// Copyright 2017 Google Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// The controller is not available for versions of Unity without the
// GVR native integration.

using UnityEngine;
using System.Collections;

/// A lightweight tooltip designed to minimize draw calls.
[ExecuteInEditMode]
[HelpURL("https://developers.google.com/vr/unity/reference/class/GvrControllerTooltipsSimple")]
public class GvrControllerTooltipsSimple : MonoBehaviour, IGvrArmModelReceiver {

  private MeshRenderer tooltipRenderer;

  public GvrBaseArmModel ArmModel { get; set; }

  private MaterialPropertyBlock materialPropertyBlock;
  private int colorId;

  void Awake() {
    Initialize();
  }

  void OnEnable() {
    GvrControllerInput.OnPostControllerInputUpdated += OnPostControllerInputUpdated;
  }

  void OnDisable() {
    GvrControllerInput.OnPostControllerInputUpdated -= OnPostControllerInputUpdated;
  }

  void OnValidate() {
    if (!Application.isPlaying){
      Initialize();
      OnVisualUpdate();
    }
  }

  private void Initialize(){
    if(tooltipRenderer == null){
      tooltipRenderer = GetComponent<MeshRenderer>();
    }
    if(materialPropertyBlock == null){
      materialPropertyBlock = new MaterialPropertyBlock();
    }
    colorId = Shader.PropertyToID("_Color");
  }

  private void OnPostControllerInputUpdated() {
    OnVisualUpdate();
  }

  protected void OnVisualUpdate () {
    float alpha = ArmModel != null ? ArmModel.TooltipAlphaValue : 1.0f;
    materialPropertyBlock.SetColor(colorId, new Color(1,1,1,alpha));
    tooltipRenderer.SetPropertyBlock(materialPropertyBlock);
  }
}