﻿
using System;
using JetBrains.Annotations;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.IO;
using System.Linq;
using System.Reflection;
using UdonSharp;
using UdonSharp.Compiler;
using UdonSharp.Serialization;
using UdonSharp.Updater;
using UnityEditor;
using UnityEngine;
using UnityEngine.Profiling;
using VRC.Udon;
using VRC.Udon.Common;
using VRC.Udon.Common.Interfaces;
using VRC.Udon.Serialization.OdinSerializer.Utilities;
using Object = UnityEngine.Object;

namespace UdonSharpEditor
{
    /// <summary>
    /// Stored on the backing UdonBehaviour
    /// </summary>
    internal enum UdonSharpBehaviourVersion
    {
        V0,
        V0DataUpgradeNeeded,
        V1,
        NextVer,
        CurrentVersion = NextVer - 1,
    }
    
    /// <summary>
    /// Various utility functions for interacting with U# behaviours and proxies for editor scripting.
    /// </summary>
    public static class UdonSharpEditorUtility
    {
        /// <summary>
        /// Deletes an UdonSharp program asset and the serialized program asset associated with it
        /// </summary>
        [PublicAPI]
        public static void DeleteProgramAsset(UdonSharpProgramAsset programAsset)
        {
            if (programAsset == null)
                return;

            AbstractSerializedUdonProgramAsset serializedAsset = programAsset.GetSerializedUdonProgramAsset();

            if (serializedAsset != null)
            {
                string assetPath = AssetDatabase.GetAssetPath(serializedAsset);
                serializedAsset = AssetDatabase.LoadAssetAtPath<AbstractSerializedUdonProgramAsset>(assetPath);

                if (serializedAsset != null)
                {
                    AssetDatabase.DeleteAsset(assetPath);
                }
            }

            string programAssetPath = AssetDatabase.GetAssetPath(programAsset);

            programAsset = AssetDatabase.LoadAssetAtPath<UdonSharpProgramAsset>(programAssetPath);

            if (programAsset != null)
                AssetDatabase.DeleteAsset(programAssetPath);
        }

        /// <summary>
        /// Converts a set of UdonSharpBehaviour components to their equivalent UdonBehaviour components
        /// </summary>
        [Obsolete("ConvertToUdonBehaviours is no longer supported, if you want to add a new U# component use UdonSharpEditorUtility.AddComponent", true)]
        public static UdonBehaviour[] ConvertToUdonBehaviours(UdonSharpBehaviour[] components, bool convertChildren = false)
        {
            throw new NotImplementedException();
        }

        /// <summary>
        /// Converts a set of UdonSharpBehaviour components to their equivalent UdonBehaviour components
        /// Registers an Undo operation for the conversion
        /// </summary>
        /// <returns></returns>
        [Obsolete("ConvertToUdonBehavioursWithUndo is no longer supported, if you want to add a new U# component use UdonSharpUndo.AddComponent", true)]
        public static UdonBehaviour[] ConvertToUdonBehavioursWithUndo(UdonSharpBehaviour[] components, bool convertChildren = false)
        {
            throw new NotImplementedException();
        }

        private static Dictionary<MonoScript, UdonSharpProgramAsset> _programAssetLookup;
        private static Dictionary<Type, UdonSharpProgramAsset> _programAssetTypeLookup;
        
        private static void InitTypeLookups()
        {
            if (_programAssetLookup != null) 
                return;
            
            _programAssetLookup = new Dictionary<MonoScript, UdonSharpProgramAsset>();
            _programAssetTypeLookup = new Dictionary<Type, UdonSharpProgramAsset>();

            UdonSharpProgramAsset[] udonSharpProgramAssets = UdonSharpProgramAsset.GetAllUdonSharpPrograms();

            foreach (UdonSharpProgramAsset programAsset in udonSharpProgramAssets)
            {
                if (programAsset && programAsset.sourceCsScript != null && !_programAssetLookup.ContainsKey(programAsset.sourceCsScript))
                {
                    _programAssetLookup.Add(programAsset.sourceCsScript, programAsset);
                    if (programAsset.GetClass() != null)
                        _programAssetTypeLookup.Add(programAsset.GetClass(), programAsset);
                }
            }
        }

        internal static void ResetCaches()
        {
            _programAssetLookup = null;
            _programAssetTypeLookup = null;
        }

        public static void ResetAssemblyCaches()
        {
            UdonSharpUtils.ResetAssemblyCaches();
        }

        private static UdonSharpProgramAsset GetUdonSharpProgramAsset(MonoScript programScript)
        {
            InitTypeLookups();

            _programAssetLookup.TryGetValue(programScript, out var foundProgramAsset);

            return foundProgramAsset;
        }

        /// <summary>
        /// Gets the UdonSharpProgramAsset that represents the program for the given UdonSharpBehaviour
        /// </summary>
        /// <param name="udonSharpBehaviour"></param>
        /// <returns></returns>
        [PublicAPI]
        public static UdonSharpProgramAsset GetUdonSharpProgramAsset(UdonSharpBehaviour udonSharpBehaviour)
        {
            return GetUdonSharpProgramAsset(MonoScript.FromMonoBehaviour(udonSharpBehaviour));
        }

        [PublicAPI]
        public static UdonSharpProgramAsset GetUdonSharpProgramAsset(Type type)
        {
            InitTypeLookups();

            _programAssetTypeLookup.TryGetValue(type, out UdonSharpProgramAsset foundProgramAsset);

            return foundProgramAsset;
        }

        [PublicAPI]
        public static UdonSharpProgramAsset GetUdonSharpProgramAsset(UdonBehaviour udonBehaviour)
        {
            if (!IsUdonSharpBehaviour(udonBehaviour))
                return null;

            return (UdonSharpProgramAsset)udonBehaviour.programSource;
        }

        internal const string BackingFieldName = "_udonSharpBackingUdonBehaviour";

        private static readonly FieldInfo _backingBehaviourField = typeof(UdonSharpBehaviour).GetField(BackingFieldName, BindingFlags.NonPublic | BindingFlags.Instance);

