#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2011 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.Core;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
using HeuristicLab.Common;
using HeuristicLab.PDPSimulation.DomainModel;

namespace HeuristicLab.PDPSimulation {
  [StorableClass]
  public abstract class PDAction: Item {
    [Storable]
    private Guid baseObjectId;

    public Guid BaseObjectId {
      get { return baseObjectId; }
    }

    [Storable]
    protected PDAction successor;

    public PDAction Successor {
      get { return successor; }
    }

    [Storable]
    protected bool started;

    public void AppendAction(PDAction action, bool recursive) {
      if (!action.BaseObjectId.Equals(this.BaseObjectId))
        throw new Exception("Can only append actions of the same object");
      
      PDAction predecessor = this;
      while (predecessor.successor != null && 
            (recursive || predecessor.ActionCompleted()))
        predecessor = predecessor.successor;

      predecessor.successor = action;
    }

    public bool IsCompleted {
      get {
        return ActionCompleted() &&
          (successor == null || successor.IsCompleted);
      }
    }

    protected abstract bool ActionInterruptable();

    public bool Interruptable() {
      PDAction action = this;

      while (action != null && action.ActionCompleted())
        action = action.successor;

      return action == null || !action.started || action.ActionInterruptable();
    }

    public abstract bool ActionCompleted();

    protected abstract double Perform(BaseObject baseObject, double simulationTime, double tickTime, List<PDChange> changes);

    public List<PDChange> Perform(BaseObject baseObject, double simulationTime, double timeStep) {
      List<PDChange> changes = new List<PDChange>();

      lock (this) {
        double startTime = simulationTime;

        double tickTime = timeStep;
        bool complete = ActionCompleted();
        if (!complete && tickTime > 0) {
          started = true;
          simulationTime = Perform(baseObject, simulationTime, tickTime, changes);
          complete = ActionCompleted();
        }

        PDAction next = successor;
        while (complete && next != null) {
          tickTime = timeStep - (simulationTime - startTime);

          complete = next.ActionCompleted();
          if (!complete && tickTime > 0) {
            next.started = true;
            simulationTime = next.Perform(baseObject, simulationTime, tickTime, changes);
            complete = next.ActionCompleted();
          }

          next = next.successor;
        }
      }

      return changes;
    }

    public virtual bool Obsoletes(PDAction action) {
      return this.BaseObjectId.Equals(action.BaseObjectId);
    }

    protected PDAction(Guid baseObjectId) {
      this.baseObjectId = baseObjectId;
    }

    [StorableConstructor]
    protected PDAction(bool deserializing) : base(deserializing) { }
    protected PDAction(PDAction original, Cloner cloner)
      : base(original, cloner) {
        baseObjectId = original.baseObjectId;
        successor = cloner.Clone<PDAction>(original.successor);
        started = original.started;
    }
  }
}