#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2018 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.Collections.Generic;
using System.Drawing;
using System.Linq;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
using HeuristicLab.Problems.DataAnalysis;

namespace HeuristicLab.DataPreprocessing {

  [Item("Transformation", "Represents the transformation grid.")]
  [StorableClass]
  public class TransformationContent : PreprocessingContent, IViewShortcut {
    public static new Image StaticItemImage {
      get { return HeuristicLab.Common.Resources.VSImageLibrary.Method; }
    }

    [Storable]
    public IItemList<PreprocessingTransformation> TransformationList { get; private set; }

    #region Constructor, Cloning & Persistence
    public TransformationContent(IFilteredPreprocessingData preprocessingData)
      : base(preprocessingData) {
      TransformationList = new ItemList<PreprocessingTransformation>();
    }

    public TransformationContent(TransformationContent original, Cloner cloner)
      : base(original, cloner) {
      TransformationList = cloner.Clone(original.TransformationList);
    }
    public override IDeepCloneable Clone(Cloner cloner) {
      return new TransformationContent(this, cloner);
    }

    [StorableConstructor]
    protected TransformationContent(bool deserializing)
      : base(deserializing) { }
    #endregion

    public bool ApplyTransformations(out IEnumerable<string> errorMessages) {
      bool success = true;
      var errors = new List<string>();
      errorMessages = errors;

      foreach (var transformation in TransformationList.Where(x => !x.IsApplied)) {
        var sourceVariable = transformation.OriginalVariable;
        var targetVariable = transformation.TransformedVariable ?? sourceVariable + " Transformed";
        var sourceIdx = PreprocessingData.GetColumnIndex(sourceVariable);

        if (transformation.Transformation is ITransformation<double> trans && PreprocessingData.VariableHasType<double>(sourceIdx)) {
          if (!PreprocessingData.VariableNames.Contains(targetVariable))
            PreprocessingData.InsertColumn<double>(targetVariable, PreprocessingData.Columns);
          var targetIdx = PreprocessingData.GetColumnIndex(targetVariable);

          if (!PreprocessingData.VariableHasType<double>(targetIdx)) { success = false; errors.Add("Target column is not double."); continue; }

          var sourceData = PreprocessingData.GetValues<double>(sourceIdx);
          if (!trans.Check(sourceData, out string msg)) { success = false; errors.Add(msg); continue; }

          trans.Configure(sourceData);
          var transformedData = trans.Apply(sourceData).ToList();

          PreprocessingData.SetValues(targetIdx, transformedData);

          PreprocessingData.Transformations.Add(transformation);
          transformation.IsApplied = true;
          // TODO: remove unused valid values in constrainedParameters
        } else {
          success = false;
          errors.Add("Transformation datatype is not supported.");
        }
      }

      return success;
    }
  }
}