/*
 * charybdis: an advanced Internet Relay Chat Daemon(ircd).
 *
 * Copyright (C) 2003 Lee H <lee@leeh.co.uk>
 * Copyright (C) 2003-2005 ircd-ratbox development team
 * Copyright (C) 2008 William Pitcock <nenolod@sacredspiral.co.uk>
 * Copyright (C) 2016 Charybdis Development Team
 * Copyright (C) 2016 Jason Volk <jason@zemos.net>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * 1.Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * 2.Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * 3.The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

using namespace ircd;

namespace ircd {
namespace log  {

// Option toggles
std::array<bool, num_of<facility>()> file_flush;
std::array<bool, num_of<facility>()> console_flush;
std::array<const char *, num_of<facility>()> console_ansi;

// Console device toggle
std::array<bool, num_of<facility>()> console_out;
std::array<bool, num_of<facility>()> console_err;

// Logfile name and device
std::array<const char *, num_of<facility>()> fname;
std::array<std::ofstream, num_of<facility>()> file;

ConfEntry conf_log_table[] =
{
	{ "file_critical",  CF_QSTRING, NULL, PATH_MAX, &fname[CRITICAL]  },
	{ "file_error",     CF_QSTRING, NULL, PATH_MAX, &fname[ERROR]     },
	{ "file_warning",   CF_QSTRING, NULL, PATH_MAX, &fname[WARNING]   },
	{ "file_notice",    CF_QSTRING, NULL, PATH_MAX, &fname[NOTICE]    },
	{ "file_info",      CF_QSTRING, NULL, PATH_MAX, &fname[INFO]      },
	{ "file_debug",     CF_QSTRING, NULL, PATH_MAX, &fname[DEBUG]     },
};

static void open(const facility &fac);
static void prefix(const facility &fac, const char *const &date);
static void suffix(const facility &fac);

} // namespace log
} // namespace ircd

void
log::init()
{
	//TODO: XXX: config + cmd control + other fancy stuff

	add_top_conf("log", NULL, NULL, conf_log_table);

	console_err[CRITICAL]    = true;
	console_err[ERROR]       = true;
	console_err[WARNING]     = true;
	console_err[NOTICE]      = true;
	console_out[INFO]        = true;
	console_out[DEBUG]       = true;

	console_flush[CRITICAL]  = true;
	console_flush[ERROR]     = true;
	console_flush[WARNING]   = true;
	console_flush[NOTICE]    = false;
	console_flush[INFO]      = false;
	console_flush[DEBUG]     = false;

	file_flush[CRITICAL]     = true;
	file_flush[ERROR]        = true;
	file_flush[WARNING]      = true;
	file_flush[NOTICE]       = false;
	file_flush[INFO]         = false;
	file_flush[DEBUG]        = false;

	console_flush[CRITICAL]  = true;
	console_flush[ERROR]     = true;
	console_flush[WARNING]   = true;
	console_flush[NOTICE]    = false;
	console_flush[INFO]      = false;
	console_flush[DEBUG]     = true;

	console_ansi[CRITICAL]  = "\033[1;5;37;45m";
	console_ansi[ERROR]     = "\033[1;37;41m";
	console_ansi[WARNING]   = "\033[0;30;43m";
	console_ansi[NOTICE]    = "\033[1;37;46m";
	console_ansi[INFO]      = "\033[1;37;42m";
	console_ansi[DEBUG]     = "\033[1;30;47m";
}

void
log::fini()
{
	remove_top_conf("log");
}

void
log::open()
{
	for_each<facility>([](const facility &fac)
	{
		if(!fname[fac])
			return;

		if(file[fac].is_open())
			file[fac].close();

		file[fac].clear();
		file[fac].exceptions(std::ios::badbit | std::ios::failbit);
		open(fac);
	});
}

void
log::close()
{
	for_each<facility>([](const facility &fac)
	{
		file[fac].close();
	});
}

void
log::flush()
{
	for_each<facility>([](const facility &fac)
	{
		file[fac].flush();
	});
}

