/*
 * InspIRCd -- Internet Relay Chat Daemon
 *
 *   Copyright (C) 2019 Robby <robby@chatbelgie.be>
 *   Copyright (C) 2013, 2016, 2018, 2020-2021 Sadie Powell <sadie@witchery.services>
 *   Copyright (C) 2013 Attila Molnar <attilamolnar@hush.com>
 *   Copyright (C) 2012 ChrisTX <xpipe@hotmail.de>
 *
 * This file is part of InspIRCd.  InspIRCd 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 2.
 *
 * 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/>.
 */

/// $CompilerFlags: -std=c++11


#include "inspircd.h"
#include "modules/regex.h"
#include <regex>

class StdRegex : public Regex
{
	std::regex regexcl;

 public:
	StdRegex(const std::string& rx, std::regex::flag_type fltype) : Regex(rx)
	{
		try
		{
			regexcl.assign(rx, fltype | std::regex::optimize);
		}
		catch(const std::regex_error& rxerr)
		{
			throw RegexException(rx, rxerr.what());
		}
	}

	bool Matches(const std::string& text) CXX11_OVERRIDE
	{
		return std::regex_search(text, regexcl);
	}
};

class StdRegexFactory : public RegexFactory
{
 public:
	std::regex::flag_type regextype;
	StdRegexFactory(Module* m) : RegexFactory(m, "regex/stdregex") {}
	Regex* Create(const std::string& expr) CXX11_OVERRIDE
	{
		return new StdRegex(expr, regextype);
	}
};

class ModuleRegexStd : public Module
{
public:
	StdRegexFactory ref;
	ModuleRegexStd() : ref(this)
	{
	}

	Version GetVersion() CXX11_OVERRIDE
	{
		return Version("Provides the stdregex regular expression engine which uses the C++11 std::regex regular expression matching system.", VF_VENDOR);
	}

	void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
	{
		ConfigTag* Conf = ServerInstance->Config->ConfValue("stdregex");

		const std::string regextype = Conf->getString("type", "ecmascript", 1);
		if (stdalgo::string::equalsci(regextype, "bre"))
			ref.regextype = std::regex::basic;
		else if (stdalgo::string::equalsci(regextype, "ere"))
			ref.regextype = std::regex::extended;
		else if (stdalgo::string::equalsci(regextype, "awk"))
			ref.regextype = std::regex::awk;
		else if (stdalgo::string::equalsci(regextype, "grep"))
			ref.regextype = std::regex::grep;
		else if (stdalgo::string::equalsci(regextype, "egrep"))
			ref.regextype = std::regex::egrep;
		else
		{
			if (!stdalgo::string::equalsci(regextype, "ecmascript"))
				ServerInstance->SNO->WriteToSnoMask('a', "WARNING: Nonexistent regex engine '%s' specified. Falling back to ECMAScript.", regextype.c_str());
			ref.regextype = std::regex::ECMAScript;
		}
	}
};

MODULE_INIT(ModuleRegexStd)