/**
 * 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 <functional>
#include "../include/relpipe/reader/TypeId.h"
#include "../include/relpipe/reader/typedefs.h"

namespace relpipe {
namespace reader {

/**
 * This class contains common features that are independent from particular data type (generic/template type)
 */
class DataTypeReaderBase {
private:
	const TypeId typeId;
	const string_t typeCode;
public:

	DataTypeReaderBase(const TypeId typeId, const string_t typeCode) :
	typeId(typeId), typeCode(typeCode) {
	}

	virtual ~DataTypeReaderBase() {
	};

	/**
	 * TODO: delete, use handler?
	 * 
	 * @param input input stream, should be at position where the value is to be read; the stream will not be closed afred reading
	 * @return read value in form of the string representation of given data type.
	 * E.g. integer 123 is returned as a character string "123",
	 * boolean true is returned as a character string "true".
	 * See Relational pipes format specification for details.
	 */
	virtual string_t readString(std::istream &input) = 0;

	/**
	 * The value is read from the input and then passed to the handler.
	 * 
	 * @param input
	 * @param handler
	 */
	virtual void read(std::istream &input, std::function<void(const void *, const std::type_info&) > handler) = 0;

	/**
	 * TODO: documentation
	 * 
	 * @param input
	 * @param handler
	 */
	virtual void read(std::istream &input, std::function<void(const string_t&, const void *, const std::type_info&) > handler) = 0;

	/**
	 * @param dataType data type code as defined in DDP L0
	 * @return whether this class supports conversions of this type
	 */
	virtual bool supports(const TypeId &dataType) {
		return dataType == typeId;
	}

	/**
	 * @param dataType data type name as defined in DDP L0
	 * @return whether this class supports conversions of this type
	 */
	virtual bool supports(const string_t &dataType) {
		return dataType == typeCode;
	}

	TypeId getTypeId() {
		return typeId;
	}

	string_t getTypeCode() {
		return typeCode;
	}
};

}
}