mfgames-nitride-cil/src/MfGames.Nitride.Generators/WithPropertySyntaxReceiver.cs

using System.Collections.Generic;
using System.Linq;

using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp.Syntax;

namespace MfGames.Nitride.Generators;

internal class WithPropertySyntaxReceiver : ISyntaxReceiver
{
    private readonly GeneratorInitializationContext context;

    public WithPropertySyntaxReceiver(GeneratorInitializationContext context)
    {
        this.context = context;
        this.ClassList = new List<WithPropertyClass>();
        this.Messages = new List<string>();
    }

    public List<WithPropertyClass> ClassList { get; }

    public List<string> Messages { get; }

    /// <summary>
    /// Gets or sets the name of the analyzed namespace.
    /// </summary>
    public string? Namespace { get; private set; }

    public List<UsingDirectiveSyntax> UsingDirectiveList { get; set; } = new();

    public void OnVisitSyntaxNode(SyntaxNode syntaxNode)
    {
        // Check for namespaces.
        switch (syntaxNode)
        {
            case CompilationUnitSyntax:
                // Reset everything.
                this.Namespace = null!;
                this.UsingDirectiveList = new List<UsingDirectiveSyntax>();

                break;
            case NamespaceDeclarationSyntax syntax:
                this.Namespace = syntax.Name.ToString();

                return;
            case FileScopedNamespaceDeclarationSyntax syntax:
                this.Namespace = syntax.Name.ToString();

                return;
            case UsingDirectiveSyntax syntax:
                this.UsingDirectiveList.Add(syntax);

                return;
            case ClassDeclarationSyntax:
                break;
            default:
                return;
        }

        // We only care about class declarations.
        if (syntaxNode is not ClassDeclarationSyntax cds)
        {
            return;
        }

        // See if the class has our set properties attribute.
        bool found = cds.AttributeLists.AsEnumerable()
            .SelectMany(x => x.Attributes)
            .Select(x => x.Name.ToString())
            .Any(
                x => x switch
                {
                    "WithProperties" => true,
                    "WithPropertiesAttribute" => true,
                    _ => false,
                });

        if (found)
        {
            this.ClassList.Add(
                new WithPropertyClass
                {
                    Namespace = this.Namespace!,
                    UsingDirectiveList = this.UsingDirectiveList,
                    ClassDeclaration = cds,
                });
        }
    }
}