ref: project structure

application/Documents/Queries/GetDocumentTree.cs

@@ -0,0 +1,35 @@
+using AutoMapper;
+using MediatR;
+using mws.backend.dotnet.application.Common;
+using mws.backend.dotnet.application.Permissions;
+
+namespace mws.backend.dotnet.application.Documents;
+
+public record GetDocumentTreeQuery(Guid UserId, Guid ProjectId) : IRequest<List<DocumentNodeDto>>;
+
+public class GetDocumentTreeHandler(IUnitOfWork uow, IMapper mapper) : IRequestHandler<GetDocumentTreeQuery, List<DocumentNodeDto>>
+{
+    public async Task<List<DocumentNodeDto>> Handle(GetDocumentTreeQuery query, CancellationToken ct)
+    {
+        await DocumentAccess.EnsureDocumentPermissionAsync(uow, query.UserId, query.ProjectId, PermissionAction.View, ct);
+
+        var docs = await uow.Documents.GetTreeForProjectAsync(query.ProjectId, ct);
+
+        var nodes = docs.ToDictionary(d => d.Id, d => mapper.Map<DocumentNodeDto>(d));
+
+        var roots = new List<DocumentNodeDto>();
+        foreach (var node in nodes.Values)
+        {
+            if (node.ParentId is { } parentId && nodes.TryGetValue(parentId, out var parent))
+            {
+                parent.Children.Add(node);
+            }
+            else
+            {
+                roots.Add(node);
+            }
+        }
+
+        return roots;
+    }
+}