using ChartAndGraph;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using UnityEngine;

namespace Assets.Scenes.Ride.Scripts
{
    public class ChartDataSourceScript:MonoBehaviour, IComparer<DoubleVector2>
    {
        public string Category = "Player 2";
        public int DownSampleToPoints = 100;
        List<DoubleVector2> mData = new List<DoubleVector2>();  // the data held by the chart
        double pageSize = 2f;
        double currentPagePosition = 0.0;
        double currentZoom = 0f;
        GraphChartBase graph;
        double mCurrentPageSizeFactor = double.NegativeInfinity;

        private void Start()
        {
            graph = GetComponent<GraphChartBase>();
        }
        bool VerifySorted(List<DoubleVector2> data)
        {
            if (data == null)
                return true;
            for (int i = 1; i < data.Count; i++)
            {
                if (data[i].x < data[i - 1].x)
                    return false;
            }
            return true;
        }
        void LoadWithoutDownSampling(int start, int end)
        {
            for (int i = start; i < end; i++) // load the data
            {
                graph.DataSource.AddPointToCategory("Player 2", mData[i].x, mData[i].y);
            }
          
        }
        public int total;
        void LoadWithDownSampling(int start, int end)
        {
             total = end - start;

            if (DownSampleToPoints >= total)
            {
                graph.DataSource.HorizontalViewSize = total;
                LoadWithoutDownSampling(start, end);
                return;
            }

            double sampleCount = ((double)total) / (double)DownSampleToPoints;
            // graph.DataSource.AddPointToCategory(Category, mData[start].x, mData[start].y);
            for (int i = 0; i < DownSampleToPoints; i++)
            {
                int fractionStart = start + (int)(i * sampleCount); // the first point with a fraction
                int fractionEnd = start + (int)((i + 1) * sampleCount); // the first point with a fraction
                fractionEnd = Math.Min(fractionEnd, mData.Count - 1);
                double x = 0, y = 0;
                double divide = 0.0;
                for (int j = fractionStart; j < fractionEnd; j++)  // avarge the poins
                {
                    x += mData[j].x;
                    y += mData[j].y;
                    divide++;
                }
                if (divide > 0.0)
                {
                    x /= divide;
                    y /= divide;
                    graph.DataSource.AddPointToCategory("Player 2", x, y);
                }
                else
                    Debug.Log("error");
            }
            //   graph.DataSource.AddPointToCategory(Category, mData[last].x, mData[last].y);
        }

        int FindClosestIndex(double position) // if you want to know what is index is currently displayed . use binary search to find it
        {
            //NOTE :: this method assumes your data is sorted !!! 
            int res = mData.BinarySearch(new DoubleVector2(position, 0.0), this);
            if (res >= 0)
                return res;
            return ~res;
        }

        double PageSizeFactor
        {
            get
            {
                return pageSize * graph.DataSource.HorizontalViewSize;
            }
        }
        void findPointsForPage(double position, out int start, out int end) // given a page position , find the right most and left most indices in the data for that page. 
        {
            int index = FindClosestIndex(position); // use binary search to find the closest position to the current scroll point

            double endPosition = position + PageSizeFactor;
            double startPosition = position - PageSizeFactor;

            //starting from the current index , we find the page boundries
            for (start = index; start > 0; start--)
            {
                if (mData[start].x < startPosition) // take the first point that is out of the page. so the graph doesn't break at the edge
                    break;
            }

            for (end = index; end < mData.Count; end++)
            {
                if (mData[end].x > endPosition) // take the first point that is out of the page
                    break;
            }

        }

        void LoadPage(double pagePosition)
        {
            if (graph != null)
            {

                Debug.Log("Loading page :" + pagePosition);
                graph.DataSource.StartBatch(); // call start batch 
                graph.DataSource.HorizontalViewOrigin = 0;
                int start, end;
                findPointsForPage(pagePosition, out start, out end); // get the page edges
                graph.DataSource.ClearCategory("Player 2"); // clear the cateogry

                if (DownSampleToPoints <= 0)
                    LoadWithoutDownSampling(start, end);
                else
                    LoadWithDownSampling(start, end);
                graph.DataSource.EndBatch();
                graph.HorizontalScrolling = pagePosition;
            }
            currentPagePosition = pagePosition;
        }
        public void SetData(List<DoubleVector2> data)
        {
            if (data == null)
                data = new List<DoubleVector2>(); // set up an empty list instead of null
            if (VerifySorted(data) == false)
            {
                Debug.LogWarning("The data used with large data feed must be sorted acoording to the x value, aborting operation");
                return;
            }
            mData = data;
            LoadPage(currentPagePosition); // load the page at position 0
        }

        public void SetDataSource(double[] data)
        {
            graph = GetComponent<GraphChartBase>();
            List<DoubleVector2> source = new List<DoubleVector2>();

            for (int i = 0; i < data.Length; i++)    // initialize with random data
            {
                source.Add(new DoubleVector2(i, data[i]));
            }
            SetData(source);
        }

        public int Compare(DoubleVector2 x, DoubleVector2 y)
        {
            if (x.x < y.x)
                return -1;
            if (x.x > y.x)
                return 1;
            return 0;
        }

        public void Update()
        {
            if (graph != null)
            {
                //check the scrolling position of the graph. if we are past the view size , load a new page
                double pageStartThreshold = currentPagePosition - mCurrentPageSizeFactor;
                double pageEndThreshold = currentPagePosition + mCurrentPageSizeFactor - graph.DataSource.HorizontalViewSize;

                if (graph.HorizontalScrolling < pageStartThreshold || graph.HorizontalScrolling > pageEndThreshold || currentZoom >= graph.DataSource.HorizontalViewSize * 2f)
                {
                    currentZoom = graph.DataSource.HorizontalViewSize;
                    mCurrentPageSizeFactor = PageSizeFactor * 0.9f;
                    LoadPage(graph.HorizontalScrolling);
                }
            }
        }
    }
}