/**

 * 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

 *

 * 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 <cassert>

#include <relpipe/reader/typedefs.h>

#include <relpipe/reader/TypeId.h>

#include <relpipe/reader/RelpipeReaderException.h>

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

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

namespace relpipe {

namespace out {

namespace recfile {

using namespace relpipe::reader;

class RecfileHandler : public handlers::RelationalReaderStringHandler {

private:

	std::ostream& output;

	wstring_convert<codecvt_utf8<wchar_t>> convertor; // XML output will be always in UTF-8

	std::vector<TypeId> attributeTypes;

	std::vector<string_t> attributeTypeCodes;

	std::vector<string_t> attributeNames;

	integer_t valueCount = 0;

	integer_t attributeCount = 0;

	integer_t relationCount = 0;

	void writeRelationName(const string_t& name) {

		// FIXME: escaping/filtering

		output << "%rec: " << convertor.to_bytes(name) << std::endl;

	}

	const std::string toRecfileType(const TypeId& type) {

		switch (type) {

			case TypeId::BOOLEAN: return "bool";

			case TypeId::INTEGER: return "int";

			case TypeId::STRING: return "";

			default: throw RelpipeReaderException(L"Unsupported type – unable to convert to a Recfile type");

		}

	}

	void writeAttributeMetadata(const handlers::AttributeMetadata& attribute) {

		// FIXME: escaping/filtering

		std::string recfileType = toRecfileType(attribute.getTypeId());

		if (recfileType.size()) output << "%type: " << convertor.to_bytes(attribute.getAttributeName()) << " " << recfileType << std::endl;

	}

	void writeSeparator() {

		output << std::endl;

	}

	void writeAttribute(const string_t& name, const TypeId& type, const string_t& value) {

		// FIXME: escaping/filtering

		output << convertor.to_bytes(name) << ": ";

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

			output << ch;

			if (ch == '\n') output << "+ ";

		}

		output << std::endl;

	}

public:

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

	}

	void startRelation(string_t name, std::vector<handlers::AttributeMetadata> attributes) override {

		valueCount = 0;

		attributeCount = 0;

		if (relationCount) writeSeparator();

		relationCount++;

		writeRelationName(name);

		attributeCount = attributes.size();

		attributeTypes.resize(attributeCount);

		attributeTypeCodes.resize(attributeCount);

		attributeNames.resize(attributeCount);

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

			attributeNames[i] = attributes[i].getAttributeName();

			attributeTypes[i] = attributes[i].getTypeId();

			attributeTypeCodes[i] = attributes[i].getTypeName();

			writeAttributeMetadata(attributes[i]);

		}

	}

	void attribute(const string_t& value) override {

		integer_t i = valueCount % attributeCount;

		if (i == 0) writeSeparator();

		valueCount++;

		writeAttribute(attributeNames[i], attributeTypes[i], value);

	}

	void endOfPipe() {

		if (valueCount) writeSeparator();

	}

};

}

}

}