CodeStructureWalker.cs

// CodeStructureWalker.cs
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Xml.Linq; // For parsing XML comments

namespace RoslynCodeAnalyzer;

public class CodeStructureWalker : CSharpSyntaxWalker
{
    // ... (Existing fields and constructor remain the same) ...
    private readonly SemanticModel _semanticModel;
    private readonly Dictionary<string, CodeNode> _nodes = new();
    private readonly List<CodeEdge> _edges = new();
    private readonly string _filePath;
    private readonly Stack<string> _containerIdStack = new();
    private static readonly SymbolDisplayFormat FullyQualifiedFormat = new(/* ... existing format options ... */);

    public CodeStructureWalker(SemanticModel semanticModel, string filePath)
    {
        _semanticModel = semanticModel ?? throw new ArgumentNullException(nameof(semanticModel));
        _filePath = filePath;
    }
    // --- Public Methods ---
    public (Dictionary<string, CodeNode> Nodes, List<CodeEdge> Edges) GetResults()
    {
        return (_nodes, _edges);
    }

    private void AddNode(CodeNode node)
    {
        _nodes.TryAdd(node.Id, node);
        if (_containerIdStack.TryPeek(out var containerId))
        {
            AddEdge(new CodeEdge(containerId, node.Id, "CONTAINS"));
        }
    }

    private void AddEdge(CodeEdge edge)
    {
        _edges.Add(edge);
    }

    private LocationInfo GetLocation(SyntaxNode node)
    {
        var lineSpan = node.GetLocation().GetLineSpan();
        return new LocationInfo(
            _filePath,
            lineSpan.StartLinePosition.Line + 1,
            lineSpan.EndLinePosition.Line + 1
        );
    }

    private string? GetSummaryComment(SyntaxNode node)
    {
        var xmlTrivia = node.GetLeadingTrivia()
            .Select(i => i.GetStructure())
            .OfType<DocumentationCommentTriviaSyntax>()
            .FirstOrDefault();

        if (xmlTrivia != null)
        {
            try
            {
                var xmlContent = xmlTrivia.Content.ToString();
                var xmlDoc = XDocument.Parse("<root>" + xmlContent + "</root>", LoadOptions.PreserveWhitespace);
                return xmlDoc.Descendants("summary").FirstOrDefault()?.Value.Trim();
            }
            catch (Exception ex)
            {
                Console.Error.WriteLine($"Warning: Failed to parse XML comment for node near line {GetLocation(node).StartLine}. Error: {ex.Message}");
                return null;
            }
        }
        return null;
    }

    // --- Visit Methods ---

    public override void VisitNamespaceDeclaration(NamespaceDeclarationSyntax node)
    {
        var symbol = _semanticModel.GetDeclaredSymbol(node);
        if (symbol != null)
        {
            string id = symbol.ToDisplayString(FullyQualifiedFormat);
            var location = GetLocation(node);
            // Typically don't need full code snippet for namespace declaration itself
            var codeNode = new CodeNode(id, "Namespace", symbol.Name, location.FilePath, location.StartLine, location.EndLine);
            AddNode(codeNode);

            _containerIdStack.Push(id);
            base.VisitNamespaceDeclaration(node);
            _containerIdStack.Pop();
        }
        else
        {
            base.VisitNamespaceDeclaration(node);
        }
    }

    public override void VisitFileScopedNamespaceDeclaration(FileScopedNamespaceDeclarationSyntax node)
    {
        var symbol = _semanticModel.GetDeclaredSymbol(node);
        if (symbol != null)
        {
            string id = symbol.ToDisplayString(FullyQualifiedFormat);
            var location = GetLocation(node);
            // Typically don't need full code snippet for namespace declaration itself
            var codeNode = new CodeNode(id, "Namespace", symbol.Name, location.FilePath, location.StartLine, location.EndLine);
            AddNode(codeNode);

