// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: t -*-

#include "AC_AttitudeControl_Multi.h"
#include <AP_HAL/AP_HAL.h>
#include <AP_Math/AP_Math.h>

// table of user settable parameters
const AP_Param::GroupInfo AC_AttitudeControl_Multi::var_info[] = {
    // parameters from parent vehicle
    AP_NESTEDGROUPINFO(AC_AttitudeControl, 0),

    // @Param: RAT_RLL_P
    // @DisplayName: Roll axis rate controller P gain
    // @Description: Roll axis rate controller P gain.  Converts the difference between desired roll rate and actual roll rate into a motor speed output
    // @Range: 0.08 0.30
    // @Increment: 0.005
    // @User: Standard

    // @Param: RAT_RLL_I
    // @DisplayName: Roll axis rate controller I gain
    // @Description: Roll axis rate controller I gain.  Corrects long-term difference in desired roll rate vs actual roll rate
    // @Range: 0.01 0.5
    // @Increment: 0.01
    // @User: Standard

    // @Param: RAT_RLL_IMAX
    // @DisplayName: Roll axis rate controller I gain maximum
    // @Description: Roll axis rate controller I gain maximum.  Constrains the maximum motor output that the I gain will output
    // @Range: 0 1
    // @Increment: 0.01
    // @Units: Percent
    // @User: Standard

    // @Param: RAT_RLL_D
    // @DisplayName: Roll axis rate controller D gain
    // @Description: Roll axis rate controller D gain.  Compensates for short-term change in desired roll rate vs actual roll rate
    // @Range: 0.0 0.02
    // @Increment: 0.001
    // @User: Standard

    // @Param: RAT_RLL_FILT
    // @DisplayName: Roll axis rate conroller input frequency in Hz
    // @Description: Roll axis rate conroller input frequency in Hz
    // @Range: 1 100
    // @Increment: 1
    // @Units: Hz
    AP_SUBGROUPINFO(_pid_rate_roll, "RAT_RLL_", 1, AC_AttitudeControl_Multi, AC_PID),

    // @Param: RAT_PIT_P
    // @DisplayName: Pitch axis rate controller P gain
    // @Description: Pitch axis rate controller P gain.  Converts the difference between desired pitch rate and actual pitch rate into a motor speed output
    // @Range: 0.08 0.30
    // @Increment: 0.005
    // @User: Standard

    // @Param: RAT_PIT_I
    // @DisplayName: Pitch axis rate controller I gain
    // @Description: Pitch axis rate controller I gain.  Corrects long-term difference in desired pitch rate vs actual pitch rate
    // @Range: 0.01 0.5
    // @Increment: 0.01
    // @User: Standard

    // @Param: RAT_PIT_IMAX
    // @DisplayName: Pitch axis rate controller I gain maximum
    // @Description: Pitch axis rate controller I gain maximum.  Constrains the maximum motor output that the I gain will output
    // @Range: 0 1
    // @Increment: 0.01
    // @Units: Percent
    // @User: Standard

    // @Param: RAT_PIT_D
    // @DisplayName: Pitch axis rate controller D gain
    // @Description: Pitch axis rate controller D gain.  Compensates for short-term change in desired pitch rate vs actual pitch rate
    // @Range: 0.0 0.02
    // @Increment: 0.001
    // @User: Standard

    // @Param: RAT_PIT_FILT
    // @DisplayName: Pitch axis rate conroller input frequency in Hz
    // @Description: Pitch axis rate conroller input frequency in Hz
    // @Range: 1 100
    // @Increment: 1
    // @Units: Hz
    AP_SUBGROUPINFO(_pid_rate_pitch, "RAT_PIT_", 2, AC_AttitudeControl_Multi, AC_PID),

    // @Param: RAT_YAW_P
    // @DisplayName: Yaw axis rate controller P gain
    // @Description: Yaw axis rate controller P gain.  Converts the difference between desired yaw rate and actual yaw rate into a motor speed output
    // @Range: 0.10 0.50
    // @Increment: 0.005
    // @User: Standard

