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

Your use of this SDK or tool is subject to the Oculus SDK License Agreement, available at
https://developer.oculus.com/licenses/oculussdk/

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.Collections;
using System.Collections.Generic;
using UnityEngine;

public class OVRMixedRealityCaptureTest : MonoBehaviour {

	bool inited = false;

	enum CameraMode
	{
		Normal = 0,
		OverrideFov,
		ThirdPerson,
	}

	CameraMode currentMode = CameraMode.Normal;

	public Camera defaultExternalCamera;
	OVRPlugin.Fovf defaultFov;

	// Use this for initialization
	void Start () {
#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN || OVR_ANDROID_MRC
		if (!defaultExternalCamera)
		{
			Debug.LogWarning("defaultExternalCamera undefined");
		}

#if !OVR_ANDROID_MRC
		// On Quest, we enable MRC automatically through the configuration
		if (!OVRManager.instance.enableMixedReality)
		{
			OVRManager.instance.enableMixedReality = true;
		}
#endif
#endif
	}

	void Initialize()
	{
#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN || OVR_ANDROID_MRC
		if (inited)
			return;

#if OVR_ANDROID_MRC
		if (!OVRPlugin.Media.GetInitialized())
			return;
#else
		if (!OVRPlugin.IsMixedRealityInitialized())
			return;
#endif

		OVRPlugin.ResetDefaultExternalCamera();
		Debug.LogFormat("GetExternalCameraCount before adding manual external camera {0}", OVRPlugin.GetExternalCameraCount());
		UpdateDefaultExternalCamera();
		Debug.LogFormat("GetExternalCameraCount after adding manual external camera {0}", OVRPlugin.GetExternalCameraCount());

		// obtain default FOV
		{
			OVRPlugin.CameraIntrinsics cameraIntrinsics;
			OVRPlugin.CameraExtrinsics cameraExtrinsics;
			OVRPlugin.GetMixedRealityCameraInfo(0, out cameraExtrinsics, out cameraIntrinsics);
			defaultFov = cameraIntrinsics.FOVPort;
		}

		inited = true;
#endif
	}

	void UpdateDefaultExternalCamera()
	{
#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN || OVR_ANDROID_MRC
		// always build a 1080p external camera
		const int cameraPixelWidth = 1920;
		const int cameraPixelHeight = 1080;
		const float cameraAspect = (float)cameraPixelWidth / cameraPixelHeight;


		string cameraName = "UnityExternalCamera";
		OVRPlugin.CameraIntrinsics cameraIntrinsics = new OVRPlugin.CameraIntrinsics();
		OVRPlugin.CameraExtrinsics cameraExtrinsics = new OVRPlugin.CameraExtrinsics();

		// intrinsics

		cameraIntrinsics.IsValid = OVRPlugin.Bool.True;
		cameraIntrinsics.LastChangedTimeSeconds = Time.time;

		float vFov = defaultExternalCamera.fieldOfView * Mathf.Deg2Rad;
		float hFov = Mathf.Atan(Mathf.Tan(vFov * 0.5f) * cameraAspect) * 2.0f;
		OVRPlugin.Fovf fov = new OVRPlugin.Fovf();
		fov.UpTan = fov.DownTan = Mathf.Tan(vFov * 0.5f);
		fov.LeftTan = fov.RightTan = Mathf.Tan(hFov * 0.5f);

		cameraIntrinsics.FOVPort = fov;
		cameraIntrinsics.VirtualNearPlaneDistanceMeters = defaultExternalCamera.nearClipPlane;
		cameraIntrinsics.VirtualFarPlaneDistanceMeters = defaultExternalCamera.farClipPlane;
		cameraIntrinsics.ImageSensorPixelResolution.w = cameraPixelWidth;
		cameraIntrinsics.ImageSensorPixelResolution.h = cameraPixelHeight;

		// extrinsics

		cameraExtrinsics.IsValid = OVRPlugin.Bool.True;
		cameraExtrinsics.LastChangedTimeSeconds = Time.time;
		cameraExtrinsics.CameraStatusData = OVRPlugin.CameraStatus.CameraStatus_Calibrated;
		cameraExtrinsics.AttachedToNode = OVRPlugin.Node.None;

