#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2016 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 System.Text;
using HeuristicLab.Collections;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
using HeuristicLab.Problems.DataAnalysis;

namespace HeuristicLab.DatastreamAnalysis {
  [StorableClass]
  [Item("Datastream", "Represents an item containing a data source and reading options for a certain data stream.")]
  [Creatable(CreatableAttribute.Categories.Problems)]
  public class Datastream : ParameterizedNamedItem, IDatastream {

    protected const string ProblemDataParameterName = "ProblemData";
    protected const string InitialSlidingWindowParameterName = "InitialSlidingWindowParameter";
    protected const string SlidingWindowSizeParameterName = "SlidingWindowSize";
    protected const string SlidingWindowStepWidthParameterName = "SlidingWindowStepWidth";
    protected const string SlidingWindowMovementDelayParameterName = "SlidingWindowMovementDelay";
    protected const string FitnessPartitionParameterName = "FitnessPartition";
    protected const string SlidingWindowSonarRatioParameterName = "SlidingWindowSonarRatio";

    #region parameter properites

    public IValueParameter<RegressionProblemData> ProblemDataParameter {
      get { return (IValueParameter<RegressionProblemData>) Parameters[ProblemDataParameterName]; }  
    }

    public IValueParameter<IntRange> InitialSlidingWindowParameter {
      get { return (IValueParameter<IntRange>) Parameters[InitialSlidingWindowParameterName]; }
    }

    public IValueParameter<IntValue> SlidingWindowSizeParameter {
      get { return (IValueParameter<IntValue>) Parameters[SlidingWindowSizeParameterName]; }
    }

    public IValueParameter<IntValue> SlidingWindowStepWidthParameter {
      get { return (IValueParameter<IntValue>) Parameters[SlidingWindowStepWidthParameterName]; }
    }

    public IValueParameter<IntValue> SlidingWindowMovementDelayParameter {
      get { return (IValueParameter<IntValue>) Parameters[SlidingWindowMovementDelayParameterName]; }
    }

    public IValueParameter<DoubleValue> SlidingWindowSonarRatioParameter {
      get { return (IValueParameter<DoubleValue>) Parameters[SlidingWindowSonarRatioParameterName]; }
    }

    //public IValueParameter<IntRange> FitnessPartitionParameter {
    //  get { return (IValueParameter<IntRange>) Parameters[FitnessPartitionParameterName]; }
    //}

    #endregion

    #region properties

    public RegressionProblemData ProblemData {
      get { return ProblemDataParameter.Value; }
      set {
        if(value == null) throw new ArgumentNullException("ProblemData", "The provided value for problemData is null.");
        ProblemDataParameter.Value = value;
        //OnProblemDataChanged();
      }
    }
    

    public IntRange InitialSlidingWindow {
      get { return InitialSlidingWindowParameter.Value; }
      set { InitialSlidingWindowParameter.Value = value; }
    }

    public IntValue SlidingWindowSize {
      get { return SlidingWindowSizeParameter.Value; }
      set { SlidingWindowSizeParameter.Value = value; }
    }

    public IntValue SlidingWindowStepWidth {
      get { return SlidingWindowStepWidthParameter.Value; }
      set { SlidingWindowStepWidthParameter.Value = value; }
    }

    public IntValue SlidingWindowMovementDelay {
      get { return SlidingWindowMovementDelayParameter.Value; }
      set { SlidingWindowMovementDelayParameter.Value = value; }
    }

    public DoubleValue SlidingWindowSonarRatio {
      get { return SlidingWindowSonarRatioParameter.Value; }
      set { SlidingWindowSonarRatioParameter.Value = value; }
    }

    #endregion

    #region internal properties

    public IntRange FitnessPartition { get; set; }

    public bool UpdateAvailable {
      get { return false; }
    }

    public bool SlidingWindowMovementPossible {
      get {
        return ProblemData != null && ProblemData.Dataset != null &&
               (
                (FitnessPartition.End + SlidingWindowStepWidth.Value <= ProblemData.Dataset.Rows) // shift end
                || (FitnessPartition.Size > SlidingWindowSize.Value && (FitnessPartition.Start + SlidingWindowStepWidth.Value) < FitnessPartition.End) // shift start
               );
      }
    }

    public bool SlidingWindowEvaluationPossible {
      get {
        //return ProblemData != null && ProblemData.Dataset != null && ProblemData.Dataset.Rows > 0 && FitnessPartition.Size > 0;
        return FitnessPartition.Size > 0;
      }
    }

    public bool MoveSlidingWindow() {
      if (ProblemData?.Dataset == null || ProblemData.Dataset.Rows == 0) return false;
      if (FitnessPartition.End + SlidingWindowStepWidth.Value > ProblemData.Dataset.Rows) return false;

      if (FitnessPartition.Size == SlidingWindowSize.Value) {
        FitnessPartition.Start += SlidingWindowStepWidth.Value;
        FitnessPartition.End += SlidingWindowStepWidth.Value;
      } else { 
        FitnessPartition.End += SlidingWindowStepWidth.Value;
        FitnessPartition.Start += FitnessPartition.End - SlidingWindowSize.Value;
      } 

