/**
 ******************************************************************************
 * @addtogroup OpenPilotModules OpenPilot Modules
 * @{
 * @addtogroup Sensors
 * @brief Acquires sensor data 
 * Specifically updates the the @ref Gyros, @ref Accels, and @ref Magnetometer objects
 * @{
 *
 * @file       sensors.c
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 * @brief      Module to handle all comms to the AHRS on a periodic basis.
 *
 * @see        The GNU Public License (GPL) Version 3
 *
 ******************************************************************************/
/*
 * This program 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 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/**
 * Input objects: None, takes sensor data via pios
 * Output objects: @ref Gyros @ref Accels @ref Magnetometer
 *
 * The module executes in its own thread.
 *
 * UAVObjects are automatically generated by the UAVObjectGenerator from
 * the object definition XML file.
 *
 * Modules have no API, all communication to other modules is done through UAVObjects.
 * However modules may use the API exposed by shared libraries.
 * See the OpenPilot wiki for more details.
 * http://www.openpilot.org/OpenPilot_Application_Architecture
 *
 */

#include "pios.h"
#include "attitude.h"

#include "accels.h"
#include "actuatordesired.h"
#include "attitudeactual.h"
#include "attitudesettings.h"
#include "baroaltitude.h"
#include "gyros.h"
#include "gyrosbias.h"
#include "flightstatus.h"
#include "gpsposition.h"
#include "homelocation.h"
#include "magnetometer.h"
#include "ratedesired.h"
#include "revocalibration.h"

#include "CoordinateConversions.h"

// Private constants
#define STACK_SIZE_BYTES 1540
#define TASK_PRIORITY (tskIDLE_PRIORITY+3)
#define SENSOR_PERIOD 2

#define F_PI 3.14159265358979323846f
#define PI_MOD(x) (fmod(x + F_PI, F_PI * 2) - F_PI)
// Private types

// Private variables
static xTaskHandle sensorsTaskHandle;

// Private functions
static void SensorsTask(void *parameters);
static void simulateConstant();
static void simulateModelAgnostic();
static void simulateModelQuadcopter();

static float rand_gauss();

enum sensor_sim_type {CONSTANT, MODEL_AGNOSTIC, MODEL_QUADCOPTER} sensor_sim_type;

/**
 * Initialise the module.  Called before the start function
 * \returns 0 on success or -1 if initialisation failed
 */
int32_t SensorsInitialize(void)
{
	AccelsInitialize();
	BaroAltitudeInitialize();
	GyrosInitialize();
	GyrosBiasInitialize();
	MagnetometerInitialize();
	RevoCalibrationInitialize();

	return 0;
}

/**
 * Start the task.  Expects all objects to be initialized by this point.
 * \returns 0 on success or -1 if initialisation failed
 */
int32_t SensorsStart(void)
{
	// Start main task
	xTaskCreate(SensorsTask, (signed char *)"Sensors", STACK_SIZE_BYTES/4, NULL, TASK_PRIORITY, &sensorsTaskHandle);
	TaskMonitorAdd(TASKINFO_RUNNING_SENSORS, sensorsTaskHandle);
	PIOS_WDG_RegisterFlag(PIOS_WDG_SENSORS);

	return 0;
}

MODULE_INITCALL(SensorsInitialize, SensorsStart)

/**
 * Simulated sensor task.  Run a model of the airframe and produce sensor values
 */
static void SensorsTask(void *parameters)
{
	portTickType lastSysTime;

	AlarmsClear(SYSTEMALARMS_ALARM_SENSORS);
	
	HomeLocationData homeLocation;
	HomeLocationGet(&homeLocation);
	homeLocation.Latitude = 0;
	homeLocation.Longitude = 0;
	homeLocation.Altitude = 0;
	homeLocation.Be[0] = 26000;
	homeLocation.Be[1] = 400;
	homeLocation.Be[2] = 40000;
	homeLocation.Set = HOMELOCATION_SET_TRUE;
	HomeLocationSet(&homeLocation);

	sensor_sim_type = MODEL_QUADCOPTER;

	// Main task loop
	lastSysTime = xTaskGetTickCount();
	uint32_t last_time = PIOS_DELAY_GetRaw();
	while (1) {
		PIOS_WDG_UpdateFlag(PIOS_WDG_SENSORS);

		float dT = PIOS_DELAY_DiffuS(last_time) / 1.0e6;
		if(dT > 0.010) {
			fprintf(stderr,"Long sensor update\n");
		}
		last_time = PIOS_DELAY_GetRaw();

		switch(sensor_sim_type) {
			case CONSTANT:
				simulateConstant();
				break;
			case MODEL_AGNOSTIC:
				simulateModelAgnostic();
				break;
			case MODEL_QUADCOPTER:
				simulateModelQuadcopter();
				break;
		}

		vTaskDelay(2 / portTICK_RATE_MS);

