using System.Linq;
using System.Text;
using Microsoft.CodeAnalysis;

namespace Polonium.Generators.Generators;
[Generator]
public class RegistryEntityGenerator : AssetProcessGenerator
{
    public override void Execute(GeneratorExecutionContext context)
    {
        if (!(context.SyntaxReceiver is ClassSyntaxReceiver receiver))
            return;
        Compilation compilation = context.Compilation;
        INamedTypeSymbol? regEntity = compilation.GetTypeByMetadataName("Polonium.Attributes.RegistryEntity");
        foreach (var derivedClassDeclaration in receiver.Classes)
        {
            SemanticModel model = compilation.GetSemanticModel(derivedClassDeclaration.SyntaxTree);
            if (
                model.GetDeclaredSymbol(derivedClassDeclaration) is INamedTypeSymbol symbol && 
                symbol.GetAttributes().Any(x => SymbolEqualityComparer.Default.Equals(x.AttributeClass, regEntity))
                )
            {
                StringBuilder sb = new();
                sb
                    .AppendLine("public static partial class GlobalRegistry")
                    .AppendLine("{")
                    .AppendLine($"    public static {symbol.ToDisplayString()} {symbol.Name} {{ get; set; }}  ")
                    .AppendLine("}");
                context.AddSource($"RegistryEntity_{symbol.Name}.g.cs", sb.ToString());
            }
        }
    }
}