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.Problems.Programmable {
  [Item("Single-objective Analyzer", "Calls the script's Analyze method to be able to write into the results collection.")]
  [StorableClass]
  public class SingleObjectiveAnalyzer : SingleSuccessorOperator, ISingleObjectiveProgrammableProblemAnalyzer {
    public bool EnabledByDefault { get { return true; } }

    public ILookupParameter<ISingleObjectiveProblemDefinition> ProblemDefinitionParameter {
      get { return (ILookupParameter<ISingleObjectiveProblemDefinition>)Parameters["ProblemDefinition"]; }
    }

    public ILookupParameter<IEncoding> EncodingParameter {
      get { return (ILookupParameter<IEncoding>)Parameters["Encoding"]; }
    }

    public IScopeTreeLookupParameter<DoubleValue> QualityParameter {
      get { return (IScopeTreeLookupParameter<DoubleValue>)Parameters["Quality"]; }
    }

    public ILookupParameter<ResultCollection> ResultsParameter {
      get { return (ILookupParameter<ResultCollection>)Parameters["Results"]; }
    }

    [StorableConstructor]
    protected SingleObjectiveAnalyzer(bool deserializing) : base(deserializing) { }
    protected SingleObjectiveAnalyzer(SingleObjectiveAnalyzer original, Cloner cloner) : base(original, cloner) { }
    public SingleObjectiveAnalyzer() {
      Parameters.Add(new LookupParameter<IRandom>("Random", "The random number generator to use."));
      Parameters.Add(new LookupParameter<ISingleObjectiveProblemDefinition>("ProblemDefinition", "The host that holds the problem definition."));
      Parameters.Add(new LookupParameter<IEncoding>("Encoding", "An item that holds the problem's encoding."));
      Parameters.Add(new ScopeTreeLookupParameter<DoubleValue>("Quality", "The quality of the parameter vector."));
      Parameters.Add(new LookupParameter<ResultCollection>("Results", "The results collection to write to."));
    }

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

    public override IOperation Apply() {
      var definition = ProblemDefinitionParameter.ActualValue;
      if (definition == null) throw new InvalidOperationException("Problem definition is null");
      var encoding = EncodingParameter.ActualValue;
      var results = ResultsParameter.ActualValue;

      IEnumerable<IScope> scopes = new[] { ExecutionContext.Scope };
      for (var i = 0; i < QualityParameter.Depth; i++)
        scopes = scopes.Select(x => (IEnumerable<IScope>)x.SubScopes).Aggregate((a, b) => a.Concat(b));

      var individuals = scopes.Select(encoding.CreateIndividual).ToArray();
      definition.Analyze(individuals, QualityParameter.ActualValue.Select(x => x.Value).ToArray(), results);
      return base.Apply();
    }
  }
}