/// @file	AP_MotorsTri.h
/// @brief	Motor control class for Tricopters
#pragma once

#include <AP_Common/AP_Common.h>
#include <AP_Math/AP_Math.h>        // ArduPilot Mega Vector/Matrix math Library
#include <RC_Channel/RC_Channel.h>     // RC Channel Library
#include "AP_MotorsMulticopter.h"

// tail servo uses channel 7
#define AP_MOTORS_CH_TRI_YAW    CH_7

#define AP_MOTORS_TRI_SERVO_RANGE_DEG_MIN   5   // minimum angle movement of tail servo in degrees
#define AP_MOTORS_TRI_SERVO_RANGE_DEG_MAX   80  // maximum angle movement of tail servo in degrees

/// @class      AP_MotorsTri
class AP_MotorsTri : public AP_MotorsMulticopter {
public:

    /// Constructor
    AP_MotorsTri(uint16_t loop_rate, uint16_t speed_hz = AP_MOTORS_SPEED_DEFAULT) :
        AP_MotorsMulticopter(loop_rate, speed_hz)
    {
        AP_Param::setup_object_defaults(this, var_info);
    };

    // init
    virtual void        Init();

    // set update rate to motors - a value in hertz
    void                set_update_rate( uint16_t speed_hz );

    // enable - starts allowing signals to be sent to motors
    virtual void        enable();

    // output_test - spin a motor at the pwm value specified
    //  motor_seq is the motor's sequence number from 1 to the number of motors on the frame
    //  pwm value is an actual pwm value that will be output, normally in the range of 1000 ~ 2000
    virtual void        output_test(uint8_t motor_seq, int16_t pwm);

    // output_to_motors - sends minimum values out to the motors
    virtual void        output_to_motors();

    // get_motor_mask - returns a bitmask of which outputs are being used for motors or servos (1 means being used)
    //  this can be used to ensure other pwm outputs (i.e. for servos) do not conflict
    virtual uint16_t    get_motor_mask();

    // var_info for holding Parameter information
    static const struct AP_Param::GroupInfo var_info[];

protected:
    // output - sends commands to the motors
    void                output_armed_stabilizing();

    // call vehicle supplied thrust compensation if set
    void                thrust_compensation(void) override;
    
    // calc_yaw_radio_output - calculate final radio output for yaw channel
    int16_t             calc_yaw_radio_output(float yaw_input, float yaw_input_max);        // calculate radio output for yaw servo, typically in range of 1100-1900

    // parameters
    AP_Int8         _yaw_reverse;                       // Reverse yaw output
    AP_Int16        _yaw_servo_trim;                    // Trim or center position of yaw servo
    AP_Int16        _yaw_servo_min;                     // Minimum pwm of yaw servo
    AP_Int16        _yaw_servo_max;                     // Maximum pwm of yaw servo
    AP_Float        _yaw_servo_angle_max_deg;           // Maximum lean angle of yaw servo in degrees
    float           _pivot_angle;                       // Angle of yaw pivot
    float           _thrust_right;
    float           _thrust_rear;
    float           _thrust_left;
};