using System.Linq;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UIElements;
using UnityEngine.XR.Interaction.Toolkit;
using UnityEngine.XR.Interaction.Toolkit.Inputs.Simulation;

namespace UnityEditor.XR.Interaction.Toolkit
{
    /// <summary>
    /// Class configuration to display XR Interaction Toolkit settings in the Project Settings window.
    /// </summary>
    class XRInteractionToolkitSettingsProvider : SettingsProvider
    {
        /// <summary>
        /// Scope that adds a top and a left margin.
        /// </summary>
        class SettingsMarginScope : GUI.Scope
        {
            internal SettingsMarginScope()
            {
                const float topMargin = 10f;
                const float leftMargin = 10f;

                GUILayout.BeginHorizontal();
                GUILayout.Space(leftMargin);
                GUILayout.BeginVertical();
                GUILayout.Space(topMargin);
            }

            protected override void CloseScope()
            {
                GUILayout.EndVertical();
                GUILayout.EndHorizontal();
            }
        }

        /// <summary>
        /// Contents of GUI elements used by this settings provider.
        /// </summary>
        internal static class Contents
        {
            public static readonly GUIContent interactionSimulatorSettingsTitle = new GUIContent("Interaction Simulator Settings");
            public static readonly GUIContent interactionLayerSettingsTitle = new GUIContent("Interaction Layer Settings");
            public static readonly GUIContent editorSettingsTitle = new GUIContent("Editor Settings");

            public static readonly GUIStyle sectionTitleStyle = new GUIStyle("Label")
            {
                fontSize = 15,
                fontStyle = FontStyle.Bold,
            };
        }

        /// <summary>
        /// The path to display this settings provider in the Project Settings window.
        /// </summary>
        internal const string k_SettingsPath = "Project/XR Plug-in Management/XR Interaction Toolkit";

        Editor m_InteractionLayerSettingsEditor;
        Editor m_XRInteractionEditorSettingsEditor;
        Editor m_XRDeviceSimulatorSettingsEditor;

        /// <summary>
        /// Create and returns this settings provider.
        /// </summary>
        /// <returns>Returns a new instance of this settings provider.</returns>
        [SettingsProvider]
#pragma warning disable IDE0051 // Remove unused private members -- Invoked by Unity due to attribute
        static SettingsProvider CreateInteractionLayerProvider()
#pragma warning restore IDE0051
        {
            var keywordsList = GetSearchKeywordsFromPath(AssetDatabase.GetAssetPath(InteractionLayerSettings.Instance)).ToList();
            return new XRInteractionToolkitSettingsProvider { keywords = keywordsList };
        }

        XRInteractionToolkitSettingsProvider(string path = k_SettingsPath, SettingsScope scopes = SettingsScope.Project,
            IEnumerable<string> keywords = null)
            : base(path, scopes, keywords)
        {
        }

        /// <summary>
        /// Draws the <see cref="XRInteractionEditorSettings"/> editor.
        /// </summary>
        void DrawXRInteractionEditorSettingsEditor()
        {
            if (m_XRInteractionEditorSettingsEditor != null)
            {
                GUILayout.Label(Contents.editorSettingsTitle, Contents.sectionTitleStyle);
                m_XRInteractionEditorSettingsEditor.OnInspectorGUI();
            }
        }

        /// <summary>
        /// Draws the <see cref="InteractionLayerSettings"/> editor.
        /// </summary>
        void DrawInteractionLayerSettingsEditor()
        {
            if (m_InteractionLayerSettingsEditor != null)
            {
                GUILayout.Label(Contents.interactionLayerSettingsTitle, Contents.sectionTitleStyle);
                m_InteractionLayerSettingsEditor.OnInspectorGUI();
            }
        }

        /// <summary>
        /// Draws the <see cref="XRDeviceSimulatorSettings"/> editor.
        /// </summary>
        void DrawXRDeviceSimulatorSettingsEditor()
        {
            if (m_InteractionLayerSettingsEditor != null)
            {
                GUILayout.Label(Contents.interactionSimulatorSettingsTitle, Contents.sectionTitleStyle);
                m_XRDeviceSimulatorSettingsEditor.OnInspectorGUI();
            }
        }

        /// <inheritdoc />
        public override void OnActivate(string searchContext, VisualElement rootElement)
        {
            base.OnActivate(searchContext, rootElement);

            m_InteractionLayerSettingsEditor = Editor.CreateEditor(InteractionLayerSettings.Instance);
            m_XRInteractionEditorSettingsEditor = Editor.CreateEditor(XRInteractionEditorSettings.Instance);
            m_XRDeviceSimulatorSettingsEditor = Editor.CreateEditor(XRDeviceSimulatorSettings.Instance);
        }

        /// <inheritdoc />
        public override void OnDeactivate()
        {
            base.OnDeactivate();

            if (m_InteractionLayerSettingsEditor != null)
                Object.DestroyImmediate(m_InteractionLayerSettingsEditor);

            if (m_XRInteractionEditorSettingsEditor != null)
                Object.DestroyImmediate(m_XRInteractionEditorSettingsEditor);

            if (m_XRDeviceSimulatorSettingsEditor != null)
                Object.DestroyImmediate(m_XRDeviceSimulatorSettingsEditor);
        }

        /// <inheritdoc />
        public override void OnGUI(string searchContext)
        {
            base.OnGUI(searchContext);

            using (new SettingsMarginScope())
            {
                DrawXRDeviceSimulatorSettingsEditor();
                EditorGUILayout.Space();
                DrawXRInteractionEditorSettingsEditor();
                EditorGUILayout.Space();
                DrawInteractionLayerSettingsEditor();
            }
        }
    }
}