/****************************************************************************
 *
 *   Copyright (c) 2013-2018 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 <lib/mathlib/mathlib.h>
#include <lib/mixer/mixer.h>
#include <mathlib/math/filter/LowPassFilter2p.hpp>
#include <systemlib/perf_counter.h>
#include <px4_config.h>
#include <px4_defines.h>
#include <px4_module.h>
#include <px4_module_params.h>
#include <px4_posix.h>
#include <px4_tasks.h>
#include <uORB/topics/actuator_controls.h>
#include <uORB/topics/battery_status.h>
#include <uORB/topics/manual_control_setpoint.h>
#include <uORB/topics/multirotor_motor_limits.h>
#include <uORB/topics/parameter_update.h>
#include <uORB/topics/rate_ctrl_status.h>
#include <uORB/topics/sensor_bias.h>
#include <uORB/topics/sensor_correction.h>
#include <uORB/topics/sensor_gyro.h>
#include <uORB/topics/vehicle_attitude.h>
#include <uORB/topics/vehicle_attitude_setpoint.h>
#include <uORB/topics/vehicle_control_mode.h>
#include <uORB/topics/vehicle_rates_setpoint.h>
#include <uORB/topics/vehicle_status.h>

/**
 * Multicopter attitude control app start / stop handling function
 */
extern "C" __EXPORT int mc_att_control_main(int argc, char *argv[]);

#define MAX_GYRO_COUNT 3


class MulticopterAttitudeControl : public ModuleBase<MulticopterAttitudeControl>, public ModuleParams
{
public:
	MulticopterAttitudeControl();

	virtual ~MulticopterAttitudeControl() = default;

	/** @see ModuleBase */
	static int task_spawn(int argc, char *argv[]);

	/** @see ModuleBase */
	static MulticopterAttitudeControl *instantiate(int argc, char *argv[]);

	/** @see ModuleBase */
	static int custom_command(int argc, char *argv[]);

	/** @see ModuleBase */
	static int print_usage(const char *reason = nullptr);

	/** @see ModuleBase::run() */
	void run() override;

private:

	/**
	 * initialize some vectors/matrices from parameters
	 */
	void			parameters_updated();

	/**
	 * Check for parameter update and handle it.
	 */
	void		battery_status_poll();
	void		parameter_update_poll();
	void		sensor_bias_poll();
	void		sensor_correction_poll();
	void		vehicle_attitude_poll();
	void		vehicle_attitude_setpoint_poll();
	void		vehicle_control_mode_poll();
	void		vehicle_manual_poll();
	void		vehicle_motor_limits_poll();
	void		vehicle_rates_setpoint_poll();
	void		vehicle_status_poll();

	/**
	 * Attitude controller.
	 */
	void		control_attitude(float dt);

	/**
	 * Attitude rates controller.
	 */
	void		control_attitude_rates(float dt);

	/**
	 * Throttle PID attenuation.
	 */
	math::Vector<3> pid_attenuations(float tpa_breakpoint, float tpa_rate);


	int		_v_att_sub{-1};			/**< vehicle attitude subscription */
	int		_v_att_sp_sub{-1};		/**< vehicle attitude setpoint subscription */
	int		_v_rates_sp_sub{-1};		/**< vehicle rates setpoint subscription */
	int		_v_control_mode_sub{-1};	/**< vehicle control mode subscription */
	int		_params_sub{-1};		/**< parameter updates subscription */
	int		_manual_control_sp_sub{-1};	/**< manual control setpoint subscription */
	int		_vehicle_status_sub{-1};	/**< vehicle status subscription */
	int		_motor_limits_sub{-1};		/**< motor limits subscription */
	int		_battery_status_sub{-1};	/**< battery status subscription */
	int		_sensor_gyro_sub[MAX_GYRO_COUNT];	/**< gyro data subscription */
	int		_sensor_correction_sub{-1};	/**< sensor thermal correction subscription */
	int		_sensor_bias_sub{-1};		/**< sensor in-run bias correction subscription */

	unsigned _gyro_count{1};
	int _selected_gyro{0};

