipDecorTrainsets">
+    /// Drops AI trainsets the user marked irrelevant, which shortens loading.
+    /// </param>
+    public string BuildExportContent(bool skipDecorTrainsets, IRandomSource random)
+    {
+        string result = Template;
+
+        if (Weather.Dirty)
+            result = SceneryWeatherWriter.Rewrite(result, Weather, random);
+
+        result = InjectIncludes(result);
+
+        for (int i = 0; i < Trainsets.Count; i++)
+        {
+            string entry = skipDecorTrainsets && Trainsets[i].Decor
+                ? string.Empty
+                : Trainsets[i].ToSceneryEntry();
+            result = result.Replace("{{" + i + "}}", entry);
+        }
+
+        if (LooseVehicles.Count > 0)
+            result = AppendLooseVehicles(result);
+
+        return result;
+    }
+
+    private string AppendLooseVehicles(string text)
+    {
+        var sb = new StringBuilder();
+        foreach (var vehicle in LooseVehicles)
+            sb.Append(vehicle.ToLooseNode());
+        if (sb.Length == 0)
+            return text;
+
+        return InsertBeforeFirstInit(text, sb.ToString(), fallbackAtEnd: true);
+    }
+
+    private string InjectIncludes(string text)
+    {
+        if (Includes.Count == 0)
+            return text;
+
+        var sb = new StringBuilder();
+        foreach (var include in Includes)
+        {
+            // Kind 2 is the scenery's own timetable stand-in: it is only wanted
+            // when the user has not supplied a companion .sbt.
+            if (include.Kind == 2)
+            {
+                if (!HasCompanionTimetable)
+                    sb.Append("include ").Append(include.FilePath).Append(" end\r\n");
+                continue;
+            }
+            if (include.Selected)
+                sb.Append("include ").Append(include.FilePath).Append(" end\r\n");
+        }
+
+        if (sb.Length == 0)
+            return text;
+
+        return InsertBeforeFirstInit(text, sb.ToString(), fallbackAtEnd: false);
+    }
+
+    /// <summary>
+    /// Places generated content ahead of <c>FirstInit</c>, which the simulator
+    /// treats as the end of the definition section.
+    /// </summary>
+    private static string InsertBeforeFirstInit(string text, string addition, bool fallbackAtEnd)
+    {
+        var firstInit = Regex.Match(text, @"\bFirstInit\b", RegexOptions.IgnoreCase);
+        if (firstInit.Success)
+            return text[..firstInit.Index] + addition + text[firstInit.Index..];
+
+        return fallbackAtEnd ? text + addition : addition + text;
+    }
+}

