// Copyright 2018 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.

using UnityEngine;
using System.Collections;

#if UNITY_2017_2_OR_NEWER
using UnityEngine.XR;
#else
using XRDevice = UnityEngine.VR.VRDevice;
using XRSettings = UnityEngine.VR.VRSettings;
#endif  // UNITY_2017_2_OR_NEWER

// Handler for subscribing XR Unity actions to GVR Actions.
public class GvrXREventsSubscriber : MonoBehaviour {
    private static GvrXREventsSubscriber instance;
    private string _loadedDeviceName;
    public static string loadedDeviceName {
        get {
            return GetInstance()._loadedDeviceName;
        }
        set {
            GetInstance()._loadedDeviceName = value;
        }
    }

    private static void OnDeviceLoadAction(string newLoadedDeviceName) {
        loadedDeviceName = newLoadedDeviceName;
    }

    void Awake() {
      instance = this;
      _loadedDeviceName = XRSettings.loadedDeviceName;
#if UNITY_2018_3_OR_NEWER
      XRDevice.deviceLoaded += OnDeviceLoadAction;
#endif // UNITY_2018_3_OR_NEWER
    }

    private static GvrXREventsSubscriber GetInstance() {
        if (instance == null) {
            GameObject gvrXREventsSubscriber = new GameObject("GvrXREventsSubscriber");
            gvrXREventsSubscriber.AddComponent<GvrXREventsSubscriber>();
        }
        return instance;
    }
}