#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2012 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 HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
using HeuristicLab.Core;
using HeuristicLab.Problems.BinPacking.Dimensions;
using HeuristicLab.Problems.BinPacking.PackingBin;
using HeuristicLab.Problems.BinPacking.PackingItem;
using HeuristicLab.Problems.BinPacking.PackingPlans;
using HeuristicLab.Encodings.PermutationEncoding;
using HeuristicLab.Common;
using HeuristicLab.Data;
using HeuristicLab.Collections;
using HeuristicLab.Encodings.PackingEncoding.PackingSequence;
using HeuristicLab.Problems.BinPacking.Interfaces;
using HeuristicLab.Encodings.PackingEncoding.GroupingVector;

namespace HeuristicLab.Problems.BinPacking.Decoders {
  [Item("Identical bin two dimensional grouping vector decoder", "<Description missing...>")]
  [StorableClass]
  public class TwoDimensionalBottomLeftGroupingVectorDecoder : IdenticalBinPackingSolutionDecoder<
      TwoDimensionalPacking,
      RectangularPackingBin,
      RectangularPackingItem,
      PackingPlan<TwoDimensionalPacking, RectangularPackingBin, RectangularPackingItem>> {

    public TwoDimensionalBottomLeftGroupingVectorDecoder()
      : base() {
        //EncodedSolutionParameter.ActualName = "EncodedSolution";
    }
    [StorableConstructor]
    protected TwoDimensionalBottomLeftGroupingVectorDecoder(bool deserializing) : base(deserializing) { }
    protected TwoDimensionalBottomLeftGroupingVectorDecoder(TwoDimensionalBottomLeftGroupingVectorDecoder original, Cloner cloner)
      : base(original, cloner) {
    }
    public override IDeepCloneable Clone(Cloner cloner) {
      return new TwoDimensionalBottomLeftGroupingVectorDecoder(this, cloner);
    }


    protected override PackingPlan<TwoDimensionalPacking, RectangularPackingBin, RectangularPackingItem> CreatePackingPlanFromEncoding(IPackingSolutionEncoding encodedSolution) {

      var solution = encodedSolution as GroupingVectorEncoding;
      if (solution == null) throw new InvalidOperationException("Encoding is not of type GroupingVector");

      RegularSimpleRotationPackingPlan<TwoDimensionalPacking, RectangularPackingBin, RectangularPackingItem> result = 
        new RegularSimpleRotationPackingPlan<TwoDimensionalPacking, RectangularPackingBin, RectangularPackingItem>(PackingBinMeasuresParameter.ActualValue, PackingItemMeasuresParameter.ActualValue);

      int nrOfBins = solution.GroupingVector.Max() + 1;

      //Get all indexes of items for every bin according to grouping-vector
      //It is assumed, that at this point the item-indexes are sorted according to their item-size!
      Dictionary<int, List<int>> unpackedItemIndexesPerBin = new Dictionary<int, List<int>>();

      for (int i = 0; i < nrOfBins; i++) {
        unpackedItemIndexesPerBin[i] = solution.GroupingVector
          .Select((Value, Index) => new { Value, Index })
          .Where(temp => temp.Value == i)
          .Select(temp => temp.Index).ToList();
      }

      ObservableDictionary<int, TwoDimensionalPacking> packingPositions = new ObservableDictionary<int, TwoDimensionalPacking>();
      var remainingItems = new List<int>();

      //Iterate over all bin-lists
      for (int binNr = 0; binNr < nrOfBins; binNr++ ) {
        //Iterate over the current bin-item-list and find feasible positions in the current bin for each item
        var unpackedItems = unpackedItemIndexesPerBin [binNr];
        for (int i = 0; i < unpackedItems.Count; i++ ) {
          var itemIndex = unpackedItems[i];
          var item = PackingItemMeasuresParameter.ActualValue[itemIndex];
          TwoDimensionalPacking position = null;

          //Look for space in current bin
          position = PackingHeuristics.BottomLeftPosition(PackingBinMeasuresParameter.ActualValue, binNr, item, packingPositions, PackingItemMeasuresParameter.ActualValue);

          //Did not find enough space in current bin
          if (position == null) {
            remainingItems.Add(itemIndex);
            //if (binNr + 1 >= nrOfBins) {
            //  nrOfBins++;
            //  unpackedItemIndexesPerBin[binNr + 1] = new List<int>();
            //  unpackedItemIndexesPerBin[binNr + 1].Add(itemIndex);
            //  unpackedItemIndexesPerBin[binNr].Remove(itemIndex);
            //} else {
            //  unpackedItemIndexesPerBin[binNr + 1].Add(itemIndex);
            //  unpackedItemIndexesPerBin[binNr + 1].Sort();
            //}
            //solution.GroupingVector[itemIndex] = binNr + 1;
          } else
            packingPositions[itemIndex] = position;
        }
      }

      //Packing of remaining items
      //Iterate over all bin-lists
      for (int binNr = 0; binNr < nrOfBins && remainingItems.Count > 0; binNr++) {
        var unpackedItems = new List<int>(remainingItems);
        for (int i = 0; i < unpackedItems.Count; i++) {
          var itemIndex = unpackedItems[i];
          var item = PackingItemMeasuresParameter.ActualValue[itemIndex];
          TwoDimensionalPacking position = null;

          //Look for space in current bin
          position = PackingHeuristics.BottomLeftPosition(PackingBinMeasuresParameter.ActualValue, binNr, item, packingPositions, PackingItemMeasuresParameter.ActualValue);

          if (position != null) {
            packingPositions[itemIndex] = position;
            remainingItems.Remove(itemIndex);
            solution.GroupingVector[itemIndex] = binNr;
          }
        }
        if (remainingItems.Count > 0 && binNr + 1 >= nrOfBins) {
          nrOfBins++;
        }
      }

      result.PackingItemPositions = packingPositions;


      return result;
    }
  }
}