/**
 ******************************************************************************
 * @addtogroup OpenPilotModules OpenPilot Modules
 * @{
 * @addtogroup State Estimation
 * @brief Acquires sensor data and computes state estimate
 * @{
 *
 * @file       stateestimation.c
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2013.
 * @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
 */

#include "inc/stateestimation.h"

#include <gyrosensor.h>
#include <accelsensor.h>
#include <magsensor.h>
#include <barosensor.h>
#include <airspeedsensor.h>
#include <gpspositionsensor.h>
#include <gpsvelocitysensor.h>

#include <gyrostate.h>
#include <accelstate.h>
#include <magstate.h>
#include <airspeedstate.h>
#include <attitudestate.h>
#include <positionstate.h>
#include <velocitystate.h>

#include "revosettings.h"
#include "flightstatus.h"

#include "CoordinateConversions.h"

// Private constants
#define STACK_SIZE_BYTES  256
#define CALLBACK_PRIORITY CALLBACK_PRIORITY_REGULAR
#define TASK_PRIORITY     CALLBACK_TASK_FLIGHTCONTROL
#define TIMEOUT_MS        10

// local macros, ONLY to be used in the middle of StateEstimationCb in section RUNSTATE_LOAD after the update of states updated!
#define FETCH_SENSOR_FROM_UAVOBJECT_CHECK_AND_LOAD_TO_STATE_3_DIMENSIONS(sensorname, shortname, a1, a2, a3) \
    if (IS_SET(states.updated, SENSORUPDATES_##shortname)) { \
        sensorname##Data s; \
        sensorname##Get(&s); \
        if (IS_REAL(s.a1) && IS_REAL(s.a2) && IS_REAL(s.a3)) { \
            states.shortname[0] = s.a1; \
            states.shortname[1] = s.a2; \
            states.shortname[2] = s.a3; \
        } \
        else { \
            UNSET_MASK(states.updated, SENSORUPDATES_##shortname); \
        } \
    }
#define FETCH_SENSOR_FROM_UAVOBJECT_CHECK_AND_LOAD_TO_STATE_1_DIMENSION_WITH_CUSTOM_EXTRA_CHECK(sensorname, shortname, a1, EXTRACHECK) \
    if (IS_SET(states.updated, SENSORUPDATES_##shortname)) { \
        sensorname##Data s; \
        sensorname##Get(&s); \
        if (IS_REAL(s.a1) && EXTRACHECK) { \
            states.shortname[0] = s.a1; \
        } \
        else { \
            UNSET_MASK(states.updated, SENSORUPDATES_##shortname); \
        } \
    }

// local macros, ONLY to be used in the middle of StateEstimationCb in section RUNSTATE_SAVE before the check of alarms!
#define EXPORT_STATE_TO_UAVOBJECT_IF_UPDATED_3_DIMENSIONS(statename, shortname, a1, a2, a3) \
    if (IS_SET(states.updated, SENSORUPDATES_##shortname)) { \
        statename##Data s; \
        statename##Get(&s); \
        s.a1 = states.shortname[0]; \
        s.a2 = states.shortname[1]; \
        s.a3 = states.shortname[2]; \
        statename##Set(&s); \
    }
#define EXPORT_STATE_TO_UAVOBJECT_IF_UPDATED_2_DIMENSIONS(statename, shortname, a1, a2) \
    if (IS_SET(states.updated, SENSORUPDATES_##shortname)) { \
        statename##Data s; \
        statename##Get(&s); \
        s.a1 = states.shortname[0]; \
        s.a2 = states.shortname[1]; \
        statename##Set(&s); \
    }

// Private types

struct filterPipelineStruct;

typedef const struct filterPipelineStruct {
    const stateFilter *filter;
    const struct filterPipelineStruct *next;
} filterPipeline;

