#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2015 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.Linq;
using HeuristicLab.Algorithms.GeneticAlgorithm;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Operators;
using HeuristicLab.Optimization;
using HeuristicLab.Optimization.Operators;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
using HeuristicLab.Selection;

namespace HeuristicLab.Algorithms.ALPS {

  [Item("AlpsGeneticAlgorithmMainLoop", "An ALPS genetic algorithm main loop operator.")]
  [StorableClass]
  public sealed class AlpsGeneticAlgorithmMainLoop : AlgorithmOperator {
    #region Parameter Properties
    public ValueLookupParameter<BoolValue> MaximizationParameter {
      get { return (ValueLookupParameter<BoolValue>)Parameters["Maximization"]; }
    }
    public ScopeTreeLookupParameter<DoubleValue> QualityParameter {
      get { return (ScopeTreeLookupParameter<DoubleValue>)Parameters["Quality"]; }
    }
    public ILookupParameter<IOperator> AnalyzerParameter {
      get { return (ILookupParameter<IOperator>)Parameters["Analyzer"]; }
    }
    public ILookupParameter<IOperator> LayerAnalyzerParameter {
      get { return (ILookupParameter<IOperator>)Parameters["LayerAnalyzer"]; }
    }
    #endregion

    public GeneticAlgorithmMainLoop MainOperator {
      get { return OperatorGraph.Iterate().OfType<GeneticAlgorithmMainLoop>().First(); }
    }

    [StorableConstructor]
    private AlpsGeneticAlgorithmMainLoop(bool deserializing)
      : base(deserializing) { }
    private AlpsGeneticAlgorithmMainLoop(AlpsGeneticAlgorithmMainLoop original, Cloner cloner)
      : base(original, cloner) { }
    public override IDeepCloneable Clone(Cloner cloner) {
      return new AlpsGeneticAlgorithmMainLoop(this, cloner);
    }
    public AlpsGeneticAlgorithmMainLoop()
      : base() {
      Parameters.Add(new ValueLookupParameter<BoolValue>("Maximization", "True if the problem is a maximization problem, otherwise false.") { Hidden = true });
      Parameters.Add(new ScopeTreeLookupParameter<DoubleValue>("Quality", "The value which represents the quality of a solution."));
      Parameters.Add(new LookupParameter<IntValue>("MaximumGenerations", "The maximum number of generations that the algorithm should process."));
      Parameters.Add(new LookupParameter<IOperator>("Analyzer", "The operator used to the analyze all individuals."));
      Parameters.Add(new LookupParameter<IOperator>("LayerAnalyzer", "The operator used to analyze each layer."));

      var variableCreator = new VariableCreator() { Name = "Initialize" };
      var initLayerAnalyzerProcessor = new SubScopesProcessor();
      var layerVariableCreator = new VariableCreator() { Name = "Initialize Layer" };
      var initLayerAnalyzerPlaceholder = new Placeholder() { Name = "LayerAnalyzer (Placeholder)" };
      var initAnalyzerPlaceholder = new Placeholder() { Name = "Analyzer (Placeholder)" };
      var resultsCollector = new ResultsCollector();
      var matingPoolCreator = new MatingPoolCreator() { Name = "Create Mating Pools" };
      var matingPoolProcessor = new UniformSubScopesProcessor();
      var initializeLayer = new Assigner() { Name = "Reset LayerEvaluatedSolutions" };
      var mainOperator = AlpsGeneticAlgorithmMainOperator.Create();
      var generationsIcrementor = new IntCounter() { Name = "Increment Generations" };
      var evaluatedSolutionsReducer = new DataReducer() { Name = "Increment EvaluatedSolutions" };
      var eldersEmigrator = CreateEldersEmigrator();
      var layerOpener = CreateLayerOpener();
      var layerReseeder = CreateReseeder();
      var layerAnalyzerProcessor = new UniformSubScopesProcessor();
      var layerAnalyzerPlaceholder = new Placeholder() { Name = "LayerAnalyzer (Placeholder)" };
      var analyzerPlaceholder = new Placeholder() { Name = "Analyzer (Placeholder)" };
      var termination = new TerminationOperator();

      OperatorGraph.InitialOperator = variableCreator;

      variableCreator.CollectedValues.Add(new ValueParameter<IntValue>("Generations", new IntValue(0)));
      variableCreator.CollectedValues.Add(new ValueParameter<IntValue>("GenerationsSinceLastRefresh", new IntValue(0)));
      variableCreator.CollectedValues.Add(new ValueParameter<IntValue>("OpenLayers", new IntValue(1)));
      variableCreator.Successor = initLayerAnalyzerProcessor;

      initLayerAnalyzerProcessor.Operators.Add(layerVariableCreator);
      initLayerAnalyzerProcessor.Successor = initAnalyzerPlaceholder;

      layerVariableCreator.CollectedValues.Add(new ValueParameter<IntValue>("LayerEvaluatedSolutions"));
      layerVariableCreator.CollectedValues.Add(new ValueParameter<ResultCollection>("LayerResults"));
      layerVariableCreator.Successor = initLayerAnalyzerPlaceholder;

