#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2017 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 HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Core.Networks;
using HeuristicLab.Optimization;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Networks.IntegratedOptimization.TravelingThief {
  [Item("TtpNetwork", "An abstract base class for TTP optimization networks.")]
  [StorableClass]
  public abstract class TtpNetwork : Network, IOptimizer {
    #region Constants
    protected const string OrchestratorNodeName = "Orchestrator";
    protected const string MetaSolverNodeName = "MetaSolver";
    protected const string TspSolverNodeName = "TspSolver";
    protected const string KspSolverNodeName = "KspSolver";
    #endregion

    #region Nodes
    public TtpOrchestratorNode Orchestrator {
      get { return (TtpOrchestratorNode)Nodes[OrchestratorNodeName]; }
      protected set {
        if (Nodes.ContainsKey(OrchestratorNodeName))
          throw new InvalidOperationException("Orchestrator already set.");
        Nodes.Add(value);
      }
    }

    public OrchestratedAlgorithmNode MetaSolver {
      get { return (OrchestratedAlgorithmNode)Nodes[MetaSolverNodeName]; }
      protected set {
        if (Nodes.ContainsKey(MetaSolverNodeName))
          throw new InvalidOperationException("MetaSolver already set.");
        Nodes.Add(value);
        RegisterEvents();
      }
    }

    public OrchestratedAlgorithmNode TspSolver {
      get { return (OrchestratedAlgorithmNode)Nodes[TspSolverNodeName]; }
      protected set {
        if (Nodes.ContainsKey(TspSolverNodeName))
          throw new InvalidOperationException("TspSolver already set.");
        Nodes.Add(value);
      }
    }

    public OrchestratedAlgorithmNode KspSolver {
      get { return (OrchestratedAlgorithmNode)Nodes[KspSolverNodeName]; }
      protected set {
        if (Nodes.ContainsKey(KspSolverNodeName))
          throw new InvalidOperationException("KspSolver already set.");
        Nodes.Add(value);
      }
    }
    #endregion

    [StorableConstructor]
    protected TtpNetwork(bool deserializing) : base(deserializing) { }
    protected TtpNetwork(TtpNetwork original, Cloner cloner) : base(original, cloner) {
      RegisterEvents();
    }
    protected TtpNetwork() : this("TtpNetwork") { }
    protected TtpNetwork(string name) : base(name) { }

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

    private void RegisterEvents() {
      MetaSolver.AlgorithmChanged += MetaSolver_AlgorithmChanged;
      RegisterAlgorithmEvents();
    }

    private void MetaSolver_AlgorithmChanged(object sender, EventArgs e) {
      RegisterAlgorithmEvents();
    }

    private void RegisterAlgorithmEvents() {
      var algorithm = MetaSolver.Algorithm;
      if (algorithm == null) return;

      algorithm.ExecutionStateChanged += (s, e) => OnExecutionStateChanged();
      algorithm.ExecutionTimeChanged += (s, e) => OnExecutionTimeChanged();
      algorithm.Prepared += (s, e) => OnPrepared();
      algorithm.Started += (s, e) => OnStarted();
      algorithm.Paused += (s, e) => OnPaused();
      algorithm.Stopped += (s, e) => OnStopped();
      algorithm.ExceptionOccurred += (s, e) => OnExceptionOccurred(e.Value);
    }

    #region IOptimizer Members
    public RunCollection Runs { get { return MetaSolver.Algorithm.Runs; } }
    public IEnumerable<IOptimizer> NestedOptimizers { get { yield break; } }
    public ExecutionState ExecutionState { get { return MetaSolver.Algorithm.ExecutionState; } }
    public TimeSpan ExecutionTime { get { return MetaSolver.Algorithm.ExecutionTime; } }

    public void Prepare() { Prepare(false); }
    public void Prepare(bool clearRuns) { Orchestrator.Prepare(clearRuns); }
    public void Start() { Orchestrator.StartAsync(); }
    public void Pause() { Orchestrator.Pause(); }
    public void Stop() { Orchestrator.Stop(); }

    public event EventHandler ExecutionStateChanged;
    private void OnExecutionStateChanged() {
      var handler = ExecutionStateChanged;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public event EventHandler ExecutionTimeChanged;
    private void OnExecutionTimeChanged() {
      var handler = ExecutionTimeChanged;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public event EventHandler Prepared;
    private void OnPrepared() {
      var handler = Prepared;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public event EventHandler Started;
    private void OnStarted() {
      var handler = Started;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public event EventHandler Paused;
    private void OnPaused() {
      var handler = Paused;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public event EventHandler Stopped;
    private void OnStopped() {
      var handler = Stopped;
      if (handler != null) handler(this, EventArgs.Empty);
    }

    public event EventHandler<EventArgs<Exception>> ExceptionOccurred;
    private void OnExceptionOccurred(Exception exception) {
      var handler = ExceptionOccurred;
      if (handler != null) handler(this, new EventArgs<Exception>(exception));
    }
    #endregion
  }
}