#include "pugixml.hpp"

#include <string.h>
#include <iostream>

// tag::code[]
bool load_preprocess(pugi::xml_document& doc, const char* path);

bool preprocess(pugi::xml_node node)
{
    for (pugi::xml_node child = node.first_child(); child; )
    {
        if (child.type() == pugi::node_pi && strcmp(child.name(), "include") == 0)
        {
            pugi::xml_node include = child;

            // load new preprocessed document (note: ideally this should handle relative paths)
            const char* path = include.value();

            pugi::xml_document doc;
            if (!load_preprocess(doc, path)) return false;

            // insert the comment marker above include directive
            node.insert_child_before(pugi::node_comment, include).set_value(path);

            // copy the document above the include directive (this retains the original order!)
            for (pugi::xml_node ic = doc.first_child(); ic; ic = ic.next_sibling())
            {
                node.insert_copy_before(ic, include);
            }

            // remove the include node and move to the next child
            child = child.next_sibling();

            node.remove_child(include);
        }
        else
        {
            if (!preprocess(child)) return false;

            child = child.next_sibling();
        }
    }

    return true;
}

bool load_preprocess(pugi::xml_document& doc, const char* path)
{
    pugi::xml_parse_result result = doc.load_file(path, pugi::parse_default | pugi::parse_pi); // for <?include?>
    
    return result ? preprocess(doc) : false;
}
// end::code[]

int main()
{
    pugi::xml_document doc;
    if (!load_preprocess(doc, "character.xml")) return -1;

    doc.print(std::cout);
}

// vim:et