        /// <summary>
        /// Gets the backing UdonBehaviour for a proxy
        /// </summary>
        /// <param name="behaviour"></param>
        /// <returns></returns>
        [PublicAPI]
        public static UdonBehaviour GetBackingUdonBehaviour(UdonSharpBehaviour behaviour)
        {
            return (UdonBehaviour)_backingBehaviourField.GetValue(behaviour);
        }

        internal static void SetBackingUdonBehaviour(UdonSharpBehaviour behaviour, UdonBehaviour backingBehaviour)
        {
            _backingBehaviourField.SetValue(behaviour, backingBehaviour);
        }

        private const string UDONSHARP_BEHAVIOUR_VERSION_KEY = "___UdonSharpBehaviourVersion___";
        private const string UDONSHARP_BEHAVIOUR_UPGRADE_MARKER = "___UdonSharpBehaviourPersistDataFromUpgrade___";
        private const string UDONSHARP_SCENE_BEHAVIOUR_UPGRADE_MARKER = "___UdonSharpBehaviourHasDoneSceneUpgrade___";

        private static bool ShouldPersistVariable(string variableSymbol)
        {
            return variableSymbol == UDONSHARP_BEHAVIOUR_VERSION_KEY ||
                   variableSymbol == UDONSHARP_BEHAVIOUR_UPGRADE_MARKER ||
                   variableSymbol == UDONSHARP_SCENE_BEHAVIOUR_UPGRADE_MARKER;
        }

        internal static UdonSharpBehaviourVersion GetBehaviourVersion(UdonBehaviour behaviour)
        {
            if (behaviour.publicVariables.TryGetVariableValue<int>(UDONSHARP_BEHAVIOUR_VERSION_KEY, out int val))
                return (UdonSharpBehaviourVersion)val;
            
            return UdonSharpBehaviourVersion.V0;
        }

        internal static void SetBehaviourVersion(UdonBehaviour behaviour, UdonSharpBehaviourVersion version)
        {
            UdonSharpBehaviourVersion lastVer = GetBehaviourVersion(behaviour);

            if (lastVer == version && lastVer != UdonSharpBehaviourVersion.V0)
                return;
            
            bool setVer = behaviour.publicVariables.TrySetVariableValue<int>(UDONSHARP_BEHAVIOUR_VERSION_KEY, (int)version);

            if (!setVer)
            {
                behaviour.publicVariables.RemoveVariable(UDONSHARP_BEHAVIOUR_VERSION_KEY);
                IUdonVariable newVar = new UdonVariable<int>(UDONSHARP_BEHAVIOUR_VERSION_KEY, (int)version);
                setVer = behaviour.publicVariables.TryAddVariable(newVar);
            }

            if (setVer)
            {
                UdonSharpUtils.SetDirty(behaviour);
                return;
            }
            
            UdonSharpUtils.LogError("Could not set version variable");
        }

        private static bool BehaviourRequiresBackwardsCompatibilityPersistence(UdonBehaviour behaviour)
        {
            if (behaviour.publicVariables.TryGetVariableValue<bool>(UDONSHARP_BEHAVIOUR_UPGRADE_MARKER, out bool needsBackwardsCompat) && PrefabUtility.IsPartOfPrefabAsset(behaviour))
                return needsBackwardsCompat;

            return false;
        }

        internal static void ClearBehaviourVariables(UdonBehaviour behaviour, bool clearPersistentVariables = false)
        {
            foreach (string publicVarSymbol in behaviour.publicVariables.VariableSymbols.ToArray()) // ToArray so we don't modify the collection while iterating it
            {
                if (!clearPersistentVariables && ShouldPersistVariable(publicVarSymbol))
                    continue;
                
                behaviour.publicVariables.RemoveVariable(publicVarSymbol);
            }
        }

        private static void SetBehaviourUpgraded(UdonBehaviour behaviour)
        {
            if (!PrefabUtility.IsPartOfPrefabAsset(behaviour))
                return;

            if (!behaviour.publicVariables.TrySetVariableValue<bool>(UDONSHARP_BEHAVIOUR_UPGRADE_MARKER, true))
            {
                behaviour.publicVariables.RemoveVariable(UDONSHARP_BEHAVIOUR_UPGRADE_MARKER);
                
                IUdonVariable newVar = new UdonVariable<bool>(UDONSHARP_BEHAVIOUR_UPGRADE_MARKER, true);
                behaviour.publicVariables.TryAddVariable(newVar);
            }
            
            UdonSharpUtils.SetDirty(behaviour);
        }

        internal static void SetSceneBehaviourUpgraded(UdonBehaviour behaviour)
        {
            if (!PrefabUtility.IsPartOfPrefabInstance(behaviour) && !PrefabUtility.IsPartOfPrefabAsset(behaviour))
                return;
            
            if (!behaviour.publicVariables.TrySetVariableValue<bool>(UDONSHARP_SCENE_BEHAVIOUR_UPGRADE_MARKER, true))
            {
                behaviour.publicVariables.RemoveVariable(UDONSHARP_SCENE_BEHAVIOUR_UPGRADE_MARKER);
                
                IUdonVariable newVar = new UdonVariable<bool>(UDONSHARP_SCENE_BEHAVIOUR_UPGRADE_MARKER, true);
                behaviour.publicVariables.TryAddVariable(newVar);
            }
            
            UdonSharpUtils.SetDirty(behaviour);
        }

        private static bool HasSceneBehaviourUpgradeFlag(UdonBehaviour behaviour)
        {
            return behaviour.publicVariables.TryGetVariableValue<bool>(UDONSHARP_SCENE_BEHAVIOUR_UPGRADE_MARKER, out bool sceneBehaviourUpgraded) && sceneBehaviourUpgraded;
        }

        private static readonly FieldInfo _publicVariablesBytesStrField = typeof(UdonBehaviour)
            .GetFields(BindingFlags.NonPublic | BindingFlags.Instance)
            .First(fieldInfo => fieldInfo.Name == "serializedPublicVariablesBytesString");

        private static readonly FieldInfo _publicVariablesObjectReferences = typeof(UdonBehaviour)
            .GetFields(BindingFlags.NonPublic | BindingFlags.Instance)
            .First(e => e.Name == "publicVariablesUnityEngineObjects");

        /// <summary>
        /// Runs a two pass upgrade of a set of prefabs, assumes all dependencies of the prefabs are included, otherwise the process could fail to maintain references.
        /// First creates a new UdonSharpBehaviour proxy script and hooks it to a given UdonBehaviour. Then in a second pass goes over all behaviours and serializes their data into the C# proxy and wipes their old data out.
        /// </summary>
        /// <param name="prefabRootEnumerable"></param>
        internal static void UpgradePrefabs(IEnumerable<GameObject> prefabRootEnumerable)
        {
            if (UdonSharpProgramAsset.IsAnyProgramAssetSourceDirty() ||
                UdonSharpProgramAsset.IsAnyProgramAssetOutOfDate())
            {
                UdonSharpCompilerV1.CompileSync();
            }
            
