/************************************************************************************
Copyright : Copyright (c) Facebook Technologies, LLC and its affiliates. All rights reserved.

Licensed under the Oculus Utilities SDK License Version 1.31 (the "License"); you may not use
the Utilities SDK except in compliance with the License, which is provided at the time of installation
or download, or which otherwise accompanies this software in either electronic or hard copy form.

You may obtain a copy of the License at
https://developer.oculus.com/licenses/utilities-1.31

Unless required by applicable law or agreed to in writing, the Utilities SDK 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.
************************************************************************************/

#if UNITY_ANDROID && !UNITY_EDITOR
#define OVR_ANDROID_MRC
#endif

using System;
using System.Runtime.InteropServices;
using System.Text.RegularExpressions;
using System.Collections.Generic;
using UnityEngine;

#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN || UNITY_ANDROID

/// <summary>
/// Manages mix-reality elements
/// </summary>
internal static class OVRMixedReality
{
	/// <summary>
	/// For Debugging purpose, we can use preset parameters to fake a camera when external camera is not available
	/// </summary>
	public static bool useFakeExternalCamera = false;
	public static Vector3 fakeCameraFloorLevelPosition = new Vector3(0.0f, 2.0f, -0.5f);
	public static Vector3 fakeCameraEyeLevelPosition = fakeCameraFloorLevelPosition - new Vector3(0.0f, 1.8f, 0.0f);
	public static Quaternion fakeCameraRotation = Quaternion.LookRotation((new Vector3(0.0f, fakeCameraFloorLevelPosition.y, 0.0f) - fakeCameraFloorLevelPosition).normalized, Vector3.up);
	public static float fakeCameraFov = 60.0f;
	public static float fakeCameraAspect = 16.0f / 9.0f;

	/// <summary>
	/// Composition object
	/// </summary>
	public static OVRComposition currentComposition = null;

	/// <summary>
	/// Updates the internal state of the Mixed Reality Camera. Called by OVRManager.
	/// </summary>

	public static void Update(GameObject parentObject, Camera mainCamera, OVRManager.CompositionMethod compositionMethod, bool useDynamicLighting, OVRManager.CameraDevice cameraDevice, OVRManager.DepthQuality depthQuality)
	{
		if (!OVRPlugin.initialized)
		{
			Debug.LogError("OVRPlugin not initialized");
			return;
		}

		if (!OVRPlugin.IsMixedRealityInitialized())
		{
			OVRPlugin.InitializeMixedReality();
			if (OVRPlugin.IsMixedRealityInitialized())
			{
				Debug.Log("OVRPlugin_MixedReality initialized");
			}
			else
			{
				Debug.LogError("Unable to initialize OVRPlugin_MixedReality");
				return;
			}
		}

		if (!OVRPlugin.IsMixedRealityInitialized())
		{
			return;
		}

		OVRPlugin.UpdateExternalCamera();
#if !OVR_ANDROID_MRC
		OVRPlugin.UpdateCameraDevices();
#endif

#if OVR_ANDROID_MRC
		useFakeExternalCamera = OVRPlugin.Media.UseMrcDebugCamera();
#endif

		if (currentComposition != null && currentComposition.CompositionMethod() != compositionMethod)
		{
			currentComposition.Cleanup();
			currentComposition = null;
		}

		if (compositionMethod == OVRManager.CompositionMethod.External)
		{
			if (currentComposition == null)
			{
				currentComposition = new OVRExternalComposition(parentObject, mainCamera);
			}
		}
#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN
		else if (compositionMethod == OVRManager.CompositionMethod.Direct)
		{
			if (currentComposition == null)
			{
				currentComposition = new OVRDirectComposition(parentObject, mainCamera, cameraDevice, useDynamicLighting, depthQuality);
			}
		}
#endif
		else
		{
			Debug.LogError("Unknown CompositionMethod : " + compositionMethod);
			return;
		}
		currentComposition.Update(parentObject, mainCamera);
	}

	public static void Cleanup()
	{
		if (currentComposition != null)
		{
			currentComposition.Cleanup();
			currentComposition = null;
		}
		if (OVRPlugin.IsMixedRealityInitialized())
		{
			OVRPlugin.ShutdownMixedReality();
		}
	}

	public static void RecenterPose()
	{
		if (currentComposition != null)
		{
			currentComposition.RecenterPose();
		}
	}

}

#endif