using UnityEngine;
using UnityEngine.UI;
using UnityEngine.SceneManagement;
using System.Collections;
using System.Collections.Generic;
using OpenCVForUnity.CoreModule;
using OpenCVForUnity.Calib3dModule;
using OpenCVForUnity.ArucoModule;
using OpenCVForUnity.UnityUtils;

namespace OpenCVForUnityExample
{
    /// <summary>
    /// ArUco Example
    /// An example of marker-based AR view and camera pose estimation using the aruco (ArUco Marker Detection) module.
    /// Referring to https://github.com/opencv/opencv_contrib/blob/master/modules/aruco/samples/detect_markers.cpp.
    /// http://docs.opencv.org/3.1.0/d5/dae/tutorial_aruco_detection.html
    /// </summary>
    public class ArUcoExample : MonoBehaviour
    {
        /// <summary>
        /// The image texture.
        /// </summary>
        public Texture2D imgTexture;

        [Space (10)]

        /// <summary>
        /// The dictionary identifier.
        /// </summary>
        public ArUcoDictionary dictionaryId = ArUcoDictionary.DICT_6X6_250;

        /// <summary>
        /// The dictionary id dropdown.
        /// </summary>
        public Dropdown dictionaryIdDropdown;
        
        /// <summary>
        /// Determines if shows rejected corners.
        /// </summary>
        public bool showRejectedCorners = false;

        /// <summary>
        /// The shows rejected corners toggle.
        /// </summary>
        public Toggle showRejectedCornersToggle;
        
        /// <summary>
        /// Determines if applied the pose estimation.
        /// </summary>
        public bool applyEstimationPose = true;
        
        /// <summary>
        /// The length of the markers' side. Normally, unit is meters.
        /// </summary>
        public float markerLength = 0.1f;

        /// <summary>
        /// The AR game object.
        /// </summary>
        public GameObject arGameObject;
        
        /// <summary>
        /// The AR camera.
        /// </summary>
        public Camera arCamera;

        [Space (10)]

        /// <summary>
        /// Determines if request the AR camera moving.
        /// </summary>
        public bool shouldMoveARCamera = false;

        /// <summary>
        /// The rgb mat.
        /// </summary>
        Mat rgbMat;

        /// <summary>
        /// The texture.
        /// </summary>
        Texture2D texture;
        
        // Use this for initialization
        void Start ()
        {
            rgbMat = new Mat (imgTexture.height, imgTexture.width, CvType.CV_8UC3);
            texture = new Texture2D (rgbMat.cols (), rgbMat.rows (), TextureFormat.RGBA32, false);
            gameObject.GetComponent<Renderer> ().material.mainTexture = texture;

            dictionaryIdDropdown.value = (int)dictionaryId;
            showRejectedCornersToggle.isOn = showRejectedCorners;
            DetectMarkers ();
        }
        
        // Update is called once per frame
        void Update ()
        {
            
        }

        private void DetectMarkers ()
        {
            Utils.texture2DToMat (imgTexture, rgbMat);
            Debug.Log ("imgMat dst ToString " + rgbMat.ToString ());

            gameObject.transform.localScale = new Vector3 (imgTexture.width, imgTexture.height, 1);
            Debug.Log ("Screen.width " + Screen.width + " Screen.height " + Screen.height + " Screen.orientation " + Screen.orientation);

            float width = rgbMat.width ();
            float height = rgbMat.height ();

            float imageSizeScale = 1.0f;
            float widthScale = (float)Screen.width / width;
            float heightScale = (float)Screen.height / height;
            if (widthScale < heightScale) {
                Camera.main.orthographicSize = (width * (float)Screen.height / (float)Screen.width) / 2;
                imageSizeScale = (float)Screen.height / (float)Screen.width;
            } else {
                Camera.main.orthographicSize = height / 2;
            }


            // set camera parameters.
            int max_d = (int)Mathf.Max (width, height);
            double fx = max_d;
            double fy = max_d;
            double cx = width / 2.0f;
            double cy = height / 2.0f;
            Mat camMatrix = new Mat (3, 3, CvType.CV_64FC1);
            camMatrix.put (0, 0, fx);
            camMatrix.put (0, 1, 0);
            camMatrix.put (0, 2, cx);
            camMatrix.put (1, 0, 0);
            camMatrix.put (1, 1, fy);
            camMatrix.put (1, 2, cy);
            camMatrix.put (2, 0, 0);
            camMatrix.put (2, 1, 0);
            camMatrix.put (2, 2, 1.0f);
            Debug.Log ("camMatrix " + camMatrix.dump ());


            MatOfDouble distCoeffs = new MatOfDouble (0, 0, 0, 0);
            Debug.Log ("distCoeffs " + distCoeffs.dump ());