            List<GameObject> prefabRoots = new List<GameObject>();

            // Skip upgrades on any intermediate prefab assets which may be considered invalid during the build process, mostly to avoid spamming people's console with logs that may be confusing but also gives slightly faster builds.
            string intermediatePrefabPath = UdonSharpLocator.IntermediatePrefabPath.Replace("\\", "/");
            
            foreach (GameObject prefabRoot in prefabRootEnumerable)
            {
                string prefabPath = AssetDatabase.GetAssetPath(prefabRoot);
                if (prefabPath.StartsWith(intermediatePrefabPath))
                {
                    continue;
                }
                
                prefabRoots.Add(prefabRoot);
            }

            bool NeedsNewProxy(UdonBehaviour udonBehaviour)
            {
                if (!IsUdonSharpBehaviour(udonBehaviour))
                    return false;

                if (GetProxyBehaviour(udonBehaviour))
                    return false;
                
                return true;
            }

            bool NeedsSerializationUpgrade(UdonBehaviour udonBehaviour)
            {
                if (!IsUdonSharpBehaviour(udonBehaviour))
                    return false;
                
                if (NeedsNewProxy(udonBehaviour))
                    return true;

                if (GetBehaviourVersion(udonBehaviour) == UdonSharpBehaviourVersion.V0DataUpgradeNeeded)
                    return true;
                
                return false;
            }

            HashSet<string> phase1FixupPrefabRoots = new HashSet<string>();

            // Phase 1 Pruning - Add missing proxy behaviours
            foreach (GameObject prefabRoot in prefabRoots)
            {
                if (!prefabRoot.GetComponentsInChildren<UdonBehaviour>(true).Any(NeedsNewProxy)) 
                    continue;
                
                string prefabPath = AssetDatabase.GetAssetPath(prefabRoot);

                if (!prefabPath.IsNullOrWhitespace())
                    phase1FixupPrefabRoots.Add(prefabPath);
            }

            HashSet<string> phase2FixupPrefabRoots = new HashSet<string>(phase1FixupPrefabRoots);

            // Phase 2 Pruning - Check for behaviours that require their data ownership to be transferred Udon -> C#
            foreach (GameObject prefabRoot in prefabRoots)
            {
                foreach (UdonBehaviour udonBehaviour in prefabRoot.GetComponentsInChildren<UdonBehaviour>(true))
                {
                    if (NeedsSerializationUpgrade(udonBehaviour))
                    {
                        string prefabPath = AssetDatabase.GetAssetPath(prefabRoot);

                        if (!prefabPath.IsNullOrWhitespace())
                            phase2FixupPrefabRoots.Add(prefabPath);

                        break;
                    }
                }
            }
            
            // Now we have a set of prefabs that we can actually load and run the two upgrade phases on.
            // Todo: look at merging the two passes since we don't actually need to load prefabs into scenes apparently

            // Early out and avoid the edit scope
            if (phase1FixupPrefabRoots.Count == 0 && phase2FixupPrefabRoots.Count == 0)
                return;
            
            UdonSharpPrefabDAG prefabDag = new UdonSharpPrefabDAG(prefabRoots);

            // Walk up from children -> parents and mark prefab deltas on all U# behaviours to be upgraded
            // Prevents versioning from being overwritten when a parent prefab is upgraded
            foreach (string prefabPath in prefabDag.Reverse())
            {
                GameObject prefabRoot = PrefabUtility.LoadPrefabContents(prefabPath);

                bool needsSave = false;

                try
                {
                    HashSet<UdonBehaviour> behavioursToPrepare = new HashSet<UdonBehaviour>();
                    
                    foreach (UdonBehaviour behaviour in prefabRoot.GetComponentsInChildren<UdonBehaviour>(true))
                    {
                        if (PrefabUtility.GetCorrespondingObjectFromSource(behaviour) != behaviour && (NeedsNewProxy(behaviour) || NeedsSerializationUpgrade(behaviour)))
                        {
                            behavioursToPrepare.Add(behaviour);
                        }
                    }
                    
                    // Deltas are stored per-prefab-instance-root in a given prefab, don't question it. Thanks.
                    // We take care to not accidentally hit any non-U#-behaviour deltas here
                    // These APIs are not documented properly at all and the only mentions of them on forum posts are how they don't work with no solutions posted :))))
                    if (behavioursToPrepare.Count > 0)
                    {
                        HashSet<GameObject> rootGameObjects = new HashSet<GameObject>();

                        foreach (UdonBehaviour behaviourToPrepare in behavioursToPrepare)
                        {
                            GameObject rootPrefab = PrefabUtility.GetOutermostPrefabInstanceRoot(behaviourToPrepare);

                            rootGameObjects.Add(rootPrefab ? rootPrefab : behaviourToPrepare.gameObject);
                        }
                        
                        HashSet<Object> originalObjects = new HashSet<Object>(behavioursToPrepare.Select(PrefabUtility.GetCorrespondingObjectFromOriginalSource));

                        foreach (UdonBehaviour behaviour in behavioursToPrepare)
                        {
                            UdonBehaviour currentBehaviour = behaviour;
                        
                            while (currentBehaviour)
                            {
                                originalObjects.Add(currentBehaviour);
                                
                                UdonBehaviour newBehaviour = PrefabUtility.GetCorrespondingObjectFromSource(currentBehaviour);
                        
                                currentBehaviour = newBehaviour != currentBehaviour ? newBehaviour : null;
                            }
                        }

                        foreach (GameObject rootGameObject in rootGameObjects)
                        {
                            List<PropertyModification> propertyModifications = PrefabUtility.GetPropertyModifications(rootGameObject)?.ToList();

                            if (propertyModifications != null)
                            {
                                propertyModifications = propertyModifications.Where(
                                    modification =>
                                    {
                                        if (modification.target == null)
                                        {
                                            return true;
                                        }
                                        
                                        if (!originalObjects.Contains(modification.target))
                                        {
                                            return true;
                                        }
                                    
                                        if (modification.propertyPath == "serializedPublicVariablesBytesString" ||
                                            modification.propertyPath.StartsWith("publicVariablesUnityEngineObjects", StringComparison.Ordinal))
                                        {
                                            // UdonSharpUtils.Log($"Removed property override for {modification.propertyPath} on {modification.target}");
                                            return false;
                                        }

                                        return true;
                                    }).ToList();
                                
                                // UdonSharpUtils.Log($"Modifications found on {rootGameObject}");
                            }
                            else
                            {
                                propertyModifications = new List<PropertyModification>();
                            }

