#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2014 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.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Operators;
using HeuristicLab.Optimization;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Algorithms.VOffspringSelectionGeneticAlgorithm {
  [Item("ProbabilitiesGenerator", "An operator the generates the probability vector for Multi Crossovers/Mutators")]
  [StorableClass]
  public class ProbabilitiesGenerator : SingleSuccessorOperator, IAnalyzer {
    public bool EnabledByDefault {
      get { return false; }
    }
    public ValueParameter<StringValue> SuccessfulOffspringFlagParameter {
      get { return (ValueParameter<StringValue>)Parameters["SuccessfulOffspringFlag"]; }
    }
    public ValueParameter<StringValue> OperatorNameVariableParameter {
      get { return (ValueParameter<StringValue>)Parameters["OperatorNameVariable"]; }
    }
    public LookupParameter<IOperator> OperatorParameter {
      get { return (LookupParameter<IOperator>)Parameters["Operator"]; }
    }
    public LookupParameter<DoubleArray> ProbablilitiesParameter {
      get { return (LookupParameter<DoubleArray>)Parameters["Probabilities"]; }

    }
    public ValueParameter<DoubleValue> MinimumOperatorUsageParameter {
      get { return (ValueParameter<DoubleValue>)Parameters["MinimumOperatorUsage"]; }
    }
    public LookupParameter<ItemList<IScope>> GeneratedOffspringParameter {
      get { return (LookupParameter<ItemList<IScope>>)Parameters["GeneratedOffspring"]; }
    }
    public ValueLookupParameter<ResultCollection> ResultsParameter {
      get { return (ValueLookupParameter<ResultCollection>)Parameters["Results"]; }
    }
    public override IDeepCloneable Clone(Cloner cloner) {
      return new ProbabilitiesGenerator(this, cloner);
    }
    [StorableConstructor]
    private ProbabilitiesGenerator(bool deserializing) : base(deserializing) { }
    private ProbabilitiesGenerator(ProbabilitiesGenerator original, Cloner cloner) : base(original, cloner) { }
    public ProbabilitiesGenerator()
      : base() {
      Parameters.Add(new ValueParameter<StringValue>("SuccessfulOffspringFlag", "The name of the flag which indicates if the individual was successful.", new StringValue("SuccessfulOffspring")));
      Parameters.Add(new ValueParameter<StringValue>("OperatorNameVariable", "The properties of the successful offspring that should be collected.", new StringValue("SelectedCrossoverOperator")));
      Parameters.Add(new LookupParameter<DoubleArray>("Probabilities", "The probability vector a multi crossover/mutator uses to decide which operator to use"));
      Parameters.Add(new LookupParameter<IOperator>("Operator", "The multioperator that contains the list of used crossovers/mutators", "Crossover"));
      Parameters.Add(new ValueParameter<DoubleValue>("MinimumOperatorUsage", "Minimum percentage of operator usage. ", new DoubleValue(0.05)));
      Parameters.Add(new LookupParameter<ItemList<IScope>>("GeneratedOffspring", "Temporary store of the offspring population."));
      Parameters.Add(new ValueLookupParameter<ResultCollection>("Results", "The result collection where the population diversity analysis results should be stored."));

    }

    public override IOperation Apply() {
      if (GeneratedOffspringParameter.ActualValue == null) {
        GeneratedOffspringParameter.ActualValue = new ItemList<IScope>();
      }

      var offspring = GeneratedOffspringParameter.ActualValue;
      string operatorName = OperatorNameVariableParameter.Value.Value;
      string succssFlag = SuccessfulOffspringFlagParameter.Value.Value;
      Dictionary<string, int> operatorCount = new Dictionary<string, int>();
      Dictionary<string, int> successfulOperatorCount = new Dictionary<string, int>();

      var crossover = OperatorParameter.ActualValue;
      if (crossover.GetType().GetInterfaces().Any(x => x.IsGenericType &&
        x.GetGenericTypeDefinition() == typeof(ICheckedMultiOperator<>))) {

        for (int i = 0; i < offspring.Count; i++) {
          // fetch values from scopes
          IVariable tmpVar;
          if (!offspring[i].Variables.TryGetValue(succssFlag, out tmpVar))
            throw new InvalidOperationException(Name + ": Could not determine if an offspring was successful or not.");
          BoolValue success = (tmpVar.Value as BoolValue);
          if (success == null) throw new InvalidOperationException(Name + ": The variable that indicates whether an offspring is successful or not must contain a BoolValue.");

          if (!offspring[i].Variables.TryGetValue(operatorName, out tmpVar))
            throw new InvalidOperationException(Name + ": Could not determine operator an offspring was created with.");
          StringValue op = (tmpVar.Value as StringValue);
          if (op == null) throw new InvalidOperationException(Name + ": The variable the contains the operator name must be a string.");

          if (!operatorCount.ContainsKey(op.Value)) {
            operatorCount.Add(op.Value, 1);
          } else {
            operatorCount[op.Value]++;
          }

          if (success.Value) {
            if (!successfulOperatorCount.ContainsKey(op.Value)) {
              successfulOperatorCount.Add(op.Value, 1);
            } else {
              successfulOperatorCount[op.Value]++;
            }
          }
        }

        dynamic opCrossover = (dynamic)crossover;
        int crossoverCount = (int)opCrossover.Operators.Count;
        int checkedCrossoverCount = Enumerable.Count(opCrossover.Operators.CheckedItems);
        dynamic[] crossoverNames = new dynamic[checkedCrossoverCount];
        dynamic checkedItemsArray = Enumerable.ToArray(opCrossover.Operators.CheckedItems);

        for (int i = 0; i < checkedCrossoverCount; i++) {
          crossoverNames[i] = checkedItemsArray[i];
        }

        //initialize probabilities vector
        if (ProbablilitiesParameter.ActualValue == null) {
          ProbablilitiesParameter.ActualValue = new DoubleArray(crossoverCount);
          ResultsParameter.ActualValue.Add(new Result("Probabilities", ProbablilitiesParameter.ActualValue));
          for (int i = 0; i < crossoverCount; i++) {
            ProbablilitiesParameter.ActualValue[i] = 1.0;
          }
          return base.Apply();
        }

        //fill probabilities vector
        for (int i = 0; i < crossoverCount; i++) {
          var cxNames = Enumerable.Where(crossoverNames, x => x.Index == i);

          if (Enumerable.Any(cxNames)) {
            var cxName = (string)Enumerable.Single(cxNames).Value.ItemName;
            if (operatorCount.Any(x => x.Key.Contains(cxName))) {
              int overallCount = operatorCount.Single(x => x.Key.Contains(cxName)).Value;
              int successCount = 0;

              if (successfulOperatorCount.Any(x => x.Key.Contains(cxName))) {
                successCount = successfulOperatorCount.Single(x => x.Key.Contains(cxName)).Value;
              }

              double ratio = successCount / (double)overallCount;
              if (ratio < MinimumOperatorUsageParameter.Value.Value) {
                ratio = MinimumOperatorUsageParameter.Value.Value;
              }
              ProbablilitiesParameter.ActualValue[i] = ratio;
            } else {
              ProbablilitiesParameter.ActualValue[i] = MinimumOperatorUsageParameter.Value.Value;
            }
          } else {
            ProbablilitiesParameter.ActualValue[i] = 0.0;
          }
        }

        GeneratedOffspringParameter.ActualValue.Clear();
      }

      return base.Apply();
    }
  }
}