using System;
using System.Collections.Immutable;
using System.IO;
using System.Linq;
using System.Text;
using Microsoft.CodeAnalysis;

namespace Polonium.Generators.Generators;
[Generator]
public class AssetRegisterGenerator : AssetProcessGenerator
{
    public override void Execute(GeneratorExecutionContext context)
    {
        if (!(context.SyntaxReceiver is ClassSyntaxReceiver receiver))
            return;
        Compilation compilation = context.Compilation;
        StringBuilder sb = new();
        sb
            .AppendLine("using System;")
            .AppendLine("using Godot;")
            .AppendLine("using Polonium;")
            .AppendLine("using Polonium.Attributes;")
            .AppendLine("[AutoRegister]")
            .AppendLine("public static class AssetRegister")
            .AppendLine("{")
            .AppendLine("    public static void Register()")
            .AppendLine("    {");
        foreach (var derivedClassDeclaration in receiver.Classes)
        {
            SemanticModel model = compilation.GetSemanticModel(derivedClassDeclaration.SyntaxTree);
            INamedTypeSymbol? symbol = model.GetDeclaredSymbol(derivedClassDeclaration) as INamedTypeSymbol;
            string filePath = derivedClassDeclaration.SyntaxTree.FilePath.Replace(".cs", ".tscn");
            if(!filePath.Contains("Assets") || symbol == null)
                continue;
            ImmutableArray<AdditionalText> additionalFiles = context.AdditionalFiles;
            if (additionalFiles.Select(y => y.Path).Contains(filePath))
            {
                string rs = filePath.Replace("\\", "/").Replace(" ", "%20");
                rs = rs.Substring(rs.IndexOf("Assets", StringComparison.Ordinal));
                string gdPath = "res://" + rs;
                string className = Path.GetFileNameWithoutExtension(filePath);
                sb
                    .AppendLine(
                        $"        PoloniumRegistry.Asset<{className}>.Scene = ResourceLoader.Load<PackedScene>(\"{gdPath}\");"
                    );
            }
        }
        sb
            .AppendLine("    }")
            .AppendLine("}");
        context.AddSource("AssetRegistry.g.cs", sb.ToString());
    }
}