            _containerIdStack.Push(id);
            base.VisitFileScopedNamespaceDeclaration(node);
            _containerIdStack.Pop();
        }
        else
        {
            base.VisitFileScopedNamespaceDeclaration(node);
        }
    }

    public override void VisitPropertyDeclaration(PropertyDeclarationSyntax node)
    {
        var symbol = _semanticModel.GetDeclaredSymbol(node);
        if (symbol != null)
        {
            string id = symbol.ToDisplayString(FullyQualifiedFormat);
            var location = GetLocation(node);
            var comment = GetSummaryComment(node);
            string codeSnippet = node.ToString();

            // Properties don't have a separate "Signature" field in our model
            var codeNode = new CodeNode(id, "Property", symbol.Name, location.FilePath, location.StartLine, location.EndLine, Comment: comment, CodeSnippet: codeSnippet);
            AddNode(codeNode);

            // Visit accessor methods (get/set) if needed for deeper analysis later
            base.VisitPropertyDeclaration(node);
        }
        else
        {
            base.VisitPropertyDeclaration(node);
        }
    }

    public override void VisitFieldDeclaration(FieldDeclarationSyntax node)
    {
        // A single FieldDeclaration can declare multiple variables (e.g., public int x, y;)
        // We need to create a node for each variable declarator.
        var comment = GetSummaryComment(node); // Comment applies to the whole declaration
        string fullSnippet = node.ToString(); // Snippet for the whole declaration line

        foreach (VariableDeclaratorSyntax variableDeclarator in node.Declaration.Variables)
        {
            var symbol = _semanticModel.GetDeclaredSymbol(variableDeclarator);
            if (symbol != null && symbol is IFieldSymbol fieldSymbol) // Ensure it's a field symbol
            {
                string id = fieldSymbol.ToDisplayString(FullyQualifiedFormat);
                // Use the location of the specific variable declarator if possible,
                // otherwise fallback to the whole declaration's location.
                var location = GetLocation(variableDeclarator);

                // Use the variable name, associate comment/snippet from parent declaration
                var codeNode = new CodeNode(id, "Field", fieldSymbol.Name, location.FilePath, location.StartLine, location.EndLine, Comment: comment, CodeSnippet: fullSnippet);
                AddNode(codeNode);
            }
        }
        // Don't call base.VisitFieldDeclaration(node) unless you want to analyze initializers etc.
    }

    public override void VisitEnumDeclaration(EnumDeclarationSyntax node)
    {
        var symbol = _semanticModel.GetDeclaredSymbol(node);
        if (symbol != null)
        {
            string id = symbol.ToDisplayString(FullyQualifiedFormat);
            var location = GetLocation(node);
            var comment = GetSummaryComment(node);
            string codeSnippet = node.ToString();

            var codeNode = new CodeNode(id, "Enum", symbol.Name, location.FilePath, location.StartLine, location.EndLine, Comment: comment, CodeSnippet: codeSnippet);
            AddNode(codeNode);

            _containerIdStack.Push(id); // Push Enum onto stack for containing members
            base.VisitEnumDeclaration(node); // Visit Enum Members
            _containerIdStack.Pop(); // Pop Enum from stack
        }
        else
        {
            base.VisitEnumDeclaration(node);
        }
    }

    public override void VisitEnumMemberDeclaration(EnumMemberDeclarationSyntax node)
    {
        var symbol = _semanticModel.GetDeclaredSymbol(node);
        if (symbol != null) // Enum members are field symbols
        {
            string id = symbol.ToDisplayString(FullyQualifiedFormat);
            var location = GetLocation(node);
            var comment = GetSummaryComment(node); // Get comment specific to the member
            string codeSnippet = node.ToString();

            var codeNode = new CodeNode(id, "EnumMember", symbol.Name, location.FilePath, location.StartLine, location.EndLine, Comment: comment, CodeSnippet: codeSnippet);
            AddNode(codeNode);

            // Don't call base.VisitEnumMemberDeclaration unless analyzing attributes etc.
        }
        else
        {
            base.VisitEnumMemberDeclaration(node);
        }
    }

    public override void VisitClassDeclaration(ClassDeclarationSyntax node)
    {
        var symbol = _semanticModel.GetDeclaredSymbol(node);
        if (symbol != null)
        {
            string id = symbol.ToDisplayString(FullyQualifiedFormat);
            var location = GetLocation(node);
            var comment = GetSummaryComment(node);
            string codeSnippet = node.ToString(); // <<< GET THE CODE SNIPPET