void
log::open(const facility &fac)
try
{
	const auto &mode(std::ios::app);
	file[fac].open(fname[fac], mode);
}
catch(const std::exception &e)
{
	char buf[BUFSIZE];
	snprintf(buf, sizeof(buf), "!!! Opening log file [%s] failed: %s",
	         fname[fac],
	         e.what());

	std::cerr << buf << std::endl;
	throw;
}

void
log::debug(const char *const fmt,
           ...)
{
	#ifndef NDEBUG
	va_list ap;
	va_start(ap, fmt);
	vlog(facility::DEBUG, fmt, ap);
	va_end(ap);
	#endif
}

void
log::info(const char *const fmt,
          ...)
{
	va_list ap;
	va_start(ap, fmt);
	vlog(facility::INFO, fmt, ap);
	va_end(ap);
}

void
log::notice(const char *const fmt,
            ...)
{
	va_list ap;
	va_start(ap, fmt);
	vlog(facility::NOTICE, fmt, ap);
	va_end(ap);
}

void
log::warning(const char *const fmt,
             ...)
{
	va_list ap;
	va_start(ap, fmt);
	vlog(facility::WARNING, fmt, ap);
	va_end(ap);
}

void
log::error(const char *const fmt,
           ...)
{
	va_list ap;
	va_start(ap, fmt);
	vlog(facility::ERROR, fmt, ap);
	va_end(ap);
}

void
log::critical(const char *const fmt,
              ...)
{
	va_list ap;
	va_start(ap, fmt);
	vlog(facility::CRITICAL, fmt, ap);
	va_end(ap);
}

log::log::log(const std::string &name)
:name{name}
{
}

log::log::log(const std::string &name,
              const char &snote)
:log
{
	name, std::make_shared<sno::mode>(snote)
}
{
}

log::log::log(const std::string &name,
              const lease_ptr &lease)
:name{name}
,snote{lease}
{
}

void
log::log::debug(const char *const fmt,
                ...)
{
	va_list ap;
	va_start(ap, fmt);
	vlog(DEBUG, name, snote? sno::mask(*snote) : sno::mask(0), fmt, ap);
	va_end(ap);
}

void
log::log::info(const char *const fmt,
               ...)
{
	va_list ap;
	va_start(ap, fmt);
	vlog(INFO, name, snote? sno::mask(*snote) : sno::mask(0), fmt, ap);
	va_end(ap);
}

void
log::log::notice(const char *const fmt,
                 ...)
{
	va_list ap;
	va_start(ap, fmt);
	vlog(NOTICE, name, snote? sno::mask(*snote) : sno::mask(0), fmt, ap);
	va_end(ap);
}

void
log::log::warning(const char *const fmt,
                  ...)
{
	va_list ap;
	va_start(ap, fmt);
	vlog(WARNING, name, snote? sno::mask(*snote) : sno::mask(0), fmt, ap);
	va_end(ap);
}

void
log::log::error(const char *const fmt,
                ...)
{
	va_list ap;
	va_start(ap, fmt);
	vlog(ERROR, name, snote? sno::mask(*snote) : sno::mask(0), fmt, ap);
	va_end(ap);
}

void
log::log::critical(const char *const fmt,
                   ...)
{
	va_list ap;
	va_start(ap, fmt);
	vlog(CRITICAL, name, snote? sno::mask(*snote) : sno::mask(0), fmt, ap);
	va_end(ap);
}

void
log::mark(const char *const &msg)
{
	for_each<facility>([&msg]
	(const auto &fac)
	{
		mark(fac, msg);
	});
}

void
log::mark(const facility &fac,
          const char *const &msg)
{
	slog(fac, [&msg]
	(std::ostream &s)
	{
		s << "*** " << (msg? msg : "mark") << " ***";
	});
}

void
log::logf(const facility &fac,
          const char *const fmt,
          ...)
{
	va_list ap;
	va_start(ap, fmt);
	vlog(fac, fmt, ap);
	va_end(ap);
}

