#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2010 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.Collections;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Operators;
using HeuristicLab.Optimization.Operators;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Analysis.FitnessLandscape.Analysis {

  [StorableClass]
  public class UpDownWalkAnalyzer : AlgorithmOperator, IQualityTrailAnalyzer {
    public bool EnabledByDefault {
      get { return false; }
    }

    #region Parameters
    public LookupParameter<DataTable> QualityTrailParameter {
      get { return (LookupParameter<DataTable>)Parameters["Quality Trail"]; }
    }
    public LookupParameter<VariableCollection> ResultsParameter {
      get { return (LookupParameter<VariableCollection>)Parameters["Results"]; }
    }
    public LookupParameter<DataTable> UpDownStepsParameter {
      get { return (LookupParameter<DataTable>)Parameters["UpDownSteps"]; }
    }
    public LookupParameter<DataTable> UpDownLevelsParameter {
      get { return (LookupParameter<DataTable>)Parameters["UpDownLevels"]; }
    }
    public LookupParameter<DoubleValue> UpWalkLengthParameter {
      get { return (LookupParameter<DoubleValue>)Parameters["UpWalkLength"]; }
    }
    public LookupParameter<DoubleValue> DownWalkLengthParameter {
      get { return (LookupParameter<DoubleValue>)Parameters["DownWalkLength"]; }
    }
    public LookupParameter<DoubleValue> UpWalkLenVarParameter {
      get { return (LookupParameter<DoubleValue>)Parameters["UpWalkLenVar"]; }
    }
    public LookupParameter<DoubleValue> DownWalkLenVarParameter {
      get { return (LookupParameter<DoubleValue>)Parameters["DownWalkLenVar"]; }
    }
    public LookupParameter<DoubleValue> UpperLevelParameter {
      get { return (LookupParameter<DoubleValue>)Parameters["UpperLevel"]; }
    }
    public LookupParameter<DoubleValue> LowerLevelParameter {
      get { return (LookupParameter<DoubleValue>)Parameters["LowerLevel"]; }
    }
    public LookupParameter<DoubleValue> UpperVarianceParameter {
      get { return (LookupParameter<DoubleValue>)Parameters["UpperVariance"]; }
    }
    public LookupParameter<DoubleValue> LowerVarianceParameter {
      get { return (LookupParameter<DoubleValue>)Parameters["LowerVariance"]; }
    }
    #endregion

    [StorableConstructor]
    protected UpDownWalkAnalyzer(bool deserializing) : base(deserializing) { }
    protected UpDownWalkAnalyzer(UpDownWalkAnalyzer original, Cloner cloner) : base(original, cloner) { }

    public UpDownWalkAnalyzer() {
      Parameters.Add(new LookupParameter<DataTable>("Quality Trail", "The qualities of the solutions"));
      Parameters.Add(new LookupParameter<VariableCollection>("Results", "The collection of all results of this algorithm"));
      Parameters.Add(new LookupParameter<DataTable>("UpDownSteps", "Distribution of upward and downward steps between extremes."));
      Parameters.Add(new LookupParameter<DataTable>("UpDownLevels", "Distribution of upper and lower levels in up-down walks."));
      Parameters.Add(new LookupParameter<DoubleValue>("DownWalkLength", "Average downward walk length."));
      Parameters.Add(new LookupParameter<DoubleValue>("UpWalkLength", "Average updward walk length."));
      Parameters.Add(new LookupParameter<DoubleValue>("UpWalkLenVar", "Upward walk length variance."));
      Parameters.Add(new LookupParameter<DoubleValue>("DownWalkLenVar", "Downward walk length variance."));
      Parameters.Add(new LookupParameter<DoubleValue>("UpperLevel", "Average maximum fitness value."));
      Parameters.Add(new LookupParameter<DoubleValue>("LowerLevel", "Average minimum fitness value."));
      Parameters.Add(new LookupParameter<DoubleValue>("LowerVariance", "Lower level variance."));
      Parameters.Add(new LookupParameter<DoubleValue>("UpperVariance", "Upper level variance."));
    

      var resultsCollector = new ResultsCollector();
      resultsCollector.CollectedValues.Add(new LookupParameter<DataTable>(UpDownStepsParameter.Name));
      resultsCollector.CollectedValues.Add(new LookupParameter<DataTable>(UpDownLevelsParameter.Name));
      resultsCollector.CollectedValues.Add(new LookupParameter<DoubleValue>(DownWalkLengthParameter.Name));
      resultsCollector.CollectedValues.Add(new LookupParameter<DoubleValue>(UpWalkLengthParameter.Name));
      resultsCollector.CollectedValues.Add(new LookupParameter<DoubleValue>(UpWalkLenVarParameter.Name));
      resultsCollector.CollectedValues.Add(new LookupParameter<DoubleValue>(DownWalkLenVarParameter.Name));
      resultsCollector.CollectedValues.Add(new LookupParameter<DoubleValue>(UpperLevelParameter.Name));
      resultsCollector.CollectedValues.Add(new LookupParameter<DoubleValue>(LowerLevelParameter.Name));
      resultsCollector.CollectedValues.Add(new LookupParameter<DoubleValue>(UpperVarianceParameter.Name));
      resultsCollector.CollectedValues.Add(new LookupParameter<DoubleValue>(LowerVarianceParameter.Name));

