#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;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using DistributedGA.Core.Domain;
using DistributedGA.Core.Implementation;
using DistributedGA.Core.Interface;
using DistributedGA.Hive;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Operators;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Optimization.Operators {
  [Item("P2PMigrationAnalyzer", "Migrates individuals using a P2P network.")]
  [StorableClass]
  public class P2PMigrationAnalyzer : SingleSuccessorOperator, IAnalyzer, ISingleObjectiveOperator {
    // state: messagehandler
    [ExcludeFromObjectGraphTraversalAttribute]
    private IMessageHandler h;

    public bool EnabledByDefault { get { return false; } }

    public ILookupParameter<BoolValue> MaximizationParameter {
      get { return (ILookupParameter<BoolValue>)Parameters["Maximization"]; }
    }
    // for name translation
    public ScopeTreeLookupParameter<DoubleValue> QualityParameter {
      get { return (ScopeTreeLookupParameter<DoubleValue>)Parameters["Quality"]; }
    }
    public ILookupParameter<IntValue> MigrationIterationsParameter {
      get { return (ILookupParameter<IntValue>)Parameters["MigrationIterations"]; }
    }
    public ILookupParameter<PercentValue> MigrationRatesParameter {
      get { return (ILookupParameter<PercentValue>)Parameters["MigrationRate"]; }
    }
    public ILookupParameter<PercentValue> CommunicationRatesParameter {
      get { return (ILookupParameter<PercentValue>)Parameters["CommunicationRate"]; }
    }
    public ILookupParameter<IntValue> MessageCacheCapacityParameter {
      get { return (ILookupParameter<IntValue>)Parameters["MessageCacheCapacity"]; }
    }
    public ILookupParameter<IRandom> RandomParameter {
      get { return (ILookupParameter<IRandom>)Parameters["Random"]; }
    }
    public IValueParameter<IntValue> MigrationIntervalParameter {
      get { return (IValueParameter<IntValue>)Parameters["MigrationInterval"]; }
    }
    public IValueParameter<ILog> LogParameter {
      get { return (IValueParameter<ILog>)Parameters["Log"]; }
    }
    public ILookupParameter<StringValue> JobGuidParameter {
      get { return (ILookupParameter<StringValue>)Parameters["JobGUID"]; }
    }

    public IConstrainedValueParameter<EnumValue<MigrationStrategy>> MigrationStrategySelectParameter {
      get { return (IConstrainedValueParameter<EnumValue<MigrationStrategy>>)Parameters["MigrationStrategySelect"]; }
    }

    public IConstrainedValueParameter<EnumValue<MigrationStrategy>> MigrationStrategyReplaceParameter {
      get { return (IConstrainedValueParameter<EnumValue<MigrationStrategy>>)Parameters["MigrationStrategyReplace"]; }
    }

    public BoolValue Maximization {
      get { return MaximizationParameter.ActualValue; }
    }
    public IntValue MigrationIterations {
      get { return MigrationIterationsParameter.ActualValue; }
    }

    public IntValue MigrationInterval {
      get { return MigrationIntervalParameter.Value; }
    }

    public IRandom Random {
      get { return RandomParameter.ActualValue; }
    }

    [StorableConstructor]
    protected P2PMigrationAnalyzer(bool deserializing) : base(deserializing) { }
    protected P2PMigrationAnalyzer(P2PMigrationAnalyzer original, Cloner cloner) : base(original, cloner) { }

