Establish canonical story position context

PlotLine.Tests/Program.cs

@@ -70,7 +70,10 @@ var tests = new (string Name, Action Test)[]
     ("Scan review post supports full-book form submissions", ScanReviewPostSupportsFullBookFormSubmissions),
     ("Story Intelligence experience boot does not serialise live model", StoryIntelligenceExperienceBootDoesNotSerialiseLiveModel),
     ("Live visualisation strips illustration diagnostics", LiveVisualisationStripsIllustrationDiagnostics),
-    ("Illustration evidence trace does not recursively store previous evidence", IllustrationEvidenceTraceDoesNotRecursivelyStorePreviousEvidence)
+    ("Illustration evidence trace does not recursively store previous evidence", IllustrationEvidenceTraceDoesNotRecursivelyStorePreviousEvidence),
+    ("StoryPosition rejects incomplete or invalid runtime scene positions", StoryPositionRejectsInvalidRuntimeScenePositions),
+    ("StoryPosition builds canonical runtime scene navigation", StoryPositionBuildsCanonicalRuntimeSceneNavigation),
+    ("StoryPosition derives canonical scene context identity", StoryPositionDerivesCanonicalSceneContextIdentity)
 };
 
 foreach (var test in tests)
@@ -86,6 +89,53 @@ static void RepairsTrailingDecimalConfidence()
     Assert(result.RepairedJson.Contains("\"confidence\":0.0", StringComparison.Ordinal), result.RepairedJson);
 }
 
+static void StoryPositionRejectsInvalidRuntimeScenePositions()
+{
+    Assert(StoryPosition.FromRuntimeCurrentScene(new WordCompanionRuntimeCurrentSceneRequest
+    {
+        DocumentGuid = Guid.NewGuid(),
+        ProjectId = 1,
+        BookId = 2,
+        ChapterId = 3,
+        SceneId = 0
+    }) is null, "Runtime scene positions require a valid SceneId.");
+
+    Assert(StoryPosition.FromTimelineSelection(0, 2, 3, 4) is null, "Story positions require a valid ProjectId.");
+}
+
+static void StoryPositionBuildsCanonicalRuntimeSceneNavigation()
+{
+    var response = new WordCompanionRuntimeCurrentSceneResponse
+    {
+        ProjectId = 10,
+        BookId = 20,
+        ChapterId = 30,
+        SceneId = 40,
+        SceneUrl = "/Scenes/Edit/40"
+    };
+
+    var position = response.Position;
+    Assert(position is not null, "Runtime response should expose a canonical StoryPosition.");
+    Assert(position!.ProjectId == 10 && position.BookId == 20 && position.ChapterId == 30 && position.SceneId == 40, "Runtime response position IDs were not preserved.");
+    Assert(position.SceneEditUrl == "/Scenes/Edit/40", "Scene positions must use the canonical Scene Edit route.");
+}
+
+static void StoryPositionDerivesCanonicalSceneContextIdentity()
+{
+    var model = new SceneEditViewModel
+    {
+        SceneID = 7,
+        ChapterID = 6,
+        Project = new Project { ProjectID = 4 },
+        Book = new Book { BookID = 5 },
+        Chapter = new Chapter { ChapterID = 6 }
+    };
+
+    var position = StoryPosition.FromScene(model);
+    Assert(position is not null, "Scene workspace should expose a canonical StoryPosition.");
+    Assert(position!.ProjectId == 4 && position.BookId == 5 && position.ChapterId == 6 && position.SceneId == 7, "Scene workspace position IDs were not preserved.");
+}
+
 static void StripsMarkdownFence()
 {
     var result = StoryIntelligenceJsonRepair.Repair("""

PlotLine/Controllers/RelationshipMapController.cs

@@ -1,5 +1,6 @@
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Authorization;
+using PlotLine.Models;
 using PlotLine.Services;
 
 namespace PlotLine.Controllers;
@@ -9,7 +10,10 @@ public sealed class RelationshipMapController(IRelationshipMapService relationsh
 {
     public async Task<IActionResult> Index(int projectId, int? bookId, int? chapterId, int? sceneId, int? focusCharacterId, bool showFullNetwork = false)
     {
-        var model = await relationshipMap.GetAsync(projectId, bookId, chapterId, sceneId, focusCharacterId, showFullNetwork);
+        var position = StoryPosition.FromTimelineSelection(projectId, bookId, chapterId, sceneId);
+        var model = position is null
+            ? null
+            : await relationshipMap.GetAsync(position, focusCharacterId, showFullNetwork);
         return model is null ? NotFound() : View(model);
     }
 }