// Private variables
static DelayedCallbackInfo *stateEstimationCallback;

static volatile RevoSettingsData revoSettings;
static volatile sensorUpdates updatedSensors;
static int32_t fusionAlgorithm     = -1;
static filterPipeline *filterChain = NULL;

// different filters available to state estimation
static stateFilter magFilter;
static stateFilter baroFilter;
static stateFilter altitudeFilter;
static stateFilter airFilter;
static stateFilter stationaryFilter;
static stateFilter llaFilter;
static stateFilter cfFilter;
static stateFilter cfmFilter;
static stateFilter ekf13iFilter;
static stateFilter ekf13Filter;

// preconfigured filter chains selectable via revoSettings.FusionAlgorithm
static filterPipeline *cfQueue = &(filterPipeline) {
    .filter = &magFilter,
    .next   = &(filterPipeline) {
        .filter = &airFilter,
        .next   = &(filterPipeline) {
            .filter = &llaFilter,
            .next   = &(filterPipeline) {
                .filter = &baroFilter,
                .next   = &(filterPipeline) {
                    .filter = &altitudeFilter,
                    .next   = &(filterPipeline) {
                        .filter = &cfFilter,
                        .next   = NULL,
                    }
                }
            }
        }
    }
};
static const filterPipeline *cfmQueue = &(filterPipeline) {
    .filter = &magFilter,
    .next   = &(filterPipeline) {
        .filter = &airFilter,
        .next   = &(filterPipeline) {
            .filter = &llaFilter,
            .next   = &(filterPipeline) {
                .filter = &baroFilter,
                .next   = &(filterPipeline) {
                    .filter = &altitudeFilter,
                    .next   = &(filterPipeline) {
                        .filter = &cfmFilter,
                        .next   = NULL,
                    }
                }
            }
        }
    }
};
static const filterPipeline *ekf13iQueue = &(filterPipeline) {
    .filter = &magFilter,
    .next   = &(filterPipeline) {
        .filter = &airFilter,
        .next   = &(filterPipeline) {
            .filter = &llaFilter,
            .next   = &(filterPipeline) {
                .filter = &baroFilter,
                .next   = &(filterPipeline) {
                    .filter = &stationaryFilter,
                    .next   = &(filterPipeline) {
                        .filter = &ekf13iFilter,
                        .next   = NULL,
                    }
                }
            }
        }
    }
};
static const filterPipeline *ekf13Queue = &(filterPipeline) {
    .filter = &magFilter,
    .next   = &(filterPipeline) {
        .filter = &airFilter,
        .next   = &(filterPipeline) {
            .filter = &llaFilter,
            .next   = &(filterPipeline) {
                .filter = &baroFilter,
                .next   = &(filterPipeline) {
                    .filter = &ekf13Filter,
                    .next   = NULL,
                }
            }
        }
    }
};

// Private functions

static void settingsUpdatedCb(UAVObjEvent *objEv);
static void sensorUpdatedCb(UAVObjEvent *objEv);
static void StateEstimationCb(void);

static inline int32_t maxint32_t(int32_t a, int32_t b)
{
    if (a > b) {
        return a;
    }
    return b;
}

/**
 * Initialise the module.  Called before the start function
 * \returns 0 on success or -1 if initialisation failed
 */
int32_t StateEstimationInitialize(void)
{
    RevoSettingsInitialize();

    GyroSensorInitialize();
    MagSensorInitialize();
    BaroSensorInitialize();
    AirspeedSensorInitialize();
    GPSVelocitySensorInitialize();
    GPSPositionSensorInitialize();

    GyroStateInitialize();
    AccelStateInitialize();
    MagStateInitialize();
    AirspeedStateInitialize();
    PositionStateInitialize();
    VelocityStateInitialize();

    RevoSettingsConnectCallback(&settingsUpdatedCb);

