#pragma once

#include <string>

#include <sstream>

#include <iostream>

#include <vector>

#include <locale>

#include <codecvt>

#include "DataType.h"

#include "RelpipeException.h"

#include "IntegerDataType.h"

using namespace std;

namespace rp_prototype {

/**

 * 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 StringDataType : public DataType<wstring> {

private:

	IntegerDataType integerType;

	wstring_convert<codecvt_utf8<wchar_t>> convertor; // TODO: support also other encodings.

public:

	StringDataType() : DataType<wstring>(DATA_TYPE_ID_STRING, DATA_TYPE_CODE_STRING) {

	}

	wstring readValue(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);

		vector<char> buf(length);

		input.read(buf.data(), length);

		if (input.good()) {

			return convertor.from_bytes(string(buf.data(), length));

		} else {

			throw RelpipeException(L"Error while reading string from the stream.", EXIT_CODE_DATA_ERROR);

		}

	}

	void writeValue(ostream &output, const wstring &value) override {

		string s = convertor.to_bytes(value);

		integerType.writeValue(output, s.length());

		output << s.c_str();

	}

	wstring toValue(const wstring &stringValue) override {

		return stringValue;

	}

	wstring toString(const wstring &value) override {

		return value;

	}

};

}