- shit: Cleanup this mess

Nebula.SourceGenerators/DependencyAutoGenerator.cs

@@ -0,0 +1,132 @@
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+using System.Text;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Text;
+
+namespace Nebula.SourceGenerators;
+
+[Generator]
+public class DependencyAutoGenerator : IIncrementalGenerator
+{
+    private static readonly string ConstructGeneratorAttributeName = "ConstructGeneratorAttribute";
+    private static readonly string GeneratePropertyAttributeName = "GeneratePropertyAttribute";
+
+    public void Initialize(IncrementalGeneratorInitializationContext context)
+    {
+        GenerateAttribute(ConstructGeneratorAttributeName, "Class", context);
+        GenerateAttribute(GeneratePropertyAttributeName, "Property", context);
+
+        var provider = context.SyntaxProvider
+            .CreateSyntaxProvider(
+                (s, _) => s is ClassDeclarationSyntax,
+                (ctx, _) => GetClassDeclarationForSourceGen(ctx))
+            .Where(t => t.reportAttributeFound)
+            .Select((t, _) => t.Item1);
+
+        context.RegisterSourceOutput(context.CompilationProvider.Combine(provider.Collect()),
+            (ctx, t) => GenerateCode(ctx, t.Left, t.Right));
+    }
+
+    private static void GenerateAttribute(string attributeName, string usage,
+        IncrementalGeneratorInitializationContext context)
+    {
+        var attributeSourceCode = $@"// <auto-generated/>
+
+namespace SourceGen
+{{
+    [System.AttributeUsage(System.AttributeTargets.{usage})]
+    public class {attributeName} : System.Attribute
+    {{
+    }}
+}}";
+
+        context.RegisterPostInitializationOutput(ctx => ctx.AddSource(
+            $"{attributeName}.g.cs",
+            SourceText.From(attributeSourceCode, Encoding.UTF8)));
+    }
+
+    private static (ClassDeclarationSyntax, bool reportAttributeFound) GetClassDeclarationForSourceGen(
+        GeneratorSyntaxContext context)
+    {
+        var classDeclarationSyntax = (ClassDeclarationSyntax)context.Node;
+
+        foreach (var attributeListSyntax in classDeclarationSyntax.AttributeLists)
+        foreach (var attributeSyntax in attributeListSyntax.Attributes)
+        {
+            if (context.SemanticModel.GetSymbolInfo(attributeSyntax).Symbol is not IMethodSymbol attributeSymbol)
+                continue;
+
+            var attributeName = attributeSymbol.ContainingType.ToDisplayString();
+
+            if (attributeName == $"SourceGen.{ConstructGeneratorAttributeName}")
+                return (classDeclarationSyntax, true);
+        }
+
+        return (classDeclarationSyntax, false);
+    }
+
+    private void GenerateCode(SourceProductionContext context, Compilation compilation,
+        ImmutableArray<ClassDeclarationSyntax> classDeclarations)
+    {
+        foreach (var classDeclarationSyntax in classDeclarations)
+        {
+            var semanticModel = compilation.GetSemanticModel(classDeclarationSyntax.SyntaxTree);
+            if (semanticModel.GetDeclaredSymbol(classDeclarationSyntax) is not INamedTypeSymbol classSymbol)
+                continue;
+
+            var namespaceName = classSymbol.ContainingNamespace.ToDisplayString();
+            var className = classDeclarationSyntax.Identifier.Text;
+            
+            var defaultConstruct = $@"public {className}(){{}}";
+            
+            var propertiesGenerated = GetProperties(classSymbol).ToList();
+            
+            var constr = propertiesGenerated.Select(a => $"{a.Type.ToDisplayString()} g{a.Name}");
+            var body = propertiesGenerated.Select(a => $"this.{a.Name} = g{a.Name};");
+
+            if (!constr.Any()) defaultConstruct = "";
+            
+            var code = $@"// <auto-generated/>
+
+using System;
+using System.Collections.Generic;
+
+namespace {namespaceName};
+
+partial class {className}
+{{
+    
+    {defaultConstruct}
+    public {className}(
+        {string.Join(",\n\t\t", constr)}
+    ) : base(){{
+        {string.Join("\n\t\t", body)}
+        if (Avalonia.Controls.Design.IsDesignMode) InitialiseInDesignMode();
+                else Initialise();
+    }}
+}}
+            ";
+
+            // Add the source code to the compilation.
+            context.AddSource($"{className}.g.cs", SourceText.From(code, Encoding.UTF8));
+        }
+    }
+
+    private static IEnumerable<IPropertySymbol> GetProperties(INamedTypeSymbol classSymbol)
+    {
+        return  classSymbol.GetMembers().OfType<IPropertySymbol>().Where(a =>
+            HasAttribute(a, $"SourceGen.{GeneratePropertyAttributeName}"));
+    }
+
+    private static bool HasAttribute(ISymbol type, string attributeName)
+    {
+        foreach (var attribute in type.GetAttributes())
+            if (attribute.AttributeClass?.ToDisplayString() == attributeName)
+                return true;
+
+        return false;
+    }
+}