StarterNG/Domain/Sceneries/SceneryWeather.cs

@@ -0,0 +1,105 @@
+using System;
+using StarterNG.Application.Abstractions;
+
+namespace StarterNG.Domain.Sceneries;
+
+/// <summary>
+/// The weather and time-of-day a scenery starts with: what the .scn file
+/// declared, what the user has changed it to, and whether that differs.
+/// </summary>
+/// <remarks>
+/// Split out of <c>Scenery</c> so the "is this still the authored weather?"
+/// rule lives next to the values it compares, instead of being spread over the
+/// aggregate and the weather tab. The aggregate owns one of these; the parser
+/// fills it and calls <see cref="AcceptAsAuthored"/> once.
+/// </remarks>
+public sealed class SceneryWeather
+{
+    public const int FogMin = 10;
+    public const int FogMax = 10000;
+
+    /// <summary>Overcast values the "random" option picks between.</summary>
+    private static readonly double[] OvercastPresets = { -1.5, 0, 0.3, 0.7, 1, 1.1, 1.5 };
+
+    private string _authoredTime = "10:30";
+    private string _authoredTimeOverride = "10:30";
+    private int _authoredDay;
+    private double _authoredTemperature = 15;
+    private int _authoredFogEnd = 2000;
+    private double _authoredOvercast;
+    private bool _authoredOvercastRandom;
+
+    public string Time { get; set; } = "10:30";
+
+    public string ScenarioTimeOverride { get; set; } = "10:30";
+
+    /// <summary>Day of the year driving the sun position (movelight).</summary>
+    public int Day { get; set; }
+
+    public double Temperature { get; set; } = 15;
+
+    public int FogStart { get; set; } = 10;
+
+    public int FogEnd { get; set; } = 2000;
+
+    public double Overcast { get; set; }
+
+    /// <summary>When set, each export draws a fresh overcast from the presets.</summary>
+    public bool OvercastRandom { get; set; }
+
+    /// <summary>True when the .scn actually declared weather, rather than us defaulting it.</summary>
+    public bool IsAuthored { get; set; }
+
+    /// <summary>Set once the user has touched the weather, so export rewrites the config block.</summary>
+    public bool Dirty { get; set; }
+
+    /// <summary>Takes the current values as the baseline "what the file said".</summary>
+    public void AcceptAsAuthored()
+    {
+        _authoredTime = Time;
+        _authoredTimeOverride = ScenarioTimeOverride;
+        _authoredDay = Day;
+        _authoredTemperature = Temperature;
+        _authoredFogEnd = FogEnd;
+        _authoredOvercast = Overcast;
+        _authoredOvercastRandom = OvercastRandom;
+    }
+
+    /// <summary>True when the user's weather differs from what the .scn declared.</summary>
+    public bool Changed =>
+        Day != _authoredDay ||
+        ScenarioTimeOverride != _authoredTimeOverride ||
+        Math.Abs(Temperature - _authoredTemperature) > 0.001 ||
+        FogEnd != _authoredFogEnd ||
+        OvercastRandom != _authoredOvercastRandom ||
+        (!OvercastRandom && Math.Abs(Overcast - _authoredOvercast) > 0.001);
+
+    /// <summary>
+    /// Puts back the authored weather. Stays <see cref="Dirty"/>: the export must
+    /// still rewrite the config block, because the file on disk may already carry
+    /// an edit from an earlier run.
+    /// </summary>
+    public void Restore()
+    {
+        Time = _authoredTime;
+        ScenarioTimeOverride = _authoredTimeOverride;
+        Day = _authoredDay;
+        Temperature = _authoredTemperature;
+        FogEnd = _authoredFogEnd;
+        Overcast = _authoredOvercast;
+        OvercastRandom = _authoredOvercastRandom;
+        Dirty = true;
+    }
+
+    /// <summary>Clamps a parsed fog range and picks the distance to run with.</summary>
+    public void SetFogRange(int start, int end, IRandomSource random)
+    {
+        FogStart = Math.Clamp(start, FogMin, FogMax);
+        end = Math.Clamp(end, FogStart, FogMax);
+        FogEnd = end > FogStart ? random.Next(FogStart, end + 1) : end;
+    }
+
+    /// <summary>The overcast to export, drawing a preset when randomisation is on.</summary>
+    public double EffectiveOvercast(IRandomSource random) =>
+        OvercastRandom ? OvercastPresets[random.Next(0, OvercastPresets.Length)] : Overcast;
+}

StarterNG/Domain/Sceneries/SceneryWeatherWriter.cs

@@ -0,0 +1,93 @@
+using System;
+using System.Globalization;
+using System.Text;
+using System.Text.RegularExpressions;
+using StarterNG.Application.Abstractions;
+
+namespace StarterNG.Domain.Sceneries;
+
+/// <summary>
+/// Renders a <see cref="SceneryWeather"/> back into the .scn dialect: strips the
+/// blocks the starter owns and prepends freshly written ones.
+/// </summary>
+/// <remarks>
+/// A pure text transformation, kept out of the aggregate because it is entirely
+/// about the file format rather than about the scenario.
+/// </remarks>
+public static class SceneryWeatherWriter
+{
+    /// <summary>Config lines the starter writes itself and must not carry over.</summary>
+    private static readonly Regex ManagedConfigLine = new(
+        @"^\s*(movelight|scenario\.weather\.temperature|scenario\.time\.override)\b",
+        RegexOptions.IgnoreCase | RegexOptions.Compiled);
+
+    public static string Rewrite(string text, SceneryWeather weather, IRandomSource random)
+    {
+        try
+        {
+            string carried = CarriedConfigLines(text);
+
+            string stripped = text;
+            stripped = Regex.Replace(stripped, @"(?is)\bconfig\b.*?\bendconfig\b", " ");
+            stripped = Regex.Replace(stripped, @"(?is)\btime\b\s+\d[^\r\n]*?\bendtime\b", " ");
+            stripped = Regex.Replace(stripped, @"(?is)\batmo\b.*?\bendatmo\b", " ");
+            stripped = Regex.Replace(stripped, @"(?im)^[ \t]*movelight\s+\S+", " ");
+            stripped = Regex.Replace(stripped, @"(?i)scenario\.weather\.temperature\s+\S+", " ");
+            stripped = Regex.Replace(stripped, @"(?i)scenario\.time\.override\s+\S+", " ");
+
+            var inv = CultureInfo.InvariantCulture;
+            string config =
+                "config\r\n" +
+                $"movelight {weather.Day}\r\n" +
+                $"scenario.weather.temperature {weather.Temperature.ToString(inv)}\r\n" +
+                $"scenario.time.override {DelphiHourMinute(weather.ScenarioTimeOverride)}\r\n" +
+                carried +
+                "endconfig\r\n" +
+                $"atmo 0 0 0 {weather.FogEnd} {weather.FogEnd} 0 0 0 " +
+                $"{weather.EffectiveOvercast(random).ToString(inv)} endatmo\r\n" +
+                $"time {DelphiHourMinute(weather.Time)} 0 0 endtime\r\n";
+
+            return config + stripped;
+        }
+        catch
+        {
+            // A scenery we cannot rewrite is still worth starting unmodified.
+            return text;
+        }
+    }
+
+    /// <summary>
+    /// The simulator's parser expects an unpadded hour ("7:30", not "07:30").
+    /// </summary>
+    private static string DelphiHourMinute(string hhmm)
+    {
+        int colon = hhmm.IndexOf(':');
+        if (colon <= 0)
+            return hhmm;
+
+        return hhmm[..colon].TrimStart('0') is { Length: > 0 } hour
+            ? hour + hhmm[colon..]
+            : "0" + hhmm[colon..];
+    }
+
+    /// <summary>
+    /// Config entries the scenery author wrote that are none of the starter's
+    /// business, preserved verbatim across a rewrite.
+    /// </summary>
+    private static string CarriedConfigLines(string text)
+    {
+        var block = Regex.Match(text, @"(?is)\bconfig\b(.*?)\bendconfig\b");
+        if (!block.Success)
+            return "";
+
+        var sb = new StringBuilder();
+        foreach (string raw in block.Groups[1].Value.Split('\n'))
+        {
+            string line = raw.TrimEnd('\r').Trim();
+            if (line.Length == 0 || ManagedConfigLine.IsMatch(line))
+                continue;
+            sb.Append(line).Append("\r\n");
+        }
+        return sb.ToString();
+    }
+}

