/****************************************************************************
 *
 *   Copyright (c) 2015-2016 PX4 Development Team. All rights reserved.
 *
 * 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. Neither the name PX4 nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "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
 * COPYRIGHT OWNER OR CONTRIBUTORS 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.
 *
 ****************************************************************************/

#include <stdint.h>

#include <px4_tasks.h>
#include <px4_getopt.h>
#include <px4_posix.h>
#include <errno.h>
#include <cmath>	// NAN


#include <uORB/uORB.h>
#include <uORB/topics/actuator_controls.h>
#include <uORB/topics/actuator_outputs.h>
#include <uORB/topics/actuator_armed.h>
#include <uORB/topics/parameter_update.h>

#include <drivers/drv_hrt.h>
#include <drivers/drv_mixer.h>
#include <mixer/mixer.h>
#include <mixer/mixer_load.h>
#include <mixer/mixer_multirotor_normalized.generated.h>
#include <parameters/param.h>
#include <perf/perf_counter.h>
#include <pwm_limit/pwm_limit.h>
#include <dev_fs_lib_pwm.h>

/*
 * PWM Driver for snapdragon.
 * @author: Dennis Mannhart <dennis.mannhart@gmail.com>
 */
namespace snapdragon_pwm
{

static px4_task_t _task_handle = -1;
volatile bool _task_should_exit = false;
static bool _is_running = false;
static const int NUM_PWM = 4;
static char _device[] = "/dev/pwm-1";

// snapdragon pins 27,28,29,30 configured for pwm (port J13)
static const int PIN_GPIO = 27;
static struct ::dspal_pwm_ioctl_signal_definition _signal_definition;
static struct ::dspal_pwm _pwm_gpio[NUM_PWM];
static struct ::dspal_pwm_ioctl_update_buffer *_update_buffer;
static struct ::dspal_pwm *_pwm;

// TODO: check frequency required
static const int FREQUENCY_PWM_HZ = 400;

/* TODO: copied from pwm_out_rc_in: check how that works
 * filename: /dev/fs is mapped to /usr/share/data/adsp */
static char _mixer_filename[32] = "/dev/fs/quad_x.main.mix";

// subscriptions
int	_controls_subs[actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS];
int	_armed_sub;
int _fd = -1;

// publications
orb_advert_t    _outputs_pub = nullptr;

// topic structures
actuator_controls_s _controls[actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS];
orb_id_t _controls_topics[actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS];
actuator_outputs_s  _outputs;
actuator_armed_s    _armed;

// polling
uint8_t _poll_fds_num = 0;
px4_pollfd_struct_t _poll_fds[actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS];

// control group
uint32_t	_groups_required = 0;

// limit for pwm
pwm_limit_t     _pwm_limit;

// esc parameters
int32_t _pwm_disarmed;
int32_t _pwm_min;
int32_t _pwm_max;

MultirotorMixer *_mixer = nullptr;

perf_counter_t	_perf_control_latency = nullptr;

/*
 * forward declaration
 */

static void usage();

static void start();

static void stop();

static int pwm_initialize(const char *device);

static void pwm_deinitialize();

static void send_outputs_pwm(const uint16_t *pwm);

static void task_main_trampoline(int argc, char *argv[]);

static void subscribe();

static void task_main(int argc, char *argv[]);

static void update_params(bool &airmode);

int initialize_mixer(const char *mixer_filename);

int mixer_control_callback(uintptr_t handle, uint8_t control_group, uint8_t control_index, float &input);



