#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;
using HeuristicLab.DataImporter.Data.CommandBase;
using HeuristicLab.DataImporter.Data.Model;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.DataImporter.Command {
  [StorableClass]
  [ViewableCommandInfo("Split Dictionary-style Data", 1, ColumnGroupState.ColumnSelected | ColumnGroupState.Sorted, "Column Commands",
    Position = 15)]
  public class SplitDictionaryStyleDataCommand : ColumnGroupCommandWithAffectedColumnsBase {
    private int addedColumnsCount;
    [StorableConstructor]
    protected SplitDictionaryStyleDataCommand(bool deserializing) : base(deserializing) { }

    public SplitDictionaryStyleDataCommand(DataSet dataSet, string columnGroupName, int[] affectedColumns)
      : base(dataSet, columnGroupName, affectedColumns) {
    }

    public override string Description {
      get { return "Split dictionary style data"; }
    }

    public override void Execute() {
      base.Execute();
      if (ColumnGroup.SortedColumnIndexes.Except(AffectedColumns).Count() != 1 &&
        ColumnGroup.SortedColumnIndexes.Except(AffectedColumns).FirstOrDefault() == ColumnGroup.SortedColumnIndexes.ElementAt(0))
        throw new CommandExecutionException("Exactly one column must be sorted as first sorted column and not selected to define the equality of the rows.", this);
      if (AffectedColumns.Intersect(ColumnGroup.SortedColumnIndexes).Count() != 1)
        throw new CommandExecutionException("Exactly one column must be sorted and selected to define the column which holds the grouping value.", this);
      if (!AffectedColumns.Except(ColumnGroup.SortedColumnIndexes).Any())
        throw new CommandExecutionException("At least one column must not be sorted but selected to define the column which holds the values for new columns.", this);

      Dictionary<IComparable, List<ColumnBase>> newColumns = new Dictionary<IComparable, List<ColumnBase>>();

      ColumnBase groupColumn = ColumnGroup.GetColumn(ColumnGroup.SortedColumnIndexes.Except(AffectedColumns).First());
      if (groupColumn.ContainsNullValues) throw new CommandExecutionException("Column which defines the equality (" + groupColumn.Name + ") must not contain NULL values.", this);

      ColumnBase splitColumn = ColumnGroup.GetColumn(ColumnGroup.SortedColumnIndexes.Intersect(AffectedColumns).First());
      var valueColumns = AffectedColumns.Except(ColumnGroup.SortedColumnIndexes).Select(index => ColumnGroup.GetColumn(index)).ToList();

      IComparable groupValue = groupColumn.GetValue(0); ;
      IComparable splitValue;
      int groupStartIndex = 0;
      for (int row = 0; row < ColumnGroup.RowCount; row++) {
        //check if equality value is still the same
        if (groupValue.CompareTo(groupColumn.GetValue(row)) != 0) {
          groupValue = groupColumn.GetValue(row);
          groupStartIndex = row;
        }
        splitValue = splitColumn.GetValue(row);

        //create new column if new group value was detected
        if (!newColumns.ContainsKey(splitValue)) {
          newColumns.Add(splitValue, new List<ColumnBase>(valueColumns.Count));
          int i = 0;
          foreach (var valueColumn in valueColumns) {
            var newColumn = valueColumn.CreateCopyOfColumnWithoutValues(valueColumn.TotalValuesCount);
            newColumn.Name += "_" + splitValue;
            newColumn.Resize(ColumnGroup.RowCount);
            newColumns[splitValue].Add(newColumn);
            i++;
          }
        }


        for (int i = groupStartIndex; i < ColumnGroup.RowCount && groupValue.CompareTo(groupColumn.GetValue(i)) == 0; i++) {
          for (int col = 0; col < valueColumns.Count; col++)
            newColumns[splitValue][col].ChangeValue(i, valueColumns[col].GetValue(row));
        }
      }

      ColumnGroup.AddColumns(newColumns.Values.SelectMany(col => col));
      addedColumnsCount = newColumns.Values.Sum(columns => columns.Count);
      this.ColumnGroup.FireChanged();
      this.ColumnGroup = null;
    }

    public override void UndoExecute() {
      base.UndoExecute();
      for (int i = 0; i < addedColumnsCount; i++)
        ColumnGroup.RemoveColumn(ColumnGroup.Columns.Count() - 1);
      this.ColumnGroup.FireChanged();
      this.ColumnGroup = null;
    }
  }
}