using System;
using System.Collections.Generic;
using UnityEditor;
using UnityEngine.UIElements;

namespace SubAssetsToolbox.Editor
{
    internal static class SubAssetsToolboxSettingsProvider
    {
        private const string SettingsPath = "Project/SubAssets Toolbox";
        private const string UxmlPath = "Packages/io.continis.subassets/UI/UIToolkit/ProjectSettings.uxml";

        private static List<string> _extensions;
        private static ListView _listView;
        private static EnumField _redirectionModeField;
        private static Button _resetFileTypesBtn;

        [SettingsProvider]
        private static SettingsProvider CreateSettingsProvider()
        {
            return new SettingsProvider(SettingsPath, SettingsScope.Project)
            {
                activateHandler = (_, rootElement) => CreateUI(rootElement),
                keywords = new[] { "subassets", "sub-assets", "redirect", "extensions" }
            };
        }

        private static void SyncToSetting()
        {
            SubAssetsToolboxSettings.PatchExtensions.SetValue(_extensions.ToArray(), true);
        }

        private static void CreateUI(VisualElement root)
        {
            ReferencePatchingMode currentMode = SubAssetsToolboxSettings.PatchReferences.value;
            bool redirectionIsEnabled = currentMode != ReferencePatchingMode.Disabled;
            _extensions = new List<string>(SubAssetsToolboxSettings.PatchExtensions.value);

            VisualTreeAsset visualTree = AssetDatabase.LoadAssetAtPath<VisualTreeAsset>(UxmlPath);
            VisualElement template = visualTree.Instantiate();
            template.style.flexGrow = 1f;

            _redirectionModeField = template.Q<EnumField>("RedirectionModeField");
            _redirectionModeField.Init(ReferencePatchingMode.Disabled);
            _redirectionModeField.SetValueWithoutNotify(currentMode);
            _redirectionModeField.RegisterValueChangedCallback(OnRedirectionModeChanged);

            _listView = template.Q<ListView>("ExtensionsList");
            _listView.itemsSource = _extensions;
            _listView.SetEnabled(redirectionIsEnabled);
            _listView.makeItem = MakeItem;
            _listView.bindItem = BindItem;
            _listView.unbindItem = UnbindItem;

            _listView.itemsAdded += indices =>
            {
                foreach (int i in indices)
                    _extensions[i] = "ext";
                _listView.RefreshItems();
                SyncToSetting();
            };

            _listView.itemsRemoved += _ => SyncToSetting();
            _listView.itemIndexChanged += (_, _) => SyncToSetting();

            _resetFileTypesBtn = template.Q<Button>("ResetBtn");
            _resetFileTypesBtn.SetEnabled(redirectionIsEnabled);
            _resetFileTypesBtn.clicked += ResetExtensionsToDefaults;

            root.Add(template);
        }

        private static void OnRedirectionModeChanged(ChangeEvent<Enum> evt)
        {
            ReferencePatchingMode mode = (ReferencePatchingMode)evt.newValue;
            SubAssetsToolboxSettings.PatchReferences.SetValue(mode, true);
            bool enabled = mode != ReferencePatchingMode.Disabled;
            _listView.SetEnabled(enabled);
            _resetFileTypesBtn.SetEnabled(enabled);
        }

        private static void ResetExtensionsToDefaults()
        {
            _extensions.Clear();
            _extensions.AddRange(SubAssetsToolboxSettings.DefaultExtensionsToScan);
            _listView.RefreshItems();
            SyncToSetting();
        }

        private static VisualElement MakeItem()
        {
            return new TextField();
        }

        private static void BindItem(VisualElement element, int index)
        {
            TextField field = (TextField)element;
            field.SetValueWithoutNotify(_extensions[index]);
            field.userData = index;
            field.RegisterValueChangedCallback(OnExtensionChanged);
        }

        private static void UnbindItem(VisualElement element, int index)
        {
            TextField field = (TextField)element;
            field.UnregisterValueChangedCallback(OnExtensionChanged);
        }

        private static void OnExtensionChanged(ChangeEvent<string> evt)
        {
            TextField field = (TextField)evt.target;
            int index = (int)field.userData;
            _extensions[index] = evt.newValue;
            SyncToSetting();
        }
    }
}