/*
 * functions
 */

int mixer_control_callback(uintptr_t handle,
			   uint8_t control_group,
			   uint8_t control_index,
			   float &input)
{
	const actuator_controls_s *controls = (actuator_controls_s *)handle;

	input = controls[control_group].control[control_index];

	return 0;
}

void update_params(bool &airmode)
{
	// multicopter air-mode
	param_t param_handle = param_find("MC_AIRMODE");

	if (param_handle != PARAM_INVALID) {
		int32_t val;
		param_get(param_handle, &val);
		airmode = val > 0;
	}
}

int initialize_mixer(const char *mixer_filename)
{

	char buf[2048];
	size_t buflen = sizeof(buf);
	PX4_INFO("Trying to initialize mixer from config file %s", mixer_filename);
	int fd_load = ::open(mixer_filename, O_RDONLY);

	if (fd_load != -1) {
		int nRead = ::read(fd_load, buf, buflen);
		close(fd_load);

		if (nRead > 0) {
			_mixer = MultirotorMixer::from_text(mixer_control_callback, (uintptr_t)&_controls, buf, buflen);

			if (_mixer != nullptr) {
				PX4_INFO("Successfully initialized mixer from config file");
				return 0;

			} else {
				PX4_ERR("Unable to parse from mixer config file");
				return -1;
			}

		} else {
			PX4_WARN("Unable to read from mixer config file");
			return -2;
		}

	} else {
		PX4_WARN("No mixer config file found, using default mixer.");

		/* Mixer file loading failed, fall back to default mixer configuration for
		* QUAD_X airframe. */
		float roll_scale = 1;
		float pitch_scale = 1;
		float yaw_scale = 1;
		float deadband = 0;

		_mixer = new MultirotorMixer(mixer_control_callback, (uintptr_t)&_controls,
					     MultirotorGeometry::QUAD_X,
					     roll_scale, pitch_scale, yaw_scale, deadband);

		if (_mixer == nullptr) {
			return -1;
		}

		return 0;

	}

}

void subscribe()
{
	memset(_controls, 0, sizeof(_controls));
	memset(_poll_fds, 0, sizeof(_poll_fds));

	/*
	 * ORB topic names to msg actuator_controls
	 */
	_controls_topics[0] = ORB_ID(actuator_controls_0);
	_controls_topics[1] = ORB_ID(actuator_controls_1);
	_controls_topics[2] = ORB_ID(actuator_controls_2);
	_controls_topics[3] = ORB_ID(actuator_controls_3);


	/*
	 * subscibe to orb topic
	 */
	for (uint8_t i = 0; i < actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS; i++) {

		if (_groups_required & (1 << i)) {

			PX4_DEBUG("subscribe to actuator_controls_%d", i);

			_controls_subs[i] = orb_subscribe(_controls_topics[i]);

		} else {

			_controls_subs[i] = -1;

		}

		if (_controls_subs[i] >= 0) {

			_poll_fds[_poll_fds_num].fd = _controls_subs[i];
			_poll_fds[_poll_fds_num].events = POLLIN;
			_poll_fds_num++;

		}

	}

	_armed_sub = orb_subscribe(ORB_ID(actuator_armed));

}



int pwm_initialize(const char *device)
{
	/*
	 * open PWM device
	 */
	_fd = open(_device, 0);

	if (_fd < 0) {
		PX4_ERR("failed to open PWM device!");
		return -1;
	}

	/*
	 * configure PWM
	 */
	for (int i = 0; i < NUM_PWM; i++) {
		_pwm_gpio[i].gpio_id = PIN_GPIO + i;
	}

	/*
	 * description of signal
	 */
	_signal_definition.num_gpios = NUM_PWM;
	_signal_definition.period_in_usecs = 1000000 / FREQUENCY_PWM_HZ;
	_signal_definition.pwm_signal = _pwm_gpio;


	/*
	 * send signal definition to DSP
	 */
	if (::ioctl(_fd, PWM_IOCTL_SIGNAL_DEFINITION, &_signal_definition) != 0) {
		PX4_ERR("failed to send signal to DSP");
		return -1;
	}

	/*
	 * retrieve shared buffer which will be used to update desired pulse width
	 */
	if (::ioctl(_fd, PWM_IOCTL_GET_UPDATE_BUFFER, &_update_buffer) != 0) {
		PX4_ERR("failed to receive update buffer ");
		return -1;
	}

	_pwm = _update_buffer->pwm_signal;


	return 0;
}

void pwm_deinitialize()
{
	delete _mixer;
	close(_fd);

