/**

 * Relational pipes

 * Copyright © 2022 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 <memory>

#include <string>

#include <vector>

#include <iostream>

#include <sstream>

#include <locale>

#include <codecvt>

#include <random>

#include <mosquittopp.h>

#include <relpipe/common/type/typedefs.h>

#include <relpipe/reader/TypeId.h>

#include <relpipe/reader/handlers/RelationalReaderStringHandler.h>

#include <relpipe/reader/handlers/AttributeMetadata.h>

#include "Configuration.h"

#include "Hex.h"

namespace relpipe {

namespace out {

namespace mqtt {

class MQTTHandler : public relpipe::reader::handlers::RelationalReaderStringHandler {

private:

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

	Configuration configuration;

	std::shared_ptr<mosqpp::mosquittopp> mq = std::make_shared<mosqpp::mosquittopp>(generateClientID().c_str());

	/**

	 * @return unique (random) client ID for MQTT to allow multiple simultaneous connections

	 */

	static std::string generateClientID() {

		std::stringstream result;

		std::string symbols("0123456789abcdef");

		std::random_device dev;

		std::mt19937 rng(dev());

		return result.str();

	}

	struct CurrentRelation {

		relpipe::common::type::StringX name;

		std::vector<relpipe::reader::handlers::AttributeMetadata> attributes;

		relpipe::common::type::Integer attributeIndex = 0;

		std::string currentValue;

	} currentRelation;

public:

	}

	void startRelation(relpipe::common::type::StringX name, std::vector<relpipe::reader::handlers::AttributeMetadata> attributes) override {

		// TODO: check relation name according to the configuration

		currentRelation = CurrentRelation{name, attributes};

	}

	void attribute(const relpipe::common::type::StringX& value) override {

		auto attributeName = currentRelation.attributes[currentRelation.attributeIndex].getAttributeName();

		if (attributeName == L"text" && value.size()) currentRelation.currentValue = convertor.to_bytes(value);

		else if (attributeName == L"data" && value.size()) currentRelation.currentValue = Hex::fromHex(value).str();

		else if (attributeName == L"text"); // keep empty or value from 'data'

		else if (attributeName == L"data"); // keep empty or value from 'text'

		currentRelation.attributeIndex++;

		if (currentRelation.attributeIndex == currentRelation.attributes.size()) {

			currentRelation.attributeIndex = 0;

			int mid = -1;

			// std::cerr << "MQTT message enqueued: " << mid << std::endl;

		}

	}

	void endOfPipe() {

	}

};

}

}

}