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

#if UNITY_5_3 || UNITY_5_3_OR_NEWER
using UnityEngine.SceneManagement;
#endif
using OpenCVForUnity;

namespace OpenCVForUnitySample
{
		/// <summary>
		/// Optical flow sample.
		/// http://stackoverflow.com/questions/6505779/android-optical-flow-with-opencv?rq=1
		/// </summary>
		public class OpticalFlowSample : MonoBehaviour
		{

				/// <summary>
				/// The colors.
				/// </summary>
				Color32[] colors;
		
				/// <summary>
				/// The mat op flow this.
				/// </summary>
				Mat matOpFlowThis;

				/// <summary>
				/// The mat op flow previous.
				/// </summary>
				Mat matOpFlowPrev;

				/// <summary>
				/// The i GFFT max.
				/// </summary>
				int iGFFTMax = 40;

				/// <summary>
				/// The MO pcorners.
				/// </summary>
				MatOfPoint MOPcorners;

				/// <summary>
				/// The m MO p2fpts this.
				/// </summary>
				MatOfPoint2f mMOP2fptsThis;

				/// <summary>
				/// The m MO p2fpts previous.
				/// </summary>
				MatOfPoint2f mMOP2fptsPrev;

				/// <summary>
				/// The m MO p2fpts safe.
				/// </summary>
				MatOfPoint2f mMOP2fptsSafe;

				/// <summary>
				/// The m MOB status.
				/// </summary>
				MatOfByte mMOBStatus;

				/// <summary>
				/// The m MO ferr.
				/// </summary>
				MatOfFloat mMOFerr;

				/// <summary>
				/// The color red.
				/// </summary>
				Scalar colorRed = new Scalar (255, 0, 0, 255);

				/// <summary>
				/// The i line thickness.
				/// </summary>
				int iLineThickness = 3;

				/// <summary>
				/// The texture.
				/// </summary>
				Texture2D texture;

				/// <summary>
				/// The web cam texture to mat helper.
				/// </summary>
				WebCamTextureToMatHelper webCamTextureToMatHelper;

	
				// Use this for initialization
				void Start ()
				{

						webCamTextureToMatHelper = gameObject.GetComponent<WebCamTextureToMatHelper> ();
						webCamTextureToMatHelper.Init ();
	
				}

				/// <summary>
				/// Raises the web cam texture to mat helper inited event.
				/// </summary>
				public void OnWebCamTextureToMatHelperInited ()
				{
						Debug.Log ("OnWebCamTextureToMatHelperInited");
			
						Mat webCamTextureMat = webCamTextureToMatHelper.GetMat ();
			
						colors = new Color32[webCamTextureMat.cols () * webCamTextureMat.rows ()];
						texture = new Texture2D (webCamTextureMat.cols (), webCamTextureMat.rows (), TextureFormat.RGBA32, false);

						matOpFlowThis = new Mat ();
						matOpFlowPrev = new Mat ();
						MOPcorners = new MatOfPoint ();
						mMOP2fptsThis = new MatOfPoint2f ();
						mMOP2fptsPrev = new MatOfPoint2f ();
						mMOP2fptsSafe = new MatOfPoint2f ();
						mMOBStatus = new MatOfByte ();
						mMOFerr = new MatOfFloat ();

			
						gameObject.transform.localScale = new Vector3 (webCamTextureMat.cols (), webCamTextureMat.rows (), 1);
			
						Debug.Log ("Screen.width " + Screen.width + " Screen.height " + Screen.height + " Screen.orientation " + Screen.orientation);
			
						float width = 0;
						float height = 0;
			
						width = gameObject.transform.localScale.x;
						height = gameObject.transform.localScale.y;
			
						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;
						} else {
								Camera.main.orthographicSize = height / 2;
						}
			
						gameObject.GetComponent<Renderer> ().material.mainTexture = texture;
			
						//			webCamTextureToMatHelper.Play ();
				}

				/// <summary>
				/// Raises the web cam texture to mat helper disposed event.
				/// </summary>
				public void OnWebCamTextureToMatHelperDisposed ()
				{
						Debug.Log ("OnWebCamTextureToMatHelperDisposed");

						if (matOpFlowThis != null)
								matOpFlowThis.Dispose ();
						if (matOpFlowPrev != null)
								matOpFlowPrev.Dispose ();
						if (MOPcorners != null)
								MOPcorners.Dispose ();
						if (mMOP2fptsThis != null)
								mMOP2fptsThis.Dispose ();
						if (mMOP2fptsPrev != null)
								mMOP2fptsPrev.Dispose ();
						if (mMOP2fptsSafe != null)
								mMOP2fptsSafe.Dispose ();
						if (mMOBStatus != null)
								mMOBStatus.Dispose ();
						if (mMOFerr != null)
								mMOFerr.Dispose ();
				}
		

				// Update is called once per frame
				void Update ()
				{

						if (webCamTextureToMatHelper.isPlaying () && webCamTextureToMatHelper.didUpdateThisFrame ()) {
				
