#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2008 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.Text;
using System.Xml;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.DataAnalysis;
using HeuristicLab.Constraints;
using StructId = HeuristicLab.GP.StructureIdentification;

namespace HeuristicLab.GP.StructureIdentification {
  public class FunctionLibraryInjector : OperatorBase {
    private const string TARGETVARIABLE = "TargetVariable";
    private const string ALLOWEDFEATURES = "AllowedFeatures";
    protected const string FUNCTIONLIBRARY = "FunctionLibrary";

    public override string Description {
      get { return @"Injects a default function library for regression and classification problems."; }
    }

    public FunctionLibraryInjector()
      : base() {
      AddVariableInfo(new VariableInfo(TARGETVARIABLE, "The target variable", typeof(IntData), VariableKind.In));
      AddVariableInfo(new VariableInfo(ALLOWEDFEATURES, "List of indexes of allowed features", typeof(ItemList<IntData>), VariableKind.In));
      AddVariableInfo(new VariableInfo(FUNCTIONLIBRARY, "Preconfigured default operator library", typeof(GPOperatorLibrary), VariableKind.New));
    }

    public override IOperation Apply(IScope scope) {
      StructId.Variable variable;
      GPOperatorLibrary operatorLibrary;

      ItemList<IntData> allowedFeatures = GetVariableValue<ItemList<IntData>>(ALLOWEDFEATURES, scope, true);
      int targetVariable = GetVariableValue<IntData>(TARGETVARIABLE, scope, true).Data;

      // remove the target-variable in case it occures in allowed features
      List<IntData> ts = allowedFeatures.FindAll(d => d.Data == targetVariable);
      foreach (IntData t in ts) allowedFeatures.Remove(t);

      variable = new StructId.Variable();
      StructId.Constant constant = new StructId.Constant();

      StructId.Addition addition = new StructId.Addition();
      StructId.And and = new StructId.And();
      StructId.Average average = new StructId.Average();
      StructId.Cosinus cosinus = new StructId.Cosinus();
      StructId.Division division = new StructId.Division();
      StructId.Equal equal = new StructId.Equal();
      StructId.Exponential exponential = new StructId.Exponential();
      StructId.GreaterThan greaterThan = new StructId.GreaterThan();
      StructId.IfThenElse ifThenElse = new StructId.IfThenElse();
      StructId.LessThan lessThan = new StructId.LessThan();
      StructId.Logarithm logarithm = new StructId.Logarithm();
      StructId.Multiplication multiplication = new StructId.Multiplication();
      StructId.Not not = new StructId.Not();
      StructId.Or or = new StructId.Or();
      StructId.Power power = new StructId.Power();
      StructId.Signum signum = new StructId.Signum();
      StructId.Sinus sinus = new StructId.Sinus();
      StructId.Sqrt sqrt = new StructId.Sqrt();
      StructId.Subtraction subtraction = new StructId.Subtraction();
      StructId.Tangens tangens = new StructId.Tangens();
      StructId.Xor xor = new StructId.Xor();

      IFunction[] booleanFunctions = new IFunction[] {
        and,
        equal,
        greaterThan,
        lessThan,
        not,
        or,
        xor 
      };
      IFunction[] doubleFunctions = new IFunction[] {
        variable,
        constant,
        addition,
        average,
        cosinus,
        division,
        exponential,
        ifThenElse,
        logarithm,
        multiplication,
        power,
        signum,
        sinus,
        sqrt,
        subtraction,
        tangens
      };

