/**

 * Relational pipes

 * Copyright © 2018 František Kučera (Frantovo.cz, GlobalCode.info)

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program. If not, see <http://www.gnu.org/licenses/>.

 */

#pragma once

#include <cstdlib>

#include <iostream>

#include <string>

#include <vector>

#include <algorithm>

#include <xercesc/sax2/SAX2XMLReader.hpp>

#include <xercesc/sax2/XMLReaderFactory.hpp>

#include <xercesc/sax2/DefaultHandler.hpp>

#include <xercesc/sax2/Attributes.hpp>

#include <xercesc/util/XMLString.hpp>

#include <relpipe/writer/typedefs.h>

#include "StreamInputSource.h"

namespace relpipe {

namespace in {

namespace xml {

using namespace relpipe::writer;

using namespace xercesc;

class XMLCommand {

private:

	class RelpipeSaxHandler : public xercesc::DefaultHandler {

	private:

		unique_ptr<RelationalWriter> writer;

	public:

		RelpipeSaxHandler(std::ostream& output) : DefaultHandler(), writer(Factory::create(output)) {

		}

		void startDocument() override {

			//XMLString::

			// TODO: remove demo

			writer->startRelation(L"xml",{

				{L"event", TypeId::STRING},

				{L"uri", TypeId::STRING},

				{L"localname", TypeId::STRING},

				{L"qname", TypeId::STRING},

				{L"chars", TypeId::STRING}

			}, true);

		}

		void startElement(const XMLCh * const uri, const XMLCh * const localname, const XMLCh * const qname, const Attributes& attrs) override {

			writer->writeAttribute(L"startElement");

			writer->writeAttribute(L"");

			for (int i = 0; i < attrs.getLength(); i++) {

				writer->writeAttribute(L"attribute");

			}

		}

		void endElement(const XMLCh * const uri, const XMLCh * const localname, const XMLCh * const qname) override {

			writer->writeAttribute(L"endElement");

			writer->writeAttribute(L"");

		}

		void characters(const XMLCh * const chars, const XMLSize_t length) override {

			writer->writeAttribute(L"characters");

			writer->writeAttribute(L"");

			writer->writeAttribute(L"");

			writer->writeAttribute(L"");

		}

		void comment(const XMLCh * const chars, const XMLSize_t length) override {

			writer->writeAttribute(L"comment");

			writer->writeAttribute(L"");

			writer->writeAttribute(L"");

			writer->writeAttribute(L"");

		}

		void startCDATA() override {

			writer->writeAttribute(L"startCDATA");

			writer->writeAttribute(L"");

			writer->writeAttribute(L"");

			writer->writeAttribute(L"");

			writer->writeAttribute(L"");

		}

		void endCDATA() override {

			writer->writeAttribute(L"endCDATA");

			writer->writeAttribute(L"");

			writer->writeAttribute(L"");

			writer->writeAttribute(L"");

			writer->writeAttribute(L"");

		}

		void endDocument() override {

			writer->writeAttribute(L"endDocument");

			writer->writeAttribute(L"");

			writer->writeAttribute(L"");

			writer->writeAttribute(L"");

			writer->writeAttribute(L"");

		}

	};

public:

	void process(std::istream& input, std::ostream& output) {

		XMLPlatformUtils::Initialize();

		unique_ptr<SAX2XMLReader> parser(XMLReaderFactory::createXMLReader());

		parser->setFeature(XMLUni::fgSAX2CoreValidation, true);

		parser->setFeature(XMLUni::fgSAX2CoreNameSpaces, true);

		// TODO: optional unbuffered mode for more fluent output?

		// http://xerces.apache.org/xerces-c/program-sax2-3.html#SAX2Features

		// parser->setProperty(XMLUni::fgXercesLowWaterMark, ...);

		// parser->setInputBufferSize(...);

		RelpipeSaxHandler saxHandler(output);

		parser->setContentHandler(&saxHandler);

		parser->setLexicalHandler(&saxHandler); // TODO: remove – needed only for comments

		parser->setErrorHandler(&saxHandler);

		StreamInputSource inputSource(input);

		parser->parse(inputSource);

	}

};

}

}

}