StarterNG/Domain/SceneryI18n.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.IO;
 using System.Text.Json;
 using StarterNG.Classes;
+using StarterNG.Domain.Sceneries;
 
 namespace StarterNG.Domain;
 

StarterNG/Domain/TrainsetDisplay.cs

@@ -5,6 +5,7 @@ using System.IO;
 using System.Linq;
 using System.Text;
 using StarterNG.Classes;
+using StarterNG.Domain.Sceneries;
 
 namespace StarterNG.Domain;
 

StarterNG/Infrastructure/Adapters/SystemRandomSource.cs

@@ -0,0 +1,12 @@
+using System;
+using StarterNG.Application.Abstractions;
+
+namespace StarterNG.Infrastructure.Adapters;
+
+/// <summary><see cref="IRandomSource"/> backed by <see cref="Random.Shared"/>.</summary>
+public sealed class SystemRandomSource : IRandomSource
+{
+    public int Next(int minInclusive, int maxExclusive) => Random.Shared.Next(minInclusive, maxExclusive);
+
+    public double NextDouble() => Random.Shared.NextDouble();
+}

StarterNG/Infrastructure/Sceneries/SceneryImageLocator.cs

@@ -0,0 +1,65 @@
+using System.Collections.Generic;
+using System.IO;
+using StarterNG.Application.Abstractions;
+using StarterNG.Domain.Sceneries;
+
+namespace StarterNG.Infrastructure.Sceneries;
+
+/// <summary>
+/// Finds the preview image a scenery names, which authors place in any of
+/// several conventional spots relative to the .scn.
+/// </summary>
+/// <remarks>
+/// Was a lazy property on the aggregate; moved out because it is a lookup on
+/// disk. Results are cached per scenery path, which is what the lazy field
+/// bought us before.
+/// </remarks>
+public sealed class SceneryImageLocator
+{
+    private readonly IFileSystem _files;
+    private readonly Dictionary<string, string?> _cache = new();
+
+    public SceneryImageLocator(IFileSystem files)
+    {
+        _files = files;
+    }
+
+    /// <summary>The image file for this scenery, or null when there is none.</summary>
+    public string? Resolve(Scenery scenery)
+    {
+        lock (_cache)
+        {
+            if (_cache.TryGetValue(scenery.Path, out string? cached))
+                return cached;
+
+            string? resolved = Search(scenery);
+            _cache[scenery.Path] = resolved;
+            return resolved;
+        }
+    }
+
+    private string? Search(Scenery scenery)
+    {
+        if (string.IsNullOrWhiteSpace(scenery.ImageName))
+            return null;
+
+        string name = scenery.ImageName.Replace('\\', '/').Trim();
+        string sceneryDir = Path.GetDirectoryName(scenery.Path) ?? ".";
+        string root = Path.GetDirectoryName(sceneryDir) ?? ".";
+
+        string[] candidates =
+        {
+            name,
+            Path.Combine(root, name),
+            Path.Combine(sceneryDir, name),
+            Path.Combine(sceneryDir, "images", name),
+            Path.Combine(root, "scenery", "images", name)
+        };
+
+        foreach (string candidate in candidates)
+            if (_files.FileExists(candidate))
+                return candidate;
+
+        return null;
+    }
+}