PlotLine/Models/StoryPosition.cs

@@ -0,0 +1,59 @@
+using PlotLine.ViewModels;
+
+namespace PlotLine.Models;
+
+public sealed record StoryPosition(int ProjectId, int? BookId = null, int? ChapterId = null, int? SceneId = null)
+{
+    public bool IsValid => ProjectId > 0 && (BookId is null or > 0) && (ChapterId is null or > 0) && (SceneId is null or > 0);
+    public bool IsScenePosition => SceneId.HasValue;
+
+    public static StoryPosition? FromScene(SceneEditViewModel? scene)
+    {
+        if (scene?.Project is null)
+        {
+            return null;
+        }
+
+        return new StoryPosition(scene.Project.ProjectID, scene.Book?.BookID, scene.ChapterID, scene.SceneID > 0 ? scene.SceneID : null);
+    }
+
+    public static StoryPosition? FromScene(Scene? scene, int projectId)
+    {
+        if (scene is null || projectId <= 0)
+        {
+            return null;
+        }
+
+        return new StoryPosition(projectId, scene.BookID > 0 ? scene.BookID : null, scene.ChapterID, scene.SceneID);
+    }
+
+    public static StoryPosition? FromRuntimeCurrentScene(WordCompanionRuntimeCurrentSceneRequest request)
+    {
+        var position = new StoryPosition(request.ProjectId, request.BookId, request.ChapterId, request.SceneId);
+        return position.IsValid ? position : null;
+    }
+
+    public static StoryPosition? FromRuntimeCurrentScene(WordCompanionRuntimeCurrentSceneResponse? response)
+    {
+        if (response is null)
+        {
+            return null;
+        }
+
+        var position = new StoryPosition(response.ProjectId, response.BookId, response.ChapterId, response.SceneId);
+        return position.IsValid ? position : null;
+    }
+
+    public static StoryPosition? FromTimelineSelection(int projectId, int? bookId, int? chapterId, int? sceneId)
+    {
+        if (projectId <= 0)
+        {
+            return null;
+        }
+
+        var position = new StoryPosition(projectId, bookId, chapterId, sceneId);
+        return position.IsValid ? position : null;
+    }
+
+    public string? SceneEditUrl => SceneId.HasValue ? $"/Scenes/Edit/{SceneId.Value}" : null;
+}

PlotLine/Program.cs

@@ -167,6 +167,7 @@ public class Program
         builder.Services.AddScoped<IChapterService, ChapterService>();
         builder.Services.AddScoped<ISceneService, SceneService>();
         builder.Services.AddScoped<IStoryStateService, StoryStateService>();
+        builder.Services.AddScoped<IStoryContextService, StoryContextService>();
         builder.Services.AddScoped<ITimelineService, TimelineService>();
         builder.Services.AddScoped<ISceneMetricTypeService, SceneMetricTypeService>();
         builder.Services.AddScoped<ISceneMetricValueService, SceneMetricValueService>();

PlotLine/Services/CoreServices.cs

@@ -146,6 +146,23 @@ public interface IStoryStateService
     Task<List<ContinuityWarningAcknowledgement>> GetAcknowledgementsAsync(int projectId);
 }
 
+public interface IStoryContextService
+{
+    Task<StoryContextViewModel?> GetAsync(StoryPosition position);
+    Task<StoryContextViewModel?> GetForSceneAsync(int sceneId, int? projectId = null, int? bookId = null);
+}
+
+public sealed class StoryContextViewModel
+{
+    public StoryPosition Position { get; init; } = new(0);
+    public Project? Project { get; init; }
+    public Book? Book { get; init; }
+    public Chapter? Chapter { get; init; }
+    public SceneEditViewModel? Scene { get; init; }
+    public StoryStateViewModel StoryState { get; init; } = new();
+    public string? CanonicalUrl => Position.SceneEditUrl;
+}
+
 public interface IPlotService
 {
     Task<PlotLineListViewModel?> GetPlotLinesAsync(int projectId);
@@ -313,6 +330,7 @@ public interface IStoryBibleService
 
 public interface IRelationshipMapService
 {
+    Task<RelationshipMapViewModel?> GetAsync(StoryPosition position, int? focusCharacterId, bool showFullNetwork);
     Task<RelationshipMapViewModel?> GetAsync(int projectId, int? bookId, int? chapterId, int? sceneId, int? focusCharacterId, bool showFullNetwork);
 }
 
