using System;
using System.Collections;
using System.Collections.Generic;
using System.Reflection;
using System.Runtime.Serialization;
using UnityEditor;
using UnityEngine;

namespace VF.Model {
    public abstract class VRCFuryComponent : MonoBehaviour, ISerializationCallbackReceiver {
        private static readonly int VRCFURY_SER_VERSION = 7;
        private static readonly HashSet<string> attemptedReload = new HashSet<string>();

        public int vrcfSerVersion;
        [NonSerialized]
        public bool failedToLoad = false;

        public bool IsBroken() {
            return vrcfSerVersion > VRCFURY_SER_VERSION || ContainsNullsInList(this);
        }

        public virtual void OnAfterDeserialize() {
            if (IsBroken()) {
                failedToLoad = true;
#if UNITY_EDITOR
                EditorApplication.delayCall += () => {
                    var path = AssetDatabase.GetAssetPath(this);
                    if (!string.IsNullOrWhiteSpace(path) && !attemptedReload.Contains(path)) {
                        //Debug.LogError("VRCFury is triggering manual reload of asset " + path + " (previous import corrupted)");
                        Debug.LogWarning(
                            $"VRCFury detected VRCFury component in asset at path ${path} is corrupted. " +
                            "Hopefully it will be fixed during the prefab import auto-fix.");
                        attemptedReload.Add(path);
                        //AssetDatabase.ImportAsset(path, ImportAssetOptions.ForceSynchronousImport);
                    }
                };
#endif
            } else {
                vrcfSerVersion = VRCFURY_SER_VERSION;
                failedToLoad = false;
            }
        }
        
        public virtual void OnBeforeSerialize() {
        }
        
        private static bool ContainsNullsInList(object obj) {
            if (obj == null) return false;
            var objType = obj.GetType();
            if (!objType.FullName.StartsWith("VF")) return false;
            var fields = objType.GetFields();
            foreach (var field in fields) {
                var value = field.GetValue(obj);
                if (value is IList) {
                    var list = value as IList;
                    var isRef = field.GetCustomAttribute<SerializeReference>() != null;
                    foreach (var t in list) {
                        if (t == null && isRef) return true;
                        if (ContainsNullsInList(t)) return true;
                    }
                } else {
                    var type = field.FieldType;
                    if (type.IsClass) {
                        if (ContainsNullsInList(value)) return true;
                    }
                }
            }
            return false;
        }
    }
}