using System.Text;
using Microsoft.CodeAnalysis;

namespace Polonium.Generators.Generators;
[Generator]
public class GlobalRegistryGenerator : ISourceGenerator
{
    public void Initialize(GeneratorInitializationContext context)
    {
    }

    public void Execute(GeneratorExecutionContext context)
    {
        StringBuilder sb = new();
        sb
            .AppendLine("using Godot;")
            .AppendLine("using System;")
            .AppendLine("using System.Collections.Generic;")
            .AppendLine("using System.Linq;")
            .AppendLine("using System.Reflection;")
            .AppendLine("using Polonium.Attributes;")
            .AppendLine("using Polonium;")
            .AppendLine("using Polonium.Interfaces;")
            .AppendLine("public static partial class GlobalRegistry")
            .AppendLine("{")
            .AppendLine("    public static void Start()")
            .AppendLine("    {")
            .AppendLine("        PoloniumRegistry.Prepare();")
            .AppendLine("        Assembly assembly = Assembly.GetExecutingAssembly();")
            .AppendLine("        IEnumerable<Type> registerTypes = Utils.GetLoadableTypes(assembly);")
            .AppendLine("        registerTypes = registerTypes.Where(t => t.IsClass && t.GetCustomAttributes(typeof(AutoRegister), false).Any());")
            .AppendLine("        foreach(Type t in registerTypes)")
            .AppendLine("        {")
            .AppendLine("            MethodInfo registerMethod = t.GetMethod(\"Register\", BindingFlags.Static | BindingFlags.Public);")
            .AppendLine("            if (registerMethod != null)")
            .AppendLine("                registerMethod.Invoke(null, null);")
            .AppendLine("        }")
            .AppendLine("    }")
            .AppendLine("    public static class Asset<T> where T : Node")
            .AppendLine("    {")
            .AppendLine("        private static readonly Queue<T> Pool = new();")
            .AppendLine("        public static PackedScene Scene { get; set; }")
            .AppendLine("        public static T Instance => Scene.Instantiate<T>();")
            .AppendLine("        public static T Get() => Pool.Count > 0 ? Pool.Dequeue() : Instance;")
            .AppendLine("        public static void Return(T obj)")
            .AppendLine("        {")
            .AppendLine("            if(Pool.Count < 10)")
            .AppendLine("                Pool.Enqueue(obj);")
            .AppendLine("            else")
            .AppendLine("                obj.QueueFree();")
            .AppendLine("        }")
            .AppendLine("    }")
            .AppendLine("    public static PoloniumRegistry PoloniumRegistry => PoloniumRegistry.Instance;")
            .AppendLine("    public static bool Paused { get; set; }")
            .AppendLine("    public static HashSet<ITimeConsumer> TimeConsumers { get; } = new ();")
            .AppendLine("}");
        context.AddSource("GlobalRegistry.g.cs", sb.ToString());
    }
}