/*
    Copyright (C) 2012-2021 Carl Hetherington <cth@carlh.net>

    This file is part of DCP-o-matic.

    DCP-o-matic 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 2 of the License, or
    (at your option) any later version.

    DCP-o-matic 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 DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.

*/


/** @file src/j2k_encoder.cc
 *  @brief J2K encoder class.
 */


#include "config.h"
#include "cross.h"
#include "dcp_video.h"
#include "dcpomatic_log.h"
#include "encode_server_description.h"
#include "encode_server_finder.h"
#include "film.h"
#include "cpu_j2k_encoder_thread.h"
#ifdef DCPOMATIC_GROK
#include "grok/context.h"
#include "grok_j2k_encoder_thread.h"
#endif
#include "remote_j2k_encoder_thread.h"
#include "j2k_encoder.h"
#include "log.h"
#include "player_video.h"
#include "util.h"
#include "writer.h"
#include <libcxml/cxml.h>
#include <iostream>

#include "i18n.h"


using std::cout;
using std::dynamic_pointer_cast;
using std::exception;
using std::list;
using std::make_shared;
using std::shared_ptr;
using std::weak_ptr;
using boost::optional;
using dcp::Data;
using namespace dcpomatic;

#ifdef DCPOMATIC_GROK

namespace grk_plugin {

IMessengerLogger* sLogger = nullptr;

#if defined(__GNUC__) || defined(__clang__)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-function"
#endif
void setMessengerLogger(grk_plugin::IMessengerLogger* logger)
{
 	delete sLogger;
 	sLogger = logger;
}
#if defined(__GNUC__) || defined(__clang__)
#pragma GCC diagnostic pop
#endif
grk_plugin::IMessengerLogger* getMessengerLogger(void)
{
	return sLogger;
}

}

#endif


/** @param film Film that we are encoding.
 *  @param writer Writer that we are using.
 */
J2KEncoder::J2KEncoder(shared_ptr<const Film> film, Writer& writer)
	: VideoEncoder(film, writer)
	, _waker(Waker::Reason::ENCODING)
#ifdef DCPOMATIC_GROK
	, _give_up(false)
#endif
{
#ifdef DCPOMATIC_GROK
	auto grok = Config::instance()->grok();
	_dcpomatic_context = new grk_plugin::DcpomaticContext(film, writer, _history, grok.binary_location);
	if (grok.enable) {
		_context = new grk_plugin::GrokContext(_dcpomatic_context);
	}
#endif
}


J2KEncoder::~J2KEncoder()
{
	_server_found_connection.disconnect();

	/* One of our encoder threads may be waiting on Writer::write() to return, if that method
	 * is blocked with the writer queue full waiting for _full_condition.  In that case, the
	 * attempt to terminate the encoder threads below (in terminate_threads()) will fail because
	 * the encoder thread waiting for ::write() will have interruption disabled.
	 *
	 * To work around that, make the writer into a zombie to unblock any pending write()s and
	 * not block on any future ones.
	 */
	_writer.zombify();

	terminate_threads();

#ifdef DCPOMATIC_GROK
	delete _context;
	delete _dcpomatic_context;
#endif
}


void
J2KEncoder::servers_list_changed()
{
	auto config = Config::instance();
#ifdef DCPOMATIC_GROK
	auto const grok_enable = config->grok().enable;
#else
	auto const grok_enable = false;
#endif

	auto const cpu = (grok_enable || config->only_servers_encode()) ? 0 : config->master_encoding_threads();
	auto const gpu = grok_enable ? config->master_encoding_threads() : 0;

	LOG_GENERAL("Thread counts from: grok={}, only_servers={}, master={}", grok_enable ? "yes" : "no", config->only_servers_encode() ? "yes" : "no", config->master_encoding_threads());
	remake_threads(cpu, gpu, EncodeServerFinder::instance()->servers());
}


void
J2KEncoder::begin()
{
	_server_found_connection = EncodeServerFinder::instance()->ServersListChanged.connect(
		boost::bind(&J2KEncoder::servers_list_changed, this)
		);
	servers_list_changed();
}


void
J2KEncoder::pause()
{
#ifdef DCPOMATIC_GROK
	if (!Config::instance()->grok().enable) {
		return;
	}
	return;

	/* XXX; the same problem may occur here as in the destructor, perhaps? */

	terminate_threads();

	/* Something might have been thrown during terminate_threads */
	rethrow();

	delete _context;
	_context = nullptr;
#endif
}


void J2KEncoder::resume()
{
#ifdef DCPOMATIC_GROK
	if (!Config::instance()->grok().enable) {
		return;
	}

	_context = new grk_plugin::GrokContext(_dcpomatic_context);
	servers_list_changed();
#endif
}


void
J2KEncoder::end()
{
	boost::mutex::scoped_lock lock(_queue_mutex);

	LOG_GENERAL(N_("Clearing queue of {}"), _queue.size());