                            foreach (UdonBehaviour behaviour in rootGameObject.GetComponentsInChildren<UdonBehaviour>(true))
                            {
                                if (!behavioursToPrepare.Contains(behaviour))
                                {
                                    continue;
                                }

                                UdonBehaviour originalBehaviour = PrefabUtility.GetCorrespondingObjectFromSource(behaviour);
                                
                                propertyModifications.Add(new PropertyModification()
                                {
                                    target = originalBehaviour, 
                                    propertyPath = "serializedPublicVariablesBytesString",
                                    value = (string)_publicVariablesBytesStrField.GetValue(behaviour)
                                });

                                List<Object> objectRefs = (List<Object>)_publicVariablesObjectReferences.GetValue(behaviour);

                                propertyModifications.Add(new PropertyModification()
                                {
                                    target = originalBehaviour, 
                                    propertyPath = "publicVariablesUnityEngineObjects.Array.size",
                                    value = objectRefs.Count.ToString()
                                });

                                for (int i = 0; i < objectRefs.Count; ++i)
                                {
                                    propertyModifications.Add(new PropertyModification()
                                    {
                                        target = originalBehaviour,
                                        propertyPath = $"publicVariablesUnityEngineObjects.Array.data[{i}]",
                                        objectReference = objectRefs[i], 
                                        value = ""
                                    });
                                }
                            }

                            PrefabUtility.SetPropertyModifications(rootGameObject, propertyModifications.ToArray());
                            EditorUtility.SetDirty(rootGameObject);

                            needsSave = true;
                        }
                        
                        // UdonSharpUtils.Log($"Marking delta on prefab {prefabRoot} because it is not the original definition.");
                    }
                    
                    if (needsSave)
                    {
                        PrefabUtility.SaveAsPrefabAsset(prefabRoot, prefabPath);
                    }
                }
                finally
                {
                    PrefabUtility.UnloadPrefabContents(prefabRoot);
                }
            }
            
            if (phase2FixupPrefabRoots.Count > 0)
                UdonSharpUtils.Log($"Running upgrade process on {phase2FixupPrefabRoots.Count} prefabs: {string.Join(", ", phase2FixupPrefabRoots.Select(Path.GetFileName))}");
            
            foreach (string prefabRootPath in prefabDag)
            {
                if (!phase1FixupPrefabRoots.Contains(prefabRootPath))
                {
                    continue;
                }

                GameObject prefabRoot = PrefabUtility.LoadPrefabContents(prefabRootPath);

                try
                {
                    bool needsSave = false;
                    
                    foreach (UdonBehaviour udonBehaviour in prefabRoot.GetComponentsInChildren<UdonBehaviour>(true))
                    {
                        if (!NeedsNewProxy(udonBehaviour))
                        {
                            if (GetBehaviourVersion(udonBehaviour) == UdonSharpBehaviourVersion.V0)
                            {
                                SetBehaviourVersion(udonBehaviour, UdonSharpBehaviourVersion.V0DataUpgradeNeeded);
                                needsSave = true;
                            }
                            
                            continue;
                        }

                        UdonSharpBehaviour newProxy = (UdonSharpBehaviour)udonBehaviour.gameObject.AddComponent(GetUdonSharpBehaviourType(udonBehaviour));
                        newProxy.enabled = udonBehaviour.enabled;

                        SetBackingUdonBehaviour(newProxy, udonBehaviour);

                        MoveComponentRelativeToComponent(newProxy, udonBehaviour, true);

                        SetBehaviourVersion(udonBehaviour, UdonSharpBehaviourVersion.V0DataUpgradeNeeded);

                        UdonSharpUtils.SetDirty(udonBehaviour);
                        UdonSharpUtils.SetDirty(newProxy);

                        needsSave = true;
                    }

                    if (needsSave)
                    {
                        PrefabUtility.SaveAsPrefabAsset(prefabRoot, prefabRootPath);
                    }

                    // UdonSharpUtils.Log($"Ran prefab upgrade phase 1 on {prefabRoot}");
                }
                catch (Exception e)
                {
                    UdonSharpUtils.LogError($"Encountered exception while upgrading prefab {prefabRootPath}: {e}");
                }
                finally
                {
                    PrefabUtility.UnloadPrefabContents(prefabRoot);
                }
            }

            foreach (string prefabRootPath in prefabDag)
            {
                if (!phase2FixupPrefabRoots.Contains(prefabRootPath))
                {
                    continue;
                }

                GameObject prefabRoot = PrefabUtility.LoadPrefabContents(prefabRootPath);

                try
                {
                    foreach (UdonBehaviour udonBehaviour in prefabRoot.GetComponentsInChildren<UdonBehaviour>(true))
                    {
                        if (!NeedsSerializationUpgrade(udonBehaviour))
                            continue;

                        CopyUdonToProxy(GetProxyBehaviour(udonBehaviour), ProxySerializationPolicy.RootOnly);

                        // We can't remove this data for backwards compatibility :'(
                        // If we nuke the data, the unity object array on the underlying storage may change.
                        // Which means that if people have copies of this prefab in the scene with no object reference changes, their data will also get nuked which we do not want.
                        // Public variable data on the prefabs will never be touched again by U# after upgrading
                        // We will probably provide an optional upgrade process that strips this extra data, and takes into account all scenes in the project

                        // foreach (string publicVarSymbol in udonBehaviour.publicVariables.VariableSymbols.ToArray())
                        //     udonBehaviour.publicVariables.RemoveVariable(publicVarSymbol);

                        SetBehaviourVersion(udonBehaviour, UdonSharpBehaviourVersion.V1);
                        SetBehaviourUpgraded(udonBehaviour);

                        UdonSharpUtils.SetDirty(udonBehaviour);
                        UdonSharpUtils.SetDirty(GetProxyBehaviour(udonBehaviour));
                    }

                    PrefabUtility.SaveAsPrefabAsset(prefabRoot, prefabRootPath);

                    // UdonSharpUtils.Log($"Ran prefab upgrade phase 2 on {prefabRoot}");
                }
                catch (Exception e)
                {
                    UdonSharpUtils.LogError($"Encountered exception while upgrading prefab {prefabRootPath}: {e}");
                }
                finally
                {
                    PrefabUtility.UnloadPrefabContents(prefabRoot);
                }
            }
            
            UdonSharpUtils.Log("Prefab upgrade pass finished");
        }
        
        internal static void UpgradeSceneBehaviours(IEnumerable<UdonBehaviour> behaviours)
        {
            if (EditorApplication.isPlaying)
                return;

            if (UdonSharpUtils.DoesUnityProjectHaveCompileErrors())
            {
                UdonSharpUtils.LogError("C# scripts have compile errors, cannot run scene upgrade.");
                return;
            }
            