      initLayerAnalyzerPlaceholder.OperatorParameter.ActualName = LayerAnalyzerParameter.Name;
      initLayerAnalyzerPlaceholder.Successor = null;

      initAnalyzerPlaceholder.OperatorParameter.ActualName = AnalyzerParameter.Name;
      initAnalyzerPlaceholder.Successor = resultsCollector;

      resultsCollector.CollectedValues.Add(new LookupParameter<IntValue>("Generations"));
      resultsCollector.CollectedValues.Add(new ScopeTreeLookupParameter<ResultCollection>("LayerResults", "Result set for each layer", "LayerResults"));
      resultsCollector.CollectedValues.Add(new LookupParameter<IntValue>("OpenLayers"));
      resultsCollector.CopyValue = new BoolValue(false);
      resultsCollector.Successor = matingPoolCreator;

      matingPoolCreator.Successor = matingPoolProcessor;

      matingPoolProcessor.Parallel.Value = true;
      matingPoolProcessor.Operator = initializeLayer;
      matingPoolProcessor.Successor = generationsIcrementor;

      initializeLayer.LeftSideParameter.ActualName = "LayerEvaluatedSolutions";
      initializeLayer.RightSideParameter.Value = new IntValue(0);
      initializeLayer.Successor = mainOperator;

      generationsIcrementor.ValueParameter.ActualName = "Generations";
      generationsIcrementor.Increment = new IntValue(1);
      generationsIcrementor.Successor = evaluatedSolutionsReducer;

      evaluatedSolutionsReducer.ParameterToReduce.ActualName = "LayerEvaluatedSolutions";
      evaluatedSolutionsReducer.TargetParameter.ActualName = "EvaluatedSolutions";
      evaluatedSolutionsReducer.ReductionOperation.Value = new ReductionOperation(ReductionOperations.Sum);
      evaluatedSolutionsReducer.TargetOperation.Value = new ReductionOperation(ReductionOperations.Sum);
      evaluatedSolutionsReducer.Successor = eldersEmigrator;

      eldersEmigrator.Successor = layerOpener;

      layerOpener.Successor = layerReseeder;

      layerReseeder.Successor = layerAnalyzerProcessor;

      layerAnalyzerProcessor.Operator = layerAnalyzerPlaceholder;
      layerAnalyzerProcessor.Successor = analyzerPlaceholder;

      layerAnalyzerPlaceholder.OperatorParameter.ActualName = LayerAnalyzerParameter.Name;

      analyzerPlaceholder.OperatorParameter.ActualName = AnalyzerParameter.Name;
      analyzerPlaceholder.Successor = termination;

      termination.ContinueBranch = matingPoolCreator;
    }

    private static CombinedOperator CreateEldersEmigrator() {
      var eldersEmigrator = new CombinedOperator() { Name = "Emigrate Elders" };
      var selectorProsessor = new UniformSubScopesProcessor();
      var eldersSelector = new EldersSelector();
      var shiftToRightMigrator = new UnidirectionalRingMigrator();
      var mergingProsessor = new UniformSubScopesProcessor();
      var mergingReducer = new MergingReducer();
      var subScopesCounter = new SubScopesCounter();
      var countCalculator = new ExpressionCalculator() { Name = "LayerPopulationSize = Min(LayerPopulationSize, PopulationSize)" };
      var bestSelector = new BestSelector();
      var rightReducer = new RightReducer();

      eldersEmigrator.OperatorGraph.InitialOperator = selectorProsessor;

      selectorProsessor.Operator = eldersSelector;
      selectorProsessor.Successor = shiftToRightMigrator;

      shiftToRightMigrator.ClockwiseMigrationParameter.Value = new BoolValue(true);
      shiftToRightMigrator.Successor = mergingProsessor;

      mergingProsessor.Operator = mergingReducer;

      mergingReducer.Successor = subScopesCounter;

      subScopesCounter.ValueParameter.ActualName = "LayerPopulationSize";
      subScopesCounter.AccumulateParameter.Value = new BoolValue(false);
      subScopesCounter.Successor = countCalculator;

      countCalculator.CollectedValues.Add(new LookupParameter<IntValue>("PopulationSize"));
      countCalculator.CollectedValues.Add(new LookupParameter<IntValue>("LayerPopulationSize"));
      countCalculator.ExpressionParameter.Value = new StringValue("LayerPopulationSize PopulationSize LayerPopulationSize PopulationSize < if toint");
      countCalculator.ExpressionResultParameter.ActualName = "LayerPopulationSize";
      countCalculator.Successor = bestSelector;

      bestSelector.NumberOfSelectedSubScopesParameter.ActualName = "LayerPopulationSize";
      bestSelector.CopySelected = new BoolValue(false);
      bestSelector.Successor = rightReducer;