	}
}

static void simulateConstant()
{
	AccelsData accelsData; // Skip get as we set all the fields
	accelsData.x = 0;
	accelsData.y = 0;
	accelsData.z = -9.81;
	accelsData.temperature = 0;
	AccelsSet(&accelsData);

	GyrosData gyrosData; // Skip get as we set all the fields
	gyrosData.x = 0;
	gyrosData.y = 0;
	gyrosData.z = 0;

	// Apply bias correction to the gyros
	GyrosBiasData gyrosBias;
	GyrosBiasGet(&gyrosBias);
	gyrosData.x += gyrosBias.x;
	gyrosData.y += gyrosBias.y;
	gyrosData.z += gyrosBias.z;

	GyrosSet(&gyrosData);

	BaroAltitudeData baroAltitude;
	BaroAltitudeGet(&baroAltitude);
	baroAltitude.Altitude = 1;
	BaroAltitudeSet(&baroAltitude);

	GPSPositionData gpsPosition;
	GPSPositionGet(&gpsPosition);
	gpsPosition.Latitude = 0;
	gpsPosition.Longitude = 0;
	gpsPosition.Altitude = 0;
	GPSPositionSet(&gpsPosition);

	// Because most crafts wont get enough information from gravity to zero yaw gyro, we try
	// and make it average zero (weakly)
	MagnetometerData mag;
	mag.x = 400;
	mag.y = 0;
	mag.z = 800;
	MagnetometerSet(&mag);
}

static void simulateModelAgnostic()
{
	float Rbe[3][3];
	float q[4];

	// Simulate accels based on current attitude
	AttitudeActualData attitudeActual;
	AttitudeActualGet(&attitudeActual);
	q[0] = attitudeActual.q1;
	q[1] = attitudeActual.q2;
	q[2] = attitudeActual.q3;
	q[3] = attitudeActual.q4;
	Quaternion2R(q,Rbe);

	AccelsData accelsData; // Skip get as we set all the fields
	accelsData.x = -9.81 * Rbe[0][2];
	accelsData.y = -9.81 * Rbe[1][2];
	accelsData.z = -9.81 * Rbe[2][2];
	accelsData.temperature = 30;
	AccelsSet(&accelsData);

	RateDesiredData rateDesired;
	RateDesiredGet(&rateDesired);

	GyrosData gyrosData; // Skip get as we set all the fields
	gyrosData.x = rateDesired.Roll + rand_gauss();
	gyrosData.y = rateDesired.Pitch + rand_gauss();
	gyrosData.z = rateDesired.Yaw + rand_gauss();

	// Apply bias correction to the gyros
	GyrosBiasData gyrosBias;
	GyrosBiasGet(&gyrosBias);
	gyrosData.x += gyrosBias.x;
	gyrosData.y += gyrosBias.y;
	gyrosData.z += gyrosBias.z;

	GyrosSet(&gyrosData);

	BaroAltitudeData baroAltitude;
	BaroAltitudeGet(&baroAltitude);
	baroAltitude.Altitude = 1;
	BaroAltitudeSet(&baroAltitude);

	GPSPositionData gpsPosition;
	GPSPositionGet(&gpsPosition);
	gpsPosition.Latitude = 0;
	gpsPosition.Longitude = 0;
	gpsPosition.Altitude = 0;
	GPSPositionSet(&gpsPosition);

	// Because most crafts wont get enough information from gravity to zero yaw gyro, we try
	// and make it average zero (weakly)
	MagnetometerData mag;
	mag.x = 400;
	mag.y = 0;
	mag.z = 800;
	MagnetometerSet(&mag);
}

static void simulateModelQuadcopter()
{
	static float pos[3] = {0,0,0};
	static float vel[3] = {0,0,0};
	static float ned_accel[3] = {0,0,0};
	static float q[4] = {1,0,0,0};
	static float rpy[3] = {0,0,0}; // Low pass filtered actuator
	float T[3];
	float Rbe[3][3];
	
	const float ACTUATOR_ALPHA = 0.99;
	const float MAX_THRUST = 9.81 * 2;

	static uint32_t last_time;
	
	float dT = (PIOS_DELAY_DiffuS(last_time) / 1e6);
	if(dT < 1e-3)
		dT = 2e-3;
	last_time = PIOS_DELAY_GetRaw();
	
	ActuatorDesiredData actuatorDesired;
	ActuatorDesiredGet(&actuatorDesired);
	rpy[0] = actuatorDesired.Roll * (1 - ACTUATOR_ALPHA) + rpy[0] * ACTUATOR_ALPHA;
	rpy[1] = actuatorDesired.Pitch * (1 - ACTUATOR_ALPHA) + rpy[1] * ACTUATOR_ALPHA;
	rpy[2] = actuatorDesired.Yaw * (1 - ACTUATOR_ALPHA) + rpy[2] * ACTUATOR_ALPHA;
	
