using HeuristicLab.BioBoost.ProblemDescription;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Encodings.IntegerVectorEncoding;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
using HeuristicLab.Random;
using System;
using System.Linq;

namespace HeuristicLab.BioBoost.Operators.Mutation {
  [StorableClass]
  public class TargetMergingIntegerVectorManipulator : BoundedIntegerVectorManipulator {

    #region Parameters
    public LookupParameter<DistanceMatrix> DistanceMatrixParameter {
      get { return (LookupParameter<DistanceMatrix>) Parameters["DistanceMatrix"]; }
    }
    public ValueParameter<BoolValue> DistanceMatrixInProblemDataParameter {
      get { return (ValueParameter<BoolValue>) Parameters["DistanceMatrixInProblemData"]; }
    }
    public ILookupParameter<BioBoostProblemData> ProblemDataParameter {
      get { return (ILookupParameter<BioBoostProblemData>) Parameters["ProblemData"]; }
    }
    public ValueLookupParameter<DoubleValue> AvgBundleMutationRatioParameter {
      get { return (ValueLookupParameter<DoubleValue>) Parameters["AvgBundleMutationRatio"]; }
    }
    #endregion

    #region Parameter Values
    public DistanceMatrix DistanceMatrix {
      get {
        if (DistanceMatrixInProblemData) {
          return ((IValueParameter<DistanceMatrix>) ProblemData.Parameters[DistanceMatrixParameter.ActualName]).Value;
        } else {
          return DistanceMatrixParameter.ActualValue;
        }
      }
    }
    public bool DistanceMatrixInProblemData { get { return DistanceMatrixInProblemDataParameter.Value.Value; } }
    public BioBoostProblemData ProblemData { get { return ProblemDataParameter.ActualValue; } }
    public double AvgBundleMutationRatio { get { return AvgBundleMutationRatioParameter.ActualValue.Value; } }
    #endregion

    #region Construction & Cloning
    [StorableConstructor]
    protected TargetMergingIntegerVectorManipulator(bool isDeserializing) : base(isDeserializing) {}
    protected TargetMergingIntegerVectorManipulator(TargetMergingIntegerVectorManipulator orig, Cloner cloner) : base(orig, cloner) {}
    public TargetMergingIntegerVectorManipulator() {
      Parameters.Add(new LookupParameter<DistanceMatrix>("DistanceMatrix", "The distance matrix to use", "StreetDistanceMatrix"));
      Parameters.Add(new ValueParameter<BoolValue>("DistanceMatrixInProblemData", "Whether to look for the distance matrix in problem data or in scope.", new BoolValue(true)));
      Parameters.Add(new LookupParameter<BioBoostProblemData>("ProblemData", "The problem instance description container."));
      Parameters.Add(new ValueLookupParameter<DoubleValue>("AvgBundleMutationRatio", "The average ratio of modified targets in a bundle.", new PercentValue(1)));
    }
    public override IDeepCloneable Clone(Cloner cloner) {
      return new TargetMergingIntegerVectorManipulator(this, cloner);
    }
    #endregion

    protected override void ManipulateBounded(IRandom random, IntegerVector integerVector, IntMatrix bounds) {
      var ratio =
        new NormalDistributedRandom(random, Math.Min(1, Math.Max(0, AvgBundleMutationRatio)), 0.5).NextDouble();
      var targetGroups = integerVector
        .Select((t, i) => new {t, i})
        .GroupBy(x => x.t, x => x.i)
        .Shuffle(random)
        .Take(2)
        .ToList();
      if (targetGroups.Count == 2) {
        var dm = DistanceMatrix;
        var key1 = targetGroups[0].Key;
        var key2 = targetGroups[1].Key;
        var targetList1 = targetGroups[0].Shuffle(random).ToList();
        var targetList2 = targetGroups[1].Shuffle(random).ToList();
        var center = Enumerable
          .Range(0, integerVector.Length)
          .Select(i => new {idx = i, dist = dm[key1, i] + dm[key2, i]})
          .MinItems(d => d.dist)
          .Shuffle(random)
          .First();
        foreach (var i in targetList1.Take(Math.Max(1, (int)Math.Round(ratio*targetList1.Count)))) {
          integerVector[i] = center.idx;
        }
        foreach (var i in targetList2.Take(Math.Max(1, (int)Math.Round(ratio*targetList2.Count)))) {
          integerVector[i] = center.idx;
        }
      } else if (targetGroups.Count == 1) {
        integerVector[random.Next(integerVector.Length)] = random.Next(integerVector.Length);
      }
    }
  }
}