/**

 * Relational pipes

 * Copyright © 2019 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 <cstdlib>

#include <iostream>

#include <string>

#include <sstream>

#include <vector>

#include <algorithm>

#include <libxml++-2.6/libxml++/libxml++.h>

#include <relpipe/writer/typedefs.h>

#include "Configuration.h"

namespace relpipe {

namespace in {

namespace xmltable {

using namespace relpipe::writer;

class XMLCommand {

private:

	std::wstring_convert<codecvt_utf8<wchar_t>> convertor; // TODO: support also other encodings.

public:

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

		std::shared_ptr<RelationalWriter> writer(Factory::create(output));

		xmlpp::DomParser parser;

		parser.parse_stream(input);

		xmlpp::Element* root = parser.get_document()->get_root_node();

		xmlpp::Node::PrefixNsMap ns;

		for (int i = 0; i < configuration.namespaceMappings.size(); i++) {

			std::string prefix = convertor.to_bytes(configuration.namespaceMappings[i]);

			std::string uri = convertor.to_bytes(configuration.namespaceMappings[++i]);

			ns[prefix] = uri;

		}

		for (const RelationConfiguration& r : configuration.relationConfigurations) {

			std::vector<relpipe::writer::AttributeMetadata> attributesMetadata;

			for (AttributeRecipe a : r.attributes) attributesMetadata.push_back(AttributeMetadata{a.name, a.type});

			relpipe::writer::string_t name = r.nameIsXPath ? convertor.from_bytes(root->eval_to_string(convertor.to_bytes(r.relation), ns)) : r.relation;

			writer->startRelation(name, attributesMetadata, true);

			for (xmlpp::Node* n : root->find(convertor.to_bytes(r.xpath), ns)) {

				for (AttributeRecipe a : r.attributes) {

					// TODO: convert to bytes only once

					writer->writeAttribute(convertor.from_bytes(n->eval_to_string(convertor.to_bytes(a.xpath), ns)));

				}

			}

		}

	}

};

}

}

}