// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
/*
   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, see <http://www.gnu.org/licenses/>.
 */

/*
 *       AP_MotorsHeli.cpp - ArduCopter motors library
 *       Code by RandyMackay. DIYDrones.com
 *
 */
#include <stdlib.h>
#include <AP_HAL/AP_HAL.h>
#include "AP_MotorsHeli.h"

extern const AP_HAL::HAL& hal;

const AP_Param::GroupInfo AP_MotorsHeli::var_info[] PROGMEM = {

    // @Param: ROL_MAX
    // @DisplayName: Swash Roll Angle Max
    // @Description: Maximum roll angle of the swash plate
    // @Range: 0 18000
    // @Units: Centi-Degrees
    // @Increment: 100
    // @User: Advanced
    AP_GROUPINFO("ROL_MAX", 1, AP_MotorsHeli, _roll_max, AP_MOTORS_HELI_SWASH_ROLL_MAX),

    // @Param: PIT_MAX
    // @DisplayName: Swash Pitch Angle Max
    // @Description: Maximum pitch angle of the swash plate
    // @Range: 0 18000
    // @Units: Centi-Degrees
    // @Increment: 100
    // @User: Advanced
    AP_GROUPINFO("PIT_MAX", 2, AP_MotorsHeli, _pitch_max, AP_MOTORS_HELI_SWASH_PITCH_MAX),

    // @Param: COL_MIN
    // @DisplayName: Collective Pitch Minimum
    // @Description: Lowest possible servo position for the swashplate
    // @Range: 1000 2000
    // @Units: PWM
    // @Increment: 1
    // @User: Standard
    AP_GROUPINFO("COL_MIN", 3, AP_MotorsHeli, _collective_min, AP_MOTORS_HELI_COLLECTIVE_MIN),

    // @Param: COL_MAX
    // @DisplayName: Collective Pitch Maximum
    // @Description: Highest possible servo position for the swashplate
    // @Range: 1000 2000
    // @Units: PWM
    // @Increment: 1
    // @User: Standard
    AP_GROUPINFO("COL_MAX", 4, AP_MotorsHeli, _collective_max, AP_MOTORS_HELI_COLLECTIVE_MAX),

    // @Param: COL_MID
    // @DisplayName: Collective Pitch Mid-Point
    // @Description: Swash servo position corresponding to zero collective pitch (or zero lift for Assymetrical blades)
    // @Range: 1000 2000
    // @Units: PWM
    // @Increment: 1
    // @User: Standard
    AP_GROUPINFO("COL_MID", 5, AP_MotorsHeli, _collective_mid, AP_MOTORS_HELI_COLLECTIVE_MID),

    // @Param: SV_MAN
    // @DisplayName: Manual Servo Mode
    // @Description: Pass radio inputs directly to servos for set-up. Do not set this manually!
    // @Values: 0:Disabled,1:Enabled
    // @User: Standard
    AP_GROUPINFO("SV_MAN",  6, AP_MotorsHeli, _servo_manual, 0),

    // @Param: GOV_SETPOINT
    // @DisplayName: External Motor Governor Setpoint
    // @Description: PWM passed to the external motor governor when external governor is enabled
    // @Range: 0 1000
    // @Units: PWM
    // @Increment: 10
    // @User: Standard
    AP_GROUPINFO("RSC_SETPOINT", 7, AP_MotorsHeli, _rsc_setpoint, AP_MOTORS_HELI_RSC_SETPOINT),

    // @Param: RSC_MODE
    // @DisplayName: Rotor Speed Control Mode
    // @Description: Determines the method of rotor speed control
    // @Values: 1:Ch8 Input, 2:SetPoint, 3:Throttle Curve
    // @User: Standard
    AP_GROUPINFO("RSC_MODE", 8, AP_MotorsHeli, _rsc_mode, AP_MOTORS_HELI_RSC_MODE_CH8_PASSTHROUGH),

    // @Param: LAND_COL_MIN
    // @DisplayName: Landing Collective Minimum
    // @Description: Minimum collective position while landed or landing
    // @Range: 0 500
    // @Units: pwm
    // @Increment: 1
    // @User: Standard
    AP_GROUPINFO("LAND_COL_MIN", 9, AP_MotorsHeli, _land_collective_min, AP_MOTORS_HELI_LAND_COLLECTIVE_MIN),

    // @Param: RSC_RAMP_TIME
    // @DisplayName: RSC Ramp Time
    // @Description: Time in seconds for the output to the main rotor's ESC to reach full speed
    // @Range: 0 60
    // @Units: Seconds
    // @User: Standard
    AP_GROUPINFO("RSC_RAMP_TIME", 10, AP_MotorsHeli, _rsc_ramp_time, AP_MOTORS_HELI_RSC_RAMP_TIME),

    // @Param: RSC_RUNUP_TIME
    // @DisplayName: RSC Runup Time
    // @Description: Time in seconds for the main rotor to reach full speed.  Must be longer than RSC_RAMP_TIME
    // @Range: 0 60
    // @Units: Seconds
    // @User: Standard
    AP_GROUPINFO("RSC_RUNUP_TIME", 11, AP_MotorsHeli, _rsc_runup_time, AP_MOTORS_HELI_RSC_RUNUP_TIME),