    public P2PMigrationAnalyzer()
      : base() {
      Parameters.Add(new LookupParameter<IntValue>("MigrationIterations"));
      Parameters.Add(new LookupParameter<BoolValue>("Maximization"));
      Parameters.Add(new ScopeTreeLookupParameter<DoubleValue>("Quality", 1));
      Parameters.Add(new ValueParameter<IntValue>("MigrationInterval", "", new IntValue(5)));
      Parameters.Add(new ValueParameter<PercentValue>("MigrationRate", "", new PercentValue(0.05)));
      Parameters.Add(new ValueParameter<PercentValue>("CommunicationRate", "", new PercentValue(0.10)));
      Parameters.Add(new ValueParameter<IntValue>("MessageCacheCapacity", "", new IntValue(1000)));
      Parameters.Add(new ValueParameter<StringValue>("LanIpPrefix", "", new StringValue("10.")));
      Parameters.Add(new LookupParameter<IRandom>("Random", "The random number generator"));
      Parameters.Add(new ValueParameter<StringValue>("ContactServerURL", "", new StringValue("net.tcp://10.42.1.150:9090/DistributedGA.ContactServer/ContactService")));
      Parameters.Add(new ValueParameter<StringValue>("JobGUID", "", new StringValue(Guid.NewGuid().ToString())));
      Parameters.Add(new ValueParameter<ILog>("Log", "The log", new Log(1000)));

      var validValues = new ItemSet<EnumValue<MigrationStrategy>>();
      validValues.Add(new EnumValue<MigrationStrategy>(MigrationStrategy.Best));
      validValues.Add(new EnumValue<MigrationStrategy>(MigrationStrategy.Worst));
      validValues.Add(new EnumValue<MigrationStrategy>(MigrationStrategy.Random));
      Parameters.Add(new ConstrainedValueParameter<EnumValue<MigrationStrategy>>("MigrationStrategySelect", validValues, (new EnumValue<MigrationStrategy>(MigrationStrategy.Random))));
      Parameters.Add(new ConstrainedValueParameter<EnumValue<MigrationStrategy>>("MigrationStrategyReplace", validValues, (new EnumValue<MigrationStrategy>(MigrationStrategy.Random))));

    }

    public override IDeepCloneable Clone(Cloner cloner) {
      return new P2PMigrationAnalyzer(this, cloner);
    }

    public override void ClearState() {
      base.ClearState();
      h.Dispose();
      h = null;
    }

    private void Init() {
      h = new PeerNetworkMessageHandler();
      var lanIpPrefix = ((StringValue)(Parameters["LanIpPrefix"].ActualValue)).Value;
      var contactServerUri = ((StringValue)(Parameters["ContactServerURL"].ActualValue)).Value;
      var problemInstance = ((StringValue)Parameters["JobGUID"].ActualValue).Value;
      var communicationRate = ((PercentValue)Parameters["CommunicationRate"].ActualValue).Value;
      var messageCacheCapacity = ((IntValue)Parameters["MessageCacheCapacity"].ActualValue).Value;
      h.Init(lanIpPrefix, contactServerUri, problemInstance, (int)(100 * messageCacheCapacity), (int)(100 * communicationRate));
      h.ExceptionOccurend += ExceptionThrown;
    }

    public override IOperation Apply() {
      if (h == null) {
        Init();
      }

      if (MigrationIterationsParameter.ActualValue == null) {
        MigrationIterationsParameter.ActualValue = new IntValue(0);
      }

      if (MigrationIterations.Value % MigrationInterval.Value == 0) {

        IScope scope = ExecutionContext.Scope;
        List<IScope> emigrantsList = new List<IScope>();

        //define how many migrants to send
        var migrationRate = ((PercentValue)Parameters["MigrationRate"].ActualValue).Value;
        int noOfEmigrants = Convert.ToInt32(scope.SubScopes.Count * migrationRate);
        if (noOfEmigrants == 0 && scope.SubScopes.Count > 0) {
          noOfEmigrants = 1;
        }
        var popQualities = QualityParameter.ActualValue;
        var pop = new List<IScope>(scope.SubScopes);