		Camera mainCamera = Camera.main;
		OVRCameraRig cameraRig = mainCamera.GetComponentInParent<OVRCameraRig>();
		if (cameraRig)
		{
			Transform trackingSpace = cameraRig.trackingSpace;
			OVRPose trackingSpacePose = trackingSpace.ToOVRPose(false);
			OVRPose cameraPose = defaultExternalCamera.transform.ToOVRPose(false);
			OVRPose relativePose = trackingSpacePose.Inverse() * cameraPose;
#if OVR_ANDROID_MRC
			OVRPose stageToLocalPose = OVRPlugin.GetTrackingTransformRelativePose(OVRPlugin.TrackingOrigin.Stage).ToOVRPose();
			OVRPose localToStagePose = stageToLocalPose.Inverse();
			relativePose = localToStagePose * relativePose;
#endif
			cameraExtrinsics.RelativePose = relativePose.ToPosef();
		}
		else
		{
			cameraExtrinsics.RelativePose = OVRPlugin.Posef.identity;
		}

		if (!OVRPlugin.SetDefaultExternalCamera(cameraName, ref cameraIntrinsics, ref cameraExtrinsics))
		{
			Debug.LogError("SetDefaultExternalCamera() failed");
		}
#endif
	}

	// Update is called once per frame
	void Update () {
#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN || OVR_ANDROID_MRC
		if (!inited)
		{
			Initialize();
			return;
		}

		if (!defaultExternalCamera)
		{
			return;
		}

#if OVR_ANDROID_MRC
		if (!OVRPlugin.Media.GetInitialized())
		{
			return;
		}
#else
		if (!OVRPlugin.IsMixedRealityInitialized())
		{
			return;
		}
#endif

		if (OVRInput.GetDown(OVRInput.Button.One))
		{
			if (currentMode == CameraMode.ThirdPerson)
			{
				currentMode = CameraMode.Normal;
			}
			else
			{
				currentMode = currentMode + 1;
			}

			Debug.LogFormat("Camera mode change to {0}", currentMode);
		}
		
		if (currentMode == CameraMode.Normal)
		{
			UpdateDefaultExternalCamera();
			OVRPlugin.OverrideExternalCameraFov(0, false, new OVRPlugin.Fovf());
			OVRPlugin.OverrideExternalCameraStaticPose(0, false, OVRPlugin.Posef.identity);
		}
		else if (currentMode == CameraMode.OverrideFov)
		{
			OVRPlugin.Fovf fov = defaultFov;
			OVRPlugin.Fovf newFov = new OVRPlugin.Fovf();
			newFov.LeftTan = fov.LeftTan * 2.0f;
			newFov.RightTan = fov.RightTan * 2.0f;
			newFov.UpTan = fov.UpTan * 2.0f;
			newFov.DownTan = fov.DownTan * 2.0f;

			OVRPlugin.OverrideExternalCameraFov(0, true, newFov);
			OVRPlugin.OverrideExternalCameraStaticPose(0, false, OVRPlugin.Posef.identity);

			if (!OVRPlugin.GetUseOverriddenExternalCameraFov(0))
			{
				Debug.LogWarning("FOV not overridden");
			}
		}
		else if (currentMode == CameraMode.ThirdPerson)
		{
			Camera camera = GetComponent<Camera>();
			if (camera == null)
			{
				return;
			}

			float vFov = camera.fieldOfView * Mathf.Deg2Rad;
			float hFov = Mathf.Atan(Mathf.Tan(vFov * 0.5f) * camera.aspect) * 2.0f;
			OVRPlugin.Fovf fov = new OVRPlugin.Fovf();
			fov.UpTan = fov.DownTan = Mathf.Tan(vFov * 0.5f);
			fov.LeftTan = fov.RightTan = Mathf.Tan(hFov * 0.5f);
			OVRPlugin.OverrideExternalCameraFov(0, true, fov);

			Camera mainCamera = Camera.main;
			OVRCameraRig cameraRig = mainCamera.GetComponentInParent<OVRCameraRig>();
			if (cameraRig)
			{
				Transform trackingSpace = cameraRig.trackingSpace;
				OVRPose trackingSpacePose = trackingSpace.ToOVRPose(false);
				OVRPose cameraPose = transform.ToOVRPose(false);
				OVRPose relativePose = trackingSpacePose.Inverse() * cameraPose;
				OVRPose stageToLocalPose = OVRPlugin.GetTrackingTransformRelativePose(OVRPlugin.TrackingOrigin.Stage).ToOVRPose();
				OVRPose localToStagePose = stageToLocalPose.Inverse();
				OVRPose relativePoseInStage = localToStagePose * relativePose;
				OVRPlugin.Posef relativePosef = relativePoseInStage.ToPosef();
				OVRPlugin.OverrideExternalCameraStaticPose(0, true, relativePosef);
			}
			else
			{
				OVRPlugin.OverrideExternalCameraStaticPose(0, false, OVRPlugin.Posef.identity);
			}

			if (!OVRPlugin.GetUseOverriddenExternalCameraFov(0))
			{
				Debug.LogWarning("FOV not overridden");
			}

			if (!OVRPlugin.GetUseOverriddenExternalCameraStaticPose(0))
			{
				Debug.LogWarning("StaticPose not overridden");
			}
		}
#endif
	}
}