TClass.h

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/*
 * Copyright (C) 2012 by
 *   MetraLabs GmbH (MLAB), GERMANY
 * and
 *   Neuroinformatics and Cognitive Robotics Labs (NICR) at TU Ilmenau, GERMANY
 * All rights reserved.
 *
 * Contact: info@mira-project.org
 *
 * Commercial Usage:
 *   Licensees holding valid commercial licenses may use this file in
 *   accordance with the commercial license agreement provided with the
 *   software or, alternatively, in accordance with the terms contained in
 *   a written agreement between you and MLAB or NICR.
 *
 * GNU General Public License Usage:
 *   Alternatively, this file may be used under the terms of the GNU
 *   General Public License version 3.0 as published by the Free Software
 *   Foundation and appearing in the file LICENSE.GPL3 included in the
 *   packaging of this file. Please review the following information to
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 *   met: http://www.gnu.org/copyleft/gpl.html.
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 */

#ifndef _MIRA_TCLASS_H_
#define _MIRA_TCLASS_H_

#include <string>

#include <utils/HasMember.h>
#include <utils/Foreach.h>
#include <factory/Class.h>
#include <factory/HasDefaultConstructor.h>

namespace mira {


MIRA_MEMBER_DETECTOR( mNoPublicDefaultConstructor );

// *****************************************************************************
// *** TClass
// *****************************************************************************

template<typename CLASS>
class TClass: public Class
{
    friend class ClassFactory;
public:
    TClass( std::string const& identifier,
            std::string const& name,
            bool libLoaded );

    virtual int getTypeId() const;

    virtual Typename getTypename() const;

    CLASS* newInstance() const;

    virtual Object* newInstance( int paramCount, ... ) const;

    CLASS* newInstance( std::string const& childIdentifier ) const;

    Object* newInstance( std::string const& childIdentifier,
                         int paramCount, ... ) const;

    virtual bool isAbstract() const;

protected:

    Object* newVAInstance( std::string const& childIdentifier,
                           int paramCount,
                           std::va_list ap ) const;

    Object* newVAInstance( int paramCount, std::va_list ap ) const;

private:
    TClass( )
    {
    }

};

// *****************************************************************************
// *** TClass implementation
// *****************************************************************************

template<typename CLASS>
inline TClass<CLASS>::TClass( std::string const& identifier,
                              std::string const& name, bool libLoaded ) :
    Class( identifier, name, libLoaded )
{
    // add meta info
    CLASS::addMetaInfo( mMetaInfo );
}

template<typename CLASS>
inline int TClass<CLASS>::getTypeId() const
{
    return typeId<CLASS>();
}

template<typename CLASS>
inline Typename TClass<CLASS>::getTypename() const
{
    return typeName<CLASS>();
}

template<typename CLASS>
inline bool TClass<CLASS>::isAbstract() const
{
    return std::is_abstract<CLASS>::value;
}


template<typename CLASS>
CLASS* TClass<CLASS>::newInstance() const
{
    // check if the class is abstract and / or do have a default constructor
    // since the check for the default constructor fails on some compilers,
    // we have to check for the mNoPublicDefaultConstructor member additionally
    typedef typename
        boost::mpl::eval_if<std::is_abstract<CLASS>,
            boost::mpl::identity<ClassFactoryAbstractClassBuilder>,
            // else
            boost::mpl::eval_if< typename HasPublicDefaultConstructor<CLASS>::type,
                boost::mpl::identity< ClassFactoryDefaultConstClassBuilder >,
                boost::mpl::identity< ClassFactoryNoDefaultConstClassBuilder > >
            >::type ClassType;

    return ClassType::template invoke<CLASS>( );
}

template<typename CLASS>
Object* TClass<CLASS>::newInstance( int paramCount, ... ) const
{
    std::va_list ap;
    va_start(ap, paramCount);
    return newVAInstance( paramCount, ap);
}

template<typename CLASS>
CLASS* TClass<CLASS>::newInstance( std::string const& childIdentifier ) const
{
    // handle the case that someone wants to create an instance of US.
    // obtain identifier by function since it might be different from
    // mIdentifier (template classes)
    if( childIdentifier == getIdentifier() )
        return newInstance();
    // check if the desired object is a registered derived child
    if ( mDerivedChildren.find( childIdentifier ) ==
            mDerivedChildren.end() ) {
        MIRA_THROW( XFactoryUnknown, "Unknown class identifier ("
                  + childIdentifier +") calling newInstance on " + getIdentifier()
                  + " !" );
    }
    Object* tObject = mDerivedChildren.find( childIdentifier )->second.newInstance();
    if ( !tObject ) {
        MIRA_THROW( XFactoryLogical, "Class creation failed (" + childIdentifier
                  + ") calling newInstance on " + getIdentifier() + "!" );
    }
    // try to cast object to desired class
    return mira_factoryDynamicCast<CLASS>( tObject );
}

template<typename CLASS>
Object* TClass<CLASS>::newInstance( std::string const& childIdentifier,
                                    int paramCount, ... ) const
{
    std::va_list ap;
    va_start(ap, paramCount);
    
    return newVAInstance( childIdentifier, paramCount, ap );
}

template<typename CLASS>
Object* TClass<CLASS>::newVAInstance( std::string const& childIdentifier,
                        int paramCount,
                        std::va_list ap ) const
{
    // obtain identifier by function since it might be different from
    // mIdentifier (template classes)
    if(childIdentifier==getIdentifier())
        return newVAInstance(paramCount, ap);
    // check if the desired object is a registered derived child
    if ( mDerivedChildren.find( childIdentifier ) ==
            mDerivedChildren.end() ) {
        MIRA_THROW( XFactoryUnknown, "Unknown class identifier ("
                  + childIdentifier + ") calling newInstance on " + getIdentifier()
                  + "!" );
    }

    Object* tObject = mDerivedChildren.find( childIdentifier )->second
            .newVAInstance(paramCount, ap);
    if ( !tObject ) {
        MIRA_THROW( XFactoryLogical, "Class creation failed (" + childIdentifier
                  + ") calling newInstance on " + getIdentifier() + "!" );
    }
    return tObject;
}

template<typename CLASS>
Object* TClass<CLASS>::newVAInstance( int paramCount, std::va_list ap ) const
{
    // Check if we should use the normal createClass template or the special
    // instantiation for classes with abstract functions
    typedef typename boost::mpl::eval_if<std::is_abstract<CLASS>,
            boost::mpl::identity<ClassFactoryAbstractClassBuilder>,
            boost::mpl::identity<ClassFactoryDefaultConstClassBuilder>
    >::type ClassType;

    switch(paramCount){
    case 0:
        return newInstance();
    case 1:
        return ClassType::template invoke<1,CLASS>( ap);
    case 2:
        return ClassType::template invoke<2,CLASS>( ap);
    case 3:
        return ClassType::template invoke<3,CLASS>( ap);
    case 4:
        return ClassType::template invoke<4,CLASS>( ap);
    default:
        MIRA_THROW( XFactoryLogical, "Invalid number of arguments for "
                    "constructor (" + std::to_string((uint64)paramCount) + " arguments for "
                  + getIdentifier() + ")!");
    }
    return NULL;
}


} // namespace

#endif /* _MIRA_TCLASS_H_ */