nntpchan/contrib/backends/nntpchan-daemon/libmustache/visitor/render_node.hpp

#pragma once

#include <boost/variant/static_visitor.hpp>
#include <sstream>

#include "../render_context.hpp"
#include "../utils.hpp"
#include "mstch/mstch.hpp"

namespace mstch
{

class render_node : public boost::static_visitor<std::string>
{
public:
  enum class flag
  {
    none,
    escape_html
  };
  render_node(render_context &ctx, flag p_flag = flag::none) : m_ctx(ctx), m_flag(p_flag) {}

  template <class T> std::string operator()(const T &) const { return ""; }

  std::string operator()(const int &value) const { return std::to_string(value); }

  std::string operator()(const double &value) const
  {
    std::stringstream ss;
    ss << value;
    return ss.str();
  }

  std::string operator()(const bool &value) const { return value ? "true" : "false"; }

  std::string operator()(const lambda &value) const
  {
    template_type interpreted{value([this](const mstch::node &n) { return visit(render_node(m_ctx), n); })};
    auto rendered = render_context::push(m_ctx).render(interpreted);
    return (m_flag == flag::escape_html) ? html_escape(rendered) : rendered;
  }

  std::string operator()(const std::string &value) const
  {
    return (m_flag == flag::escape_html) ? html_escape(value) : value;
  }

private:
  render_context &m_ctx;
  flag m_flag;
};
}