/******************************** LICENSE ********************************

 Copyright 2007 European Centre for Medium-Range Weather Forecasts (ECMWF)

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at 

    http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.

 ******************************** LICENSE ********************************/

/*! \file XmlReader.cc
    \brief Implementation of the Reader for Xml.
    
    Magics Team - ECMWF 2005
    
    Started: 2005
    
    Changes:
    
*/ 

#include "XmlReader.h"
#include "expat.h"
#include "MagLog.h"
#include "MagException.h"
using namespace magics;

XmlReader::XmlReader(bool tag) : dataAsTag_(tag) 
{
}


XmlReader::~XmlReader() 
{
}

static void XMLCALL startElementHandler(void *data, const char *name, const char **atts)
{
	XmlReader* reader  = (XmlReader*) data; 
	map<string, string> def;
	while (*atts) {         
		def.insert(std::make_pair(*atts,*(atts+1)));
		atts+=2;
	}	
	reader->newElement(name, def);      
}


static void XMLCALL endElementHandler(void* data, const char* tag)
{
	XmlReader* reader  = (XmlReader*) data; 
	reader->endElement(tag);
}

static bool empty(const string& value)
{
	for (string::const_iterator c = value.begin(); c != value.end(); ++c) {
		if ( !isspace(*c) ) return false;
	}
	return true;
}

static void XMLCALL dataHandler (void *data, const char *value, int len)
{
	string stringval = string(value, len);
	if (  empty(stringval) ) return;
	XmlReader* reader  = (XmlReader*) data;
	
	if ( reader->dataAsTag() ) {
		map<string, string> def;
    	def["data"] = stringval;
		reader->newElement("data", def);     
		reader->endElement("data");
	}
	else 
		reader->addData(stringval);
}


static int externalEntityRefHandler( XML_Parser ,//	 parser,
		const XML_Char *  	context,
		const XML_Char *  	base,
		const XML_Char *  	systemID,
		const XML_Char *  	publicID
	)
{
	//MagLog::dev()<< "context--->" << context << endl;
	//MagLog::dev()<< "base--->" << base << endl;
	//MagLog::dev()<< "systemID--->" << systemID << endl;
	//MagLog::dev()<< "publicID--->" << publicID << endl;
	return 0;
}



void XmlReader::newElement(const string& name, const map<string, string>& def)
{

	// Here we create a XmlNode you put in the tree...
	XmlNode* parent = tree_->getParent(name);
	if ( parent ) {
		//MagLog::dev()<< "push-->empty " << name << endl;
		push(parent);
	}
	if ( empty() )
		push(tree_->root());
	XmlNode* node = tree_->newNode(name, def);
	top()->push_back(node);
	push(node); 
}

void XmlReader::endElement(const string& tag)
{
	tree_->endElement(tag);
	pop();
	//MagLog::dev()<< "pop-->" << tag << endl;
	if ( tag == "definition" ) {
		pop();
		//MagLog::dev()<< "pop-->empty" << tag << endl;
	}
	if ( tag == "magics" ) {
		pop();
		//MagLog::dev()<< "pop-->empty" << tag << endl;
	}
}

void XmlReader::addData(const string& data)
{
	top()->setData(data);
}



void XmlReader::interpret(const string& xml, XmlTree* tree)
{
	tree_ = tree;
	char buf[BUFSIZ];
	XML_Parser parser = XML_ParserCreate(NULL);
	int done;
	XML_SetUserData(parser, this);
	XML_SetParamEntityParsing(parser, XML_PARAM_ENTITY_PARSING_ALWAYS);
	XML_SetElementHandler(parser, startElementHandler, endElementHandler);
	XML_SetCharacterDataHandler(parser, dataHandler);

	FILE* in  = fopen(xml.c_str(), "r");

	if (!in) {
		MagLog::dev()<< "XmlDecoder: can not open file " << xml << endl;
		MagLog::error() << "XmlDecoder: can not open file " << xml << endl;
		return;
	}

	do
	{
		size_t len = fread(buf, 1, sizeof(buf), in);
		done = len < sizeof(buf);
		if (XML_Parse(parser, buf, len, done) == XML_STATUS_ERROR)
		{
			ostringstream s;
			s << "XmlMagException : " << XML_ErrorString(XML_GetErrorCode(parser))  << " at line  " <<  XML_GetCurrentLineNumber(parser)  << ends;
			cerr <<  s.str() << "\n";
		}
	} while (!done);
	XML_ParserFree(parser);
	fclose(in);
}

void XmlReader::decode(const string& xml, XmlTree* tree)
{
	tree_ = tree;
//	char buf[BUFSIZ];
	XML_Parser parser = XML_ParserCreate(NULL);
//	int done;
	XML_SetUserData(parser, this);
	XML_SetParamEntityParsing(parser, XML_PARAM_ENTITY_PARSING_ALWAYS);
	XML_SetElementHandler(parser, startElementHandler, endElementHandler);
	XML_SetCharacterDataHandler(parser, dataHandler);
		
	if (XML_Parse(parser, xml.c_str(), xml.size(), true) == XML_STATUS_ERROR)
	{
		ostringstream s;
		s << "XmlMagException : " << XML_ErrorString(XML_GetErrorCode(parser))  << " at line  " <<  XML_GetCurrentLineNumber(parser)  << ends;
		throw MagicsException(s.str());
	}
	XML_ParserFree(parser);
}


/*!
 Class information are given to the output-stream.
*/		
void XmlReader::print(ostream& out)  const
{
	out << "XmlReader[";
	out << "]";
}
