//////////////////////////////////////////////////
// expat [XMLReader.cpp]
//////////////////////////////////////////////////

#include "XMLReader.h"

#include <cstdio>
#include <string>
#include <string.h>
#include <stdlib.h>

XMLReader::XMLReader() {
	_parser              = NULL;
	_xml_entity          = NULL;
	_curr_entity         = NULL;
	_curr_character_data = "";

	_please_reset        = false;
	
	// Create parser
    _parser = XML_ParserCreate(NULL);	

	if (_parser) {
		XML_SetUserData(_parser, this);
	    XML_SetElementHandler(_parser, _StaticOnStartTag, _StaticOnEndTag);
    	XML_SetCharacterDataHandler(_parser, _StaticOnCharacterData);
	}
}

XMLReader::~XMLReader() {
	if (_parser)
	    XML_ParserFree(_parser);
	    
	delete _xml_entity;

	//if (_xml_entity != _curr_entity) {
	//	delete _curr_entity;
	//}
}

void XMLReader::Reset() {
	_please_reset = true;
}

void XMLReader::FeedData(const char *data, int len) {
    // do we need to reset?
    if (_please_reset) {
		XML_ParserFree(_parser);
		_parser = NULL;
		
		delete _xml_entity;

		_xml_entity          = NULL;
		_curr_entity         = NULL;

		_curr_character_data = "";

		_please_reset        = false;

		// Create parser
	    _parser = XML_ParserCreate(NULL);	

		if (_parser) {
			XML_SetUserData(_parser, this);
		    XML_SetElementHandler(_parser, _StaticOnStartTag, _StaticOnEndTag);
	    	XML_SetCharacterDataHandler(_parser, _StaticOnCharacterData);
		}
    }

	// weed out
    if (_parser && !XML_Parse(_parser, data, len, 0)) {
		_please_reset = true;
    }    
}

void XMLReader::_StaticOnStartTag(void *userData, const char *name, const char **atts) {
	((XMLReader *)userData)->_OnStartTag(name, atts);
}

void XMLReader::_StaticOnEndTag(void *userData, const char *name) {
	((XMLReader *)userData)->_OnEndTag(name);	
}

void XMLReader::_StaticOnCharacterData(void *userData, const XML_Char *data, int len) {
	((XMLReader *)userData)->_OnCharacterData(data, len);
}

void XMLReader::_OnStartTag(const char *name, const char **atts) {
	// ignore ?xml
	if (!strcasecmp(name, "?xml")) {
		return;
	}

	// clear character data
	_curr_character_data = "";

	// Make new entity: if current is NULL, set it (current)...else, make child
	XMLEntity *new_entity = new XMLEntity(name, atts);

	if (_xml_entity == NULL) {
		_curr_entity = _xml_entity = new_entity;
	} else {
		// Add child
		_curr_entity->AddChild(new_entity);

		// New current entry
		_curr_entity = new_entity;
	}

	// Callback
	OnStartTag(_curr_entity);
}

void XMLReader::_OnEndTag(__attribute__((unused)) const char *name) {
	// Add existing character data to entity
	if (_curr_character_data.size() > 0)
		_curr_entity->SetCharacterData(_curr_character_data.c_str());

	// Close it off
	_curr_entity->SetCompleted(true);

	// Clean character data buffer
	_curr_character_data = "";

	// Callback
	OnEndTag(_curr_entity);

	// end here if we've been reset
	if (_xml_entity == NULL) {
		return;
	}
		
	// Revert current entity to parent
	if (_curr_entity && (_curr_entity == _xml_entity)) {
		// Transfer XMLEntity tree to user. (They must delete)
		XMLEntity *completed_entity = _xml_entity;

		_curr_entity = _xml_entity = NULL;

		// Serve up the current tree (USER deletes)
		OnEndEntity(completed_entity);
	} else {
		_curr_entity = _curr_entity->Parent();
	}
}

void XMLReader::_OnCharacterData(const XML_Char *data, int len) {
	// Populate current entity character data
	char *new_data = (char *)malloc((len + 1) * sizeof(char));
	strncpy(new_data, data, len);
	new_data[len] = '\0';

	if (!new_data || *new_data == 0) {
		return;
	}

	// Clean up character data
	string added_data = new_data;
	
	if (_curr_character_data.size() == 0)
		while (added_data.size() > 0 && (added_data[0] == ' ' || added_data[0] == '\n'))
			added_data.erase(0, 1);

	size_t replacement;

	while ((replacement = _curr_character_data.find("&apos;")) != string::npos) {
		_curr_character_data.replace(replacement, 6, "&");
	}	

	while ((replacement = _curr_character_data.find("&lt;")) != string::npos) {
		_curr_character_data.replace(replacement, 4, "<");
	}	

	while ((replacement = _curr_character_data.find("&gt;")) != string::npos) {
		_curr_character_data.replace(replacement, 4, ">");
	}	
	
	// Add to current running data
	// TBD: put data in curr_entity instead
    _curr_character_data += added_data;

	free(new_data);
}