/**

 * 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 <memory>

#include <string>

#include <vector>

#include <iostream>

#include <sstream>

#include <locale>

#include <codecvt>

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

#include <relpipe/reader/TypeId.h>

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

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

namespace relpipe {

namespace out {

namespace yaml {

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

private:

	const char ESC = '\\';

	const char Q = '"';

	std::ostream& output;

	std::wstring_convert<std::codecvt_utf8<wchar_t>> convertor; // we generate YAML always in UTF-8 like XML?

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

	size_t currentAttributeIndex = 0;

	bool firstRecord;

	std::string escape(const relpipe::common::type::StringX& value) {

		std::stringstream result;

		result.put(Q);

		for (char ch : convertor.to_bytes(value)) {

			else result.put(ch);

		}

		result.put(Q);

		return result.str();

	}

	std::string indent(int level) {

		std::stringstream result;

		for (int i = 0; i < level; i++) result << "  ";

		return result.str();

	}

public:

	YAMLHandler(std::ostream& output) : output(output) {

	}

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

		currentAttributes = attributes;

		currentAttributeIndex = 0;

		output << escape(name);

		output << ":" << std::endl;

		output << indent(1) << R"("attribute-metadata":)" << std::endl;

		for (auto am : attributes) output << indent(2) << R"(- "name": )" << escape(am.getAttributeName()) << std::endl << indent(2) << R"(  "type": )" << escape(am.getTypeName()) << std::endl;

		firstRecord = true;

	}

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

		if (firstRecord) {

			output << indent(1) << R"("record":)" << std::endl;

			firstRecord = false;

		}

		if (currentAttributeIndex % currentAttributes.size() == 0) {

			currentAttributeIndex = 0;

			output << indent(2) << "- ";

		} else {

			output << indent(2) << "  ";

		}

		output << escape(currentAttributes[currentAttributeIndex].getAttributeName()) << ": ";

		currentAttributeIndex++;

	}

	void endOfPipe() {

		output.flush();

	}

};

}

}

}