StarterNG/Infrastructure/Sceneries/SceneryParser.cs

@@ -0,0 +1,297 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Text.RegularExpressions;
+using StarterNG.Application.Abstractions;
+using StarterNG.Classes;
+using StarterNG.Domain;
+using StarterNG.Domain.Sceneries;
+
+namespace StarterNG.Infrastructure.Sceneries;
+
+/// <summary>
+/// Turns the text of a .scn file into a <see cref="Scenery"/>.
+/// </summary>
+/// <remarks>
+/// All knowledge of the .scn dialect lives here, so the aggregate stays free of
+/// regular expressions and the parser can be exercised on a string. Anything
+/// malformed is recorded as a fault rather than thrown: a scenery with one bad
+/// consist is still worth listing.
+/// </remarks>
+public sealed class SceneryParser
+{
+    private readonly IClock _clock;
+    private readonly IRandomSource _random;
+
+    public SceneryParser(IClock clock, IRandomSource random)
+    {
+        _clock = clock;
+        _random = random;
+    }
+
+    public Scenery Parse(string path, string content)
+    {
+        // Directives, attachments and weather are read from the file as written;
+        // the placeholder rewriting below only shapes the export template.
+        string original = content;
+
+        var faults = new List<string>();
+        var attachments = ParseAttachments(original);
+
+        var includes = new List<SceneryInclude>();
+        content = StripOptionalIncludes(content, includes);
+
+        // Trainsets are lifted out first so the placeholders survive the loose
+        // vehicle sweep below, which would otherwise match nodes inside them.
+        var trainsetEntries = new List<string>();
+        content = Regex.Replace(content, @"trainset\b[\s\S]*?\bendtrainset\b",
+            match =>
+            {
+                trainsetEntries.Add(match.Value);
+                return $"{{{{{trainsetEntries.Count - 1}}}}}";
+            },
+            RegexOptions.IgnoreCase);
+
+        var looseVehicles = new List<Dynamic>();
+        var looseNames = new List<string>();
+        content = ExtractLooseVehicles(content, looseVehicles, looseNames, faults);
+
+        var scenery = new Scenery(path, content)
+        {
+            Group = MatchDirective(original, "l"),
+            Name = MatchDirective(original, "n"),
+            Description = MatchAllDirectives(original, "d"),
+            ImageName = MatchDirective(original, "i"),
+            Archival = MatchDirective(original, "a") != null
+        };
+
+        scenery.Attachments.AddRange(attachments);
+        scenery.Includes.AddRange(includes);
+        scenery.LooseVehicles.AddRange(looseVehicles);
+        scenery.LooseVehicleNames.AddRange(looseNames);
+        scenery.Faults.AddRange(faults);
+
+        ParseWeather(original, scenery.Weather);
+        scenery.Weather.AcceptAsAuthored();
+
+        foreach (string entry in trainsetEntries)
+        {
+            var trainset = new Trainset(entry);
+            scenery.Trainsets.Add(trainset);
+            if (!trainset.Parsed)
+                scenery.Faults.Add($"# trainset parse fault: {trainset.Name} ({trainset.Track})");
+        }
+
+        return scenery;
+    }
+
+    private static List<SceneryAttachment> ParseAttachments(string content)
+    {
+        var attachments = new List<SceneryAttachment>();
+
+        foreach (Match m in Regex.Matches(content, @"^//\$f\b[ \t]*([^\r\n]*)", RegexOptions.Multiline))
+        {
+            string rest = m.Groups[1].Value.Trim();
+            if (rest.Length == 0)
+                continue;
+
+            string[] parts = rest.Split((char[]?)null, StringSplitOptions.RemoveEmptyEntries);
+
+            // A leading one- or two-character token is a legacy ordering hint.
+            if (parts.Length >= 3 && parts[0].Length <= 2)
+                attachments.Add(new SceneryAttachment
+                {
+                    FilePath = parts[1],
+                    Label = string.Join(" ", parts.Skip(2))
+                });
+            else if (parts.Length >= 2)
+                attachments.Add(new SceneryAttachment
+                {
+                    FilePath = parts[0],
+                    Label = string.Join(" ", parts.Skip(1))
+                });
+            else
+                attachments.Add(new SceneryAttachment
+                {
+                    FilePath = parts[0],
+                    Label = System.IO.Path.GetFileName(parts[0])
+                });
+        }
+
+        return attachments;
+    }
+
+    /// <summary>
+    /// Removes the includes the scenery marked <c>$optional</c> from the text and
+    /// records them, so the user can pick which ones the export puts back.
+    /// </summary>
+    private static string StripOptionalIncludes(string content, List<SceneryInclude> includes)
+    {
+        if (content.IndexOf("$optional", StringComparison.OrdinalIgnoreCase) < 0)
+            return content;
+
+        return Regex.Replace(
+            content,
+            @"include\s+(\S+(?:\s+\S+)*?)\s+end\s*//[^\r\n]*\$optional([^\r\n]*)\r?\n([\s\S]*?)endoptional\b",
+            m =>
+            {
+                string includePath = Regex.Replace(m.Groups[1].Value.Trim(), @"\s+", " ");
+                string raw = m.Groups[2].Value.Trim().TrimStart(',', ' ');
+                string[] parameters = raw.Split(new[] { ',', '|', ';' },
+                    StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+
+                int kind = 1;
+                string description = includePath;
+                if (parameters.Length >= 1 && int.TryParse(parameters[0], out int parsedKind))
+                    kind = parsedKind;
+                if (parameters.Length >= 2)
+                    description = parameters[1];
+
+                includes.Add(new SceneryInclude
+                {
+                    FilePath = includePath,
+                    Desc = description,