      return eldersEmigrator;
    }

    private static CombinedOperator CreateLayerOpener() {
      var layerOpener = new CombinedOperator() { Name = "Open new Layer if needed" };
      var maxLayerReached = new Comparator() { Name = "MaxLayersReached = OpenLayers >= NumberOfLayers" };
      var maxLayerReachedBranch = new ConditionalBranch() { Name = "MaxLayersReached?" };
      var openNewLayerCalculator = new ExpressionCalculator() { Name = "OpenNewLayer = Generations >= AgeLimits[OpenLayers - 1]" };
      var openNewLayerBranch = new ConditionalBranch() { Name = "OpenNewLayer?" };
      var layerCreator = new LayerCreator() { Name = "Create Layer" };
      var createChildrenViaCrossover = AlpsGeneticAlgorithmMainOperator.Create();
      var incrEvaluatedSolutionsForNewLayer = new SubScopesCounter() { Name = "Update EvaluatedSolutions" };
      var incrOpenLayers = new IntCounter() { Name = "Incr. OpenLayers" };
      var newLayerResultsCollector = new ResultsCollector() { Name = "Collect new Layer Results" };

      layerOpener.OperatorGraph.InitialOperator = maxLayerReached;

      maxLayerReached.LeftSideParameter.ActualName = "OpenLayers";
      maxLayerReached.RightSideParameter.ActualName = "NumberOfLayers";
      maxLayerReached.ResultParameter.ActualName = "MaxLayerReached";
      maxLayerReached.Comparison = new Comparison(ComparisonType.GreaterOrEqual);
      maxLayerReached.Successor = maxLayerReachedBranch;

      maxLayerReachedBranch.ConditionParameter.ActualName = "MaxLayerReached";
      maxLayerReachedBranch.FalseBranch = openNewLayerCalculator;

      openNewLayerCalculator.CollectedValues.Add(new LookupParameter<IntArray>("AgeLimits"));
      openNewLayerCalculator.CollectedValues.Add(new LookupParameter<IntValue>("Generations"));
      openNewLayerCalculator.CollectedValues.Add(new LookupParameter<IntValue>("NumberOfLayers"));
      openNewLayerCalculator.CollectedValues.Add(new LookupParameter<IntValue>("OpenLayers"));
      openNewLayerCalculator.ExpressionResultParameter.ActualName = "OpenNewLayer";
      openNewLayerCalculator.ExpressionParameter.Value = new StringValue("Generations 1 + AgeLimits OpenLayers 1 - [] >");
      openNewLayerCalculator.Successor = openNewLayerBranch;

      openNewLayerBranch.ConditionParameter.ActualName = "OpenNewLayer";
      openNewLayerBranch.TrueBranch = layerCreator;

      layerCreator.NewLayerOperator = createChildrenViaCrossover;
      layerCreator.Successor = incrOpenLayers;

      createChildrenViaCrossover.Successor = incrEvaluatedSolutionsForNewLayer;

      incrEvaluatedSolutionsForNewLayer.ValueParameter.ActualName = "EvaluatedSolutions";
      incrEvaluatedSolutionsForNewLayer.AccumulateParameter.Value = new BoolValue(true);

      incrOpenLayers.ValueParameter.ActualName = "OpenLayers";
      incrOpenLayers.Increment = new IntValue(1);
      incrOpenLayers.Successor = newLayerResultsCollector;

      newLayerResultsCollector.CollectedValues.Add(new ScopeTreeLookupParameter<ResultCollection>("LayerResults", "Result set for each layer", "LayerResults"));
      newLayerResultsCollector.CopyValue = new BoolValue(false);
      newLayerResultsCollector.Successor = null;

      return layerOpener;
    }

    private static CombinedOperator CreateReseeder() {
      var reseeder = new CombinedOperator() { Name = "Reseed Layer Zero if needed" };
      var reseedingController = new ReseedingController() { Name = "Reseeding needed (Generation % AgeGap == 0)?" };
      var removeIndividuals = new SubScopesRemover();
      var createIndividuals = new SolutionsCreator();
      var initializeAgeProsessor = new UniformSubScopesProcessor();
      var initializeAge = new VariableCreator() { Name = "Initialize Age" };
      var incrEvaluatedSolutionsAfterReseeding = new SubScopesCounter() { Name = "Update EvaluatedSolutions" };

      reseeder.OperatorGraph.InitialOperator = reseedingController;

      reseedingController.FirstLayerOperator = removeIndividuals;

      removeIndividuals.Successor = createIndividuals;

      createIndividuals.NumberOfSolutionsParameter.ActualName = "PopulationSize";
      createIndividuals.Successor = initializeAgeProsessor;

      initializeAgeProsessor.Operator = initializeAge;
      initializeAgeProsessor.Successor = incrEvaluatedSolutionsAfterReseeding;

      initializeAge.CollectedValues.Add(new ValueParameter<DoubleValue>("Age", new DoubleValue(0)));

      incrEvaluatedSolutionsAfterReseeding.ValueParameter.ActualName = "EvaluatedSolutions";
      incrEvaluatedSolutionsAfterReseeding.AccumulateParameter.Value = new BoolValue(true);

      return reseeder;
    }
  }
}