/**
 * 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, version 3 of the License.
 *
 * 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 <string>
#include <vector>
#include <iostream>
#include <sstream>
#include <locale>
#include <codecvt>
#include <regex>

#include <relpipe/reader/typedefs.h>
#include <relpipe/reader/TypeId.h>
#include <relpipe/reader/handlers/RelationalReaderStringHandler.h>
#include <relpipe/reader/handlers/AttributeMetadata.h>
#include <relpipe/xmlwriter/XMLWriter.h>

namespace relpipe {
namespace out {
namespace xml {

using namespace relpipe::reader;
using namespace relpipe::xmlwriter;

class XmlHandler : public handlers::RelationalReaderStringHandler {
private:
	const wstring XMLNS = L"tag:globalcode.info,2018:relpipe";
	shared_ptr<XMLWriter> xmlWriter;
	std::vector<TypeId> columnTypes;
	std::vector<string_t> columnTypeCodes;
	std::vector<string_t> columnNames;
	integer_t valueCount = 0;
	integer_t columnCount = 0;
	integer_t relationCount = 0;

public:

	XmlHandler(std::ostream& output) : xmlWriter(new XMLWriter(output)) {
	}

	void startRelation(string_t name, std::vector<handlers::AttributeMetadata> attributes) override {
		valueCount = 0;
		columnCount = 0;

		if (relationCount == 0) {
			xmlWriter->writeStartElement(L"relpipe",{L"xmlns", XMLNS});
		} else {
			xmlWriter->writeEndElement();
			xmlWriter->writeEndElement();
		}
		relationCount++;
		xmlWriter->writeStartElement(L"relation");

		xmlWriter->writeTextElement(L"name",{}, name);


		xmlWriter->writeStartElement(L"attributes-metadata");
		columnCount = attributes.size();
		columnTypes.resize(columnCount);
		columnTypeCodes.resize(columnCount);
		columnNames.resize(columnCount);
		for (int i = 0; i < attributes.size(); i++) {
			columnNames[i] = attributes[i].getAttributeName();
			columnTypes[i] = attributes[i].getTypeId();
			columnTypeCodes[i] = attributes[i].getTypeName();
			xmlWriter->writeEmptyElement(L"attribute-metadata",{
				L"name", columnNames[i],
				L"type", columnTypeCodes[i]
			});
		}
		xmlWriter->writeEndElement();

		// TODO: print attribute metadata
	}

	void attribute(const string_t& value) override {
		integer_t i = valueCount % columnCount;

		if (i == 0 && valueCount) xmlWriter->writeEndElement();
		if (i == 0) xmlWriter->writeStartElement(L"record");

		valueCount++;

		// TODO: print attribute metadata (only optional, not default)
		xmlWriter->writeTextElement(L"attribute",{
			L"name", columnNames[i],
			L"type", columnTypeCodes[i]
		}, value);

	}

	void endOfPipe() {
		if (valueCount) xmlWriter->writeEndElement();
		if (relationCount) xmlWriter->writeEndElement();
		xmlWriter->writeEndElement();
	}

};

}
}
}