+                    Kind = kind,
+                    Selected = kind == 1
+                });
+                return " ";
+            },
+            RegexOptions.IgnoreCase);
+    }
+
+    /// <summary>
+    /// Lifts <c>node ... dynamic ... enddynamic</c> entries that sit outside any
+    /// trainset, so the depot can show and reorder them like a consist.
+    /// </summary>
+    private static string ExtractLooseVehicles(string content, List<Dynamic> vehicles, List<string> names,
+                                               List<string> faults)
+    {
+        var inv = CultureInfo.InvariantCulture;
+
+        return Regex.Replace(
+            content,
+            @"(?is)\bnode\s+(\S+)\s+(\S+)\s+(\S+)\s+dynamic\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)((?:\s+(?!enddynamic)\S+)*)\s*enddynamic\b",
+            m =>
+            {
+                string name = m.Groups[3].Value;
+
+                // A placeholder means the node belongs to a trainset already lifted out.
+                if (name.StartsWith("{{", StringComparison.Ordinal))
+                    return m.Value;
+
+                try
+                {
+                    var vehicle = new Dynamic
+                    {
+                        RangeMax = float.Parse(m.Groups[1].Value, inv),
+                        RangeMin = float.Parse(m.Groups[2].Value, inv),
+                        Name = name,
+                        DataFolder = m.Groups[4].Value,
+                        SkinFile = Dynamic.StripSkinExtension(m.Groups[5].Value),
+                        MmdFile = m.Groups[6].Value,
+                        PathName = m.Groups[7].Value,
+                        Offset = float.Parse(m.Groups[8].Value, inv),
+                        DriverType = m.Groups[9].Value.ToLowerInvariant() switch
+                        {
+                            "headdriver" => eDriverType.Headdriver,
+                            "reardriver" => eDriverType.Reardriver,
+                            "passenger" => eDriverType.Passenger,
+                            _ => eDriverType.Nobody
+                        },
+                        HasVelocity = true,
+                        Velocity = float.Parse(m.Groups[10].Value, inv)
+                    };
+
+                    var trailing = m.Groups[11].Value
+                        .Split((char[]?)null, StringSplitOptions.RemoveEmptyEntries)
+                        .ToList();
+                    vehicle.ReadTrailing(trailing);
+
+                    vehicles.Add(vehicle);
+                    names.Add(vehicle.Name);
+                    return "\n";
+                }
+                catch
+                {
+                    // Leave the node in the template so the export stays faithful.
+                    faults.Add($"# loose dynamic parse fault: {name}");
+                    names.Add(name);
+                    return m.Value;
+                }
+            });
+    }
+
+    private void ParseWeather(string content, SceneryWeather weather)
+    {
+        var time = Regex.Match(content, @"(?im)^\s*time\s+(\d{1,2})[:.](\d{2})\b");
+        if (time.Success)
+        {
+            weather.Time = $"{time.Groups[1].Value.PadLeft(2, '0')}:{time.Groups[2].Value}";
+            weather.ScenarioTimeOverride = weather.Time;
+        }
+
+        var over = Regex.Match(content, @"(?i)scenario\.time\.override\s+(\d{1,2})[:.](\d{2})");
+        if (over.Success)
+        {
+            weather.ScenarioTimeOverride = $"{over.Groups[1].Value.PadLeft(2, '0')}:{over.Groups[2].Value}";
+            weather.IsAuthored = true;
+        }
+        else if (!time.Success)
+        {
+            // Nothing authored: start the scenario at the player's wall clock.
+            var now = _clock.Now;
+            weather.ScenarioTimeOverride = $"{now.Hour:D2}:{now.Minute:D2}";
+        }
+
+        var move = Regex.Match(content, @"(?im)\bmovelight\s+(-?\d+)");
+        if (move.Success && int.TryParse(move.Groups[1].Value, out int day))
+        {
+            weather.Day = day;
+            weather.IsAuthored = true;
+        }
+
+        var temperature = Regex.Match(content, @"(?i)scenario\.weather\.temperature\s+(-?\d+(?:\.\d+)?)");
+        if (temperature.Success &&
+            double.TryParse(temperature.Groups[1].Value, NumberStyles.Float, CultureInfo.InvariantCulture,
+                            out double celsius))
+        {
+            weather.Temperature = celsius;
+            weather.IsAuthored = true;
+        }
+
+        var atmo = Regex.Match(content, @"(?is)\batmo\b(.*?)\bendatmo\b");
+        if (!atmo.Success)
+            return;
+
+        var numbers = Regex.Matches(atmo.Groups[1].Value, @"-?\d+(?:\.\d+)?")
+            .Select(m => m.Value)
+            .ToList();
+
+        if (numbers.Count >= 5 &&
+            int.TryParse(numbers[3], out int fogStart) &&
+            int.TryParse(numbers[4], out int fogEnd))
+        {
+            weather.SetFogRange(fogStart, fogEnd, _random);
+            weather.IsAuthored = true;
+        }
+
+        if (numbers.Count >= 6 &&
+            double.TryParse(numbers[^1], NumberStyles.Float, CultureInfo.InvariantCulture, out double overcast))
+            weather.Overcast = overcast;
+    }
+
+    private static string? MatchAllDirectives(string content, string letter)
+    {
+        var matches = Regex.Matches(content, @"^//\$" + letter + @"\b[ \t]*([^\r\n]*)", RegexOptions.Multiline);
+        return matches.Count == 0
+            ? null
+            : string.Join("\n", matches.Select(m => m.Groups[1].Value.TrimEnd()));
+    }
+
+    private static string? MatchDirective(string content, string letter)
+    {
+        var match = Regex.Match(content, @"^//\$" + letter + @"\b[ \t]*([^\r\n]*)", RegexOptions.Multiline);
+        return match.Success ? match.Groups[1].Value.Trim() : null;
+    }
+}