            UdonSharpProgramAsset.CompileAllCsPrograms();
            UdonSharpCompilerV1.WaitForCompile();
                
            if (UdonSharpProgramAsset.AnyUdonSharpScriptHasError())
            {
                // Give chance to compile and resolve errors in case they are fixed already
                UdonSharpCompilerV1.CompileSync();
                    
                if (UdonSharpProgramAsset.AnyUdonSharpScriptHasError())
                {
                    UdonSharpUtils.LogError("U# scripts have compile errors, scene upgrade deferred until script errors are resolved.");
                    return;
                }
            }
            
            // Create proxies if they do not exist
            foreach (UdonBehaviour udonBehaviour in behaviours)
            {
                if (!IsUdonSharpBehaviour(udonBehaviour))
                    continue;
                
                if (PrefabUtility.IsPartOfPrefabInstance(udonBehaviour) &&
                    PrefabUtility.IsAddedComponentOverride(udonBehaviour))
                    continue;

                if (GetProxyBehaviour(udonBehaviour) == null)
                {
                    if (PrefabUtility.IsPartOfPrefabInstance(udonBehaviour) &&
                        PrefabUtility.GetCorrespondingObjectFromSource(udonBehaviour) != udonBehaviour)
                    {
                        UdonSharpUtils.LogError($"Cannot upgrade scene behaviour '{udonBehaviour}' since its prefab must be upgraded.", udonBehaviour);
                        continue;
                    }
                    
                    Type udonSharpBehaviourType = GetUdonSharpBehaviourType(udonBehaviour);

                    if (udonSharpBehaviourType == null)
                    {
                        UdonSharpUtils.LogError($"Class script referenced by program asset '{udonBehaviour.programSource}' has no Type", udonBehaviour.programSource);
                        continue;
                    }

                    if (!udonSharpBehaviourType.IsSubclassOf(typeof(UdonSharpBehaviour)))
                    {
                        UdonSharpUtils.LogError($"Class script referenced by program asset '{udonBehaviour.programSource}' is not an UdonSharpBehaviour", udonBehaviour.programSource);
                        continue;
                    }
                    
                    UdonSharpBehaviour newProxy = (UdonSharpBehaviour)udonBehaviour.gameObject.AddComponent(udonSharpBehaviourType);
                    newProxy.enabled = udonBehaviour.enabled;

                    SetBackingUdonBehaviour(newProxy, udonBehaviour);

                    if (!PrefabUtility.IsAddedComponentOverride(udonBehaviour))
                    {
                        MoveComponentRelativeToComponent(newProxy, udonBehaviour, true);
                    }
                    else
                    {
                        UdonSharpUtils.LogWarning($"Cannot reorder internal UdonBehaviour for '{udonBehaviour}' during upgrade because it is on a prefab instance.", udonBehaviour.gameObject);
                    }

                    UdonSharpUtils.SetDirty(newProxy);
                }
                
                if (GetBehaviourVersion(udonBehaviour) == UdonSharpBehaviourVersion.V0)
                    SetBehaviourVersion(udonBehaviour, UdonSharpBehaviourVersion.V0DataUpgradeNeeded);
            }

            // Copy data over from UdonBehaviour to UdonSharpBehaviour
            foreach (UdonBehaviour udonBehaviour in behaviours)
            {
                if (!IsUdonSharpBehaviour(udonBehaviour))
                    continue;
                
                bool needsPrefabInstanceUpgrade = false;

                // Checks if the version is below V1 or if it needs the prefab instance upgrade
                UdonSharpBehaviourVersion behaviourVersion = GetBehaviourVersion(udonBehaviour);
                if (behaviourVersion >= UdonSharpBehaviourVersion.V1)
                {
                    // Check if the prefab instance has a prefab that was upgraded causing the string data to be copied, but has a delta'd UnityEngine.Object storage array
                    if (PrefabUtility.IsPartOfPrefabInstance(udonBehaviour) &&
                        !HasSceneBehaviourUpgradeFlag(udonBehaviour))
                    {
                        UdonBehaviour prefabSource = PrefabUtility.GetCorrespondingObjectFromSource(udonBehaviour);
                    
                        if (prefabSource && BehaviourRequiresBackwardsCompatibilityPersistence(prefabSource))
                        {
                            PropertyModification[] modifications =
                                PrefabUtility.GetPropertyModifications(udonBehaviour);
                    
                            if (modifications != null &&
                                modifications.Any(e => e.propertyPath.StartsWith("publicVariablesUnityEngineObjects", StringComparison.Ordinal)))
                            {
                                needsPrefabInstanceUpgrade = true;
                            }
                        }
                    }

                    if (!needsPrefabInstanceUpgrade)
                        continue;
                }
                
                UdonSharpBehaviour proxy = GetProxyBehaviour(udonBehaviour);

                if (proxy == null)
                {
                    UdonSharpUtils.LogWarning($"UdonSharpBehaviour '{udonBehaviour}' could not be upgraded since it is missing a proxy", udonBehaviour);
                    continue;
                }

                try
                {
                    CopyUdonToProxy(proxy, ProxySerializationPolicy.RootOnly);
                }
                catch (Exception e)
                {
                    UdonSharpUtils.LogError($"Encountered exception while upgrading scene behaviour {proxy}, exception: {e}", proxy);
                    continue;
                }

                // Nuke out old data now because we want only the C# side to own the data from this point on
                
                ClearBehaviourVariables(udonBehaviour, true);
                            
                SetBehaviourVersion(udonBehaviour, UdonSharpBehaviourVersion.V1);
                SetSceneBehaviourUpgraded(udonBehaviour);

                if (needsPrefabInstanceUpgrade)
                    UdonSharpUtils.Log($"Scene behaviour '{udonBehaviour.name}' needed UnityEngine.Object upgrade pass", udonBehaviour);

                UdonSharpUtils.SetDirty(proxy);
                