            // calibration camera matrix values.
            Size imageSize = new Size (width * imageSizeScale, height * imageSizeScale);
            double apertureWidth = 0;
            double apertureHeight = 0;
            double[] fovx = new double[1];
            double[] fovy = new double[1];
            double[] focalLength = new double[1];
            Point principalPoint = new Point (0, 0);
            double[] aspectratio = new double[1];

            Calib3d.calibrationMatrixValues (camMatrix, imageSize, apertureWidth, apertureHeight, fovx, fovy, focalLength, principalPoint, aspectratio);

            Debug.Log ("imageSize " + imageSize.ToString ());
            Debug.Log ("apertureWidth " + apertureWidth);
            Debug.Log ("apertureHeight " + apertureHeight);
            Debug.Log ("fovx " + fovx [0]);
            Debug.Log ("fovy " + fovy [0]);
            Debug.Log ("focalLength " + focalLength [0]);
            Debug.Log ("principalPoint " + principalPoint.ToString ());
            Debug.Log ("aspectratio " + aspectratio [0]);


            // To convert the difference of the FOV value of the OpenCV and Unity. 
            double fovXScale = (2.0 * Mathf.Atan ((float)(imageSize.width / (2.0 * fx)))) / (Mathf.Atan2 ((float)cx, (float)fx) + Mathf.Atan2 ((float)(imageSize.width - cx), (float)fx));
            double fovYScale = (2.0 * Mathf.Atan ((float)(imageSize.height / (2.0 * fy)))) / (Mathf.Atan2 ((float)cy, (float)fy) + Mathf.Atan2 ((float)(imageSize.height - cy), (float)fy));

            Debug.Log ("fovXScale " + fovXScale);
            Debug.Log ("fovYScale " + fovYScale);


            // Adjust Unity Camera FOV https://github.com/opencv/opencv/commit/8ed1945ccd52501f5ab22bdec6aa1f91f1e2cfd4
            if (widthScale < heightScale) {
                arCamera.fieldOfView = (float)(fovx [0] * fovXScale);
            } else {
                arCamera.fieldOfView = (float)(fovy [0] * fovYScale);
            }
            // Display objects near the camera.
            arCamera.nearClipPlane = 0.01f;



            Mat ids = new Mat ();
            List<Mat> corners = new List<Mat> ();
            List<Mat> rejectedCorners = new List<Mat> ();
            Mat rvecs = new Mat ();
            Mat tvecs = new Mat ();
            Mat rotMat = new Mat (3, 3, CvType.CV_64FC1);

            DetectorParameters detectorParams = DetectorParameters.create ();
            Dictionary dictionary = Aruco.getPredefinedDictionary ((int)dictionaryId);


            // detect markers.
            Aruco.detectMarkers (rgbMat, dictionary, corners, ids, detectorParams, rejectedCorners, camMatrix, distCoeffs);

            // if at least one marker detected
            if (ids.total () > 0) {
                Aruco.drawDetectedMarkers (rgbMat, corners, ids, new Scalar (0, 255, 0));

                // estimate pose.
                if (applyEstimationPose) {
                    Aruco.estimatePoseSingleMarkers (corners, markerLength, camMatrix, distCoeffs, rvecs, tvecs);

                    for (int i = 0; i < ids.total (); i++) {
                        using (Mat rvec = new Mat (rvecs, new OpenCVForUnity.CoreModule.Rect (0, i, 1, 1)))
                        using (Mat tvec = new Mat (tvecs, new OpenCVForUnity.CoreModule.Rect (0, i, 1, 1))) {
                            
                            // In this example we are processing with RGB color image, so Axis-color correspondences are X: blue, Y: green, Z: red. (Usually X: red, Y: green, Z: blue)
                            Aruco.drawAxis (rgbMat, camMatrix, distCoeffs, rvec, tvec, markerLength * 0.5f);
                        }
                        
                        // This example can display the ARObject on only first detected marker.
                        if (i == 0) {

                            // Position
                            double[] tvecArr = tvecs.get (i, 0);

                            // Rotation
                            double[] rvecArr = rvecs.get (i, 0);
                            Mat rvec = new Mat (3, 1, CvType.CV_64FC1);
                            rvec.put (0, 0, rvecArr);
                            Calib3d.Rodrigues (rvec, rotMat);

                            double[] rotMatArr = new double[rotMat.total ()];
                            rotMat.get (0, 0, rotMatArr);