StarterNG/Infrastructure/Sceneries/SceneryRepository.cs

@@ -0,0 +1,101 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using StarterNG.Application.Abstractions;
+using StarterNG.Domain.Sceneries;
+
+namespace StarterNG.Infrastructure.Sceneries;
+
+/// <summary>
+/// Loads scenarios from the installation's scenery folder.
+/// </summary>
+/// <remarks>
+/// Sceneries are code page 1250 text, and a large installation holds hundreds of
+/// them, so the sweep is parallel; each file that throws is logged and dropped
+/// rather than taking the whole load down.
+/// </remarks>
+public sealed class SceneryRepository : ISceneryRepository
+{
+    /// <summary>Files starting with '$' are authoring scratch, not scenarios.</summary>
+    private const char ExcludedPrefix = '$';
+
+    private readonly IFileSystem _files;
+    private readonly IGamePaths _paths;
+    private readonly IDiagnosticsLog _log;
+    private readonly SceneryParser _parser;
+    private readonly Encoding _encoding;
+
+    public SceneryRepository(IFileSystem files, IGamePaths paths, IDiagnosticsLog log, SceneryParser parser)
+    {
+        _files = files;
+        _paths = paths;
+        _log = log;
+        _parser = parser;
+        _encoding = CodePage1250();
+    }
+
+    public IReadOnlyList<Scenery> LoadAll(IProgress<SceneryLoadProgress>? progress = null)
+    {
+        var files = SceneryFiles().ToList();
+        var loaded = new ConcurrentBag<Scenery>();
+        int total = Math.Max(1, files.Count);
+        int done = 0;
+
+        Parallel.ForEach(files,
+            new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount },
+            file =>
+            {
+                var scenery = Load(file);
+                if (scenery is not null)
+                    loaded.Add(scenery);
+
+                progress?.Report(new SceneryLoadProgress(Interlocked.Increment(ref done), total,
+                                                         Path.GetFileName(file)));
+            });
+
+        return loaded.ToList();
+    }
+
+    public Scenery? Load(string path)
+    {
+        try
+        {
+            if (!_files.FileExists(path))
+                return null;
+
+            var scenery = _parser.Parse(path, _files.ReadAllText(path, _encoding));
+            scenery.HasCompanionTimetable = _files.FileExists(Path.ChangeExtension(path, ".sbt"));
+            return scenery;
+        }
+        catch (Exception ex)
+        {
+            _log.Log($"scenery/{Path.GetFileName(path)}", ex);
+            return null;
+        }
+    }
+
+    private IEnumerable<string> SceneryFiles() =>
+        _files.GetFiles(_paths.Scenery, "*.scn")
+              .Where(path => Path.GetFileName(path).FirstOrDefault() != ExcludedPrefix);
+
+    /// <summary>
+    /// The .scn dialect predates Unicode. The provider is registered by the entry
+    /// point; fall back to Latin-1 if that ever fails so loading still works.
+    /// </summary>
+    private static Encoding CodePage1250()
+    {
+        try
+        {
+            return Encoding.GetEncoding(1250);
+        }
+        catch (Exception)
+        {
+            return Encoding.Latin1;
+        }
+    }
+}