}

void send_outputs_pwm(const uint16_t *pwm)
{
	/*
	 * send pwm in us: TODO: check if it is in us
	 */
	for (unsigned i = 0; i < NUM_PWM; ++i) {
		_pwm[i].pulse_width_in_usecs = pwm[i];
	}
}

void task_main(int argc, char *argv[])
{
	if (pwm_initialize(_device) < 0) {
		PX4_ERR("Failed to initialize PWM.");
		return;
	}

	if (initialize_mixer(_mixer_filename) < 0) {
		PX4_ERR("Mixer initialization failed.");
		return;
	}

	_mixer->groups_required(_groups_required);

	// subscribe and set up polling
	subscribe();

	bool airmode = false;
	update_params(airmode);
	int params_sub = orb_subscribe(ORB_ID(parameter_update));

	// Start disarmed
	_armed.armed = false;
	_armed.prearmed = false;

	// set max min pwm
	pwm_limit_init(&_pwm_limit);

	_perf_control_latency = perf_alloc(PC_ELAPSED, "snapdragon_pwm_out control latency");

	_is_running = true;

	// Main loop
	while (!_task_should_exit) {

		if (_mixer) {
			_mixer->set_airmode(airmode);
		}

		/* wait up to 10ms for data */
		int pret = px4_poll(_poll_fds, _poll_fds_num, 10);

		/* Timed out, do a periodic check for _task_should_exit. */
		bool timeout = false;

		if (pret == 0) {
			timeout = true;
		}

		/* This is undesirable but not much we can do. */
		if (pret < 0) {
			PX4_WARN("poll error %d, %d", pret, errno);
			/* sleep a bit before next try */
			usleep(10000);
			continue;
		}

		bool updated;
		orb_check(_armed_sub, &updated);

		if (updated) {
			orb_copy(ORB_ID(actuator_armed), _armed_sub, &_armed);
		}

		/* get controls for required topics */
		unsigned poll_id = 0;

		for (uint8_t i = 0; i < actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS; i++) {
			if (_controls_subs[i] >= 0) {
				if (_poll_fds[poll_id].revents & POLLIN) {
					orb_copy(_controls_topics[i], _controls_subs[i], &_controls[i]);
				}

				poll_id++;
			}
		}

		if (_mixer == nullptr) {
			PX4_ERR("Could not mix output! Exiting...");
			_task_should_exit = true;
			continue;
		}

		/* do  mixing for virtual control group */
		_outputs.noutputs = _mixer->mix(_outputs.output, _outputs.NUM_ACTUATOR_OUTPUTS);

		//set max, min and disarmed pwm
		const uint16_t reverse_mask = 0;
		uint16_t disarmed_pwm[4];
		uint16_t min_pwm[4];
		uint16_t max_pwm[4];
		uint16_t pwm[4];

		for (unsigned int i = 0; i < 4; i++) {
			disarmed_pwm[i] = _pwm_disarmed;
			min_pwm[i] = _pwm_min;
			max_pwm[i] = _pwm_max;
		}


		// TODO FIXME: pre-armed seems broken -> copied and pasted from pwm_out_rc_in: needs to be tested
		pwm_limit_calc(_armed.armed,
			       false/*_armed.prearmed*/, _outputs.noutputs, reverse_mask, disarmed_pwm,
			       min_pwm, max_pwm, _outputs.output, pwm, &_pwm_limit);

		// send and publish outputs
		if (_armed.lockdown || _armed.manual_lockdown || timeout) {
			send_outputs_pwm(disarmed_pwm);

		} else {
			send_outputs_pwm(pwm);
		}

		_outputs.timestamp = hrt_absolute_time();

		if (_outputs_pub != nullptr) {
			orb_publish(ORB_ID(actuator_outputs), _outputs_pub, &_outputs);

		} else {
			_outputs_pub = orb_advertise(ORB_ID(actuator_outputs), &_outputs);
		}

