/*
 * Copyright (C) 2016 Emeric Poupon
 *
 * This file is part of LMS.
 *
 * LMS 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, either version 3 of the License, or
 * (at your option) any later version.
 *
 * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "utils/Path.hpp"

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#include <array>
#include <fstream>

#include <boost/tokenizer.hpp>

#include "utils/Crc32Calculator.hpp"
#include "utils/Exception.hpp"
#include "utils/Logger.hpp"

std::uint32_t
computeCrc32(const std::filesystem::path& p)
{
	Utils::Crc32Calculator crc32;

	std::ifstream ifs {p.string().c_str(), std::ios_base::binary};
	if (ifs)
	{
		do
		{
			std::array<char,1024>	buffer;

			ifs.read( buffer.data(), buffer.size() );
			crc32.processBytes( reinterpret_cast<const std::byte*>(buffer.data()), ifs.gcount() );
		}
		while (ifs);
	}
	else
	{
		LMS_LOG(DBUPDATER, ERROR) << "Failed to open file '" << p.string() << "'";
		throw LmsException("Failed to open file '" + p.string() + "'" );
	}

	return crc32.getResult();
}

bool
ensureDirectory(const std::filesystem::path& dir)
{
	if (std::filesystem::exists(dir))
		return std::filesystem::is_directory(dir);
	else
		return std::filesystem::create_directory(dir);
}

Wt::WDateTime
getLastWriteTime(const std::filesystem::path& file)
{
	struct stat sb {};

	if (stat(file.string().c_str(), &sb) == -1)
		throw LmsException("Failed to get stats on file '" + file.string() + "'" );

	return Wt::WDateTime::fromTime_t(sb.st_mtime);
}

void
exploreFilesRecursive(const std::filesystem::path& directory, std::function<bool(std::error_code, const std::filesystem::path&)> cb)
{
	std::error_code ec;
	std::filesystem::directory_iterator itPath {directory, std::filesystem::directory_options::follow_directory_symlink, ec};

	if (ec)
	{
		cb(ec, directory);
		return;
	}

	std::filesystem::directory_iterator itEnd;
	while (itPath != itEnd)
	{
		bool continueExploring {true};

		if (ec)
		{
			continueExploring = cb(ec, *itPath);
		}
		else
		{
			if (std::filesystem::is_regular_file(*itPath, ec))
			{
				continueExploring = cb(ec, *itPath);
			}
			else if (std::filesystem::is_directory(*itPath, ec))
			{
				if (!ec)
					exploreFilesRecursive(*itPath, cb);
				else
					continueExploring = cb(ec, *itPath);
			}
		}

		if (!continueExploring)
			break;

		itPath.increment(ec);
	}
}