/**
 * Relational pipes (library)
 * 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 Lesser General Public License as published by the Free Software Foundation;
 *    version 3 of the License or (at your option)
 *  - GNU General Public License as published by the Free Software Foundation;
 *    version 2 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 <sstream>
#include <iostream>
#include <vector>
#include <locale>
#include <codecvt>

#include <relpipe/protocol/constants.h>

#include "../../include/relpipe/reader/RelpipeReaderException.h"
#include "../../include/relpipe/reader/typedefs.h"
#include "../DataTypeReader.h"

namespace relpipe {
namespace reader {
namespace types {

using namespace relpipe::protocol;
using namespace relpipe::reader;

/**
 * The prototype does not recognize any encoding,
 * it just works with c++ strings in encoding default to given platform. 
 * In the real implementation of relational pipes, there will be DataTypes for particular encodings.
 */
class StringDataTypeReader : public DataTypeReader<string_t> {
private:
	IntegerDataTypeReader integerType;
	std::wstring_convert<std::codecvt_utf8<wchar_t>> convertor; // TODO: support also other encodings.
public:

	StringDataTypeReader() : DataTypeReader<string_t>(TypeId::STRING, DATA_TYPE_CODE_STRING) {
	}

	string_t readValue(std::istream &input) override {
		integer_t length = integerType.readValue(input);
		// TODO: check maximum length of single field
		// if (length > 4000) throw RelpipeException("data too long", EXIT_CODE_DATA_ERROR);
		std::vector<char> buf(length);
		input.read(buf.data(), length);
		if (input.good()) {
			return convertor.from_bytes(std::string(buf.data(), length));
		} else {
			throw RelpipeReaderException(L"Error while reading string from the stream.");
		}
	}

	string_t toString(const string_t &value) override {
		return value;
	}

};

}
}
}