/**
 * Relational pipes
 * 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 General Public License as published by
 * the Free Software Foundation, version 3 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 <cstdlib>
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <string>
#include <locale>

#include <relpipe/writer/typedefs.h>
#include <relpipe/writer/AttributeMetadata.h>
#include <relpipe/cli/CLI.h>
#include <relpipe/cli/RelpipeCLIException.h>

#include "Command.h"

namespace relpipe {
namespace in {
namespace cli {

/**
 * TODO: consider code merge with ArgumentsCommand
 */
class StdInCommand : public Command {
private:
	relpipe::writer::boolean_t readStdIn;
	std::wstring_convert<codecvt_utf8<wchar_t>> convertor; // TODO: support also other encodings.

	/**
	 * Reads next value from arguments and (if no arguments left) from input
	 * @param input
	 * @param arguments
	 * @param i current index in the arguments vector
	 * @param required if true, exception is thrown when no data found
	 * @return 
	 */
	relpipe::writer::string_t readNext(std::istream& input, const std::vector<relpipe::writer::string_t>& arguments, size_t& i, relpipe::writer::boolean_t required) {
		using namespace relpipe::writer;
		using namespace relpipe::cli;

		if (i < arguments.size()) {
			return arguments[i++];
		} else if (readStdIn) {
			std::stringstream value;

			while (true) {
				char ch;
				input.get(ch);
				if (ch == 0 || input.eof() || input.fail()) break;
				else value << ch;
			}

			if (required && value.str().empty()) throw RelpipeCLIException(L"Missing value on STDIN.", CLI::EXIT_CODE_BAD_SYNTAX);

			return convertor.from_bytes(value.str());
		} else {
			if (required) throw RelpipeCLIException(L"Missing value on CLI.", CLI::EXIT_CODE_BAD_SYNTAX);
			return L"";
		}
	}


public:

	StdInCommand(relpipe::writer::boolean_t readStdIn) :
	readStdIn(readStdIn) {
	}

	void process(std::istream& input, std::ostream& output, const relpipe::writer::string_t& command, const std::vector<relpipe::writer::string_t>& arguments) override {
		using namespace relpipe::writer;

		size_t i = 0;
		string_t relationName = readNext(input, arguments, i, true);
		integer_t attributeCount = std::stol(readNext(input, arguments, i, true)); // TODO: use integer data type's method? + unsigned type
		boolean_t writeHeader = true; // TODO: add option for header omitting

		std::shared_ptr<RelationalWriter> writer(Factory::create(output));

		std::vector<AttributeMetadata> attributes(attributeCount);

		for (size_t j = 0; j < attributeCount; j++) {
			string_t attributeName = readNext(input, arguments, i, true);
			TypeId attributeType = writer->toTypeId(readNext(input, arguments, i, true));
			attributes[j] = {attributeName, attributeType};
		}

		writer->startRelation(relationName, attributes, writeHeader);

		while (true) {
			string_t value = readNext(input, arguments, i, false);
			if (value.empty() && (input.eof() || input.fail() || (!readStdIn && i >= arguments.size()))) break;
			else writer->writeAttribute(value);
			// TODO: check attribute count (avoid unfinished records)
		}
	}
};

}
}
}