      OperatorGraph.InitialOperator = resultsCollector;
      resultsCollector.Successor = null;
    }

    public override IDeepCloneable Clone(Cloner cloner) {
      return new UpDownWalkAnalyzer(this, cloner);
    }

    public override IOperation Apply() {
      var stepsTable = GetOrCreateTable(UpDownStepsParameter, "Up", "Down");
      var levelsTable = GetOrCreateTable(UpDownLevelsParameter, "Top", "Bottom");
      DataTable qualityTrail = QualityTrailParameter.ActualValue;
      if (qualityTrail != null && qualityTrail.Rows.Count > 0) {
        var qualities = qualityTrail.Rows.First().Values.ToList();
        if (qualities.Count > 2) {
          var extremes = qualities
            .Delta((a, b) => new {a, b, diff = b - a})
            .Select((p, i) => new {p.a, p.b, p.diff, i = i+1})
            .Delta((s1, s2) => new {
              s1.i,
              value = s2.a,
              top = s1.diff >= 0 && s2.diff < 0,
              bottom = s1.diff <= 0 && s2.diff > 0
            })
            .Where(x => x.top || x.bottom)
            .GroupConsecutive(x => x.bottom)
            .Select(g => g.Count() == 1
                           ? g.First()
                           : (g.First().bottom
                                ? g.OrderBy(x => x.value).First()
                                : g.OrderByDescending(x => x.value).First())).ToList();
          var maxima = extremes.Where(x => x.top).ToList();
          var minima = extremes.Where(x => x.bottom).ToList();
          var tops = Enumerable.Repeat(new {length = 0, value = 0.0}, 0).ToList();
          var bottoms = tops;
          if (maxima.Count > 0 && minima.Count > 0) {
            if (maxima.First().i < minima.First().i) {
              bottoms = maxima.Zip(minima, (t, b) => new {length = b.i - t.i, b.value}).ToList();
              minima.Insert(0, new {i = -1, value = 0.0, top = false, bottom = false});
              tops = maxima.Zip(minima, (t, b) => new {length = t.i - b.i, t.value}).ToList();
            } else {
              tops = maxima.Zip(minima, (t, b) => new {length = t.i - b.i, t.value}).ToList();
              maxima.Insert(0, new {i = -1, value = 0.0, top = false, bottom = false});
              bottoms = maxima.Zip(minima, (t, b) => new {length = b.i - t.i, b.value}).ToList();
            }
            if (tops.Count > 0) {
              var topLengths = tops.Select(t => (double) t.length).ToList();
              var topVals = tops.Select(t => t.value).ToList();
              ReplaceHistogram(stepsTable.Rows["Up"], topLengths);
              ReplaceHistogram(levelsTable.Rows["Top"], topVals);
              UpperLevelParameter.ActualValue = new DoubleValue(topVals.Average());
              UpperVarianceParameter.ActualValue = new DoubleValue(topVals.Variance());
              UpWalkLengthParameter.ActualValue = new DoubleValue(topLengths.Average());
              UpWalkLenVarParameter.ActualValue = new DoubleValue(topLengths.Variance());
            }
            if (bottoms.Count > 0) {
              var bottomLengths = bottoms.Select(b => (double) b.length).ToList();
              var bottomVals = bottoms.Select(b => b.value).ToList();
              ReplaceHistogram(stepsTable.Rows["Down"], bottomLengths);
              ReplaceHistogram(levelsTable.Rows["Bottom"], bottomVals);
              LowerLevelParameter.ActualValue = new DoubleValue(bottomVals.Average());
              LowerVarianceParameter.ActualValue = new DoubleValue(bottomVals.Variance());
              DownWalkLengthParameter.ActualValue = new DoubleValue(bottomLengths.Average());
              DownWalkLenVarParameter.ActualValue = new DoubleValue(bottomLengths.Variance());
            }
          }
        }
      }
      return base.Apply();
    }

    private void ReplaceHistogram(DataRow row, IEnumerable<double> values) {
      row.VisualProperties.ChartType = DataRowVisualProperties.DataRowChartType.Histogram;
      row.VisualProperties.Bins = 25;
      row.Values.Clear();
      row.Values.AddRange(values);
    }

    private DataTable GetOrCreateTable(LookupParameter<DataTable> tableParameter, params string[] rowNames) {
      DataTable table = tableParameter.ActualValue;
      if (table == null) {
        table = new DataTable(tableParameter.Name, tableParameter.Description);
        tableParameter.ActualValue = table;
        foreach (var name in rowNames) {
          table.Rows.Add(new DataRow(name));
        }
      }
      return table;
    }
  }
}