StarterNG/MainWindow.axaml.cs

@@ -17,6 +17,8 @@ using StarterNG.Infrastructure;
 using StarterNG.Services;
 using StarterNG.Views;
 using SettingsModel = StarterNG.Classes.Settings;
+using StarterNG.Application;
+using StarterNG.Domain.Sceneries;
 
 namespace StarterNG;
 
@@ -443,14 +445,14 @@ public partial class MainWindow : Window
 
         LoadingScreen.Prepare(trainset.Logo, Path.GetFileNameWithoutExtension(scenery.Path));
 
-        scenery.WeatherDirty = true;
+        scenery.Weather.Dirty = true;
 
         string dir = Path.GetDirectoryName(scenery.Path) ?? "scenery";
         string exportName = "$" + Path.GetFileName(scenery.Path);
         string exportPath = Path.Combine(dir, exportName);
         try
         {
-            File.WriteAllText(exportPath, scenery.BuildExportContent(SettingsModel.Instance.IgnoreIrrelevantTrains), Encoding.GetEncoding(1250));
+            File.WriteAllText(exportPath, scenery.BuildExportContent(SettingsModel.Instance.IgnoreIrrelevantTrains, AppServices.Current.Random), Encoding.GetEncoding(1250));
         }
         catch (Exception ex)
         {

StarterNG/Views/Depot.axaml.cs

@@ -18,6 +18,7 @@ using Avalonia.Threading;
 using Avalonia.VisualTree;
 using StarterNG.Classes;
 using StarterNG.Domain;
+using StarterNG.Domain.Sceneries;
 
 namespace StarterNG.Views;
 

StarterNG/Views/Depot/VehicleBrowser.cs

@@ -14,6 +14,7 @@ using Avalonia.Threading;
 
 using StarterNG.Classes;
 using StarterNG.Domain;
+using StarterNG.Domain.Sceneries;
 
 namespace StarterNG.Views;
 

StarterNG/Views/Scenarios.axaml.cs

@@ -17,6 +17,8 @@ using Avalonia.Markup.Xaml;
 using Avalonia.Media.Imaging;
 using StarterNG.Classes;
 using StarterNG.Domain;
+using StarterNG.Application;
+using StarterNG.Domain.Sceneries;
 
 namespace StarterNG.Views;
 
@@ -310,7 +312,7 @@ public partial class Scenarios : UserControl
         SceneryI18n.LoadFor(scenery, App.Loc.CurrentLangCode);
         sceneryDescription.Text = scenery.LocalizedDescription;
 
-        string? imagePath = scenery.ImagePath;
+        string? imagePath = AppServices.Current.SceneryImages.Resolve(scenery);
         if (imagePath is not null)
         {
             try
@@ -551,16 +553,17 @@ public partial class Scenarios : UserControl
         try
         {
             weatherForm.IsEnabled = true;
-            weatherTime.SelectedTime = ParseTime(scenery.ScenarioTimeOverride);
-            weatherDate.SelectedDate = DateOfDayOfYear(scenery.Day);
-            weatherTemp.Value = scenery.Temperature;
-            weatherFog.Value = SliderFromFog(scenery.FogEnd);
-            SelectByTag(weatherSeason, scenery.Day.ToString(), excludeFromNearest: "0");
-            SelectByTag(weatherOvercast, scenery.OvercastRandom
+            var weather = scenery.Weather;
+            weatherTime.SelectedTime = ParseTime(weather.ScenarioTimeOverride);
+            weatherDate.SelectedDate = DateOfDayOfYear(weather.Day);
+            weatherTemp.Value = weather.Temperature;
+            weatherFog.Value = SliderFromFog(weather.FogEnd);
+            SelectByTag(weatherSeason, weather.Day.ToString(), excludeFromNearest: "0");
+            SelectByTag(weatherOvercast, weather.OvercastRandom
                 ? RandomTag
-                : scenery.Overcast.ToString(CultureInfo.InvariantCulture));
+                : weather.Overcast.ToString(CultureInfo.InvariantCulture));
 