void
log::vlog(const facility &fac,
          const char *const &fmt,
          va_list ap)
{
	char buf[1024];
	vsnprintf(buf, sizeof(buf), fmt, ap);
	slog(fac, [&buf]
	(std::ostream &s)
	{
		s << "ircd :" << buf;
	});
}

void
log::vlog(const facility &fac,
          const std::string &name,
          const char *const &fmt,
          va_list ap)
{
	char buf[1024];
	vsnprintf(buf, sizeof(buf), fmt, ap);
	slog(fac, [&buf, &name]
	(std::ostream &s)
	{
		s << name << " :" << buf;
	});
}

void
log::vlog(const facility &fac,
          const std::string &name,
          const sno::mask &snomask,
          const char *const &fmt,
          va_list ap)
{
	char buf[1024];
	vsnprintf(buf, sizeof(buf), fmt, ap);

	if(snomask)
		sendto_realops_snomask(snomask, L_NETWIDE, "%s %s :%s",
		                       reflect(fac),
		                       name.size()? name.c_str() : "*",
		                       buf);

	slog(fac, [&buf, &name]
	(std::ostream &s)
	{
		s << name << " :" << buf;
	});
}

void
log::slog(const facility &fac,
          const std::function<void (std::ostream &)> &closure)
{
	if(!file[fac].is_open() && !console_out[fac] && !console_err[fac])
		return;

	const scope always_newline([&fac]
	{
		suffix(fac);
	});

	//TODO: XXX: Add option toggle for smalldate()
	char date[64];
	microtime(date, sizeof(date));
	prefix(fac, date);

	if(console_err[fac])
		closure(std::cerr);

	if(console_out[fac])
		closure(std::cout);

	if(file[fac].is_open())
		closure(file[fac]);
}

void
log::prefix(const facility &fac,
            const char *const &date)
{
	const auto console_prefix([&fac, &date]
	(auto &stream)
	{
		stream << date << ' ';

		if(console_ansi[fac])
			stream << console_ansi[fac];

		stream << std::setw(8) << std::right << reflect(fac);

		if(console_ansi[fac])
			stream << "\033[0m ";
		else
			stream << ' ';
	});

	if(console_err[fac])
		console_prefix(std::cerr);

	if(console_out[fac])
		console_prefix(std::cout);

	file[fac] << date << ' ' << reflect(fac) << ' ';
}

void
log::suffix(const facility &fac)
{
	const auto console_newline([&fac]
	(auto &stream)
	{
		if(console_flush[fac])
			stream << std::endl;
		else
			stream << '\n';
	});

	if(console_err[fac])
		console_newline(std::cerr);

	if(console_out[fac])
		console_newline(std::cout);

	// If the user's own code triggered an exception while streaming we still want to
	// provide a newline. But if the exception is an actual log file exception don't
	// touch the stream anymore.
	if(unlikely(std::current_exception() && !file[fac].good()))
		return;

	if(!file[fac].is_open())
		return;

	if(file_flush[fac])
		file[fac] << std::endl;
	else
		file[fac] << '\n';
}

const char *
log::reflect(const facility &f)
{
	switch(f)
	{
		case facility::DEBUG:      return "DEBUG";
		case facility::INFO:       return "INFO";
		case facility::NOTICE:     return "NOTICE";
		case facility::WARNING:    return "WARNING";
		case facility::ERROR:      return "ERROR";
		case facility::CRITICAL:   return "CRITICAL";
		case facility::_NUM_:      break; // Allows -Wswitch to remind developer to add reflection here
	};

	return "??????";
}


const char *
ircd::smalldate(const time_t &ltime)
{
	static char buf[MAX_DATE_STRING];

	struct tm *const lt(localtime(&ltime));
	snprintf(buf, sizeof(buf), "%d/%d/%d %02d.%02d",
	         lt->tm_year + 1900,
	         lt->tm_mon + 1,
	         lt->tm_mday,
	         lt->tm_hour,
	         lt->tm_min);

	return buf;
}