	orb_advert_t	_v_rates_sp_pub{nullptr};		/**< rate setpoint publication */
	orb_advert_t	_actuators_0_pub{nullptr};		/**< attitude actuator controls publication */
	orb_advert_t	_controller_status_pub{nullptr};	/**< controller status publication */

	orb_id_t _rates_sp_id{nullptr};		/**< pointer to correct rates setpoint uORB metadata structure */
	orb_id_t _actuators_id{nullptr};	/**< pointer to correct actuator controls0 uORB metadata structure */

	bool		_actuators_0_circuit_breaker_enabled{false};	/**< circuit breaker to suppress output */

	struct vehicle_attitude_s		_v_att {};		/**< vehicle attitude */
	struct vehicle_attitude_setpoint_s	_v_att_sp {};		/**< vehicle attitude setpoint */
	struct vehicle_rates_setpoint_s		_v_rates_sp {};		/**< vehicle rates setpoint */
	struct manual_control_setpoint_s	_manual_control_sp {};	/**< manual control setpoint */
	struct vehicle_control_mode_s		_v_control_mode {};	/**< vehicle control mode */
	struct actuator_controls_s		_actuators {};		/**< actuator controls */
	struct vehicle_status_s			_vehicle_status {};	/**< vehicle status */
	struct battery_status_s			_battery_status {};	/**< battery status */
	struct sensor_gyro_s			_sensor_gyro {};	/**< gyro data before thermal correctons and ekf bias estimates are applied */
	struct sensor_correction_s		_sensor_correction {};	/**< sensor thermal corrections */
	struct sensor_bias_s			_sensor_bias {};	/**< sensor in-run bias corrections */

	MultirotorMixer::saturation_status _saturation_status{};

	perf_counter_t	_loop_perf;			/**< loop performance counter */
	perf_counter_t	_controller_latency_perf;

	math::LowPassFilter2p _lp_filters_d[3];                      /**< low-pass filters for D-term (roll, pitch & yaw) */
	static constexpr const float initial_update_rate_hz = 250.f; /**< loop update rate used for initialization */
	float _loop_update_rate_hz{initial_update_rate_hz};          /**< current rate-controller loop update rate in [Hz] */

	math::Vector<3>		_rates_prev;		/**< angular rates on previous step */
	math::Vector<3>		_rates_prev_filtered;	/**< angular rates on previous step (low-pass filtered) */
	math::Vector<3>		_rates_sp;		/**< angular rates setpoint */
	math::Vector<3>		_rates_int;		/**< angular rates integral error */
	float			_thrust_sp;		/**< thrust setpoint */
	math::Vector<3>		_att_control;	/**< attitude control vector */

	math::Matrix<3, 3>	_board_rotation;	/**< rotation matrix for the orientation that the board is mounted */

	DEFINE_PARAMETERS(
		(ParamFloat<px4::params::MC_ROLL_P>) _roll_p,
		(ParamFloat<px4::params::MC_ROLLRATE_P>) _roll_rate_p,
		(ParamFloat<px4::params::MC_ROLLRATE_I>) _roll_rate_i,
		(ParamFloat<px4::params::MC_RR_INT_LIM>) _roll_rate_integ_lim,
		(ParamFloat<px4::params::MC_ROLLRATE_D>) _roll_rate_d,
		(ParamFloat<px4::params::MC_ROLLRATE_FF>) _roll_rate_ff,

		(ParamFloat<px4::params::MC_PITCH_P>) _pitch_p,
		(ParamFloat<px4::params::MC_PITCHRATE_P>) _pitch_rate_p,
		(ParamFloat<px4::params::MC_PITCHRATE_I>) _pitch_rate_i,
		(ParamFloat<px4::params::MC_PR_INT_LIM>) _pitch_rate_integ_lim,
		(ParamFloat<px4::params::MC_PITCHRATE_D>) _pitch_rate_d,
		(ParamFloat<px4::params::MC_PITCHRATE_FF>) _pitch_rate_ff,