-            ApplyTodayPreview(scenery.Day == 0);
+            ApplyTodayPreview(weather.Day == 0);
             UpdateWeatherLabels();
         }
         finally
@@ -574,22 +577,22 @@ public partial class Scenarios : UserControl
         if (_loadingWeather || _currentScenery is null)
             return;
 
-        var scn = _currentScenery;
+        var weather = _currentScenery.Weather;
         if (weatherTime.SelectedTime is { } t)
-            scn.ScenarioTimeOverride = $"{t.Hours:D2}:{t.Minutes:D2}";
+            weather.ScenarioTimeOverride = $"{t.Hours:D2}:{t.Minutes:D2}";
 
-        scn.Day = _todaySeason ? 0 : SelectedDayOfYear();
-        scn.Temperature = weatherTemp.Value;
-        scn.FogEnd = FogFromSlider(weatherFog.Value);
+        weather.Day = _todaySeason ? 0 : SelectedDayOfYear();
+        weather.Temperature = weatherTemp.Value;
+        weather.FogEnd = FogFromSlider(weatherFog.Value);
         if ((weatherOvercast.SelectedItem as ComboBoxItem)?.Tag is string ov)
         {
-            scn.OvercastRandom = ov == RandomTag;
-            if (!scn.OvercastRandom &&
+            weather.OvercastRandom = ov == RandomTag;
+            if (!weather.OvercastRandom &&
                 double.TryParse(ov, NumberStyles.Float, CultureInfo.InvariantCulture, out double oc))
-                scn.Overcast = oc;
+                weather.Overcast = oc;
         }
 
-        scn.WeatherDirty = true;
+        weather.Dirty = true;
         UpdateWeatherLabels();
     }
 
@@ -599,23 +602,23 @@ public partial class Scenarios : UserControl
         weatherFogLabel.Text = FormatFog(FogFromSlider(weatherFog.Value));
         weatherDayDate.Text = string.Format(LanguageCulture, App.Loc["DayOfYear"], SelectedDayOfYear());
 
-        weatherRestore.IsEnabled = _currentScenery?.WeatherChanged ?? false;
+        weatherRestore.IsEnabled = _currentScenery?.Weather.Changed ?? false;
     }
 
     private static int FogFromSlider(double position)
     {
-        double metres = Scenery.FogMin *
-                        System.Math.Pow((double)Scenery.FogMax / Scenery.FogMin, position / 1000.0);
+        double metres = SceneryWeather.FogMin *
+                        System.Math.Pow((double)SceneryWeather.FogMax / SceneryWeather.FogMin, position / 1000.0);
         int step = metres < 100 ? 5 : metres < 1000 ? 10 : 100;
         return System.Math.Clamp((int)(System.Math.Round(metres / step) * step),
-                                 Scenery.FogMin, Scenery.FogMax);
+                                 SceneryWeather.FogMin, SceneryWeather.FogMax);
     }
 
     private static double SliderFromFog(int metres)
     {
-        double clamped = System.Math.Clamp(metres, Scenery.FogMin, Scenery.FogMax);
-        return 1000.0 * System.Math.Log(clamped / Scenery.FogMin) /
-               System.Math.Log((double)Scenery.FogMax / Scenery.FogMin);
+        double clamped = System.Math.Clamp(metres, SceneryWeather.FogMin, SceneryWeather.FogMax);
+        return 1000.0 * System.Math.Log(clamped / SceneryWeather.FogMin) /
+               System.Math.Log((double)SceneryWeather.FogMax / SceneryWeather.FogMin);
     }
 
     private static string FormatFog(int metres) =>
@@ -688,7 +691,7 @@ public partial class Scenarios : UserControl
     private void WeatherRestore_OnClick(object? sender, RoutedEventArgs e)
     {
         if (_currentScenery is null) return;
-        _currentScenery.RestoreWeather();
+        _currentScenery.Weather.Restore();
         ShowWeather(_currentScenery);
     }