		// use first valid timestamp_sample for latency tracking
		for (int i = 0; i < actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS; i++) {
			const bool required = _groups_required & (1 << i);
			const hrt_abstime &timestamp_sample = _controls[i].timestamp_sample;

			if (required && (timestamp_sample > 0)) {
				perf_set_elapsed(_perf_control_latency, _outputs.timestamp - timestamp_sample);
				break;
			}
		}

		/* check for parameter updates */
		bool param_updated = false;
		orb_check(params_sub, &param_updated);

		if (param_updated) {
			struct parameter_update_s update;
			orb_copy(ORB_ID(parameter_update), params_sub, &update);
			update_params(airmode);
		}
	}

	pwm_deinitialize();

	for (uint8_t i = 0; i < actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS; i++) {
		if (_controls_subs[i] >= 0) {
			orb_unsubscribe(_controls_subs[i]);
		}
	}

	orb_unsubscribe(_armed_sub);
	orb_unsubscribe(params_sub);

	perf_free(_perf_control_latency);

	_is_running = false;
}

void task_main_trampoline(int argc, char *argv[])
{
	task_main(argc, argv);
}

void start()
{
	ASSERT(_task_handle == -1);

	_task_should_exit = false;

	/* start the task */
	_task_handle = px4_task_spawn_cmd("snapdragon_pwm_out_main",
					  SCHED_DEFAULT,
					  SCHED_PRIORITY_MAX,
					  1500,
					  (px4_main_t)&task_main_trampoline,
					  nullptr);

	if (_task_handle < 0) {
		warn("task start failed");
		return;
	}

}

void stop()
{
	_task_should_exit = true;

	while (_is_running) {
		usleep(200000);
		PX4_INFO(".");
	}

	_task_handle = -1;
}

void usage()
{

	PX4_INFO("usage: snapdragon_pwm_out start [-d pwmdevice] [-m mixerfile]");
	PX4_INFO("       -d pwmdevice : device for pwm generation");
	PX4_INFO("                       (default /dev/pwm-1)");
	PX4_INFO("		 -m mixerfile : path to mixerfile");
	PX4_INFO("						 (default /dev/fs/quad_x.main.mix");
	PX4_INFO("       pwm_out stop");
	PX4_INFO("       pwm_out status");

}

} // namespace snapdragon_pwm

/* driver 'main' command */
extern "C" __EXPORT int snapdragon_pwm_out_main(int argc, char *argv[]);

int snapdragon_pwm_out_main(int argc, char *argv[])
{


	int ch;
	int myoptind = 1;
	const char *myoptarg = nullptr;

	char *verb = nullptr;

	if (argc >= 2) {
		verb = argv[1];

	} else {
		return 1;
	}

	while ((ch = px4_getopt(argc, argv, "d:m", &myoptind, &myoptarg)) != EOF) {
		switch (ch) {
		case 'd':
			strncpy(snapdragon_pwm::_device, myoptarg, sizeof(snapdragon_pwm::_device));
			break;

		case 'm':
			strncpy(snapdragon_pwm::_mixer_filename, myoptarg, sizeof(snapdragon_pwm::_mixer_filename));
			break;
		}
	}

	// gets the parameters for the esc's pwm
	param_get(param_find("PWM_DISARMED"), &snapdragon_pwm::_pwm_disarmed);
	param_get(param_find("PWM_MIN"), &snapdragon_pwm::_pwm_min);
	param_get(param_find("PWM_MAX"), &snapdragon_pwm::_pwm_max);

	/*
	 * Start/load the driver.
	 */
	if (!strcmp(verb, "start")) {
		if (snapdragon_pwm::_is_running) {
			PX4_WARN("pwm_out already running");
			return 1;
		}

		snapdragon_pwm::start();
	}

	else if (!strcmp(verb, "stop")) {
		if (!snapdragon_pwm::_is_running) {
			PX4_WARN("pwm_out is not running");
			return 1;
		}

		snapdragon_pwm::stop();
	}

	else if (!strcmp(verb, "status")) {
		PX4_INFO("pwm_out is %s", snapdragon_pwm::_is_running ? "running" : "not running");
		return 0;

	} else {
		snapdragon_pwm::usage();
		return 1;
	}

	return 0;
}