#if UNITY_EDITOR && UNITY_INPUT_SYSTEM_UI_TK_ASSET_EDITOR
using System;
using System.Collections.Generic;
using System.Linq;
using UnityEditor;
using UnityEngine.UIElements;

namespace UnityEngine.InputSystem.Editor
{
    internal class CompositePartBindingPropertiesView : ViewBase<CompositePartBindingPropertiesView.ViewState>
    {
        private readonly VisualElement m_Root;
        private readonly DropdownField m_CompositePartField;
        private readonly IMGUIContainer m_PathEditorContainer;

        private const string UxmlName = InputActionsEditorConstants.PackagePath +
            InputActionsEditorConstants.ResourcesPath +
            InputActionsEditorConstants.CompositePartBindingPropertiesViewUxml;

        public CompositePartBindingPropertiesView(VisualElement root, StateContainer stateContainer)
            : base(stateContainer)
        {
            m_Root = root;
            var visualTreeAsset = AssetDatabase.LoadAssetAtPath<VisualTreeAsset>(UxmlName);
            var container = visualTreeAsset.CloneTree();
            m_Root.Add(container);

            m_PathEditorContainer = container.Q<IMGUIContainer>("path-editor-container");
            m_CompositePartField = container.Q<DropdownField>("composite-part-dropdown");

            CreateSelector(Selectors.GetSelectedBinding,
                (b, s) => b.HasValue && b.Value.isPartOfComposite ? Selectors.GetCompositePartBindingViewState(b.Value, s) : null);
        }

        public override void RedrawUI(ViewState viewState)
        {
            if (viewState == null)
                return;
            // TODO: Persist control picker state
            var controlPathEditor = new InputControlPathEditor(viewState.selectedBindingPath, new InputControlPickerState(),
                () => { Dispatch(Commands.ApplyModifiedProperties()); });

            controlPathEditor.SetExpectedControlLayout(viewState.expectedControlLayoutName);

            m_PathEditorContainer.onGUIHandler = controlPathEditor.OnGUI;

            m_CompositePartField.choices.Clear();
            m_CompositePartField.choices.AddRange(viewState.compositePartNames);
            m_CompositePartField.SetValueWithoutNotify(viewState.selectedCompositePartName);

            m_CompositePartField.RegisterValueChangedCallback(evt =>
            {
                Dispatch(Commands.SetCompositeBindingPartName(viewState.selectedBinding, evt.newValue));
            });
        }

        internal class ViewState
        {
            public SerializedProperty selectedBindingPath;
            public SerializedInputBinding selectedBinding;
            public IEnumerable<string> compositePartNames;
            public string expectedControlLayoutName;
            public string selectedCompositePartName;
        }
    }

    internal static partial class Selectors
    {
        public static CompositePartBindingPropertiesView.ViewState GetCompositePartBindingViewState(SerializedInputBinding binding,
            InputActionsEditorState state)
        {
            var compositeParts = GetCompositePartOptions(binding.name, binding.compositePath).ToList();
            var selectedCompositePartName = ObjectNames.NicifyVariableName(
                compositeParts.First(str => string.Equals(str, binding.name, StringComparison.OrdinalIgnoreCase)));

            var compositePartBindingViewState = new CompositePartBindingPropertiesView.ViewState
            {
                selectedBinding = binding,
                selectedBindingPath = GetSelectedBindingPath(state),
                selectedCompositePartName = selectedCompositePartName,
                compositePartNames = compositeParts.Select(ObjectNames.NicifyVariableName).ToList(),
                expectedControlLayoutName = InputBindingComposite.GetExpectedControlLayoutName(binding.compositePath, binding.name) ?? ""
            };
            return compositePartBindingViewState;
        }
    }
}

#endif