#pragma once

/// \file value.h
/// \author Folling <folling@ikarus.world>

#include <ikarus/errors.h>
#include <ikarus/macros.h>

/// \defgroup values Values
/// \brief The values of properties.
/// \details Each entity has a value for each property it is associated with.
/// These value classes represent plain objects. They are not associated with any entity.
/// Each value may be undefined. \see IkarusProperty
/// Values are stored as lists. If a property is "singular" then its value is a list of size 1.
/// Values are typed, with types existing for each of the corresponding property types. The data of values starts with the index 0.
/// When setting values for a property the type must match the property type and the value must be valid under the
/// property's settings. \see PropertyType
/// @{

IKARUS_BEGIN_HEADER

/// \brief The common type for all values.
struct IkarusValue;

/// \brief Visits an entity value, calling the appropriate function for the value's type.
/// \param value The entity value to visit.
/// \pre \li Must not be null.
/// \param toggle_visitor The function to call if the value is a toggle value. Skipped if null.
/// \param number_visitor The function to call if the value is a number value. Skipped if null.
/// \param text_visitor The function to call if the value is a text value. Skipped if null.
/// \param data The data passed to the visitor functions.
/// \param error_out \see errors.h
IKA_API void ikarus_value_visit(
    IkarusValue * value,
    void (*toggle_visitor)(struct IkarusToggleValue *, void *),
    void (*number_visitor)(struct IkarusNumberValue *, void *),
    void (*text_visitor)(struct IkarusTextValue *, void *),
    void * data,
    IkarusErrorData * error_out
);

/// \see ikarus_value_visit
IKA_API void ikarus_value_visit_const(
    IkarusValue const * value,
    void (*toggle_visitor)(struct IkarusToggleValue const *, void *),
    void (*number_visitor)(struct IkarusNumberValue const *, void *),
    void (*text_visitor)(struct IkarusTextValue const *, void *),
    void * data,
    IkarusErrorData * error_out
);

IKARUS_END_HEADER

/// @}