    GyroSensorConnectCallback(&sensorUpdatedCb);
    AccelSensorConnectCallback(&sensorUpdatedCb);
    MagSensorConnectCallback(&sensorUpdatedCb);
    BaroSensorConnectCallback(&sensorUpdatedCb);
    AirspeedSensorConnectCallback(&sensorUpdatedCb);
    GPSVelocitySensorConnectCallback(&sensorUpdatedCb);
    GPSPositionSensorConnectCallback(&sensorUpdatedCb);

    uint32_t stack_required = STACK_SIZE_BYTES;
    // Initialize Filters
    stack_required = maxint32_t(stack_required, filterMagInitialize(&magFilter));
    stack_required = maxint32_t(stack_required, filterBaroInitialize(&baroFilter));
    stack_required = maxint32_t(stack_required, filterAltitudeInitialize(&altitudeFilter));
    stack_required = maxint32_t(stack_required, filterAirInitialize(&airFilter));
    stack_required = maxint32_t(stack_required, filterStationaryInitialize(&stationaryFilter));
    stack_required = maxint32_t(stack_required, filterLLAInitialize(&llaFilter));
    stack_required = maxint32_t(stack_required, filterCFInitialize(&cfFilter));
    stack_required = maxint32_t(stack_required, filterCFMInitialize(&cfmFilter));
    stack_required = maxint32_t(stack_required, filterEKF13iInitialize(&ekf13iFilter));
    stack_required = maxint32_t(stack_required, filterEKF13Initialize(&ekf13Filter));

    stateEstimationCallback = DelayedCallbackCreate(&StateEstimationCb, CALLBACK_PRIORITY, TASK_PRIORITY, stack_required);

    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 StateEstimationStart(void)
{
    RevoSettingsConnectCallback(&settingsUpdatedCb);

    // Force settings update to make sure rotation loaded
    settingsUpdatedCb(NULL);

    return 0;
}

MODULE_INITCALL(StateEstimationInitialize, StateEstimationStart);


/**
 * Module callback
 */
static void StateEstimationCb(void)
{
    static enum { RUNSTATE_LOAD = 0, RUNSTATE_FILTER = 1, RUNSTATE_SAVE = 2 } runState = RUNSTATE_LOAD;
    static int8_t alarm     = 0;
    static int8_t lastAlarm = -1;
    static uint16_t alarmcounter = 0;
    static filterPipeline *current;
    static stateEstimation states;
    static uint32_t last_time;
    static uint16_t bootDelay = 64;

    // after system startup, first few sensor readings might be messed up, delay until everything has settled
    if (bootDelay) {
        bootDelay--;
        DelayedCallbackSchedule(stateEstimationCallback, TIMEOUT_MS, CALLBACK_UPDATEMODE_SOONER);
        return;
    }

    switch (runState) {
    case RUNSTATE_LOAD:

        alarm = 0;

        // set alarm to warning if called through timeout
        if (updatedSensors == 0) {
            if (PIOS_DELAY_DiffuS(last_time) > 1000 * TIMEOUT_MS) {
                alarm = 1;
            }
        } else {
            last_time = PIOS_DELAY_GetRaw();
        }

        // check if a new filter chain should be initialized
        if (fusionAlgorithm != revoSettings.FusionAlgorithm) {
            FlightStatusData fs;
            FlightStatusGet(&fs);
            if (fs.Armed == FLIGHTSTATUS_ARMED_DISARMED || fusionAlgorithm == -1) {
                const filterPipeline *newFilterChain;
                switch (revoSettings.FusionAlgorithm) {
                case REVOSETTINGS_FUSIONALGORITHM_COMPLEMENTARY:
                    newFilterChain = cfQueue;
                    break;
                case REVOSETTINGS_FUSIONALGORITHM_COMPLEMENTARYMAG:
                    newFilterChain = cfmQueue;
                    break;
                case REVOSETTINGS_FUSIONALGORITHM_INS13INDOOR:
                    newFilterChain = ekf13iQueue;
                    break;
                case REVOSETTINGS_FUSIONALGORITHM_INS13OUTDOOR:
                    newFilterChain = ekf13Queue;
                    break;
                default:
                    newFilterChain = NULL;
                }
                // initialize filters in chain
                current = (filterPipeline *)newFilterChain;
                bool error = 0;
                while (current != NULL) {
                    int32_t result = current->filter->init((stateFilter *)current->filter);
                    if (result != 0) {
                        error = 1;
                        break;
                    }
                    current = current->next;
                }
                if (error) {
                    AlarmsSet(SYSTEMALARMS_ALARM_ATTITUDE, SYSTEMALARMS_ALARM_ERROR);
                    return;
                } else {
                    // set new fusion algortithm
                    filterChain     = (filterPipeline *)newFilterChain;
                    fusionAlgorithm = revoSettings.FusionAlgorithm;
                }
            }
        }

