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/*! \file
 * \brief
 * Declares gmx::Options.
 *
 * Together with basicoptions.h, this header forms the part of the public
 * API that most classes will use to provide options.
 *
 * \author Teemu Murtola <teemu.murtola@gmail.com>
 * \inpublicapi
 * \ingroup module_options
 */
#ifndef GMX_OPTIONS_OPTIONS_H
#define GMX_OPTIONS_OPTIONS_H

#include <string>

#include "gromacs/options/ioptionscontainerwithsections.h"
#include "gromacs/utility/classhelpers.h"

namespace gmx
{

class AbstractOption;
class OptionSection;
class OptionSectionInfo;
class OptionsAssigner;

namespace internal
{
class OptionsImpl;
}

/*! \brief
 * Base class for option managers.
 *
 * This class is used as a marker for all classes that are used with
 * Options::addManager().  It doesn't provide any methods, but only supports
 * transporting these classes through the Options collection into the
 * individual option implementation classes.
 *
 * The virtual destructor is present to make this class polymorphic, such that
 * `dynamic_cast` can be used when retrieving a manager of a certain type for
 * the individual options.
 *
 * \inlibraryapi
 * \ingroup module_options
 */
class IOptionManager
{
    protected:
        virtual ~IOptionManager();
};

/*! \brief
 * Collection of options.
 *
 * See \ref module_options for an overview of how the options work.
 * The IOptionsContainerWithSections interface documents how to add options.
 *
 * In order to keep the public interface of this class simple, functionality
 * to assign values to options is provided by a separate OptionsAssigner class.
 * Similarly, functionality for looping over all options (e.g., for writing out
 * help) is provided by OptionsIterator.
 *
 * \inpublicapi
 * \ingroup module_options
 */
class Options : public IOptionsContainerWithSections
{
    public:
        //! Initializes an empty options root container.
        Options();
        ~Options();

        /*! \brief
         * Adds an option manager.
         *
         * \param    manager Manager to add.
         * \throws   std::bad_alloc if out of memory.
         *
         * Option managers are used by some types of options that require
         * interaction between different option instances (e.g., selection
         * options), or need to support globally set properties (e.g., a global
         * default file prefix).  Option objects can retrieve the pointer to
         * their manager when they are created, and the caller can alter the
         * behavior of the options through the manager.
         * See the individual managers for details.
         *
         * Caller is responsible for memory management of \p manager.
         * The Options object (and its contained options) only stores a
         * reference to the object.
         *
         * This method cannot be called after adding options or sections.
         */
        void addManager(IOptionManager *manager);

        // From IOptionsContainer
        virtual IOptionsContainer &addGroup();

        //! Returns a handle to the root section.
        OptionSectionInfo       &rootSection();
        //! Returns a handle to the root section.
        const OptionSectionInfo &rootSection() const;

        /*! \brief
         * Notifies the collection that all option values are assigned.
         *
         * \throws InvalidInputError if invalid user input is detected.
         *
         * This function should be called after no more option values are
         * to be assigned.  Values in storage variables are guaranteed to be
         * available only after this call, although in most cases, they are
         * available already during assignment.
         *
         * If invalid option values, e.g., missing required option, is detected
         * at this point, this function throws.  The thrown exception contains
         * information on all errors detected during the call.
         */
        void finish();

    private:
        // From IOptionsContainerWithSections
        virtual internal::OptionSectionImpl *
        addSectionImpl(const AbstractOptionSection &section);
        // From IOptionsContainer
        virtual OptionInfo *addOptionImpl(const AbstractOption &settings);

        PrivateImplPointer<internal::OptionsImpl> impl_;

        //! Needed to be able to extend the interface of this object.
        friend class OptionsAssigner;
};

} // namespace gmx

#endif