      //if (FitnessPartition.Size > SlidingWindowSize.Value) {
      //  FitnessPartition.Start += SlidingWindowStepWidth.Value;
      //} else if (FitnessPartition.Size == SlidingWindowSize.Value) {
      //  FitnessPartition.Start += SlidingWindowStepWidth.Value;
      //  FitnessPartition.End += SlidingWindowStepWidth.Value;
      //} else {
      //  FitnessPartition.End += SlidingWindowStepWidth.Value;
      //  if (FitnessPartition.Size > SlidingWindowSize.Value) {
      //    FitnessPartition.Start = FitnessPartition.End - FitnessPartition.Size;
      //  }
      //}   
      return true;
    }

    #endregion

    #region constructors
    [StorableConstructor]
    protected Datastream(bool deserializing) : base(deserializing) { }

    [StorableHook(HookType.AfterDeserialization)]
    private void AfterDeserialization() {
      RegisterParameterEvents();
      RecoverState();
    }

    protected Datastream(Datastream original, Cloner cloner) : base(original, cloner) {
      RegisterParameterEvents();
      RecoverState();
    }

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

    public Datastream() : base() {
      Parameters.Add(new ValueParameter<RegressionProblemData>(ProblemDataParameterName, "ProblemData for analysis with selected ensembles.", null));
      Parameters.Add(new FixedValueParameter<IntRange>(InitialSlidingWindowParameterName, "Initial sliding window boundaries", new IntRange(0, 100)));
      Parameters.Add(new FixedValueParameter<IntValue>(SlidingWindowSizeParameterName, "Sliding window size", new IntValue(100)));
      Parameters.Add(new FixedValueParameter<IntValue>(SlidingWindowStepWidthParameterName, "Sliding window step width", new IntValue(1)));
      Parameters.Add(new FixedValueParameter<IntValue>(SlidingWindowMovementDelayParameterName, "Sliding window movement delay interval (milliseconds)", new IntValue(0)));
      Parameters.Add(new FixedValueParameter<DoubleValue>(SlidingWindowSonarRatioParameterName, "Sliding window sonar ratio", new DoubleValue(0.25)));
      RegisterParameterEvents();
      InitializeState();
    }
    #endregion

    public void InitializeState(){
      if (ProblemData == null || ProblemData.Dataset == null || ProblemData.Dataset.Rows == 0) {
        FitnessPartition = new IntRange(0, 0);
      } else {
        FitnessPartition = (IntRange)InitialSlidingWindow.Clone();
        if (FitnessPartition.End > ProblemData.Dataset.Rows) {
          FitnessPartition.End = ProblemData.Dataset.Rows;
        }
      }
    }

    public void RecoverState() {
      if (ProblemData == null || ProblemData.Dataset == null || ProblemData.Dataset.Rows == 0) {
        FitnessPartition = new IntRange(0, 0);
      } else {
        if(FitnessPartition == null) FitnessPartition = (IntRange)InitialSlidingWindow.Clone();
        if (FitnessPartition.End > ProblemData.Dataset.Rows) {
          FitnessPartition.End = ProblemData.Dataset.Rows;
        }
      }
    }

    public event EventHandler ProblemDataChanged;
    public event EventHandler Reset;
    public event EventHandler SlidingWindowChanged;


    //protected virtual void OnProblemDataChanged() {
    //  EventHandler handler = ProblemDataChanged;
    //  if(handler != null) handler(this, EventArgs.Empty);
    //}

    //protected virtual void OnReset() {
    //  EventHandler handler = Reset;
    //  if (handler != null) handler(this, EventArgs.Empty);
    //}

    private void RegisterParameterEvents() {
      ProblemDataParameter.ValueChanged += new EventHandler(ProblemData_ValueChanged);
      //SlidingWindowSizeParameter.ValueChanged += new EventHandler(SlidingWindow_Changed);
      InitialSlidingWindowParameter.ValueChanged += new EventHandler(SlidingWindow_Changed);
    }

    private void ProblemData_ValueChanged(object sender, EventArgs e) {
      if (e == null) return;

      InitializeState();
      DatastreamAnalysisUtil.RaiseEvent(this, ProblemDataChanged);
    }

    private void SlidingWindow_Changed(object sender, EventArgs e) {
      InitializeState();
    }


    // TODO
    public IEnumerable<IParameterizedItem> ExecutionContextItems { get; }
    
  }
}