using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using Mono.Cecil;
using Mono.Cecil.Cil;

namespace SuppressTransformDestroy.Patcher
{
    public static class FixDestroyImmediatePatcher
    {
        public static string[] TargetAssemblyNames = {"UnityEngine.dll"};

        public static void Patch(AssemblyDefinition def)
        {
            
            AssemblyDefinition hooksAd;
            try
            {
                hooksAd = AssemblyDefinition.ReadAssembly(Path.Combine(
                    Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location), "SuppressTransformDestroy.Managed.dll"));
            }
            catch (Exception)
            {
                return;
            }

            var hooksTd = hooksAd.MainModule.GetType("SuppressTransformDestroy.Managed.DestroyFixer");
            var destroyImmediateHook = hooksTd.Methods.FirstOrDefault(m => m.Name == "DestroyCustomImmediate");

            var md = def.MainModule;
            var objTd = md.GetType("UnityEngine.Object");

            var destroyImmediate =
                objTd.Methods.FirstOrDefault(m => m.Name == "DestroyImmediate" && m.Parameters.Count == 1);

            if (destroyImmediate == null)
                return;

            var il = destroyImmediate.Body.GetILProcessor();
            var ins = destroyImmediate.Body.Instructions[0];

            il.InsertBefore(ins, il.Create(OpCodes.Ldarga, destroyImmediate.Parameters[0]));
            il.InsertBefore(ins, il.Create(OpCodes.Call, md.ImportReference(destroyImmediateHook)));
        }
    }
}