	GyrosData gyrosData; // Skip get as we set all the fields
	gyrosData.x = rpy[0] + rand_gauss();
	gyrosData.y = rpy[1] + rand_gauss();
	gyrosData.z = rpy[2] + rand_gauss();
	
	// Apply bias correction to the gyros
	GyrosBiasData gyrosBias;
	GyrosBiasGet(&gyrosBias);
	gyrosData.x += gyrosBias.x;
	gyrosData.y += gyrosBias.y;
	gyrosData.z += gyrosBias.z;
	GyrosSet(&gyrosData);
	
	// Predict the attitude forward in time
	float qdot[4];
	qdot[0] = (-q[1] * rpy[0] - q[2] * rpy[1] - q[3] * rpy[2]) * dT * M_PI / 180 / 2;
	qdot[1] = (q[0] * rpy[0] - q[3] * rpy[1] + q[2] * rpy[2]) * dT * M_PI / 180 / 2;
	qdot[2] = (q[3] * rpy[0] + q[0] * rpy[1] - q[1] * rpy[2]) * dT * M_PI / 180 / 2;
	qdot[3] = (-q[2] * rpy[0] + q[1] * rpy[1] + q[0] * rpy[2]) * dT * M_PI / 180 / 2;
	
	// Take a time step
	q[0] = q[0] + qdot[0];
	q[1] = q[1] + qdot[1];
	q[2] = q[2] + qdot[2];
	q[3] = q[3] + qdot[3];
	
	float thrust = actuatorDesired.Throttle * MAX_THRUST;
	if (thrust != thrust)
		thrust = 0;

	Quaternion2R(q,Rbe);
	ned_accel[0] = thrust * Rbe[0][2];
	ned_accel[1] = thrust * Rbe[1][2];
	ned_accel[2] = thrust * Rbe[2][2];
	ned_accel[2] -= 9.81;

	// Predict the velocity forward in time
	vel[0] = vel[0] + ned_accel[0] * dT;
	vel[1] = vel[1] + ned_accel[1] * dT;
	vel[2] = vel[2] + ned_accel[2] * dT;

	// Predict the position forward in time
	pos[0] = pos[0] + vel[0] * dT;
	pos[1] = pos[1] + vel[1] * dT;
	pos[2] = pos[2] + vel[2] * dT;

	// Transform the accels back in to body frame
	AccelsData accelsData; // Skip get as we set all the fields
	accelsData.x = ned_accel[0] * Rbe[0][0] + ned_accel[1] * Rbe[0][1] + ned_accel[2] * Rbe[0][2];
	accelsData.y = ned_accel[0] * Rbe[1][0] + ned_accel[1] * Rbe[1][1] + ned_accel[2] * Rbe[1][2];
	accelsData.z = ned_accel[0] * Rbe[2][0] + ned_accel[1] * Rbe[2][1] + ned_accel[2] * Rbe[2][2];
	accelsData.temperature = 30;
	AccelsSet(&accelsData);
	
	BaroAltitudeData baroAltitude;
	BaroAltitudeGet(&baroAltitude);
	baroAltitude.Altitude = pos[2];
	BaroAltitudeSet(&baroAltitude);
	
	HomeLocationData homeLocation;
	HomeLocationGet(&homeLocation);
	T[0] = homeLocation.Altitude+6.378137E6f;
	T[1] = cosf(homeLocation.Latitude / 10e6)*(homeLocation.Altitude+6.378137E6f);
	T[2] = -1.0f;

	GPSPositionData gpsPosition;
	GPSPositionGet(&gpsPosition);
	gpsPosition.Latitude = homeLocation.Latitude + pos[0] / T[0];
	gpsPosition.Longitude = homeLocation.Longitude + pos[1] / T[1];
	gpsPosition.Altitude = homeLocation.Altitude + pos[2] / T[2];
	GPSPositionSet(&gpsPosition);
	
	// Because most crafts wont get enough information from gravity to zero yaw gyro, we try
	// and make it average zero (weakly)
	MagnetometerData mag;
	mag.x = 400;
	mag.y = 0;
	mag.z = 800;
	MagnetometerSet(&mag);
}


static float rand_gauss (void) {
	float v1,v2,s;
	
	do {
		v1 = 2.0 * ((float) rand()/RAND_MAX) - 1;
		v2 = 2.0 * ((float) rand()/RAND_MAX) - 1;
		
		s = v1*v1 + v2*v2;
	} while ( s >= 1.0 );
	
	if (s == 0.0)
		return 0.0;
	else
		return (v1*sqrt(-2.0 * log(s) / s));
}

/**
  * @}
  * @}
  */