	/* Keep waking workers until the queue is empty */
	while (!_queue.empty()) {
		rethrow();
		_full_condition.wait(lock);
	}
	lock.unlock();

	LOG_GENERAL(N_("Terminating encoder threads"));

	terminate_threads();

	/* Something might have been thrown during terminate_threads */
	rethrow();

	LOG_GENERAL(N_("Mopping up {}"), _queue.size());

	/* The following sequence of events can occur in the above code:
	     1. a remote worker takes the last image off the queue
	     2. the loop above terminates
	     3. the remote worker fails to encode the image and puts it back on the queue
	     4. the remote worker is then terminated by terminate_threads

	     So just mop up anything left in the queue here.
	*/
	for (auto & i: _queue) {
#ifdef DCPOMATIC_GROK
		if (Config::instance()->grok().enable) {
			if (!_context->scheduleCompress(i)){
				LOG_GENERAL(N_("[{}] J2KEncoder thread pushes frame {} back onto queue after failure"), thread_id(), i.index());
				// handle error
			}
		} else {
#else
		{
#endif
			LOG_GENERAL(N_("Encode left-over frame {}"), i.index());
			try {
				_writer.write(
					make_shared<dcp::ArrayData>(i.encode_locally()),
					i.index(),
					i.eyes()
					);
				frame_done();
			} catch (std::exception& e) {
				LOG_ERROR(N_("Local encode failed ({})"), e.what());
			}
		}
	}

#ifdef DCPOMATIC_GROK
	delete _context;
	_context = nullptr;
#endif
}


/** Should be called when a frame has been encoded successfully */
void
J2KEncoder::frame_done()
{
	_history.event();
}


/** Called to request encoding of the next video frame in the DCP.  This is called in order,
 *  so each time the supplied frame is the one after the previous one.
 *  pv represents one video frame, and could be empty if there is nothing to encode
 *  for this DCP frame.
 *
 *  @param pv PlayerVideo to encode.
 *  @param time Time of \p pv within the DCP.
 */
void
J2KEncoder::encode(shared_ptr<PlayerVideo> pv, DCPTime time)
{
#ifdef DCPOMATIC_GROK
	if (_give_up) {
		throw EncodeError(_("GPU acceleration is enabled but the grok decoder is not working.  Please check your configuration and license, and ensure that you are connected to the internet."));
	}
#endif

	_waker.nudge();

	size_t threads = 0;
	{
		boost::mutex::scoped_lock lm(_threads_mutex);
		threads = _threads.size();
	}

	boost::mutex::scoped_lock queue_lock(_queue_mutex);

	/* Wait until the queue has gone down a bit.  Allow one thing in the queue even
	   when there are no threads.
	*/
	while (_queue.size() >= (threads * 2) + 1) {
		LOG_TIMING("decoder-sleep queue={} threads={}", _queue.size(), threads);
		_full_condition.wait(queue_lock);
		LOG_TIMING("decoder-wake queue={} threads={}", _queue.size(), threads);
	}

	_writer.rethrow();
	/* Re-throw any exception raised by one of our threads.  If more
	   than one has thrown an exception, only one will be rethrown, I think;
	   but then, if that happens something has gone badly wrong.
	*/
	rethrow();

	auto const position = time.frames_floor(_film->video_frame_rate());

	if (_writer.can_fake_write(position)) {
		/* We can fake-write this frame */
		LOG_DEBUG_ENCODE("Frame @ {} FAKE", to_string(time));
		_writer.fake_write(position, pv->eyes());
		frame_done();
	} else if (pv->has_j2k() && !_film->reencode_j2k()) {
		LOG_DEBUG_ENCODE("Frame @ {} J2K", to_string(time));
		/* This frame already has J2K data, so just write it */
		_writer.write(pv->j2k(), position, pv->eyes());
		frame_done();
	} else if (_last_player_video[pv->eyes()] && _writer.can_repeat(position) && pv->same(_last_player_video[pv->eyes()])) {
		LOG_DEBUG_ENCODE("Frame @ {} REPEAT", to_string(time));
		_writer.repeat(position, pv->eyes());
		frame_done();
	} else {
		LOG_DEBUG_ENCODE("Frame @ {} ENCODE", to_string(time));
		/* Queue this new frame for encoding */
		LOG_TIMING("add-frame-to-queue queue={}", _queue.size());
		auto dcpv = DCPVideo(
				pv,
				position,
				_film->video_frame_rate(),
				_film->video_bit_rate(VideoEncoding::JPEG2000),
				_film->resolution()
				);
		_queue.push_back(dcpv);

		/* The queue might not be empty any more, so notify anything which is
		   waiting on that.
		*/
		_empty_condition.notify_all();
	}