        // read updated sensor UAVObjects and set initial state
        states.updated = updatedSensors;
        updatedSensors = 0;

        // fetch sensors, check values, and load into state struct
        FETCH_SENSOR_FROM_UAVOBJECT_CHECK_AND_LOAD_TO_STATE_3_DIMENSIONS(GyroSensor, gyro, x, y, z);
        FETCH_SENSOR_FROM_UAVOBJECT_CHECK_AND_LOAD_TO_STATE_3_DIMENSIONS(AccelSensor, accel, x, y, z);
        FETCH_SENSOR_FROM_UAVOBJECT_CHECK_AND_LOAD_TO_STATE_3_DIMENSIONS(MagSensor, mag, x, y, z);
        FETCH_SENSOR_FROM_UAVOBJECT_CHECK_AND_LOAD_TO_STATE_3_DIMENSIONS(GPSVelocitySensor, vel, North, East, Down);
        FETCH_SENSOR_FROM_UAVOBJECT_CHECK_AND_LOAD_TO_STATE_1_DIMENSION_WITH_CUSTOM_EXTRA_CHECK(BaroSensor, baro, Altitude, true);
        FETCH_SENSOR_FROM_UAVOBJECT_CHECK_AND_LOAD_TO_STATE_1_DIMENSION_WITH_CUSTOM_EXTRA_CHECK(AirspeedSensor, airspeed, CalibratedAirspeed, s.SensorConnected == AIRSPEEDSENSOR_SENSORCONNECTED_TRUE);
        states.airspeed[1] = 0.0f; // sensor does not provide true airspeed, needs to be calculated by filter, set to zero for now
        // GPS position data (LLA) is not fetched here since it does not contain floats. The filter must do all checks itself

        // at this point sensor state is stored in "states" with some rudimentary filtering applied

        // apply all filters in the current filter chain
        current  = (filterPipeline *)filterChain;

        // we are not done, re-dispatch self execution
        runState = RUNSTATE_FILTER;
        DelayedCallbackDispatch(stateEstimationCallback);
        break;

    case RUNSTATE_FILTER:

        if (current != NULL) {
            int32_t result = current->filter->filter((stateFilter *)current->filter, &states);
            if (result > alarm) {
                alarm = result;
            }
            current = current->next;
        }

        // we are not done, re-dispatch self execution
        if (!current) {
            runState = RUNSTATE_SAVE;
        }
        DelayedCallbackDispatch(stateEstimationCallback);
        break;

    case RUNSTATE_SAVE:

