/**
 * 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 <iostream>
#include <cassert>
#include <limits>

#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;

/**
 * Unsigned variable-length integer.
 * ULEB128
 */
class IntegerDataTypeReader : public DataTypeReader<integer_t> {
private:

	uint8_t readNextOctet(std::istream &input) {
		uint8_t value = input.get();
		if (input.good()) return value;
		else throw RelpipeReaderException(L"Unable to read next octet of the integer.");
	}

public:

	IntegerDataTypeReader() : DataTypeReader<integer_t>(TypeId::INTEGER, DATA_TYPE_CODE_INTEGER) {
	}

	integer_t readValue(std::istream &input) override {
		integer_t value = 0;
		integer_t shift = 0;
		octet_t octet;
		do {
			octet = readNextOctet(input);
			value += integer_t(octet & 0x7F) << shift;
			shift += 7;
		} while (octet >= 128);
		return value;
	}

	string_t toString(const integer_t &value) override {
		return std::to_wstring(value);
	}

};

}
}
}