#include "Copter.h"

#if MODE_ALTHOLD_ENABLED

/*
 * Init and run calls for althold, flight mode
 */

// althold_init - initialise althold controller
bool ModeAltHold::init(bool ignore_checks)
{

    // initialise the vertical position controller
    if (!pos_control->D_is_active()) {
        pos_control->D_init_controller();
    }

    // set vertical speed and acceleration limits
    pos_control->D_set_max_speed_accel_m(get_pilot_speed_dn_ms(), get_pilot_speed_up_ms(), get_pilot_accel_D_mss());
    pos_control->D_set_correction_speed_accel_m(get_pilot_speed_dn_ms(), get_pilot_speed_up_ms(), get_pilot_accel_D_mss());

    return true;
}

// althold_run - runs the althold controller
// should be called at 100hz or more
void ModeAltHold::run()
{
    // set vertical speed and acceleration limits
    pos_control->D_set_max_speed_accel_m(get_pilot_speed_dn_ms(), get_pilot_speed_up_ms(), get_pilot_accel_D_mss());

    // get pilot desired lean angles
    float target_roll_rad, target_pitch_rad;
    get_pilot_desired_lean_angles_rad(target_roll_rad, target_pitch_rad, attitude_control->lean_angle_max_rad(), attitude_control->get_althold_lean_angle_max_rad());

    // get pilot's desired yaw rate
    float target_yaw_rate_rads = get_pilot_desired_yaw_rate_rads();

    // get pilot desired climb rate
    float target_climb_rate_ms = get_pilot_desired_climb_rate_ms();

    // Alt Hold State Machine Determination
    AltHoldModeState althold_state = get_alt_hold_state_D_ms(target_climb_rate_ms);

    // Alt Hold State Machine
    switch (althold_state) {

    case AltHoldModeState::MotorStopped:
        attitude_control->reset_rate_controller_I_terms();
        attitude_control->reset_yaw_target_and_rate(false);
        pos_control->D_relax_controller(0.0f);   // forces throttle output to decay to zero
        break;

    case AltHoldModeState::Landed_Ground_Idle:
        attitude_control->reset_yaw_target_and_rate();
        FALLTHROUGH;

    case AltHoldModeState::Landed_Pre_Takeoff:
        attitude_control->reset_rate_controller_I_terms_smoothly();
        pos_control->D_relax_controller(0.0f);   // forces throttle output to decay to zero
        break;

    case AltHoldModeState::Takeoff:
        // initiate take-off
        if (!takeoff.running()) {
            takeoff.start_m(constrain_float(g2.pilot_takeoff_alt_m, 0.0, 10.0));
        }

        // get avoidance adjusted climb rate
        target_climb_rate_ms = get_avoidance_adjusted_climbrate_ms(target_climb_rate_ms);

        // set position controller targets adjusted for pilot input
        takeoff.do_pilot_takeoff_ms(target_climb_rate_ms);
        break;

    case AltHoldModeState::Flying:

#if AP_AVOIDANCE_ALTHOLD_ENABLED
        // apply avoidance
        copter.avoid.adjust_roll_pitch_rad(target_roll_rad, target_pitch_rad, attitude_control->lean_angle_max_rad());
#endif

        // get avoidance adjusted climb rate
        target_climb_rate_ms = get_avoidance_adjusted_climbrate_ms(target_climb_rate_ms);

#if AP_RANGEFINDER_ENABLED
        // update the vertical offset based on the surface measurement
        copter.surface_tracking.update_surface_offset();
#endif

        // Send the commanded climb rate to the position controller
        pos_control->D_set_pos_target_from_climb_rate_ms(target_climb_rate_ms);
        break;
    }

    // call attitude controller
    attitude_control->input_euler_angle_roll_pitch_euler_rate_yaw_rad(target_roll_rad, target_pitch_rad, target_yaw_rate_rads);

    // run the vertical position controller and set output throttle
    pos_control->D_update_controller();
}

#endif // MODE_ALTHOLD_ENABLED