                            Matrix4x4 transformationM = new Matrix4x4 (); // from OpenCV
                            transformationM.SetRow (0, new Vector4 ((float)rotMatArr [0], (float)rotMatArr [1], (float)rotMatArr [2], (float)tvecArr [0]));
                            transformationM.SetRow (1, new Vector4 ((float)rotMatArr [3], (float)rotMatArr [4], (float)rotMatArr [5], (float)tvecArr [1]));
                            transformationM.SetRow (2, new Vector4 ((float)rotMatArr [6], (float)rotMatArr [7], (float)rotMatArr [8], (float)tvecArr [2]));
                            transformationM.SetRow (3, new Vector4 (0, 0, 0, 1));
                            Debug.Log ("transformationM " + transformationM.ToString ());

                            Matrix4x4 invertZM = Matrix4x4.TRS (Vector3.zero, Quaternion.identity, new Vector3 (1, 1, -1));
                            Debug.Log ("invertZM " + invertZM.ToString ());

                            Matrix4x4 invertYM = Matrix4x4.TRS (Vector3.zero, Quaternion.identity, new Vector3 (1, -1, 1));
                            Debug.Log ("invertYM " + invertYM.ToString ());

                            // right-handed coordinates system (OpenCV) to left-handed one (Unity)
                            Matrix4x4 ARM = invertYM * transformationM;

                            // Apply Z-axis inverted matrix.
                            ARM = ARM * invertZM;

                            if (shouldMoveARCamera) {

                                ARM = arGameObject.transform.localToWorldMatrix * ARM.inverse;

                                Debug.Log ("ARM " + ARM.ToString ());

                                ARUtils.SetTransformFromMatrix (arCamera.transform, ref ARM);

                            } else {

                                ARM = arCamera.transform.localToWorldMatrix * ARM;

                                Debug.Log ("ARM " + ARM.ToString ());

                                ARUtils.SetTransformFromMatrix (arGameObject.transform, ref ARM);
                            }
                        }
                    }
                }
            }

            if (showRejectedCorners && rejectedCorners.Count > 0)
                Aruco.drawDetectedMarkers (rgbMat, rejectedCorners, new Mat (), new Scalar (255, 0, 0));

            Utils.matToTexture2D (rgbMat, texture);
        }

        private void ResetObjectTransform ()
        {
            // reset AR object transform.
            Matrix4x4 i = Matrix4x4.identity;
            ARUtils.SetTransformFromMatrix (arCamera.transform, ref i);
            ARUtils.SetTransformFromMatrix (arGameObject.transform, ref i);
        }

        /// <summary>
        /// Raises the destroy event.
        /// </summary>
        void OnDestroy ()
        {
            if (rgbMat != null)
                rgbMat.Dispose ();
        }

        /// <summary>
        /// Raises the back button click event.
        /// </summary>
        public void OnBackButtonClick ()
        {
            SceneManager.LoadScene ("OpenCVForUnityExample");
        }

        /// <summary>
        /// Raises the dictionary id dropdown value changed event.
        /// </summary>
        public void OnDictionaryIdDropdownValueChanged (int result)
        {
            if ((int)dictionaryId != result) {
                dictionaryId = (ArUcoDictionary)result;

                ResetObjectTransform ();

                DetectMarkers ();
            }
        }

        /// <summary>
        /// Raises the show rejected corners toggle value changed event.
        /// </summary>
        public void OnShowRejectedCornersToggleValueChanged ()
        {
            if (showRejectedCorners != showRejectedCornersToggle.isOn) {
                showRejectedCorners = showRejectedCornersToggle.isOn;

                ResetObjectTransform ();

                DetectMarkers ();
            }
        }

        public enum ArUcoDictionary
        {
            DICT_4X4_50 = Aruco.DICT_4X4_50,
            DICT_4X4_100 = Aruco.DICT_4X4_100,
            DICT_4X4_250 = Aruco.DICT_4X4_250,
            DICT_4X4_1000 = Aruco.DICT_4X4_1000,
            DICT_5X5_50 = Aruco.DICT_5X5_50,
            DICT_5X5_100 = Aruco.DICT_5X5_100,
            DICT_5X5_250 = Aruco.DICT_5X5_250,
            DICT_5X5_1000 = Aruco.DICT_5X5_1000,
            DICT_6X6_50 = Aruco.DICT_6X6_50,
            DICT_6X6_100 = Aruco.DICT_6X6_100,
            DICT_6X6_250 = Aruco.DICT_6X6_250,
            DICT_6X6_1000 = Aruco.DICT_6X6_1000,
            DICT_7X7_50 = Aruco.DICT_7X7_50,
            DICT_7X7_100 = Aruco.DICT_7X7_100,
            DICT_7X7_250 = Aruco.DICT_7X7_250,
            DICT_7X7_1000 = Aruco.DICT_7X7_1000,
            DICT_ARUCO_ORIGINAL = Aruco.DICT_ARUCO_ORIGINAL,
        }
    }
}