@@ -2017,12 +2035,69 @@ public sealed class SceneService(
     }
 }
 
+public sealed class StoryContextService(ISceneService scenes) : IStoryContextService
+{
+    public async Task<StoryContextViewModel?> GetAsync(StoryPosition position)
+    {
+        if (!position.IsValid)
+        {
+            return null;
+        }
+
+        if (position.SceneId.HasValue)
+        {
+            return await GetForSceneAsync(position.SceneId.Value, position.ProjectId, position.BookId);
+        }
+
+        return new StoryContextViewModel
+        {
+            Position = position
+        };
+    }
+
+    public async Task<StoryContextViewModel?> GetForSceneAsync(int sceneId, int? projectId = null, int? bookId = null)
+    {
+        if (sceneId <= 0)
+        {
+            return null;
+        }
+
+        var scene = await scenes.GetEditAsync(sceneId);
+        var position = StoryPosition.FromScene(scene);
+        if (position is null)
+        {
+            return null;
+        }
+
+        if (projectId.HasValue && projectId.Value != position.ProjectId)
+        {
+            return null;
+        }
+
+        if (bookId.HasValue && position.BookId.HasValue && bookId.Value != position.BookId.Value)
+        {
+            return null;
+        }
+
+        return new StoryContextViewModel
+        {
+            Position = position,
+            Project = scene!.Project,
+            Book = scene.Book,
+            Chapter = scene.Chapter,
+            Scene = scene,
+            StoryState = scene.StoryState
+        };
+    }
+}
+
 public sealed class TimelineService(
     ITimelineRepository timelineRepository,
     ITimelinePresetRepository presets,
     ITimelineSettingsRepository timelineSettings,
     IProjectRepository projects,
     IBookRepository books,
+    IStoryContextService storyContext,
     ISceneService scenes,
     IAssetRepository assets,
     ICharacterRepository characters,
@@ -2141,9 +2216,10 @@ public sealed class TimelineService(
         var characterLanes = settings.ShowCharacterAppearances
             ? await TimeTimelineLoadAsync("TimelineService.BuildCharacterLanes", () => Task.FromResult(BuildCharacterLanes(characterTimeline.Characters, characterTimeline.Appearances, orderedScenes)), projectId, bookId)
             : [];
-        var selectedScene = selectedSceneId.HasValue
-            ? await TimeTimelineLoadAsync("SceneService.GetEditAsync", () => scenes.GetEditAsync(selectedSceneId.Value), projectId, bookId)
+        var selectedContext = selectedSceneId.HasValue
+            ? await TimeTimelineLoadAsync("StoryContextService.GetForSceneAsync", () => storyContext.GetForSceneAsync(selectedSceneId.Value, projectId, bookId), projectId, bookId)
             : null;
+        var selectedScene = selectedContext?.Scene;
         if (selectedScene is not null)
         {
             selectedScene.ReturnProjectID = projectId;
@@ -5340,6 +5416,13 @@ public sealed class StoryBibleService(IProjectRepository projects, IStoryBibleRe
 
 public sealed class RelationshipMapService(IProjectRepository projects, ICharacterRepository characters) : IRelationshipMapService
 {
+    public Task<RelationshipMapViewModel?> GetAsync(StoryPosition position, int? focusCharacterId, bool showFullNetwork)
+    {
+        return !position.IsValid
+            ? Task.FromResult<RelationshipMapViewModel?>(null)
+            : GetAsync(position.ProjectId, position.BookId, position.ChapterId, position.SceneId, focusCharacterId, showFullNetwork);
+    }
+
     public async Task<RelationshipMapViewModel?> GetAsync(int projectId, int? bookId, int? chapterId, int? sceneId, int? focusCharacterId, bool showFullNetwork)
     {
         if (projectId <= 0)

PlotLine/ViewModels/CoreViewModels.cs

@@ -416,6 +416,7 @@ public sealed class SceneEditViewModel
     public int? ReturnProjectID { get; set; }
     public int? ReturnBookID { get; set; }
     public bool ReturnToTimeline { get; set; }
+    public StoryPosition? Position => StoryPosition.FromScene(this);
 
     public Chapter? Chapter { get; set; }
     public Book? Book { get; set; }