// node.hpp
// Copyright (c) 2005-2012 Ben Hanson (http://www.benhanson.net/)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file licence_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
#ifndef LEXERTL_NODE_HPP
#define LEXERTL_NODE_HPP

#include <assert.h>
#include "../../containers/ptr_vector.hpp"
#include "../../runtime_error.hpp"
#include "../../size_t.hpp"
#include <stack>
#include <vector>

namespace lexertl
{
namespace detail
{
template<typename id_type>
class basic_node
{
public:
    enum node_type {LEAF, SEQUENCE, SELECTION, ITERATION, END};

    typedef std::stack<bool> bool_stack;
    typedef std::stack<basic_node<id_type> *> node_stack;
    // stack and vector not owner of node pointers
    typedef std::stack<const basic_node<id_type> *> const_node_stack;
    typedef std::vector<basic_node<id_type> *> node_vector;
    typedef ptr_vector<basic_node<id_type> > node_ptr_vector;

    basic_node () :
        _nullable (false),
        _firstpos (),
        _lastpos ()
    {
    }

    basic_node (const bool nullable_) :
        _nullable (nullable_),
        _firstpos (),
        _lastpos ()
    {
    }

    virtual ~basic_node ()
    {
    }

    static id_type null_token ()
    {
        return static_cast<id_type>(~0);
    }

    bool nullable () const
    {
        return _nullable;
    }

    void append_firstpos (node_vector &firstpos_) const
    {
        firstpos_.insert (firstpos_.end (),
            _firstpos.begin (), _firstpos.end ());
    }

    void append_lastpos (node_vector &lastpos_) const
    {
        lastpos_.insert (lastpos_.end (),
            _lastpos.begin (), _lastpos.end ());
    }

    virtual void append_followpos (const node_vector &/*followpos_*/)
    {
        throw runtime_error ("Internal error node::append_followpos().");
    }

    basic_node *copy (node_ptr_vector &node_ptr_vector_) const
    {
        basic_node *new_root_ = 0;
        const_node_stack node_stack_;
        bool_stack perform_op_stack_;
        bool down_ = true;
        node_stack new_node_stack_;

        node_stack_.push (this);

        while (!node_stack_.empty ())
        {
            while (down_)
            {
                down_ = node_stack_.top ()->traverse (node_stack_,
                    perform_op_stack_);
            }

            while (!down_ && !node_stack_.empty ())
            {
                const basic_node *top_ = node_stack_.top ();

                top_->copy_node (node_ptr_vector_, new_node_stack_,
                    perform_op_stack_, down_);

                if (!down_) node_stack_.pop ();
            }
        }

        assert (new_node_stack_.size () == 1);
        new_root_ = new_node_stack_.top ();
        new_node_stack_.pop ();
        return new_root_;
    }

    virtual node_type what_type () const = 0;

    virtual bool traverse (const_node_stack &node_stack_,
        bool_stack &perform_op_stack_) const = 0;

    node_vector &firstpos ()
    {
        return _firstpos;
    }

    const node_vector &firstpos () const
    {
        return _firstpos;
    }

    // _lastpos modified externally, so not const &
    node_vector &lastpos ()
    {
        return _lastpos;
    }

    virtual bool end_state () const
    {
        return false;
    }

    virtual id_type id () const
    {
        throw runtime_error ("Internal error node::id().");
#ifdef __SUNPRO_CC
        // Stop bogus Solaris compiler warning
        return id_type ();
#endif
    }

    virtual id_type user_id () const
    {
        throw runtime_error ("Internal error node::user_id().");
#ifdef __SUNPRO_CC
        // Stop bogus Solaris compiler warning
        return id_type ();
#endif
    }

    virtual id_type next_dfa () const
    {
        throw runtime_error ("Internal error node::next_dfa().");
#ifdef __SUNPRO_CC
        // Stop bogus Solaris compiler warning
        return id_type ();
#endif
    }

    virtual id_type push_dfa () const
    {
        throw runtime_error ("Internal error node::push_dfa().");
#ifdef __SUNPRO_CC
        // Stop bogus Solaris compiler warning
        return id_type ();
#endif
    }

    virtual bool pop_dfa () const
    {
        throw runtime_error ("Internal error node::pop_dfa().");
#ifdef __SUNPRO_CC
        // Stop bogus Solaris compiler warning
        return false;
#endif
    }

    virtual id_type token () const
    {
        throw runtime_error ("Internal error node::token().");
#ifdef __SUNPRO_CC
        // Stop bogus Solaris compiler warning
        return id_type ();
#endif
    }

    virtual void greedy (const bool /*greedy_*/)
    {
        throw runtime_error ("Internal error node::greedy(bool).");
    }

    virtual bool greedy () const
    {
        throw runtime_error ("Internal error node::greedy().");
#ifdef __SUNPRO_CC
        // Stop bogus Solaris compiler warning
        return false;
#endif
    }

    virtual const node_vector &followpos () const
    {
        throw runtime_error ("Internal error node::followpos().");
#ifdef __SUNPRO_CC
        // Stop bogus Solaris compiler warning
        return firstpos;
#endif
    }

    virtual node_vector &followpos ()
    {
        throw runtime_error ("Internal error node::followpos().");
#ifdef __SUNPRO_CC
        // Stop bogus Solaris compiler warning
        return firstpos;
#endif
    }

protected:
    const bool _nullable;
    node_vector _firstpos;
    node_vector _lastpos;

    virtual void copy_node (node_ptr_vector &node_ptr_vector_,
        node_stack &new_node_stack_, bool_stack &perform_op_stack_,
        bool &down_) const = 0;

private:
    basic_node (const basic_node &); // No copy construction.
    const basic_node &operator = (const basic_node &); // No assignment.
};
}
}

#endif