/* Name analysis.
   Copyright (C) 2025 Free Software Foundation, Inc.

GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.

GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include "elna/boot/semantic.h"

namespace elna
{
namespace boot
{
    type::type(alias_type *alias)
        : payload({ .alias = alias }), tag(type_tag::alias)
    {
    }

    type::type(primitive_type *primitive)
        : payload({ .primitive = primitive }), tag(type_tag::primitive)
    {
    }

    type::type(record_type *record)
        : payload({ .record = record }), tag(type_tag::record)
    {
    }

    type::type(union_type *_union)
        : payload({ ._union = _union }), tag(type_tag::_union)
    {
    }

    type::type(pointer_type *pointer)
        : payload({ .pointer = pointer }), tag(type_tag::pointer)
    {
    }

    template<>
    alias_type *const type::get<alias_type>() const
    {
        if (tag == type_tag::alias)
        {
            return payload.alias;
        }
        else
        {
            return nullptr;
        }
    }

    template<>
    primitive_type *const type::get<primitive_type>() const
    {
        if (tag == type_tag::primitive)
        {
            return payload.primitive;
        }
        else
        {
            return nullptr;
        }
    }

    template<>
    record_type *const type::get<record_type>() const
    {
        if (tag == type_tag::record)
        {
            return payload.record;
        }
        else
        {
            return nullptr;
        }
    }

    template<>
    union_type *const type::get<union_type>() const
    {
        if (tag == type_tag::_union)
        {
            return payload._union;
        }
        else
        {
            return nullptr;
        }
    }

    template<>
    pointer_type *const type::get<pointer_type>() const
    {
        if (tag == type_tag::pointer)
        {
            return payload.pointer;
        }
        else
        {
            return nullptr;
        }
    }

    bool type::empty() const
    {
        return tag == type_tag::empty;
    }

    pointer_type::pointer_type(type base)
        : base(base)
    {
    }

    primitive_type::primitive_type(const std::string& identifier)
        : identifier(identifier)
    {
    }

    void declaration_visitor::visit(program *program)
    {
        for (type_definition *const type : program->types)
        {
            this->unresolved.insert({ type->identifier, new alias_type() });
        }
        for (type_definition *const type : program->types)
        {
            type->accept(this);
        }
    }

    void declaration_visitor::visit(type_definition *definition)
    {
        auto unresolved_declaration = this->unresolved.at(definition->identifier);

        definition->body().accept(this);

        unresolved_declaration->reference = this->current_type;
    }

    void declaration_visitor::visit(primitive_type_expression *type_expression)
    {
        auto unresolved_alias = this->unresolved.find(type_expression->name);

        if (unresolved_alias != this->unresolved.end())
        {
            this->current_type = type(unresolved_alias->second);
        }
        else
        {
            this->current_type = type(new primitive_type(type_expression->name));
        }
    }

    void declaration_visitor::visit(array_type_expression *type_expression)
    {
    }

    void declaration_visitor::visit(pointer_type_expression *type_expression)
    {
        type_expression->base().accept(this);
        this->current_type = type(new pointer_type(this->current_type));
    }

    void declaration_visitor::visit(record_type_expression *type_expression)
    {
        auto type_definition = new record_type();

        this->current_type = type(type_definition);
    }

    void declaration_visitor::visit(union_type_expression *type_expression)
    {
        auto type_definition = new union_type();

        this->current_type = type(type_definition);
    }

    void declaration_visitor::visit(procedure_type_expression *type_expression)
    {
    }
}
}