                UdonSharpUtils.Log($"Upgraded scene behaviour '{udonBehaviour.name}'", udonBehaviour);
            }
        }

        internal static bool BehaviourNeedsSetup(UdonSharpBehaviour behaviour)
        {
            return GetBackingUdonBehaviour(behaviour) == null ||
                   behaviour.enabled != GetBackingUdonBehaviour(behaviour).enabled;
        }
        
        private static readonly MethodInfo _moveComponentRelativeToComponent = typeof(UnityEditorInternal.ComponentUtility).GetMethods(BindingFlags.NonPublic | BindingFlags.Static).First(e => e.Name == "MoveComponentRelativeToComponent" && e.GetParameters().Length == 3);

        internal static void MoveComponentRelativeToComponent(Component component, Component targetComponent, bool aboveTarget)
        {
            _moveComponentRelativeToComponent.Invoke(null, new object[] { component, targetComponent, aboveTarget });
        }
        
        private static readonly FieldInfo _serializedProgramAssetField = typeof(UdonBehaviour).GetField("serializedProgramAsset", BindingFlags.NonPublic | BindingFlags.Instance);
        
        private static void RunBehaviourSetup(UdonSharpBehaviour behaviour, bool withUndo)
        {
            UdonBehaviour backingBehaviour = GetBackingUdonBehaviour(behaviour);

            // Handle components pasted across different behaviours
            if (backingBehaviour && backingBehaviour.gameObject != behaviour.gameObject)
                backingBehaviour = null;

            // Handle pasting components on the same behaviour, assumes pasted components are always the last in the list.
            if (backingBehaviour)
            {
                int refCount = 0;
                UdonSharpBehaviour[] behaviours = backingBehaviour.GetComponents<UdonSharpBehaviour>();
                foreach (UdonSharpBehaviour udonSharpBehaviour in behaviours)
                {
                    if (GetBackingUdonBehaviour(udonSharpBehaviour) == backingBehaviour)
                        refCount++;
                }

                if (refCount > 1 && behaviour == behaviours.Last())
                {
                    backingBehaviour = null;
                }
            }

            bool isPartOfPrefabInstance = PrefabUtility.IsPartOfPrefabInstance(behaviour) && 
                                          PrefabUtility.GetCorrespondingObjectFromSource(behaviour) != behaviour;

            if (backingBehaviour == null)
            {
                if (isPartOfPrefabInstance)
                {
                    UdonSharpUtils.LogWarning("Cannot setup behaviour on prefab instance, original prefab asset needs setup");
                    return;
                }
                
                SetIgnoreEvents(true);
                
                try
                {
                    backingBehaviour = withUndo ? Undo.AddComponent<UdonBehaviour>(behaviour.gameObject) : behaviour.gameObject.AddComponent<UdonBehaviour>();
                    
                #pragma warning disable CS0618 // Type or member is obsolete
                    backingBehaviour.SynchronizePosition = false;
                    backingBehaviour.AllowCollisionOwnershipTransfer = false;
                #pragma warning restore CS0618 // Type or member is obsolete

                    MoveComponentRelativeToComponent(backingBehaviour, behaviour, false);
                    
                    SetBackingUdonBehaviour(behaviour, backingBehaviour);
                    
                    SetBehaviourVersion(backingBehaviour, UdonSharpBehaviourVersion.CurrentVersion);
                    SetSceneBehaviourUpgraded(backingBehaviour);
                    
                    // UdonSharpUtils.Log($"Created behaviour {backingBehaviour}", behaviour);
                }
                finally
                {
                    SetIgnoreEvents(false);
                }
                
                _proxyBehaviourLookup.Add(backingBehaviour, behaviour);
                
                UdonSharpUtils.SetDirty(behaviour);
                UdonSharpUtils.SetDirty(backingBehaviour);
            }
            
            // Handle U# behaviours that have been added to a prefab via Added Component > Apply To Prefab, but have not had their backing behaviour added
            // if (isPartOfPrefabInstance && 
            //     backingBehaviour != null && 
            //     !PrefabUtility.IsPartOfPrefabInstance(backingBehaviour))
            // {
            //     PropertyModification[] modifications = PrefabUtility.GetPropertyModifications(behaviour);
            //
            //     if (modifications != null)
            //     {
            //         
            //     }
            // }

            UdonSharpProgramAsset programAsset = GetUdonSharpProgramAsset(behaviour);

            if (backingBehaviour.programSource == null)
            {
                backingBehaviour.programSource = programAsset;
                if (backingBehaviour.programSource == null)
                    UdonSharpUtils.LogError($"Unable to find valid U# program asset associated with script '{behaviour}'", behaviour);
                
                UdonSharpUtils.SetDirty(backingBehaviour);
            }

            if (_serializedProgramAssetField.GetValue(backingBehaviour) == null)
            {
                SerializedObject componentAsset = new SerializedObject(backingBehaviour);
                SerializedProperty serializedProgramAssetProperty = componentAsset.FindProperty("serializedProgramAsset");

                serializedProgramAssetProperty.objectReferenceValue = programAsset.SerializedProgramAsset;

                if (withUndo)
                    componentAsset.ApplyModifiedProperties();
                else
                    componentAsset.ApplyModifiedPropertiesWithoutUndo();
            }

            if (backingBehaviour.enabled != behaviour.enabled)
            {
                if (withUndo)
                    Undo.RecordObject(backingBehaviour, "Enabled change");
                    
                backingBehaviour.enabled = behaviour.enabled;

                if (!withUndo)
                {
                    UdonSharpUtils.SetDirty(backingBehaviour);
                }
            }

            // hideFlags, delayed as Unity's layout system is corrupted otherwise
            EditorApplication.delayCall += () =>
            {
#if UDONSHARP_DEBUG
                backingBehaviour.hideFlags &= ~HideFlags.HideInInspector;
#else
                backingBehaviour.hideFlags |= HideFlags.HideInInspector;
#endif
                UdonSharpUtils.SetDirty(backingBehaviour);
            };
            
            ((UdonSharpProgramAsset)backingBehaviour.programSource)?.UpdateProgram();
        }

        internal static void RunBehaviourSetup(UdonSharpBehaviour behaviour)
        {
            RunBehaviourSetup(behaviour, false);
        }

        internal static void RunBehaviourSetupWithUndo(UdonSharpBehaviour behaviour)
        {
            RunBehaviourSetup(behaviour, true);
        }

        /// <summary>
        /// Returns true if the given behaviour is a proxy behaviour that's linked to an UdonBehaviour.
        /// </summary>
        /// <param name="behaviour"></param>
        /// <returns></returns>
        [PublicAPI]
        public static bool IsProxyBehaviour(UdonSharpBehaviour behaviour)
        {
            if (behaviour == null)
                return false;
            
            return GetBackingUdonBehaviour(behaviour) != null;
        }

        private static Dictionary<UdonBehaviour, UdonSharpBehaviour> _proxyBehaviourLookup = new Dictionary<UdonBehaviour, UdonSharpBehaviour>();