            // <<< PASS SNIPPET TO CodeNode CONSTRUCTOR
            var codeNode = new CodeNode(id, "Class", symbol.Name, location.FilePath, location.StartLine, location.EndLine, Comment: comment, CodeSnippet: codeSnippet);
            AddNode(codeNode);

            // Handle Inheritance (remains the same)
            if (symbol.BaseType != null && symbol.BaseType.SpecialType != SpecialType.System_Object)
            {
                string baseTypeId = symbol.BaseType.ToDisplayString(FullyQualifiedFormat);
                AddEdge(new CodeEdge(id, baseTypeId, "INHERITS_FROM"));
            }
            foreach (var iface in symbol.Interfaces)
            {
                string interfaceId = iface.ToDisplayString(FullyQualifiedFormat);
                AddEdge(new CodeEdge(id, interfaceId, "IMPLEMENTS"));
            }

            _containerIdStack.Push(id);
            base.VisitClassDeclaration(node);
            _containerIdStack.Pop();
        }
        else
        {
            base.VisitClassDeclaration(node);
        }
    }

    public override void VisitInterfaceDeclaration(InterfaceDeclarationSyntax node)
    {
        var symbol = _semanticModel.GetDeclaredSymbol(node);
        if (symbol != null)
        {
            string id = symbol.ToDisplayString(FullyQualifiedFormat);
            var location = GetLocation(node);
            var comment = GetSummaryComment(node);
            string codeSnippet = node.ToString(); // <<< GET THE CODE SNIPPET

            // <<< PASS SNIPPET TO CodeNode CONSTRUCTOR
            var codeNode = new CodeNode(id, "Interface", symbol.Name, location.FilePath, location.StartLine, location.EndLine, Comment: comment, CodeSnippet: codeSnippet);
            AddNode(codeNode);

            // Handle Interface Inheritance (remains the same)
            foreach (var iface in symbol.Interfaces)
            {
                string baseInterfaceId = iface.ToDisplayString(FullyQualifiedFormat);
                AddEdge(new CodeEdge(id, baseInterfaceId, "INHERITS_FROM"));
            }

            _containerIdStack.Push(id);
            base.VisitInterfaceDeclaration(node);
            _containerIdStack.Pop();
        }
        else
        {
            base.VisitInterfaceDeclaration(node);
        }
    }


    public override void VisitMethodDeclaration(MethodDeclarationSyntax node)
    {
        var symbol = _semanticModel.GetDeclaredSymbol(node);
        if (symbol != null)
        {
            string id = symbol.ToDisplayString(FullyQualifiedFormat);
            var location = GetLocation(node);
            var comment = GetSummaryComment(node);
            var signature = symbol.ToDisplayString(SymbolDisplayFormat.MinimallyQualifiedFormat
                .WithMemberOptions(SymbolDisplayMemberOptions.IncludeParameters)
                .WithGenericsOptions(SymbolDisplayGenericsOptions.IncludeTypeParameters)
                .WithParameterOptions(SymbolDisplayParameterOptions.IncludeType | SymbolDisplayParameterOptions.IncludeName | SymbolDisplayParameterOptions.IncludeParamsRefOut)
                );
            string codeSnippet = node.ToString(); // <<< GET THE CODE SNIPPET

            // <<< PASS SNIPPET TO CodeNode CONSTRUCTOR
            var codeNode = new CodeNode(id, "Method", symbol.Name, location.FilePath, location.StartLine, location.EndLine, Comment: comment, Signature: signature, CodeSnippet: codeSnippet);
            AddNode(codeNode);

            base.VisitMethodDeclaration(node); // Visit method body (e.g., for future call analysis)
        }
        else
        {
            base.VisitMethodDeclaration(node);
        }
    }

    // TODO: Add VisitInvocationExpression for CALLS edges (more complex)
    // TODO: Add Visit Struct, Enum, Property, Field etc. and include CodeSnippet as needed

}