#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2013 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.IO;
using System.Linq;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
using HeuristicLab.Problems.ParameterOptimization;

namespace HeuristicLab.Problems.ExternalEvaluation.Scilab {
  [Item("SciLabParameterVectorEvaluator", "An evaluator which takes a parameter vector and returns a quality value, calculated by a Scilab script.")]
  [StorableClass]
  public sealed class ScilabParameterVectorEvaluator : ParameterVectorEvaluator {
    private const string QualityVariableParameterName = "QualityVariableName";
    private const string ScilabEvaluationScriptParameterName = "ScilabEvaluationScript";
    private const string InitializationScriptParameterName = "InitializationScript";

    #region parameters
    public ILookupParameter<StringValue> QualityVariableParameter {
      get { return (ILookupParameter<StringValue>)Parameters[QualityVariableParameterName]; }
    }
    public ILookupParameter<TextFileValue> ScilabEvaluationScriptParameter {
      get { return (ILookupParameter<TextFileValue>)Parameters[ScilabEvaluationScriptParameterName]; }
    }
    public IFixedValueParameter<TextFileValue> InitializationScriptParameter {
      get { return (IFixedValueParameter<TextFileValue>)Parameters[InitializationScriptParameterName]; }
    }
    #endregion

    public TextFileValue InitializationScript {
      get { return InitializationScriptParameter.Value; }
    }

    [StorableConstructor]
    private ScilabParameterVectorEvaluator(bool deserializing) : base(deserializing) { }
    private ScilabParameterVectorEvaluator(ScilabParameterVectorEvaluator original, Cloner cloner)
      : base(original, cloner) {
    }
    public override IDeepCloneable Clone(Cloner cloner) {
      return new ScilabParameterVectorEvaluator(this, cloner);
    }

    public ScilabParameterVectorEvaluator()
      : base() {
      Parameters.Add(new LookupParameter<StringValue>(QualityVariableParameterName, "The name of the quality variable of the Scilab script."));
      Parameters.Add(new LookupParameter<TextFileValue>(ScilabEvaluationScriptParameterName, "The path to the Scilab evaluation script."));
      Parameters.Add(new FixedValueParameter<TextFileValue>(InitializationScriptParameterName, "The path to a Scilab script the should be execute before the evaluation starts.", new TextFileValue()));
    }

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

    public override void InitializeState() {
      base.InitializeState();

      if (string.IsNullOrEmpty(InitializationScript.Value)) return;
      if (!InitializationScript.Exists()) throw new FileNotFoundException(string.Format("The initialization script \"{0}\" cannot be found.", InitializationScript.Value));
      int result = DotNetScilab.Scilab.Instance.execScilabScript(InitializationScript.Value);
      if (result != 0) ThrowSciLabException(InitializationScript.Value, result);
    }

    private readonly object locker = new object();
    public override IOperation Apply() {
      var evaluationScript = ScilabEvaluationScriptParameter.ActualValue;
      if (string.IsNullOrEmpty(evaluationScript.Value)) throw new FileNotFoundException("The evaluation script in the problem is not set.");
      if (!evaluationScript.Exists()) throw new FileNotFoundException(string.Format("The evaluation script \"{0}\" cannot be found.", evaluationScript.Value));

      //Scilab is used via a c++ wrapper that calls static methods. Hence it is not possible to parallelize the evaluation.
      lock (locker) {
        int result;
        var parameterVector = ParameterVectorParameter.ActualValue;
        var parameterNames = ParameterNamesParameter.ActualValue;
        if (parameterNames.Any(string.IsNullOrEmpty)) throw new ArgumentException("Not all parameter names are provided.");
        var scilab = DotNetScilab.Scilab.Instance;

        for (int i = 0; i < ProblemSizeParameter.ActualValue.Value; i++) {
          result = scilab.createNamedMatrixOfDouble(parameterNames[i], 1, 1, new double[] { parameterVector[i] });
          if (result != 0) throw new InvalidOperationException("Error while setting the parameter " + parameterNames[i] + " to " + parameterVector[i] + "  (ErrorCode: " + result + ").");
        }

        string script = ScilabEvaluationScriptParameter.ActualValue.Value;
        result = scilab.execScilabScript(script);
        if (result != 0) ThrowSciLabException(script, result);

        string qualityVariableName = QualityVariableParameter.ActualValue.Value;
        double[] values = scilab.readNamedMatrixOfDouble(qualityVariableName);
        if (values == null) throw new InvalidOperationException(string.Format("Could not find the variable \"{0}\" in the Scilab workspace, that should hold the quality value.", qualityVariableName));
        double quality = values[0];

        if (double.IsNaN(quality)) quality = double.MaxValue;
        if (double.IsInfinity(quality)) quality = double.MaxValue;

        QualityParameter.ActualValue = new DoubleValue(quality);
        return base.Apply();
      }
    }

    private void ThrowSciLabException(string fileName, int errorCode) {
      const string code = "errorMsg = lasterror();";
      int result = DotNetScilab.Scilab.Instance.SendScilabJob(code);
      if (result != 0) throw new InvalidOperationException(string.Format("An error occured during the execution of the Scilab script {0}.", fileName));

      string errorMessage = DotNetScilab.Scilab.Instance.readNamedMatrixOfString("errorMsg")[0];

      string message = string.Format("The error {1} occured during the execution of the Scilab script {0}. \r\n\r\n {2}", fileName, errorCode, errorMessage);
      throw new InvalidOperationException(message);
    }
  }
}