#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2013 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 HeuristicLab.DataImporter.Data.CommandBase;
using HeuristicLab.DataImporter.Data.Model;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.DataImporter.Command {
  [StorableClass]
  public abstract class AggregateCommandBase : ColumnGroupCommandWithAffectedColumnsBase {
    [StorableConstructor]
    protected AggregateCommandBase(bool deserializing)
      : base(deserializing) {
      oldColumns = new List<ColumnBase>();
      newColumns = new List<ColumnBase>();
      positions = new List<int>();
    }

    protected AggregateCommandBase(DataSet dataSet, string columnGroupName, int[] affectedColumns)
      : base(dataSet, columnGroupName, affectedColumns) {
      oldColumns = new List<ColumnBase>();
      newColumns = new List<ColumnBase>();
      positions = new List<int>();
      changeNullValuesOnly = true;
    }

    private List<ColumnBase> oldColumns;
    protected List<ColumnBase> OldColumns {
      get { return this.oldColumns; }
    }

    private List<ColumnBase> newColumns;
    protected List<ColumnBase> NewColumns {
      get { return this.newColumns; }
    }

    private List<int> positions;
    protected List<int> Positions {
      get { return this.positions; }
    }

    [Storable]
    private bool changeNullValuesOnly;
    public bool ChangeNullValueOnly {
      get { return this.changeNullValuesOnly; }
      set { this.changeNullValuesOnly = value; }
    }

    protected abstract IComparable AggregationFunction(ColumnBase col, int startIndex, int endIndex);

    public override void Execute() {
      base.Execute();
      if (!ColumnGroup.Columns.Any()) return;
      if (!ColumnGroup.Sorted)
        throw new CommandExecutionException("ColumnGroup must be sorted to use aggregation commands.", this);
      ColumnBase col;
      for (int i = 0; i < AffectedColumns.Length; i++) {
        col = ColumnGroup.Columns.ElementAt(AffectedColumns[i]);
        if (col.DataType == typeof(double?) && !ColumnGroup.SortedColumnIndexes.Contains(AffectedColumns[i])) {
          OldColumns.Add(col);
          NewColumns.Add(col.CreateCopyOfColumnWithoutValues());
          Positions.Add(AffectedColumns[i]);
        }
      }
      IComparable keyValue = ColumnGroup.KeyString(0);
      IComparable aggregatedValue;
      int startIndex = 0;
      int endIndex = -1;
      for (int i = 1; i <= ColumnGroup.RowCount; i++) {
        if (i == ColumnGroup.RowCount || keyValue.CompareTo(ColumnGroup.KeyString(i)) != 0) {
          endIndex = i;
          for (int colIndex = 0; colIndex < OldColumns.Count; colIndex++) {
            aggregatedValue = AggregationFunction(OldColumns[colIndex], startIndex, endIndex);
            //add aggregatedValue for each row with the same keyColumnValue
            for (int j = startIndex; j < endIndex; j++) {
              if (!changeNullValuesOnly || OldColumns[colIndex].GetValue(j) == null)
                NewColumns[colIndex].AddValue(aggregatedValue);
              else
                NewColumns[colIndex].AddValue(OldColumns[colIndex].GetValue(j));
            }
          }
          if (i != ColumnGroup.RowCount) {
            startIndex = i;
            keyValue = ColumnGroup.KeyString(i);
          }
        }
      }

      for (int i = 0; i < Positions.Count; i++) {
        ColumnGroup.ReplaceColumn(Positions[i], NewColumns[i]);
        OldColumns[i].Selected = false;
      }
      NewColumns.Clear();
      ColumnGroup.FireChanged();
      ColumnGroup = null;
    }

    public override void UndoExecute() {
      base.UndoExecute();
      for (int i = 0; i < Positions.Count; i++) {
        ColumnGroup.ReplaceColumn(Positions[i], OldColumns[i]);
      }
      OldColumns.Clear();
      Positions.Clear();
      ColumnGroup.FireChanged();
      ColumnGroup = null;
    }
  }
}