using System;
using System.Collections.Generic;
using UnityEditor;
using UnityEngine;
using UnityEngine.UIElements;
using UnityEditor.UIElements;
using UnityEditorInternal;
using UnityEngine.Pool;
using Object = UnityEngine.Object;

namespace Module.ProjectValidator.Editor
{
    internal sealed class ProjectValidatorSettings : ScriptableObject
    {
        public List<string> assemblies = new();
        public List<ValidatorEnabled> validators = new();
     
        public const string MenuPath = "Project/Project Validator";
        private const string AssetPath = "ProjectSettings/ProjectValidatorSettings.asset";
        private const string StyleSheetName = "StyleSheetProjectValidatorSettings";

        internal static ProjectValidatorSettings GetOrCreate()
        {
            var objects = InternalEditorUtility.LoadSerializedFileAndForget(AssetPath);
            ProjectValidatorSettings settings;
            
            if (objects.Length != 0)
                settings = (ProjectValidatorSettings)objects[0];
            else
                settings = CreateInstance<ProjectValidatorSettings>();

            PopulateValidatorList(settings);
            InternalEditorUtility.SaveToSerializedFileAndForget(new Object[] { settings }, AssetPath, true);
            return settings;
        }
        
        [SettingsProvider]
        public static SettingsProvider CreateProvider()
        {
            return new SettingsProvider(MenuPath, SettingsScope.Project)
            {
                label = "Project Validator",
                activateHandler = (_, root) =>
                {
                    var settings = GetOrCreate();
                    var serializedObject = new SerializedObject(settings);
                    var container = new VisualElement { style = { flexDirection = FlexDirection.Column } };
                    
                    var assemblyField = new PropertyField(serializedObject.FindProperty(nameof(assemblies)), "Assemblies");
                    container.Add(assemblyField);
                    
                    var enabledField = new PropertyField(serializedObject.FindProperty(nameof(validators)), "Validators");
                    container.Add(enabledField);
                    
                    root.Add(container);
                    root.Bind(serializedObject);
                    root.RegisterCallback<SerializedObjectChangeEvent>(_ => InternalEditorUtility.SaveToSerializedFileAndForget(new[] { serializedObject.targetObject }, AssetPath, true));
                    root.RegisterCallback<SerializedPropertyChangeEvent>(_ => InternalEditorUtility.SaveToSerializedFileAndForget(new[] { serializedObject.targetObject }, AssetPath, true));
                    root.styleSheets.Add(EditorAssetUtility.LoadFirstAsset<StyleSheet>(StyleSheetName));
                },
                keywords = new HashSet<string>(new[] { "Project", "Validator", "Assemblies" })
            };
        }

        private static void PopulateValidatorList(ProjectValidatorSettings settings)
        {
            using var pool0 = ListPool<string>.Get(out var list);
            using var pool1 = ListPool<string>.Get(out var temp);
            
            FetchValidatorsOfType(typeof(IAssetValidator<>), list);
            FetchValidatorsOfType(typeof(IAttributeValidator<>), list);
            FetchValidatorsOfType(typeof(IComponentValidator<>), list);
            FetchValidatorsOfType(typeof(IGameObjectValidator), list);

            for (var i = 0; i < settings.validators.Count; i++)
            {
                temp.Add(settings.validators[i].type);
            }

            for (var i = 0; i < list.Count; i++)
            {
                if (!temp.Contains(list[i]))
                    settings.validators.Add(new ValidatorEnabled(list[i], true));
            }

            for (var i = temp.Count - 1; i >= 0; i--)
            {
                if (!list.Contains(temp[i]))
                    settings.validators.RemoveAt(i);
            }
        }

        private static void FetchValidatorsOfType(Type type, List<string> typeNames)
        {
            var types = TypeCache.GetTypesDerivedFrom(type);

            for (var i = 0; i < types.Count; i++)
            {
                if (!types[i].IsInterface && !types[i].IsAbstract)
                    typeNames.Add(types[i].FullName);
            }
        }

        [Serializable]
        public sealed class ValidatorEnabled
        {
            public string type;
            public bool enabled;

            public ValidatorEnabled(string type, bool enabled)
            {
                this.type = type;
                this.enabled = enabled;
            }
        }
    }
}