///
/// Copyright (c) 2019 Sensus Slovensko a.s.
///
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Globalization;
using System.IO;
using System.Windows.Forms;
using System.Windows.Forms.DataVisualization.Charting;
using Results.Entities;
using ResultsBrowser.Resources;
using ResultsBrowser.Output.Printers.Statistics;

namespace ResultsBrowser.Forms
{
    public partial class HistogramDlg : Form
    {
        const int NrBins = 11;

        IList<WaterMeter> waterMeters;
        HistogramOptionsDlg options;

        public HistogramDlg(IList<WaterMeter> waterMeters, HistogramOptionsDlg options, string title)
        {
            InitializeComponent();

            this.waterMeters = waterMeters;
            this.options = options;
			Text = title;

            closeButton.Text = Strings.OkBtnText;
			printButton.Text = Strings.Print;
        }

        private void HistogramDlg_Load(object sender, EventArgs e)
        {
            CalculateAndDraw();
        }

        void CalculateAndDraw()
        {
            for (int i = 0; i < options.SelectedItems.Count; i++)
            {
                Results.WMeterRsltItemSpec item = options.SelectedItems[i];

                try
                {
                    /// Find minimum and maximum
                    double min = Double.MaxValue;
                    double max = Double.MinValue;
                    double sum = 0;
                    int count = 0;
                    foreach (var wm in waterMeters)
                    {
                        string strValue = item.Print(wm);
                        double value;
			            if (!double.TryParse(strValue, NumberStyles.AllowDecimalPoint | NumberStyles.AllowLeadingSign, CultureInfo.CurrentCulture, out value) &&
			                !double.TryParse(strValue, NumberStyles.AllowDecimalPoint | NumberStyles.AllowLeadingSign, CultureInfo.InvariantCulture, out value))
                        {
                            throw new Exception(string.Format("{0} is not a number, cannot calculate histogram", item.Caption));
                        }

                        sum += value;
                        count++;
                        if (min > value) min = value;
                        if (max < value) max = value;
                    }

                    double mean = (count != 0) ? (sum / count) : 0;     /// Prevent division by zero

                    ///
                    /// Determine limits for bins
                    /// 
                    double[] binHiLim;
                    string[] labels;
                    if ((-0.55 <= min) && (max <= 0.55))
                    {
                        labels   = new string[] { "-0.6",    "", "-0.4",    "", "-0.2",    "",   "0",   "", "0.2",   "", "0.4",   "", "0.6" };
                        binHiLim = new double[] {  -0.45,  -0.35, -0.25,  -0.15, -0.05,  0.05, 0.15,  0.25, 0.35,  0.45, 0.55 };
                    }
                    else if ((-1.1 <= min) && (max <= 1.1))
                    {
                        labels   = new string[] { "-1.2",   "", "-0.8",   "", "-0.4",   "",  "0",  "", "0.4",  "", "0.8",  "", "1.2" };
                        binHiLim = new double[] { -0.9,   -0.7, -0.5,   -0.3, -0.1,  0.1, 0.3,   0.5, 0.7,   0.9, 1.1 };
                    }
                    else if ((-2.2 <= min) && (max <= 2.2))
                    {
                        labels = new string[] { "-2.4", "", "-1.6", "", "-0.8", "", "0", "", "0.8", "", "1.6", "", "2.4" };
                        binHiLim = new double[] { -1.8, -1.4, -1.0, -0.6, -0.2, 0.2, 0.6, 1.0, 1.4, 1.8, 2.2 };
                    }
                    else if ((-4.4 <= min) && (max <= 4.4))
                    {
                        labels   = new string[] { "-4.8", "", "-3.2", "", "-1.6", "", "0", "", "1.6", "", "3.2", "", "4.8" };
                        binHiLim = new double[] { -3.6, -2.8, -2.0, -1.2, -0.4, 0.4, 1.2, 2.0, 2.8, 3.6, 4.4  };
                    }
                    else
                    {
                        labels   = new string[] { "-9.6",   "", "-6.4",   "", "-3.2",   "", "0",  "", "3.2",  "", "6.4",  "", "9.6" };
                        binHiLim = new double[] { -7.2,   -5.6, -4.0,   -2.4, -0.8, 0.8, 2.4,   4.0, 5.6,   7.2, 8.8 };
                    }

                    int nrBins = Math.Min(labels.Length - 1, binHiLim.Length + 1);

                    double[] bins = new double[nrBins];
                    for (int j = 0; j < nrBins; j++) bins[j] = 0;

					/// Calculate bins
                    foreach (var wm in waterMeters)
                    {
                        string strValue = item.Print(wm);
                        double value;
			            if (!double.TryParse(strValue, NumberStyles.AllowDecimalPoint | NumberStyles.AllowLeadingSign, CultureInfo.CurrentCulture, out value) &&
			                !double.TryParse(strValue, NumberStyles.AllowDecimalPoint | NumberStyles.AllowLeadingSign, CultureInfo.InvariantCulture, out value))
                        {
                            throw new Exception(string.Format("{0} is not a number, cannot calculate histogram", item.Caption));
                        }

                        for (int j = 0; j < nrBins - 1; j++)
                        {
                            if (value < binHiLim[j])
                            {
                                bins[j] += 1.0;
                                break;
                            }
                        }
                        if (value >= binHiLim[nrBins - 2])
                        {
                            bins[nrBins - 1] += 1.0;
                        }
                    }

                    ///
                    /// Draw
                    ///
					HistogramCtrl histo = new HistogramCtrl(string.Format("{0}   mean = {1}", item.Caption, mean.ToString("F3")), bins, labels);
					flowLayoutPanel1.Controls.Add(histo);
                }
                catch (Exception exc)
                {
					string msg = exc.Message;
                }
            }
        }

        private void closeButton_Click(object sender, EventArgs e)
        {
            DialogResult = DialogResult.OK;
            Close();
        }
    }
}