        /// <summary>
        /// Finds an existing proxy behaviour, if none exists returns null
        /// </summary>
        /// <param name="udonBehaviour"></param>
        /// <returns></returns>
        [Obsolete("FindProxyBehaviour is deprecated, use GetProxyBehaviour instead.")]
        public static UdonSharpBehaviour FindProxyBehaviour(UdonBehaviour udonBehaviour)
        {
            return FindProxyBehaviour_Internal(udonBehaviour);
        }

        /// <summary>
        /// Finds an existing proxy behaviour, if none exists returns null
        /// </summary>
        /// <param name="udonBehaviour"></param>
        /// <returns></returns>
        private static UdonSharpBehaviour FindProxyBehaviour_Internal(UdonBehaviour udonBehaviour)
        {
            if (_proxyBehaviourLookup.TryGetValue(udonBehaviour, out UdonSharpBehaviour proxyBehaviour))
            {
                if (proxyBehaviour != null)
                    return proxyBehaviour;

                _proxyBehaviourLookup.Remove(udonBehaviour);
            }

            UdonSharpBehaviour[] behaviours = udonBehaviour.GetComponents<UdonSharpBehaviour>();
            
            foreach (UdonSharpBehaviour udonSharpBehaviour in behaviours)
            {
                UdonBehaviour backingBehaviour = GetBackingUdonBehaviour(udonSharpBehaviour);
                if (backingBehaviour != null && ReferenceEquals(backingBehaviour, udonBehaviour))
                {
                    _proxyBehaviourLookup.Add(udonBehaviour, udonSharpBehaviour);

                    return udonSharpBehaviour;
                }
            }

            return null;
        }

        /// <summary>
        /// Gets the C# version of an UdonSharpBehaviour that proxies an UdonBehaviour with the program asset for the matching UdonSharpBehaviour type
        /// </summary>
        /// <param name="udonBehaviour"></param>
        /// <returns></returns>
        [PublicAPI]
        public static UdonSharpBehaviour GetProxyBehaviour(UdonBehaviour udonBehaviour)
        {
            return GetProxyBehaviour_Internal(udonBehaviour);
        }

        /// <summary>
        /// Returns if the given UdonBehaviour is an UdonSharpBehaviour
        /// </summary>
        /// <param name="udonBehaviour"></param>
        /// <returns></returns>
        [PublicAPI]
        public static bool IsUdonSharpBehaviour(UdonBehaviour udonBehaviour)
        {
            return udonBehaviour.programSource != null && 
                   udonBehaviour.programSource is UdonSharpProgramAsset programAsset && 
                   programAsset.sourceCsScript != null;
        }

        /// <summary>
        /// Gets the UdonSharpBehaviour type from the given behaviour.
        /// If the behaviour is not an UdonSharpBehaviour, returns null.
        /// </summary>
        /// <param name="udonBehaviour"></param>
        /// <returns></returns>
        [PublicAPI]
        public static Type GetUdonSharpBehaviourType(UdonBehaviour udonBehaviour)
        {
            if (!IsUdonSharpBehaviour(udonBehaviour))
                return null;

            return ((UdonSharpProgramAsset)udonBehaviour.programSource).GetClass();
        }

        private static readonly FieldInfo _skipEventsField = typeof(UdonSharpBehaviour).GetField("_skipEvents", BindingFlags.Static | BindingFlags.NonPublic);

        /// <summary>
        /// Used to disable sending events to UdonSharpBehaviours for OnEnable, OnDisable, and OnDestroy since they are not always in a valid state to be recognized as proxies during these events.
        /// </summary>
        /// <param name="ignore"></param>
        internal static void SetIgnoreEvents(bool ignore)
        {
            _skipEventsField.SetValue(null, ignore);
        }

        /// <summary>
        /// Gets the C# version of an UdonSharpBehaviour that proxies an UdonBehaviour with the program asset for the matching UdonSharpBehaviour type
        /// </summary>
        /// <param name="udonBehaviour"></param>
        /// <returns></returns>
        [PublicAPI]
        private static UdonSharpBehaviour GetProxyBehaviour_Internal(UdonBehaviour udonBehaviour)
        {
            if (udonBehaviour == null)
                throw new ArgumentNullException(nameof(udonBehaviour));

            UdonSharpBehaviour proxyBehaviour = FindProxyBehaviour_Internal(udonBehaviour);
            
            return proxyBehaviour;
        }
        
        // private static readonly FieldInfo _publicVariablesUnityEngineObjectsField = typeof(UdonBehaviour).GetField("publicVariablesUnityEngineObjects", BindingFlags.NonPublic | BindingFlags.Instance);
        //
        // private static IEnumerable<Object> GetUdonBehaviourObjectReferences(UdonBehaviour behaviour)
        // {
        //     return (List<Object>)_publicVariablesUnityEngineObjectsField.GetValue(behaviour);
        // }
        //
        // internal static ImmutableHashSet<GameObject> CollectReferencedPrefabs(GameObject[] roots)
        // {
        //     HashSet<GameObject> allReferencedPrefabs = new HashSet<GameObject>();
        //
        //     foreach (var root in roots)
        //     {
        //         foreach (var udonBehaviour in root.GetComponentsInChildren<UdonBehaviour>(true))
        //         {
        //             if (PrefabUtility.IsPartOfPrefabInstance(udonBehaviour))
        //             {
        //                 allReferencedPrefabs.Add(PrefabUtility.GetNearestPrefabInstanceRoot(udonBehaviour));
        //             }
        //         }
        //     }
        //
        //     HashSet<GameObject> visitedRoots = new HashSet<GameObject>();
        //     HashSet<GameObject> currentRoots = new HashSet<GameObject>(roots);
        //
        //     while (currentRoots.Count > 0)
        //     {
        //         foreach (var root in currentRoots)
        //         {
        //             if (visitedRoots.Contains(root))
        //                 continue;
        //
        //             foreach (var udonBehaviour in root.GetComponentsInChildren<UdonBehaviour>(true))
        //             {
        //                 var objects = GetUdonBehaviourObjectReferences(udonBehaviour);
        //
        //                 foreach (var obj in objects)
        //                 {
        //                     if ((obj is GameObject || obj is Component) &&
        //                         PrefabUtility.IsPartOfPrefabAsset(obj))
        //                     {
        //                         
        //                     }
        //                 }
        //             }
        //         }
        //     }
        //
        //     return allReferencedPrefabs.ToImmutableHashSet();
        // }

        internal static ImmutableHashSet<Object> CollectUdonSharpBehaviourRootDependencies(UdonSharpBehaviour behaviour)
        {
            if (!IsProxyBehaviour(behaviour))
                return ImmutableHashSet<Object>.Empty;
            
