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// This file contains the definition of the SharedStyleParserObserver class.

#ifndef KML_ENGINE_SHARED_STYLE_PARSER_OBSERVER_H__
#define KML_ENGINE_SHARED_STYLE_PARSER_OBSERVER_H__

#include <map>
#include <string>
#include "kml/dom.h"
#include "kml/dom/parser_observer.h"
#include "kml/engine/engine_types.h"

namespace kmlengine {

// The SharedStyleParserObserver is a kmldom::ParserObserver which gathers all
// all shared StyleSelectors into the supplied SharedStyleMap.  If strict_parse
// is true AddChild() returns false on any id collision causing the parse to
// terminate when this is used with kmldom::Parse::AddObserver().  If
// strict_parse is false the "last one wins" on any duplicate.
// TODO: provide an error log for this latter case.
class SharedStyleParserObserver : public kmldom::ParserObserver {
 public:
  // A SharedStyleMap must be supplied.
  SharedStyleParserObserver(SharedStyleMap* shared_style_map,
                            bool strict_parse)
    : shared_style_map_(shared_style_map),
      strict_parse_(strict_parse) {}

  virtual ~SharedStyleParserObserver() {}

  // ParserObserver::AddChild()
  virtual bool AddChild(const kmldom::ElementPtr& parent,
                        const kmldom::ElementPtr& child) {
    // A shared style is defined to be a StyleSelector with an id that is
    // a child of a Document.  If this id already has a mapping return false
    // to terminate the parse.
    if (kmldom::DocumentPtr document = kmldom::AsDocument(parent)) {
      if (kmldom::StyleSelectorPtr ss = kmldom::AsStyleSelector(child)) {
        if (ss->has_id()) {
          if (strict_parse_ && shared_style_map_->find(ss->get_id()) !=
                               shared_style_map_->end()) {
            // TODO: provide means to send back an and error string with id
            return false;  // Duplicate id, fail parse.
          }
        }
        // No such mapping so save it, and "last one wins" on non-strict parse.
        (*shared_style_map_)[ss->get_id()] = ss;
      }
    }
    return true;  // Not a duplicate id, keep parsing.
  }
 
 private:
  SharedStyleMap* shared_style_map_;
  bool strict_parse_;
};

}  // end namespace kmlengine

#endif  // KML_ENGINE_SHARED_STYLE_PARSER_OBSERVER_H__
