IfcOpenShell/src/ifcparse/IfcBaseClass.h

/********************************************************************************
 *                                                                              *
 * This file is part of IfcOpenShell.                                           *
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 * IfcOpenShell is free software: you can redistribute it and/or modify         *
 * it under the terms of the Lesser GNU General Public License as published by  *
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 * (at your option) any later version.                                          *
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of               *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                 *
 * Lesser GNU General Public License for more details.                          *
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 * You should have received a copy of the Lesser GNU General Public License     *
 * along with this program. If not, see <http://www.gnu.org/licenses/>.         *
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 ********************************************************************************/

#ifndef IFCBASECLASS_H
#define IFCBASECLASS_H

#include "Argument.h"
#include "ifc_parse_api.h"
#include "IfcEntityInstanceData.h"
#include "IfcSchema.h"
#include "utils.h"

#include <atomic>
#include <boost/shared_ptr.hpp>

class Argument;
class aggregate_of_instance;

namespace IfcUtil {

class IFC_PARSE_API IfcBaseInterface {
  protected:
    static bool is_null(const IfcBaseInterface* not_this) {
        return not_this == nullptr;
    }

    template <typename T>
    std::enable_if_t<!std::is_same<IfcBaseClass, T>::value && !std::is_same<IfcBaseEntity, T>::value && !std::is_same<IfcBaseType, T>::value> raise_error_on_concrete_class() const {
        throw IfcParse::IfcException("Instance of type " + this->declaration().name() + " cannot be cast to " + T::Class().name());
    }

    template <typename T>
    std::enable_if_t<std::is_same<IfcBaseClass, T>::value || std::is_same<IfcBaseEntity, T>::value || std::is_same<IfcBaseType, T>::value> raise_error_on_concrete_class() const {
        throw IfcParse::IfcException("Instance of type " + this->declaration().name() + " cannot be cast to base class");
    }

  public:
    virtual const IfcEntityInstanceData& data() const = 0;
    virtual IfcEntityInstanceData& data() = 0;
    virtual const IfcParse::declaration& declaration() const = 0;

    template <class T>
    T* as(bool do_throw = false) {
        // @todo: do not allow this to be null in the first place
        if (is_null(this)) {
            return static_cast<T*>(0);
        }
        auto t = dynamic_cast<T*>(this);
        if (do_throw && !t) {
            raise_error_on_concrete_class<T>();
        }
        return t;
    }

    template <class T>
    const T* as(bool do_throw = false) const {
        if (is_null(this)) {
            return static_cast<const T*>(0);
        }
        auto t = dynamic_cast<const T*>(this);
        if (do_throw && !t) {
            raise_error_on_concrete_class<T>();
        }
        return t;
    }
};

class IFC_PARSE_API IfcBaseClass : public virtual IfcBaseInterface {
  private:
    uint32_t identity_;
    static std::atomic_uint32_t counter_;

  protected:
    IfcEntityInstanceData* data_;

    static bool is_null(const IfcBaseClass* not_this) {
        return not_this == nullptr;
    }

  public:
    IfcBaseClass() : identity_(counter_++),
                     data_(0) {}
    IfcBaseClass(IfcEntityInstanceData* d) : identity_(counter_++),
                                             data_(d) {}
    virtual ~IfcBaseClass() { delete data_; }

    const IfcEntityInstanceData& data() const { return *data_; }
    IfcEntityInstanceData& data() { return *data_; }
    void data(IfcEntityInstanceData* d);

    virtual const IfcParse::declaration& declaration() const = 0;

    uint32_t identity() const { return identity_; }
};

class IFC_PARSE_API IfcLateBoundEntity : public IfcBaseClass {
  private:
    const IfcParse::declaration* decl_;

  public:
    IfcLateBoundEntity(const IfcParse::declaration* decl, IfcEntityInstanceData* data) : IfcBaseClass(data),
                                                                                         decl_(decl) {}

    virtual const IfcParse::declaration& declaration() const {
        return *decl_;
    }
};

class IFC_PARSE_API IfcBaseEntity : public IfcBaseClass {
  public:
    IfcBaseEntity() : IfcBaseClass() {}
    IfcBaseEntity(IfcEntityInstanceData* d) : IfcBaseClass(d) {}

    virtual const IfcParse::entity& declaration() const = 0;

    Argument* get(const std::string& name) const;

    template <typename T>
    T get_value(const std::string& name) const;

    template <typename T>
    T get_value(const std::string& name, const T& default_value) const;

    boost::shared_ptr<aggregate_of_instance> get_inverse(const std::string& a) const;
};

// TODO: Investigate whether these should be template classes instead
class IFC_PARSE_API IfcBaseType : public IfcBaseClass {
  public:
    IfcBaseType() : IfcBaseClass() {}
    IfcBaseType(IfcEntityInstanceData* d) : IfcBaseClass(d) {}

    virtual const IfcParse::declaration& declaration() const = 0;
};

} // namespace IfcUtil

namespace IfcUtil {
template <typename T>
T IfcBaseEntity::get_value(const std::string& name) const {
    auto attr = get(name);
    return (T)*attr;
}

template <typename T>
T IfcBaseEntity::get_value(const std::string& name, const T& default_value) const {
    auto attr = get(name);
    if (attr->isNull()) {
        return default_value;
    }
    return (T)*attr;
}
} // namespace IfcUtil

#endif