/*****************************************************************************
 *
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2021 Artem Pavlenko
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/

#include <mapnik/parse_path.hpp>
#include <mapnik/config.hpp>
#include <mapnik/attribute.hpp>
#include <mapnik/feature.hpp>
#include <mapnik/value.hpp>

#include <mapnik/path_expression_grammar_x3.hpp>

// stl
#include <stdexcept>

namespace mapnik {

path_expression_ptr parse_path(std::string const& str)
{
    namespace x3 = boost::spirit::x3;
    auto path = std::make_shared<path_expression>();
    using boost::spirit::x3::standard_wide::space;
    std::string::const_iterator itr = str.begin();
    std::string::const_iterator end = str.end();
    bool r = x3::phrase_parse(itr, end, grammar::path_expression, space, *path);
    if (r && itr == end)
    {
        return path;
    }
    else
    {
        throw std::runtime_error("Failed to parse path expression: \"" + str + "\"");
    }
}

namespace path_processor_detail {
struct path_visitor_
{
    path_visitor_(std::string& filename, feature_impl const& f)
        : filename_(filename)
        , feature_(f)
    {}

    void operator()(std::string const& token) const { filename_ += token; }

    void operator()(attribute const& attr) const
    {
        // convert mapnik::value to std::string
        value const& val = feature_.get(attr.name());
        filename_ += val.to_string();
    }

    std::string& filename_;
    feature_impl const& feature_;
};

struct to_string_
{
    to_string_(std::string& str)
        : str_(str)
    {}

    void operator()(std::string const& token) const { str_ += token; }

    void operator()(attribute const& attr) const
    {
        str_ += "[";
        str_ += attr.name();
        str_ += "]";
    }

    std::string& str_;
};

struct collect_
{
    collect_(std::set<std::string>& cont)
        : cont_(cont)
    {}

    void operator()(std::string const&) const {}

    void operator()(attribute const& attr) const { cont_.insert(attr.name()); }

    std::set<std::string>& cont_;
};
} // namespace path_processor_detail

std::string path_processor::evaluate(path_expression const& path, feature_impl const& f)
{
    std::string out;
    path_processor_detail::path_visitor_ eval(out, f);
    for (mapnik::path_component const& token : path)
    {
        util::apply_visitor(std::ref(eval), token);
    }
    return out;
}

std::string path_processor::to_string(path_expression const& path)
{
    std::string str;
    path_processor_detail::to_string_ visitor(str);
    for (mapnik::path_component const& token : path)
    {
        util::apply_visitor(std::ref(visitor), token);
    }
    return str;
}

void path_processor::collect_attributes(path_expression const& path, std::set<std::string>& names)
{
    path_processor_detail::collect_ visitor(names);
    for (mapnik::path_component const& token : path)
    {
        util::apply_visitor(std::ref(visitor), token);
    }
}

} // namespace mapnik