    // @Param: RSC_CRITICAL
    // @DisplayName: Critical Rotor Speed
    // @Description: Rotor speed below which flight is not possible
    // @Range: 0 1000
    // @Increment: 10
    // @User: Standard
    AP_GROUPINFO("RSC_CRITICAL", 12, AP_MotorsHeli, _rsc_critical, AP_MOTORS_HELI_RSC_CRITICAL),

    // @Param: RSC_IDLE
    // @DisplayName: Rotor Speed Output at Idle
    // @Description: Rotor speed output while armed but rotor control speed is not engaged
    // @Range: 0 500
    // @Increment: 10
    // @User: Standard
    AP_GROUPINFO("RSC_IDLE", 13, AP_MotorsHeli, _rsc_idle_output, AP_MOTORS_HELI_RSC_IDLE_DEFAULT),

    // @Param: RSC_POWER_LOW
    // @DisplayName: Throttle Servo Low Power Position
    // @Description: Throttle output at zero collective pitch.
    // @Range: 0 1000
    // @Increment: 10
    // @User: Standard
    AP_GROUPINFO("RSC_POWER_LOW", 14, AP_MotorsHeli, _rsc_power_low, AP_MOTORS_HELI_RSC_POWER_LOW_DEFAULT),
    
    // @Param: RSC_POWER_HIGH
    // @DisplayName: Throttle Servo High Power Position
    // @Description: Throttle output at max collective pitch.
    // @Range: 0 1000
    // @Increment: 10
    // @User: Standard
    AP_GROUPINFO("RSC_POWER_HIGH", 15, AP_MotorsHeli, _rsc_power_high, AP_MOTORS_HELI_RSC_POWER_HIGH_DEFAULT),

    AP_GROUPEND
};

//
// public methods
//

// init
void AP_MotorsHeli::Init()
{
    // set update rate
    set_update_rate(_speed_hz);

    // ensure inputs are not passed through to servos on start-up
    _servo_manual = 0;

    // initialise swash plate
    init_outputs();

    // calculate all scalars
    calculate_scalars();
}

// output - sends commands to the servos
void AP_MotorsHeli::output()
{
    // update throttle filter
    update_throttle_filter();

    if (_flags.armed) {
        if (!_flags.interlock) {
            output_armed_zero_throttle();
        } else if (_flags.stabilizing) {
            output_armed_stabilizing();
        } else {
            output_armed_not_stabilizing();
        }
    } else {
        output_disarmed();
    }
};

// parameter_check - check if helicopter specific parameters are sensible
bool AP_MotorsHeli::parameter_check() const
{
    // returns false if _rsc_setpoint is not higher than _rsc_critical as this would not allow rotor_runup_complete to ever return true
    if (_rsc_critical >= _rsc_setpoint) {
        return false;
    }

    // returns false if RSC Mode is not set to a valid control mode
    if (_rsc_mode <= AP_MOTORS_HELI_RSC_MODE_DISABLED || _rsc_mode > AP_MOTORS_HELI_RSC_MODE_SETPOINT) {
        return false;
    }

    // returns false if RSC Runup Time is less than Ramp time as this could cause undesired behaviour of rotor speed estimate
    if (_rsc_runup_time <= _rsc_ramp_time){
        return false;
    }

    // returns false if idle output is higher than critical rotor speed as this could block runup_complete from going false
    if ( _rsc_idle_output >=  _rsc_critical){
        return false;
    }

    // all other cases parameters are OK
    return true;
}

// reset_swash_servo
void AP_MotorsHeli::reset_swash_servo(RC_Channel& servo)
{
    servo.set_range(0, 1000);

    // swash servos always use full endpoints as restricting them would lead to scaling errors
    servo.radio_min = 1000;
    servo.radio_max = 2000;
}

// update the throttle input filter
void AP_MotorsHeli::update_throttle_filter()
{
    _throttle_filter.apply(_throttle_in, 1.0f/_loop_rate);

    // constrain throttle signal to 0-1000
    _throttle_control_input = constrain_float(_throttle_filter.get(),0.0f,1000.0f);
}

// set_radio_passthrough used to pass radio inputs directly to outputs
void AP_MotorsHeli::set_radio_passthrough(int16_t radio_roll_input, int16_t radio_pitch_input, int16_t radio_throttle_input, int16_t radio_yaw_input)
{
    _roll_radio_passthrough = radio_roll_input;
    _pitch_radio_passthrough = radio_pitch_input;
    _throttle_radio_passthrough = radio_throttle_input;
    _yaw_radio_passthrough = radio_yaw_input;
}

// reset_radio_passthrough used to reset all radio inputs to center
void AP_MotorsHeli::reset_radio_passthrough()
{
    _roll_radio_passthrough = 0;
    _pitch_radio_passthrough = 0;
    _throttle_radio_passthrough = 500;
    _yaw_radio_passthrough = 0;
}