//======= Copyright (c) Valve Corporation, All rights reserved. ===============
//
// Purpose: Custom inspector display for SteamVR_RenderModel
//
//=============================================================================

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

namespace Valve.VR
{
    [CustomEditor(typeof(SteamVR_RenderModel)), CanEditMultipleObjects]
    public class SteamVR_RenderModelEditor : Editor
    {
        SerializedProperty script, index, modelOverride, shader, verbose, createComponents, updateDynamically;

        static string[] renderModelNames;
        int renderModelIndex;

        void OnEnable()
        {
            script = serializedObject.FindProperty("m_Script");
            index = serializedObject.FindProperty("index");
            modelOverride = serializedObject.FindProperty("modelOverride");
            shader = serializedObject.FindProperty("shader");
            verbose = serializedObject.FindProperty("verbose");
            createComponents = serializedObject.FindProperty("createComponents");
            updateDynamically = serializedObject.FindProperty("updateDynamically");

            // Load render model names if necessary.
            if (renderModelNames == null)
            {
                renderModelNames = LoadRenderModelNames();
            }

            // Update renderModelIndex based on current modelOverride value.
            if (modelOverride.stringValue != "")
            {
                for (int i = 0; i < renderModelNames.Length; i++)
                {
                    if (modelOverride.stringValue == renderModelNames[i])
                    {
                        renderModelIndex = i;
                        break;
                    }
                }
            }
        }

        static string[] LoadRenderModelNames()
        {
            var results = new List<string>();
            results.Add("None");

            using (var holder = new SteamVR_RenderModel.RenderModelInterfaceHolder())
            {
                var renderModels = holder.instance;
                if (renderModels != null)
                {
                    uint count = renderModels.GetRenderModelCount();
                    for (uint i = 0; i < count; i++)
                    {
                        var buffer = new StringBuilder();
                        var requiredSize = renderModels.GetRenderModelName(i, buffer, 0);
                        if (requiredSize == 0)
                            continue;

                        buffer.EnsureCapacity((int)requiredSize);
                        renderModels.GetRenderModelName(i, buffer, requiredSize);
                        results.Add(buffer.ToString());
                    }
                }
            }

            return results.ToArray();
        }

        public override void OnInspectorGUI()
        {
            serializedObject.Update();

            EditorGUILayout.PropertyField(script);
            EditorGUILayout.PropertyField(index);
            //EditorGUILayout.PropertyField(modelOverride);

            GUILayout.BeginHorizontal();
            GUILayout.Label(new GUIContent("Model Override", SteamVR_RenderModel.modelOverrideWarning));
            var selected = EditorGUILayout.Popup(renderModelIndex, renderModelNames);
            if (selected != renderModelIndex)
            {
                renderModelIndex = selected;
                modelOverride.stringValue = (selected > 0) ? renderModelNames[selected] : "";
            }
            GUILayout.EndHorizontal();

            EditorGUILayout.PropertyField(shader);
            EditorGUILayout.PropertyField(verbose);
            EditorGUILayout.PropertyField(createComponents);
            EditorGUILayout.PropertyField(updateDynamically);

            serializedObject.ApplyModifiedProperties();
        }
    }
}