#pragma once

#include <string>
#include <vector>

#include "argument_set.h"
#include "deftype.h"
#include "locator.h"
#include "util.h"

// An Option_set is the construct declared by the "o" target:
//
//     @@name.o :opt.argtype default ... : <description> @@
//
// a named group of OPTIONAL parameters declared once and used by several
// klammers, so that a writer learns one vocabulary (:hpos, :offset, the
// caption parameters) instead of a spelling per klammer.  The "o" target is
// symmetric with "k": "k" declares a klammer's interface and documents it,
// "o" declares an option interface and documents it.  Informally a klammer
// mix-in -- the term is from Flavors, where a mixin contributes slots
// without necessarily contributing methods, which is the shape here: a set
// contributes a DECLARATION, and the obligation to honor it stays with the
// klammer that uses it.
//
// A set is used in the parameter list of a ".k" declaration and nowhere
// else:
//
//     @@code.k :filename @caption_args :caption_side top @ | text.literal :
//
// Names and types come from the set and cannot be changed at the use site; a
// DEFAULT may be overridden there, because what varies between klammers is
// only what silence means for that one klammer -- and kdesc shows a klammer's
// effective defaults anyway.  Everything a reader relies on is the same
// wherever the set is used, which is the whole point of having one.
//
// The set keeps the katoms of each member as declared, because those are what
// is spliced into the using declaration's parameter list.  The parsed
// Parameter_set beside them validates a use-site override at definition time
// and describes the set for kdesc.
class Option_set
{
public:
    Option_set() = default;
    Option_set(const std::string& name, const std::string& desc,
               const Parameter_set& parameters, const katom_lists& members,
               const Locator& loc);

    // The member parameter named `name`, or nullptr if the set has none.
    const Parameter* find(const std::string& name) const;

    // ":a :b :c" -- the members, for a diagnostic that has to show them.
    std::string member_names() const;

    std::string describe(int margin = 2) const;

    std::string m_name {};
    std::string m_desc {};
    Parameter_set m_parameters {};
    // One katom list per member, in declared order, each beginning with the
    // member's option-name katom.
    katom_lists m_members {};
    Locator m_loc {};
    // How this set was declared, for the redefinition policy: the same
    // transition table that governs klammer redefinition governs sets.
    defmode_t m_defmode { defmode_t::def_create };
    // The klammers whose ".k" declaration uses this set, in declaration
    // order.  A set's users are as interesting as its members: they are the
    // klammers that promise to honor the vocabulary.
    std::vector<std::string> m_users {};
};