#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2011 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using HeuristicLab.DataImporter.Data;
using HeuristicLab.DataImporter.Data.CommandBase;
using HeuristicLab.DataImporter.Data.Model;
using HeuristicLab.DataImporter.Command.View;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.DataImporter.Command {
  [StorableClass]
  [ViewableCommandInfoAttribute("Scale to normal distribution", 1, ColumnGroupState.DoubleColumnSelected, "Change Values",
   Position = 5, OptionsView = typeof(NormalDistributionCommandView))]
  public class NormalDistributionScalingCommand : ColumnGroupCommandWithAffectedColumnsBase {
    private List<KeyValuePair<double, double>> oldNormalDistribution;

    private NormalDistributionScalingCommand()
      : base(null, string.Empty, null) {
      oldNormalDistribution = new List<KeyValuePair<double, double>>();
    }

    public NormalDistributionScalingCommand(DataSet dataSet, string columnGroupName, int[] affectedColumns)
      : base(dataSet, columnGroupName, affectedColumns) {
      oldNormalDistribution = new List<KeyValuePair<double, double>>();
    }

    public override string Description {
      get { return "Scale to normal distribution"; }
    }

    [Storable]
    private double newMean;
    public double Mean {
      get { return this.newMean; }
      set { this.newMean = value; }
    }

    [Storable]
    private double newStddev;
    public double StandardDeviation {
      get { return this.newStddev; }
      set { this.newStddev = value; }
    }

    public override void Execute() {
      base.Execute();
      DoubleColumn column;
      double oldMean;
      double oldStddev;
      for (int i = 0; i < AffectedColumns.Length; i++) {
        if (ColumnGroup.GetColumn(AffectedColumns[i]) is DoubleColumn) {
          column = (DoubleColumn)ColumnGroup.GetColumn(AffectedColumns[i]);
          if (column.NonNullValuesCount == 0)
            continue;
          oldMean = (double)column.Mean;
          oldStddev = (double)column.StandardDeviation;
          CalculateNewColumn(column, newMean, newStddev, oldMean, oldStddev);
          oldNormalDistribution.Add(new KeyValuePair<double, double>(oldMean, oldStddev));
        }
      }
      ColumnGroup.FireChanged();
      ColumnGroup = null;
    }

    public override void UndoExecute() {
      base.UndoExecute();
      DoubleColumn column;
      double oldMean;
      double oldStddev;
      int j = 0;
      for (int i = 0; i < AffectedColumns.Length; i++) {
        if (ColumnGroup.GetColumn(AffectedColumns[i]) is DoubleColumn) {
          column = (DoubleColumn)ColumnGroup.GetColumn(AffectedColumns[i]);
          if (column.NonNullValuesCount == 0)
            continue;
          oldMean = oldNormalDistribution[j].Key;
          oldStddev = oldNormalDistribution[j].Value;
          CalculateNewColumn(column, oldMean, oldStddev, newMean, newStddev);
          j++;
        }
      }
      oldNormalDistribution.Clear();
      ColumnGroup.FireChanged();
      ColumnGroup = null;

    }

    private void CalculateNewColumn(DoubleColumn column, double newMean, double newStddev, double oldMean, double oldStddev) {
      double newValue;
      double oldValue;
      for (int val = 0; val < column.TotalValuesCount; val++) {
        if (column.GetValue(val) == null)
          continue;
        oldValue = (double)column.GetValue(val);
        if (oldStddev == 0)
          newValue = oldValue - oldMean + newMean;
        else
          newValue = ((oldValue - oldMean) / oldStddev) * newStddev + newMean;
        column.ChangeValue(val, newValue);
      }
    }
  }
}