      SetAllowedSubOperators(and, booleanFunctions);
      SetAllowedSubOperators(equal, doubleFunctions);
      SetAllowedSubOperators(greaterThan, doubleFunctions);
      SetAllowedSubOperators(lessThan, doubleFunctions);
      SetAllowedSubOperators(not, booleanFunctions);
      SetAllowedSubOperators(or, booleanFunctions);
      SetAllowedSubOperators(xor, booleanFunctions);
      SetAllowedSubOperators(addition, doubleFunctions);
      SetAllowedSubOperators(average, doubleFunctions);
      SetAllowedSubOperators(cosinus, doubleFunctions);
      SetAllowedSubOperators(division, doubleFunctions);
      SetAllowedSubOperators(exponential, doubleFunctions);
      SetAllowedSubOperators(ifThenElse, 0, booleanFunctions);
      SetAllowedSubOperators(ifThenElse, 1, doubleFunctions);
      SetAllowedSubOperators(ifThenElse, 2, doubleFunctions);
      SetAllowedSubOperators(logarithm, doubleFunctions);
      SetAllowedSubOperators(multiplication, doubleFunctions);
      SetAllowedSubOperators(power, doubleFunctions);
      SetAllowedSubOperators(signum, doubleFunctions);
      SetAllowedSubOperators(sinus, doubleFunctions);
      SetAllowedSubOperators(sqrt, doubleFunctions);
      SetAllowedSubOperators(subtraction, doubleFunctions);
      SetAllowedSubOperators(tangens, doubleFunctions);

      operatorLibrary = new GPOperatorLibrary();
      operatorLibrary.GPOperatorGroup.AddOperator(variable);
      operatorLibrary.GPOperatorGroup.AddOperator(constant);
      operatorLibrary.GPOperatorGroup.AddOperator(addition);
      operatorLibrary.GPOperatorGroup.AddOperator(average);
      operatorLibrary.GPOperatorGroup.AddOperator(and);
      operatorLibrary.GPOperatorGroup.AddOperator(cosinus);
      operatorLibrary.GPOperatorGroup.AddOperator(division);
      operatorLibrary.GPOperatorGroup.AddOperator(equal);
      operatorLibrary.GPOperatorGroup.AddOperator(exponential);
      operatorLibrary.GPOperatorGroup.AddOperator(greaterThan);
      operatorLibrary.GPOperatorGroup.AddOperator(ifThenElse);
      operatorLibrary.GPOperatorGroup.AddOperator(lessThan);
      operatorLibrary.GPOperatorGroup.AddOperator(logarithm);
      operatorLibrary.GPOperatorGroup.AddOperator(multiplication);
      operatorLibrary.GPOperatorGroup.AddOperator(not);
      operatorLibrary.GPOperatorGroup.AddOperator(power);
      operatorLibrary.GPOperatorGroup.AddOperator(or);
      operatorLibrary.GPOperatorGroup.AddOperator(signum);
      operatorLibrary.GPOperatorGroup.AddOperator(sinus);
      operatorLibrary.GPOperatorGroup.AddOperator(sqrt);
      operatorLibrary.GPOperatorGroup.AddOperator(subtraction);
      operatorLibrary.GPOperatorGroup.AddOperator(tangens);
      operatorLibrary.GPOperatorGroup.AddOperator(xor);

      int[] allowedIndexes = new int[allowedFeatures.Count];
      for (int i = 0; i < allowedIndexes.Length; i++) {
        allowedIndexes[i] = allowedFeatures[i].Data;
      }

      variable.SetConstraints(allowedIndexes, 0, 0);

      scope.AddVariable(new HeuristicLab.Core.Variable(scope.TranslateName(FUNCTIONLIBRARY), operatorLibrary));
      return null;
    }

    private void SetAllowedSubOperators(IFunction f, IFunction[] gs) {
      foreach (IConstraint c in f.Constraints) {
        if (c is SubOperatorTypeConstraint) {
          SubOperatorTypeConstraint typeConstraint = c as SubOperatorTypeConstraint;
          typeConstraint.Clear();
          foreach (IFunction g in gs) {
            typeConstraint.AddOperator(g);
          }
        } else if (c is AllSubOperatorsTypeConstraint) {
          AllSubOperatorsTypeConstraint typeConstraint = c as AllSubOperatorsTypeConstraint;
          typeConstraint.Clear();
          foreach (IFunction g in gs) {
            typeConstraint.AddOperator(g);
          }
        }
      }
    }

    private void SetAllowedSubOperators(IFunction f, int p, IFunction[] gs) {
      foreach (IConstraint c in f.Constraints) {
        if (c is SubOperatorTypeConstraint) {
          SubOperatorTypeConstraint typeConstraint = c as SubOperatorTypeConstraint;
          if (typeConstraint.SubOperatorIndex.Data == p) {
            typeConstraint.Clear();
            foreach (IFunction g in gs) {
              typeConstraint.AddOperator(g);
            }
          }
        }
      }
    }
  }
}