	_last_player_video[pv->eyes()] = pv;
}


void
J2KEncoder::terminate_threads()
{
	boost::mutex::scoped_lock lm(_threads_mutex);
	boost::this_thread::disable_interruption dis;

	for (auto& thread: _threads) {
		thread->stop();
	}

	_threads.clear();
	_ending = true;
}


void
J2KEncoder::remake_threads(int cpu, int gpu, list<EncodeServerDescription> servers)
{
	LOG_GENERAL("Making threads: CPU={}, GPU={}, Remote={}", cpu, gpu, servers.size());
	if ((cpu + gpu + servers.size()) == 0) {
		/* Make at least one thread, even if all else fails.  Maybe we are configured
		 * for "only servers encode" but no servers have been registered yet.
		 */
		++cpu;
	}

	boost::mutex::scoped_lock lm(_threads_mutex);
	if (_ending) {
		return;
	}

	auto remove_threads = [this](int wanted, int current, std::function<bool (shared_ptr<J2KEncoderThread>)> predicate) {
		for (auto i = wanted; i < current; ++i) {
			auto iter = std::find_if(_threads.begin(), _threads.end(), predicate);
			if (iter != _threads.end()) {
				(*iter)->stop();
				_threads.erase(iter);
			}
		}
	};


	/* CPU */

	auto const is_cpu_thread = [](shared_ptr<J2KEncoderThread> thread) {
		return static_cast<bool>(dynamic_pointer_cast<CPUJ2KEncoderThread>(thread));
	};

	auto const current_cpu_threads = std::count_if(_threads.begin(), _threads.end(), is_cpu_thread);

	for (auto i = current_cpu_threads; i < cpu; ++i) {
		auto thread = make_shared<CPUJ2KEncoderThread>(*this);
		thread->start();
		_threads.push_back(thread);
	}

	remove_threads(cpu, current_cpu_threads, is_cpu_thread);

#ifdef DCPOMATIC_GROK
	/* GPU */

	auto const is_grok_thread = [](shared_ptr<J2KEncoderThread> thread) {
		return static_cast<bool>(dynamic_pointer_cast<GrokJ2KEncoderThread>(thread));
	};

	auto const current_gpu_threads = std::count_if(_threads.begin(), _threads.end(), is_grok_thread);

	for (auto i = current_gpu_threads; i < gpu; ++i) {
		auto thread = make_shared<GrokJ2KEncoderThread>(*this, _context);
		thread->start();
		_threads.push_back(thread);
	}

	remove_threads(gpu, current_gpu_threads, is_grok_thread);
#endif

	/* Remote */

	for (auto const& server: servers) {
		if (!server.current_link_version()) {
			continue;
		}

		auto is_remote_thread = [server](shared_ptr<J2KEncoderThread> thread) {
			auto remote = dynamic_pointer_cast<RemoteJ2KEncoderThread>(thread);
			return remote && remote->server().host_name() == server.host_name();
		};

		auto const current_threads = std::count_if(_threads.begin(), _threads.end(), is_remote_thread);

		auto const wanted_threads = server.threads();

		if (wanted_threads > current_threads) {
			LOG_GENERAL(N_("Adding {} worker threads for remote {}"), wanted_threads - current_threads, server.host_name());
		} else if (wanted_threads < current_threads) {
			LOG_GENERAL(N_("Removing {} worker threads for remote {}"), current_threads - wanted_threads, server.host_name());
		}

		for (auto i = current_threads; i < wanted_threads; ++i) {
			auto thread = make_shared<RemoteJ2KEncoderThread>(*this, server);
			thread->start();
			_threads.push_back(thread);
		}

		remove_threads(wanted_threads, current_threads, is_remote_thread);
	}

	_writer.set_encoder_threads(_threads.size());
}


DCPVideo
J2KEncoder::pop()
{
	boost::mutex::scoped_lock lock(_queue_mutex);
	while (_queue.empty()) {
		_empty_condition.wait(lock);
	}

	LOG_TIMING("encoder-wake thread={} queue={}", thread_id(), _queue.size());

	auto vf = _queue.front();
	_queue.pop_front();

	_full_condition.notify_all();
	return vf;
}


void
J2KEncoder::retry(DCPVideo video)
{
#ifdef DCPOMATIC_GROK
	{
		/* We might be destroying or remaking these threads, and hopefully in that case we'll come back here
		 * to check again; we definitely don't want to block in that case waiting to be allowed to check
		 * _threads.
		 */
		boost::mutex::scoped_lock lock(_threads_mutex, boost::try_to_lock);
		if (lock) {
			auto is_grok_thread_with_errors = [](shared_ptr<const J2KEncoderThread> thread) {
				auto grok = dynamic_pointer_cast<const GrokJ2KEncoderThread>(thread);
				return grok && grok->errors();
			};

			_give_up = std::any_of(_threads.begin(), _threads.end(), is_grok_thread_with_errors);
		}
	}
#endif

	{
		boost::mutex::scoped_lock lock(_queue_mutex);
		_queue.push_front(video);
		_empty_condition.notify_all();
	}
}


void
J2KEncoder::write(shared_ptr<const dcp::Data> data, int index, Eyes eyes)
{
	_writer.write(data, index, eyes);
	frame_done();
}