		(ParamFloat<px4::params::MC_YAW_P>) _yaw_p,
		(ParamFloat<px4::params::MC_YAWRATE_P>) _yaw_rate_p,
		(ParamFloat<px4::params::MC_YAWRATE_I>) _yaw_rate_i,
		(ParamFloat<px4::params::MC_YR_INT_LIM>) _yaw_rate_integ_lim,
		(ParamFloat<px4::params::MC_YAWRATE_D>) _yaw_rate_d,
		(ParamFloat<px4::params::MC_YAWRATE_FF>) _yaw_rate_ff,

		(ParamFloat<px4::params::MC_YAW_FF>) _yaw_ff,					/**< yaw control feed-forward */

		(ParamFloat<px4::params::MC_DTERM_CUTOFF>) _d_term_cutoff_freq,			/**< Cutoff frequency for the D-term filter */

		(ParamFloat<px4::params::MC_TPA_BREAK_P>) _tpa_breakpoint_p,			/**< Throttle PID Attenuation breakpoint */
		(ParamFloat<px4::params::MC_TPA_BREAK_I>) _tpa_breakpoint_i,			/**< Throttle PID Attenuation breakpoint */
		(ParamFloat<px4::params::MC_TPA_BREAK_D>) _tpa_breakpoint_d,			/**< Throttle PID Attenuation breakpoint */
		(ParamFloat<px4::params::MC_TPA_RATE_P>) _tpa_rate_p,				/**< Throttle PID Attenuation slope */
		(ParamFloat<px4::params::MC_TPA_RATE_I>) _tpa_rate_i,				/**< Throttle PID Attenuation slope */
		(ParamFloat<px4::params::MC_TPA_RATE_D>) _tpa_rate_d,				/**< Throttle PID Attenuation slope */

		(ParamFloat<px4::params::MC_ROLLRATE_MAX>) _roll_rate_max,
		(ParamFloat<px4::params::MC_PITCHRATE_MAX>) _pitch_rate_max,
		(ParamFloat<px4::params::MC_YAWRATE_MAX>) _yaw_rate_max,
		(ParamFloat<px4::params::MC_YAWRAUTO_MAX>) _yaw_auto_max,

		(ParamFloat<px4::params::MC_ACRO_R_MAX>) _acro_roll_max,
		(ParamFloat<px4::params::MC_ACRO_P_MAX>) _acro_pitch_max,
		(ParamFloat<px4::params::MC_ACRO_Y_MAX>) _acro_yaw_max,
		(ParamFloat<px4::params::MC_ACRO_EXPO>) _acro_expo,				/**< function parameter for expo stick curve shape */
		(ParamFloat<px4::params::MC_ACRO_SUPEXPO>) _acro_superexpo,			/**< function parameter for superexpo stick curve shape */

		(ParamFloat<px4::params::MC_RATT_TH>) _rattitude_thres,

		(ParamBool<px4::params::MC_BAT_SCALE_EN>) _bat_scale_en,

		(ParamInt<px4::params::SENS_BOARD_ROT>) _board_rotation_param,

		(ParamFloat<px4::params::SENS_BOARD_X_OFF>) _board_offset_x,
		(ParamFloat<px4::params::SENS_BOARD_Y_OFF>) _board_offset_y,
		(ParamFloat<px4::params::SENS_BOARD_Z_OFF>) _board_offset_z,

		(ParamFloat<px4::params::VT_WV_YAWR_SCL>) _vtol_wv_yaw_rate_scale		/**< Scale value [0, 1] for yaw rate setpoint  */
	)

	matrix::Vector3f _attitude_p;				/**< P gain for attitude control */
	math::Vector<3> _rate_p;				/**< P gain for angular rate error */
	math::Vector<3> _rate_i;				/**< I gain for angular rate error */
	math::Vector<3> _rate_int_lim;				/**< integrator state limit for rate loop */
	math::Vector<3> _rate_d;				/**< D gain for angular rate error */
	math::Vector<3>	_rate_ff;				/**< Feedforward gain for desired rates */

	math::Vector<3> _mc_rate_max;				/**< attitude rate limits in stabilized modes */
	math::Vector<3> _auto_rate_max;				/**< attitude rate limits in auto modes */
	matrix::Vector3f _acro_rate_max;			/**< max attitude rates in acro mode */

};