/* OperServ core functions
 *
 * (C) 2003-2024 Anope Team
 * Contact us at team@anope.org
 *
 * Please read COPYING and README for further details.
 *
 * Based on the original code of Epona by Lara.
 * Based on the original code of Services by Andy Church.
 */

#include "module.h"

static unsigned int HARDMAX = 65536;

class CommandOSLogSearch final
	: public Command
{
	static inline Anope::string CreateLogName(const Anope::string &file, time_t t = Anope::CurTime)
	{
		char timestamp[32];

		tm *tm = localtime(&t);

		strftime(timestamp, sizeof(timestamp), "%Y%m%d", tm);

		return Anope::ExpandLog(file + "." + timestamp);
	}

public:
	CommandOSLogSearch(Module *creator) : Command(creator, "operserv/logsearch", 1, 3)
	{
		this->SetDesc(_("Searches logs for a matching pattern"));
		this->SetSyntax(_("[+\037days\037d] [+\037limit\037l] \037pattern\037"));
	}

	void Execute(CommandSource &source, const std::vector<Anope::string> &params) override
	{
		int days = 7, replies = 50;

		unsigned i;
		for (i = 0; i < params.size() && params[i][0] == '+'; ++i)
		{
			switch (params[i][params[i].length() - 1])
			{
				case 'd':
					if (params[i].length() > 2)
					{
						Anope::string dur = params[i].substr(1, params[i].length() - 2);
						auto d = Anope::Convert<int>(dur, 0);
						if (d > 0)
							days = d;
						else
							source.Reply(_("Invalid duration %s, using %d days."), dur.c_str(), days);
					}
					break;
				case 'l':
					if (params[i].length() > 2)
					{
						Anope::string dur = params[i].substr(1, params[i].length() - 2);
						auto r = Anope::Convert<int>(dur, 0);
						if (r > 0)
							replies = r;
						else
							source.Reply(_("Invalid limit %s, using %d."), dur.c_str(), replies);
					}
					break;
				default:
					source.Reply(_("Unknown parameter: %s"), params[i].c_str());
			}
		}

		if (i >= params.size())
		{
			this->OnSyntaxError(source, "");
			return;
		}

		Anope::string search_string = params[i++];
		for (; i < params.size(); ++i)
			search_string += " " + params[i];

		Log(LOG_ADMIN, source, this) << "for " << search_string;

		bool wildcard = search_string.find_first_of("?*") != Anope::string::npos;
		bool regex = !search_string.empty() && search_string[0] == '/' && search_string[search_string.length() - 1] == '/';

		const Anope::string &logfile_name = Config->GetModule(this->owner)->Get<const Anope::string>("logname");
		std::vector<Anope::string> matches;
		for (int d = days - 1; d >= 0; --d)
		{
			Anope::string lf_name = CreateLogName(logfile_name, Anope::CurTime - (d * 86400));
			Log(LOG_DEBUG) << "Searching " << lf_name;
			std::fstream fd(lf_name.c_str(), std::ios_base::in);
			if (!fd.is_open())
				continue;

			for (Anope::string buf, token; std::getline(fd, buf.str());)
			{
				bool match = false;

				if (regex)
					match = Anope::Match(buf, search_string, false, true);
				else if (wildcard)
					match = Anope::Match(buf, "*" + search_string + "*");
				else
					match = buf.find_ci(search_string) != Anope::string::npos;

				if (match)
				{
					matches.push_back(buf);

					if (matches.size() >= HARDMAX)
						break;
				}
			}

			fd.close();
		}

		size_t found = matches.size();
		if (!found)
		{
			source.Reply(_("No matches for \002%s\002 found."), search_string.c_str());
			return;
		}

		if (matches.size() >= HARDMAX)
		{
			source.Reply(_("Too many results for \002%s\002."), search_string.c_str());
			return;
		}

		if (matches.size() > static_cast<unsigned int>(replies))
		{
			matches.erase(matches.begin(), matches.begin() + (matches.size() - static_cast<unsigned int>(replies)));
		}

		source.Reply(_("Matches for \002%s\002:"), search_string.c_str());
		size_t count = 0;
		for (const auto &match : matches)
			source.Reply("#%zu: %s", ++count, match.c_str());
		source.Reply(_("Showed %zu/%zu matches for \002%s\002."), matches.size(), found, search_string.c_str());
	}

	bool OnHelp(CommandSource &source, const Anope::string &subcommand) override
	{
		this->SendSyntax(source);
		source.Reply(" ");
		source.Reply(_("This command searches the services logfiles for messages\n"
				"that match the given pattern. The day and limit argument\n"
				"may be used to specify how many days of logs to search\n"
				"and the number of replies to limit to. By default this\n"
				"command searches one week of logs, and limits replies\n"
				"to 50.\n"
				" \n"
				"For example:\n"
				"    \002LOGSEARCH +21d +500l Anope\002\n"
				"      Searches the last 21 days worth of logs for messages\n"
				"      containing Anope and lists the most recent 500 of them."));
		return true;
	}
};

class OSLogSearch final
	: public Module
{
	CommandOSLogSearch commandoslogsearch;

public:
	OSLogSearch(const Anope::string &modname, const Anope::string &creator) : Module(modname, creator, VENDOR),
		commandoslogsearch(this)
	{
	}
};

MODULE_INIT(OSLogSearch)