								Mat rgbaMat = webCamTextureToMatHelper.GetMat ();

								if (mMOP2fptsPrev.rows () == 0) {
				
										// first time through the loop so we need prev and this mats
										// plus prev points
										// get this mat
										Imgproc.cvtColor (rgbaMat, matOpFlowThis, Imgproc.COLOR_RGBA2GRAY);
									
										// copy that to prev mat
										matOpFlowThis.copyTo (matOpFlowPrev);
									
										// get prev corners
										Imgproc.goodFeaturesToTrack (matOpFlowPrev, MOPcorners, iGFFTMax, 0.05, 20);
										mMOP2fptsPrev.fromArray (MOPcorners.toArray ());
									
										// get safe copy of this corners
										mMOP2fptsPrev.copyTo (mMOP2fptsSafe);
								} else {
										// we've been through before so
										// this mat is valid. Copy it to prev mat
										matOpFlowThis.copyTo (matOpFlowPrev);
									
										// get this mat
										Imgproc.cvtColor (rgbaMat, matOpFlowThis, Imgproc.COLOR_RGBA2GRAY);
									
										// get the corners for this mat
										Imgproc.goodFeaturesToTrack (matOpFlowThis, MOPcorners, iGFFTMax, 0.05, 20);
										mMOP2fptsThis.fromArray (MOPcorners.toArray ());
									
										// retrieve the corners from the prev mat
										// (saves calculating them again)
										mMOP2fptsSafe.copyTo (mMOP2fptsPrev);
									
										// and save this corners for next time through
									
										mMOP2fptsThis.copyTo (mMOP2fptsSafe);
								}
								
								
								/*
				    Parameters:
				        prevImg first 8-bit input image
				        nextImg second input image
				        prevPts vector of 2D points for which the flow needs to be found; point coordinates must be single-precision floating-point numbers.
				        nextPts output vector of 2D points (with single-precision floating-point coordinates) containing the calculated new positions of input features in the second image; when OPTFLOW_USE_INITIAL_FLOW flag is passed, the vector must have the same size as in the input.
				        status output status vector (of unsigned chars); each element of the vector is set to 1 if the flow for the corresponding features has been found, otherwise, it is set to 0.
				        err output vector of errors; each element of the vector is set to an error for the corresponding feature, type of the error measure can be set in flags parameter; if the flow wasn't found then the error is not defined (use the status parameter to find such cases).
				    */
								Video.calcOpticalFlowPyrLK (matOpFlowPrev, matOpFlowThis, mMOP2fptsPrev, mMOP2fptsThis, mMOBStatus, mMOFerr);
				
								if (!mMOBStatus.empty ()) {
										List<Point> cornersPrev = mMOP2fptsPrev.toList ();
										List<Point> cornersThis = mMOP2fptsThis.toList ();
										List<byte> byteStatus = mMOBStatus.toList ();
				
										int x = 0;
										int y = byteStatus.Count - 1;
													
										for (x = 0; x < y; x++) {
												if (byteStatus [x] == 1) {
														Point pt = cornersThis [x];
														Point pt2 = cornersPrev [x];
										
														Imgproc.circle (rgbaMat, pt, 5, colorRed, iLineThickness - 1);
										
														Imgproc.line (rgbaMat, pt, pt2, colorRed, iLineThickness);
												}
										}
								}
				
//				Imgproc.putText (rgbaMat, "W:" + rgbaMat.width () + " H:" + rgbaMat.height () + " SO:" + Screen.orientation, new Point (5, rgbaMat.rows () - 10), Core.FONT_HERSHEY_SIMPLEX, 1.0, new Scalar (255, 255, 255, 255), 2, Imgproc.LINE_AA, false);
				
								Utils.matToTexture2D (rgbaMat, texture, colors);
						}

				}
	
				/// <summary>
				/// Raises the disable event.
				/// </summary>
				void OnDisable ()
				{
						webCamTextureToMatHelper.Dispose ();
				}

				/// <summary>
				/// Raises the back button event.
				/// </summary>
				public void OnBackButton ()
				{
						#if UNITY_5_3 || UNITY_5_3_OR_NEWER
			SceneManager.LoadScene ("OpenCVForUnitySample");
						#else
						Application.LoadLevel ("OpenCVForUnitySample");
						#endif
				}

				/// <summary>
				/// Raises the play button event.
				/// </summary>
				public void OnPlayButton ()
				{
						webCamTextureToMatHelper.Play ();
				}

				/// <summary>
				/// Raises the pause button event.
				/// </summary>
				public void OnPauseButton ()
				{
						webCamTextureToMatHelper.Pause ();
				}

				/// <summary>
				/// Raises the stop button event.
				/// </summary>
				public void OnStopButton ()
				{
						webCamTextureToMatHelper.Stop ();
				}

				/// <summary>
				/// Raises the change camera button event.
				/// </summary>
				public void OnChangeCameraButton ()
				{
						webCamTextureToMatHelper.Init (null, webCamTextureToMatHelper.requestWidth, webCamTextureToMatHelper.requestHeight, !webCamTextureToMatHelper.requestIsFrontFacing);
				}
		}
}