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/*                                                                                    */
/*  Visualization Library                                                             */
/*  http://visualizationlibrary.org                                                   */
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/*  Copyright (c) 2005-2020, Michele Bosi                                             */
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#ifndef VLXVisitorLinker_INCLUDE_ONCE
#define VLXVisitorLinker_INCLUDE_ONCE

#include <vlX/Visitor.hpp>
#include <vlX/Value.hpp>

namespace vlX
{
  /** Substitutes IDs into VLXStructures using the provided link map.*/
  class VisitorLinker: public Visitor
  {
    VL_INSTRUMENT_CLASS(vlX::VisitorLinker, Visitor)

  public:
    typedef enum
    {
      NoError,
      UnresolvedID
    } EError;

  public:
    VisitorLinker(const std::map< std::string, vl::ref<VLXStructure> >* map=NULL)
    {
      mLinkMap = map;
      mError = NoError;
    }

    void setLinkMap(const std::map< std::string, vl::ref<VLXStructure> >* map)
    {
      mLinkMap = map;
    }

    VLXStructure* link(const std::string& uid)
    {
      VL_CHECK(mLinkMap)
      VL_CHECK(!uid.empty())
      std::map< std::string, vl::ref<VLXStructure> >::const_iterator it = mLinkMap->find(uid);
      if( it != mLinkMap->end() )
      {
        // this should never happen
        VL_CHECK(uid != "#NULL")

        /* vl::Log::debug( Say("- ID '%s' linked to '%s'.\n") << uid << it->second->tag() ); */
        return it->second.get_writable();
      }
      else
      {
        if (uid != "#NULL")
        {
          mError = UnresolvedID;
          vl::Log::error( vl::Say("Could not link ID '%s' to anything!\n") << uid );
        }
        return NULL;
      }
    }

    virtual void visitStructure(VLXStructure* obj)
    {
      if (isVisited(obj))
        return;

      for(size_t i=0; i<obj->value().size(); ++i)
      {
        if (obj->value()[i].value().type() == VLXValue::Structure)
          obj->value()[i].value().getStructure()->acceptVisitor(this);
        else
        if (obj->value()[i].value().type() == VLXValue::List)
          obj->value()[i].value().getList()->acceptVisitor(this);
        else
        /*
        if (obj->value()[i].value().type() == VLXValue::ArrayID)
          obj->value()[i].value().getArrayID()->acceptVisitor(this);
        else
        */
        if (obj->value()[i].value().type() == VLXValue::ID)
        {
          // transform ID -> Structure
          VLXStructure* lnk_obj = link( obj->value()[i].value().getID() );
          obj->value()[i].value().setStructure( lnk_obj );
        }
      }
    }

    virtual void visitList(VLXList* list)
    {
      // this should happen only if the user manually creates loops
      if (isVisited(list))
      {
        vl::Log::warning("VisitorLinker: cycle detected on VLXList.\n");
        return;
      }

      for(size_t i=0; i<list->value().size(); ++i)
      {
        if (list->value()[i].type() == VLXValue::Structure)
          list->value()[i].getStructure()->acceptVisitor(this);
        if (list->value()[i].type() == VLXValue::List)
          list->value()[i].getList()->acceptVisitor(this);
        else
        /*
        if (list->value()[i].type() == VLXValue::ArrayID)
          list->value()[i].getArrayID()->acceptVisitor(this);
        else
        */
        if (list->value()[i].type() == VLXValue::ID)
        {
          // transform ID -> Structure
          VLXStructure* lnk_obj = link( list->value()[i].getID() );
          list->value()[i].setStructure( lnk_obj );
        }
      }
    }

    /*
    virtual void visitArray(VLXArrayString*)  {}

    virtual void visitArray(VLXArrayID* arr)
    {
      // retrieves the assigned Structure
      for(size_t i=0 ;i<arr->value().size(); ++i)
        arr->value()[i].setStructure ( link(arr->value()[i].uid()) );
    }

    virtual void visitArray(VLXArrayIdentifier*) {}
    */

    virtual void visitArray(VLXArrayInteger*)  {}

    virtual void visitArray(VLXArrayReal*)  {}

    EError error() const { return mError; }

    void setError(EError err) { mError = err; }

  private:
    const std::map< std::string, vl::ref<VLXStructure> >* mLinkMap;
    EError mError;
  };
}

#endif