        List<IScope> sortedPop;
        if (Maximization.Value) {
          sortedPop = pop.Zip(popQualities, Tuple.Create).OrderByDescending(t => t.Item2).Select(t => t.Item1).ToList();
        } else {
          sortedPop = pop.Zip(popQualities, Tuple.Create).OrderBy(t => t.Item2).Select(t => t.Item1).ToList();
        }

        var selectedMigStratSelect = MigrationStrategySelectParameter.Value.Value;
        var selectedMigStratReplace = MigrationStrategyReplaceParameter.Value.Value;

        var rand = Random;
        int replIdx = 0;
        IScope emigrants = null;

        for (int i = 0; i < noOfEmigrants; i++) {
          //select emigrant depending on strategy
          switch (selectedMigStratSelect) {
            case MigrationStrategy.Best:
              emigrants = sortedPop[i];
              emigrantsList.Add(emigrants);
              break;

            case MigrationStrategy.Random:
              replIdx = rand.Next(sortedPop.Count);
              emigrants = sortedPop[replIdx];
              emigrantsList.Add(emigrants);
              break;

            case MigrationStrategy.Worst:
              emigrants = sortedPop[scope.SubScopes.Count - i - 1];
              emigrantsList.Add(emigrants);
              break;
          }
        }

        {
          // send
          for (int ei = 0; ei < emigrantsList.Count; ei++) {
            using (var stream = new MemoryStream()) {
              byte[] message;
              var emigrantScope = emigrantsList[ei];

              var msgScope = new Scope();
              var cloner = new Cloner();
              foreach (var variable in emigrantScope.Variables) {
                msgScope.Variables.Add((IVariable)variable.Clone(cloner));
              }
              HeuristicLab.Persistence.Default.Xml.XmlGenerator.Serialize(msgScope, stream);
              message = stream.GetBuffer();
              h.PublishDataToNetwork(message);
            }
          }
        }


        {
          // recieve
          var message = h.GetDataFromNetwork();
          List<KeyValuePair<PeerInfo, byte[]>> immigrants = new List<KeyValuePair<PeerInfo, byte[]>>();
          //limit number of immigrants to use
          if(noOfEmigrants < message.Count)
          {
            immigrants = message.Skip(Math.Max(0, message.Count() - noOfEmigrants)).ToList();
          } else {
            immigrants = message;
          }
          
          // remove individuals from population to make place for immigrants
          for (int i = 0; i < immigrants.Count; i++) {
            switch (selectedMigStratReplace) {
              case MigrationStrategy.Best:
                scope.SubScopes.Remove(sortedPop[0]);
                sortedPop.RemoveAt(0);
                break;

              case MigrationStrategy.Random:
                replIdx = rand.Next(sortedPop.Count);
                scope.SubScopes.Remove(sortedPop[replIdx]);
                sortedPop.RemoveAt(replIdx);
                break;

              case MigrationStrategy.Worst:
                //replace random
                scope.SubScopes.Remove(sortedPop[sortedPop.Count - 1]);
                sortedPop.RemoveAt(sortedPop.Count - 1);
                break;
            }
          }

          //insert individual sorted in population
          var qualities = QualityParameter.ActualValue;
          var qualityTranslatedName = QualityParameter.TranslatedName;
          foreach (var msg in immigrants) {
            using (var stream = new MemoryStream(msg.Value)) {
              var immigrantScope = HeuristicLab.Persistence.Default.Xml.XmlParser.Deserialize<IScope>(stream);

              var qImmigrant = ((DoubleValue)immigrantScope.Variables[qualityTranslatedName].Value).Value;
              var insertPos = scope.SubScopes.Count;
              var maximization = Maximization.Value;
              for (int i = 0; i < qualities.Length; i++) {
                var qi = qualities[i].Value;
                if ((maximization && qi < qImmigrant) || (!maximization && qi > qImmigrant)) {
                  insertPos = i;
                  break;
                }
              }

              scope.SubScopes.Insert(insertPos, immigrantScope);

              var log = LogParameter.Value;
              double quality = qImmigrant;
              log.LogMessage(string.Format("Recieved individual with quality {0} from peer {1}:{2} ; Job: {3}",
                                            quality, msg.Key.IpAddress, msg.Key.Port, msg.Key.ProblemInstance));
            }
          }
        }
      }

      MigrationIterations.Value++;
      return base.Apply();
    }

    private void ExceptionThrown(object sender, Exception e) {
      var log = LogParameter.Value;
      log.LogMessage(e.Message);
    }

  }
}