            UsbSerializationContext.Dependencies.Clear();
            
            CopyProxyToUdon(behaviour, ProxySerializationPolicy.CollectRootDependencies);

            return UsbSerializationContext.Dependencies.ToImmutableHashSet();
        }

        /// <summary>
        /// Copies the state of the proxy to its backing UdonBehaviour
        /// </summary>
        /// <param name="proxy"></param>
        [PublicAPI]
        public static void CopyProxyToUdon(UdonSharpBehaviour proxy)
        {
            CopyProxyToUdon(proxy, ProxySerializationPolicy.Default);
        }

        /// <summary>
        /// Copies the state of the UdonBehaviour to its proxy object
        /// </summary>
        /// <param name="proxy"></param>
        [PublicAPI]
        public static void CopyUdonToProxy(UdonSharpBehaviour proxy)
        {
            CopyUdonToProxy(proxy, ProxySerializationPolicy.Default);
        }

        /// <summary>
        /// Copies the state of the proxy to its backing UdonBehaviour
        /// </summary>
        /// <param name="proxy"></param>
        /// <param name="serializationPolicy"></param>
        [PublicAPI]
        public static void CopyProxyToUdon(UdonSharpBehaviour proxy, ProxySerializationPolicy serializationPolicy)
        {
            if (serializationPolicy.MaxSerializationDepth == 0)
                return;

            UdonSharpProgramAsset programAsset = GetUdonSharpProgramAsset(proxy);
            
            if (programAsset == null)
                throw new InvalidOperationException($"Cannot run serialization on U# behaviour '{proxy}', the U# program asset on this component is null. Try restarting Unity and if problems persist, verify that you have a UdonSharpProgramAsset with the script '{proxy.GetType()}' assigned to it.");

            if (programAsset.ScriptVersion < UdonSharpProgramVersion.CurrentVersion)
                throw new InvalidOperationException($"Cannot run serialization on U# behaviour '{proxy}' with outdated script version, wait until program assets have compiled.");

            if (programAsset.CompiledVersion < UdonSharpProgramVersion.CurrentVersion)
                throw new InvalidOperationException($"Cannot run serialization on U# behaviour '{proxy}' with outdated behaviour version, wait until program assets have compiled.");

            Profiler.BeginSample("CopyProxyToUdon");

            try
            {
                lock (UsbSerializationContext.UsbLock)
                {
                    var udonBehaviourStorage = new SimpleValueStorage<UdonBehaviour>(GetBackingUdonBehaviour(proxy));

                    ProxySerializationPolicy lastPolicy = UsbSerializationContext.CurrentPolicy;
                    UsbSerializationContext.CurrentPolicy = serializationPolicy;

                    Serializer.CreatePooled(proxy.GetType()).WriteWeak(udonBehaviourStorage, proxy);

                    UsbSerializationContext.CurrentPolicy = lastPolicy;
                }
            }
            finally
            {
                Profiler.EndSample();
            }
        }

        /// <summary>
        /// Copies the state of the UdonBehaviour to its proxy object
        /// </summary>
        /// <param name="proxy"></param>
        /// <param name="serializationPolicy"></param>
        [PublicAPI]
        public static void CopyUdonToProxy(UdonSharpBehaviour proxy, ProxySerializationPolicy serializationPolicy)
        {
            if (serializationPolicy.MaxSerializationDepth == 0)
                return;

            UdonSharpProgramAsset programAsset = GetUdonSharpProgramAsset(proxy);

            if (programAsset == null)
                throw new InvalidOperationException($"Cannot run serialization on U# behaviour '{proxy}', the U# program asset on this component is null. Try restarting Unity and if problems persist, verify that you have a UdonSharpProgramAsset with the script '{proxy.GetType()}' assigned to it.");

            if (programAsset.ScriptVersion < UdonSharpProgramVersion.CurrentVersion)
                throw new InvalidOperationException($"Cannot run serialization on U# behaviour '{proxy}' with outdated script version, wait until program assets have compiled.");

            if (programAsset.CompiledVersion < UdonSharpProgramVersion.CurrentVersion)
                throw new InvalidOperationException($"Cannot run serialization on U# behaviour '{proxy}' with outdated behaviour version, wait until program assets have compiled.");
            
            Profiler.BeginSample("CopyUdonToProxy");

            try
            {
                lock (UsbSerializationContext.UsbLock)
                {
                    var udonBehaviourStorage = new SimpleValueStorage<UdonBehaviour>(GetBackingUdonBehaviour(proxy));

                    ProxySerializationPolicy lastPolicy = UsbSerializationContext.CurrentPolicy;
                    UsbSerializationContext.CurrentPolicy = serializationPolicy;

                    object proxyObj = proxy;
                    Serializer.CreatePooled(proxy.GetType()).ReadWeak(ref proxyObj, udonBehaviourStorage);

                    UsbSerializationContext.CurrentPolicy = lastPolicy;
                }
            }
            finally
            {
                Profiler.EndSample();
            }
        }

        [PublicAPI]
        public static UdonBehaviour CreateBehaviourForProxy(UdonSharpBehaviour udonSharpBehaviour)
        {
            UdonBehaviour backingBehaviour = GetBackingUdonBehaviour(udonSharpBehaviour);

            CopyProxyToUdon(udonSharpBehaviour);

            return backingBehaviour;
        }

        /// <summary>
        /// Destroys an UdonSharpBehaviour proxy and its underlying UdonBehaviour
        /// </summary>
        /// <param name="behaviour"></param>
        [PublicAPI]
        public static void DestroyImmediate(UdonSharpBehaviour behaviour)
        {
            UdonBehaviour backingBehaviour = GetBackingUdonBehaviour(behaviour);
            
            Object.DestroyImmediate(behaviour);

            if (backingBehaviour)
            {
                _proxyBehaviourLookup.Remove(backingBehaviour);

                SetIgnoreEvents(true);

                try
                {
                    Object.DestroyImmediate(backingBehaviour);
                }
                finally
                {
                    SetIgnoreEvents(false);
                }
            }
        }

        internal static void DeletePrefabBuildAssets()
        {
        #if UDONSHARP_DEBUG
            return;
        #endif
            
            string prefabBuildPath = UdonSharpLocator.IntermediatePrefabPath;

            if (!Directory.Exists(prefabBuildPath))
                return;
            
            AssetDatabase.DeleteAsset(prefabBuildPath);
        }
    }
}