        // the final output of filters is saved in state variables
        EXPORT_STATE_TO_UAVOBJECT_IF_UPDATED_3_DIMENSIONS(GyroState, gyro, x, y, z);
        EXPORT_STATE_TO_UAVOBJECT_IF_UPDATED_3_DIMENSIONS(AccelState, accel, x, y, z);
        EXPORT_STATE_TO_UAVOBJECT_IF_UPDATED_3_DIMENSIONS(MagState, mag, x, y, z);
        EXPORT_STATE_TO_UAVOBJECT_IF_UPDATED_3_DIMENSIONS(PositionState, pos, North, East, Down);
        EXPORT_STATE_TO_UAVOBJECT_IF_UPDATED_3_DIMENSIONS(VelocityState, vel, North, East, Down);
        EXPORT_STATE_TO_UAVOBJECT_IF_UPDATED_2_DIMENSIONS(AirspeedState, airspeed, CalibratedAirspeed, TrueAirspeed);
        // attitude nees manual conversion from quaternion to euler
        if (IS_SET(states.updated, SENSORUPDATES_attitude)) { \
            AttitudeStateData s;
            AttitudeStateGet(&s);
            s.q1 = states.attitude[0];
            s.q2 = states.attitude[1];
            s.q3 = states.attitude[2];
            s.q4 = states.attitude[3];
            Quaternion2RPY(&s.q1, &s.Roll);
            AttitudeStateSet(&s);
        }

        // throttle alarms, raise alarm flags immediately
        // but require system to run for a while before decreasing
        // to prevent alarm flapping
        if (alarm >= lastAlarm) {
            lastAlarm    = alarm;
            alarmcounter = 0;
        } else {
            if (alarmcounter < 100) {
                alarmcounter++;
            } else {
                lastAlarm    = alarm;
                alarmcounter = 0;
            }
        }

        // clear alarms if everything is alright, then schedule callback execution after timeout
        if (lastAlarm == 1) {
            AlarmsSet(SYSTEMALARMS_ALARM_ATTITUDE, SYSTEMALARMS_ALARM_WARNING);
        } else if (lastAlarm == 2) {
            AlarmsSet(SYSTEMALARMS_ALARM_ATTITUDE, SYSTEMALARMS_ALARM_ERROR);
        } else if (lastAlarm >= 3) {
            AlarmsSet(SYSTEMALARMS_ALARM_ATTITUDE, SYSTEMALARMS_ALARM_CRITICAL);
        } else {
            AlarmsClear(SYSTEMALARMS_ALARM_ATTITUDE);
        }

        // we are done, re-schedule next self execution
        runState = RUNSTATE_LOAD;
        if (updatedSensors) {
            DelayedCallbackDispatch(stateEstimationCallback);
        } else {
            DelayedCallbackSchedule(stateEstimationCallback, TIMEOUT_MS, CALLBACK_UPDATEMODE_SOONER);
        }
        break;
    }
}


/**
 * Callback for eventdispatcher when RevoSettings has been updated
 */
static void settingsUpdatedCb(__attribute__((unused)) UAVObjEvent *ev)
{
    RevoSettingsGet((RevoSettingsData *)&revoSettings);
}

/**
 * Callback for eventdispatcher when any sensor UAVObject has been updated
 * updates the list of "recently updated UAVObjects" and dispatches the state estimator callback
 */
static void sensorUpdatedCb(UAVObjEvent *ev)
{
    if (!ev) {
        return;
    }

    if (ev->obj == GyroSensorHandle()) {
        updatedSensors |= SENSORUPDATES_gyro;
    }

    if (ev->obj == AccelSensorHandle()) {
        updatedSensors |= SENSORUPDATES_accel;
    }

    if (ev->obj == MagSensorHandle()) {
        updatedSensors |= SENSORUPDATES_mag;
    }

    if (ev->obj == GPSPositionSensorHandle()) {
        updatedSensors |= SENSORUPDATES_lla;
    }

    if (ev->obj == GPSVelocitySensorHandle()) {
        updatedSensors |= SENSORUPDATES_vel;
    }

    if (ev->obj == BaroSensorHandle()) {
        updatedSensors |= SENSORUPDATES_baro;
    }

    if (ev->obj == AirspeedSensorHandle()) {
        updatedSensors |= SENSORUPDATES_airspeed;
    }

    DelayedCallbackDispatch(stateEstimationCallback);
}


/**
 * @}
 * @}
 */