/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
 *  Main authors:
 *     Guido Tack <tack@gecode.org>
 *
 *  Copyright:
 *     Guido Tack, 2007
 *
 *  Last modified:
 *     $Date: 2008-07-11 09:39:08 +0200 (Fri, 11 Jul 2008) $ by $Author: tack $
 *     $Revision: 7297 $
 *
 *  This file is part of Gecode, the generic constraint
 *  development environment:
 *     http://www.gecode.org
 *
 *  Permission is hereby granted, free of charge, to any person obtaining
 *  a copy of this software and associated documentation files (the
 *  "Software"), to deal in the Software without restriction, including
 *  without limitation the rights to use, copy, modify, merge, publish,
 *  distribute, sublicense, and/or sell copies of the Software, and to
 *  permit persons to whom the Software is furnished to do so, subject to
 *  the following conditions:
 *
 *  The above copyright notice and this permission notice shall be
 *  included in all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#include <sstream>

namespace Gecode { namespace Reflection {
  
  class VarMapIter;

  /**
    * \brief Mapping %Gecode variable implementations to variable specifications
    *
    * The reflection API always references variables by indices into a VarMap.
    * The VarMap is filled with information when you access the specification 
    * of a propagator. If, for instance, a propagator references some 
    * IntVarImp, and that particular variable implementation is already 
    * contained in the VarMap, the ActorSpec for the propagator will contain a 
    * reference to the index of the variable implementation. If it is not 
    * already in the VarMap, its VarSpec is extracted, and the variable 
    * implementation is put in the map. The ActorSpec then of course 
    * references the newly created index.
    *
    * A VarMap also maps variable implementations to names. The names can be 
    * assigned in the script, using the virtual function Space::getVars (see 
    * Queens as an example). That way, the variables mentioned in an ActorSpec 
    * can be identified with variables from the model.
    *
    * \ingroup TaskReflection
    */
  class GECODE_KERNEL_EXPORT VarMap {
    friend class VarMapIter;
  private:
    class VarMapObj;
    VarMapObj* vo;
    
  public:
    /// Default constructor
    VarMap(void);
    /// Copy constructor
    VarMap(const VarMap&);
    /// Assignment operator
    VarMap& operator=(const VarMap&);
    /// Destructor
    GECODE_MSC_VIRTUAL ~VarMap(void);
    
    /// Return number of entries
    int size(void) const;
    
    /// Return index for variable implementation \a x
    int index(const VarImpBase* x) const;
    /// Return index for variable implementation with name \a n
    int index(const Support::Symbol& n) const;

    /// Return if variable implementation with name \a n is known
    bool nameIsKnown(const Support::Symbol& n) const;

    /// Return if variable implementation \a x has a name
    bool hasName(const VarImpBase* x) const;
    /// Return if variable implementation at index \a i has a name
    bool hasName(int i) const;

    /// Return name for variable implementation \a x
    Support::Symbol name(const VarImpBase* x) const;
    /// Return name for variable implementation at index \a i
    Support::Symbol name(int i) const;

    /// Return variable implementation with name \a n
    VarImpBase* varImpBase(const Support::Symbol& n) const;
    /// Return variable implementation at index \a i
    VarImpBase* varImpBase(int i) const;
    /// Return variable with name \a n
    Var var(const Support::Symbol& n) const;
    /// Return variable at index \a i
    Var var(int i) const;

    /// Return specification for variable implementation \a x
    VarSpec& spec(const VarImpBase* x) const;
    /// Return specification for variable implementation at index \a i
    VarSpec& spec(int i) const;
    /// Return specification for variable implementation with name \a n
    VarSpec& spec(const Support::Symbol& n) const;

    /// Register name \a n for variable implementation \a x
    void name(VarImpBase* x, const Support::Symbol& n);

    /// Insert specification \a vs for variable implementation \a x, return index
    int put(const VarImpBase* x, VarSpec* vs);

    /// Insert a shared object into the table
    void putMasterObject(void* obj);
    /// Get the index of a shared object from the table
    int getSharedIndex(void* obj) const;
    /// Get the shared object stored at index \a i
    void* getSharedObject(int i) const;

    /// \name Interface for modeling
    //@{
    /// Insert specification for variable \a v with name \a n
    template <class Var> void
    put(const Space* home, const Var& v, const Support::Symbol& n,
        bool registerOnly = false);
    /// Insert specifications for variables in \a x with name \a n
    template <class Var> void
    putArray(const Space* home, const VarArgArray<Var>& v,
             const Support::Symbol& n, bool registerOnly = false);
    /// Insert specifications for variables in \a x with name \a n
    template <class Var> void
    putArray(const Space* home, const VarArray<Var>& v,
             const Support::Symbol& n,
             bool registerOnly = false);

    //@}

  };
  
  /**
    * \brief Iterating a variable map
    *
    * The variable map is filled dynamically while iterating over the
    * actors of a space. The iterator will signal that it is done when all
    * currently known variables have been iterated, but it will later become
    * available again once new variables are encountered.
    *
    * \ingroup TaskReflection
    */
  class GECODE_KERNEL_EXPORT VarMapIter {
  private:
    /// The variable map to iterate
    VarMap* m;
    /// The current index
    int i;
  public:
    /// Construct iterator for variable map \a m
    VarMapIter(VarMap& m);
    /// Test whether iterator still has variables or is done
    bool operator()(void) const;
    /// Return variable specification for current iterator position
    VarSpec& spec(void) const;
    /// Return variable implementation for current iterator position
    VarImpBase* varImpBase(void) const;
    /// Return variable for current iterator position
    Var var(void) const;
    /// Move iterator to next variable
    void operator++(void);
  };

  template <> void
  inline
  VarMap::put(const Space* home, const Reflection::Var& x,
              const Support::Symbol& n, bool registerOnly) {
    if (! (n == ""))
      name(x.varImpBase(), n);
    if (!registerOnly) {
      Reflection::Arg* a = x.spec(home, *this);
      delete a;
    }
  }

  template <class V> void
  VarMap::put(const Space* home, const V& x, const Support::Symbol& n,
              bool registerOnly) {
    typename VarViewTraits<V>::View v(x);
    if (! (n == ""))
      name(v.var(), n);
    if (!registerOnly) {
      Reflection::Arg* a = v.spec(home, *this);
      delete a;
    }
  }

  template <class Var> void
  VarMap::putArray(const Space* home, const VarArgArray<Var>& x,
                   const Support::Symbol& n, bool registerOnly) {
    for (int i=0; i<x.size(); i++) {
      std::stringstream s;
      s << i;
      Support::Symbol nn = n.copy();
      nn += Support::Symbol(s.str().c_str(), true);
      put(home, x[i], nn, registerOnly);
    }
  }
  template <class Var> void
  VarMap::putArray(const Space* home, const VarArray<Var>& x,
                   const Support::Symbol& n, bool registerOnly) {
    for (int i=0; i<x.size(); i++) {
      std::stringstream s;
      s << i;
      Support::Symbol nn = n.copy();
      nn += Support::Symbol(s.str().c_str(), true);
      put(home, x[i], nn, registerOnly);
    }
  }

}}

// STATISTICS: kernel-other