    // @Param: RAT_YAW_I
    // @DisplayName: Yaw axis rate controller I gain
    // @Description: Yaw axis rate controller I gain.  Corrects long-term difference in desired yaw rate vs actual yaw rate
    // @Range: 0.010 0.05
    // @Increment: 0.01
    // @User: Standard

    // @Param: RAT_YAW_IMAX
    // @DisplayName: Yaw axis rate controller I gain maximum
    // @Description: Yaw axis rate controller I gain maximum.  Constrains the maximum motor output that the I gain will output
    // @Range: 0 1
    // @Increment: 0.01
    // @Units: Percent
    // @User: Standard

    // @Param: RAT_YAW_D
    // @DisplayName: Yaw axis rate controller D gain
    // @Description: Yaw axis rate controller D gain.  Compensates for short-term change in desired yaw rate vs actual yaw rate
    // @Range: 0.000 0.02
    // @Increment: 0.001
    // @User: Standard

    // @Param: RAT_YAW_FILT
    // @DisplayName: Yaw axis rate conroller input frequency in Hz
    // @Description: Yaw axis rate conroller input frequency in Hz
    // @Range: 1 100
    // @Increment: 1
    // @Units: Hz
    AP_SUBGROUPINFO(_pid_rate_yaw, "RAT_YAW_", 3, AC_AttitudeControl_Multi, AC_PID),

    AP_GROUPEND
};

AC_AttitudeControl_Multi::AC_AttitudeControl_Multi(AP_AHRS &ahrs, const AP_Vehicle::MultiCopter &aparm, AP_MotorsMulticopter& motors, float dt) :
    AC_AttitudeControl(ahrs, aparm, motors, dt),
    _motors_multi(motors),
    _pid_rate_roll(AC_ATC_MULTI_RATE_RP_P, AC_ATC_MULTI_RATE_RP_I, AC_ATC_MULTI_RATE_RP_D, AC_ATC_MULTI_RATE_RP_IMAX, AC_ATC_MULTI_RATE_RP_FILT_HZ, dt),
    _pid_rate_pitch(AC_ATC_MULTI_RATE_RP_P, AC_ATC_MULTI_RATE_RP_I, AC_ATC_MULTI_RATE_RP_D, AC_ATC_MULTI_RATE_RP_IMAX, AC_ATC_MULTI_RATE_RP_FILT_HZ, dt),
    _pid_rate_yaw(AC_ATC_MULTI_RATE_YAW_P, AC_ATC_MULTI_RATE_YAW_I, AC_ATC_MULTI_RATE_YAW_D, AC_ATC_MULTI_RATE_YAW_IMAX, AC_ATC_MULTI_RATE_YAW_FILT_HZ, dt)
{
    AP_Param::setup_object_defaults(this, var_info);
}

// get lean angle max for pilot input that prioritises altitude hold over lean angle
float AC_AttitudeControl_Multi::get_althold_lean_angle_max() const
{
    // calc maximum tilt angle based on throttle
    float thr_max = _motors_multi.get_throttle_thrust_max();

    // divide by zero check
    if (is_zero(thr_max)) {
        return 0.0f;
    }

    return ToDeg(acos(constrain_float(_throttle_in_filt.get()/(0.9f * thr_max), 0.0f, 1.0f))) * 100.0f;
}

// returns a throttle including compensation for roll/pitch angle
// throttle value should be 0 ~ 1
float AC_AttitudeControl_Multi::get_boosted_throttle(float throttle_in)
{
    if (!_angle_boost_enabled) {
        _angle_boost = 0;
        return throttle_in;
    }
    // inverted_factor is 1 for tilt angles below 60 degrees
    // inverted_factor reduces from 1 to 0 for tilt angles between 60 and 90 degrees

    float cos_tilt = _ahrs.cos_pitch() * _ahrs.cos_roll();
    float inverted_factor = constrain_float(2.0f*cos_tilt, 0.0f, 1.0f);
    float boost_factor = 1.0f/constrain_float(cos_tilt, 0.5f, 1.0f);

    float throttle_out = throttle_in*inverted_factor*boost_factor;
    _angle_boost = constrain_float(throttle_out - throttle_in,-1.0f,1.0f);
    return throttle_out;
}