Ancestry Manager for WE

AncestryManager.cs

// Note: We must have an option set to false for this kind of feature,
// unless there is better -- less expensive -- way to do detect cycles while walking.

using System.Collections.Generic;
using System.Linq;
using Microsoft.CSS.Editor;
using Microsoft.Web.Editor;

//public class Importer//: HypotheticalVsShellClass
//{
// ...
//   private AncestryManager _lessImportTree = new AncestryManager(LessCompiler, "LESS");
//   public AncestryManager LessImportTree { get { return _lessImportTree; } }
//   ProjectLoaded += LessImportTree.Initialize ();
//   FileSaved += delegate { LessImportTree.UpdateDependents (FilePath) };
// ...
//}

internal class AncestryManager
{
    private ICompiler _compiler;
    private readonly object _compile = new object();
    private List<ImportNode> _nodes;
    private string _serviceName;

    internal bool IsLoaded { get; private set; }

    internal AncestryManager(ICompiler compiler, string serviceName)
    {
        _compiler = compiler;
        _serviceName = serviceName;
        IsLoaded = false;
    }

    //<summary>Collect items of type ServiceName</summary>
    internal void Initialize()
    {
        // Where proj.DTE.Documents.Item(<counter>).Language == ServiceName
        // [Recursively iterate all nested folders recursively? AND / OR HOW exactly?]
        IEnumerable<IDocumentReference> documents = ProjectHelpers.GetAllSourceDocumentReferences(_serviceName);

        foreach (var document in documents)
        {
            var node = new ImportNode(document);

            node.Initialize();
            _nodes.Add(node);
        }

        IsLoaded = true;
    }

    internal void UpdateDependents(string FilePath)
    {
        lock (_compile)
        {
            if (!IsLoaded)
                return;

            var importNode = _nodes.Where(n => n.DocumentFilePath == FilePath).First();

            // last check is for reassurance; may be ommitted
            if (importNode == null ||
                !ImportNode.GetImports(importNode.SourceReference).SequenceEqual(importNode.Imports))
                return;

            // Walk once
            foreach (IDocumentReference documentReference in importNode.Children)
            {
                _compiler.Compile(TextBufferExtensions.GetFileName(documentReference.TextBuffer));
            }
        }
    }

    private class ImportNode
    {
        private List<DocumentState> _children = new List<DocumentState>();
        // for reassurance check in UpdateBranch.ImportsAncestoryManager; cascade omiision
        private List<IDocumentReference> _imports = new List<IDocumentReference>();

        // For retrieval
        public string DocumentFilePath { get; set; }
        public IDocumentReference SourceReference { get; set; }
        public List<DocumentState> Children { get { return this._children; } }
        // for reassurance check in UpdateBranch.ImportsAncestoryManager; cascade omiision
        public List<IDocumentReference> Imports { get { return this._imports; } }

        public ImportNode(IDocumentReference sourceReference)
        {
            this.DocumentFilePath = TextBufferExtensions.GetFileName(sourceReference.TextBuffer);
            this.SourceReference = sourceReference;
            this._imports = GetImports(sourceReference);
        }

        public void Initialize()
        {
            WalkDown(new DocumentState() { DocumentReference = SourceReference, IsWalked = true });
        }

        public void WalkDown(DocumentState document)
        {
            if (Children.Any(c => c.DocumentReference == document && c.IsWalked))
                return;

            this.Children.Add(document);

            foreach (var relative in GetImports(document.DocumentReference))
            {
                WalkDown(new DocumentState() { DocumentReference = relative, IsWalked = true });
            }
        }

        public static List<IDocumentReference> GetImports(IDocumentReference document)
        {
            return CssDocumentHelpers.DocumentImportManager.GetImports(
                       CssEditorDocument.FromTextBuffer(document.TextBuffer).Tree.StyleSheet
                   ).ToList();
        }

        private class DocumentState
        {
            public IDocumentReference DocumentReference { get; set; }
            public bool IsWalked { get; set; }

            public DocumentState()
            {
                IsWalked = false;
            }
        }
    }
}