#include "GCodeWriter.hpp"
#include "CustomGCode.hpp"
#include <algorithm>
#include <iomanip>
#include <iostream>
#include <map>
#include <assert.h>

#ifdef __APPLE__
    #include <boost/spirit/include/karma.hpp>
#endif

#define FLAVOR_IS(val) this->config.gcode_flavor == val
#define FLAVOR_IS_NOT(val) this->config.gcode_flavor != val

namespace Slic3r {

bool GCodeWriter::full_gcode_comment = true;
const double GCodeWriter::slope_threshold = 3 * PI / 180;

void GCodeWriter::apply_print_config(const PrintConfig &print_config)
{
    this->config.apply(print_config, true);
    m_single_extruder_multi_material = print_config.single_extruder_multi_material.value;
    bool use_mach_limits = print_config.gcode_flavor.value == gcfMarlinLegacy ||
                     print_config.gcode_flavor.value == gcfMarlinFirmware ||
                     print_config.gcode_flavor.value == gcfKlipper ||
                     print_config.gcode_flavor.value == gcfRepRapFirmware;
    m_max_acceleration = std::lrint(use_mach_limits ? print_config.machine_max_acceleration_extruding.values.front() : 0);
    m_max_jerk = std::lrint(use_mach_limits ? std::min(print_config.machine_max_jerk_x.values.front(), print_config.machine_max_jerk_y.values.front()) : 0);
    m_max_jerk_z = print_config.machine_max_jerk_z.values.front();
    m_max_jerk_e = print_config.machine_max_jerk_e.values.front();
}

void GCodeWriter::set_extruders(std::vector<unsigned int> extruder_ids)
{
    std::sort(extruder_ids.begin(), extruder_ids.end());
    m_extruders.clear();
    m_extruders.reserve(extruder_ids.size());
    for (unsigned int extruder_id : extruder_ids)
        m_extruders.emplace_back(Extruder(extruder_id, &this->config, config.single_extruder_multi_material.value));
    
    /*  we enable support for multiple extruder if any extruder greater than 0 is used
        (even if prints only uses that one) since we need to output Tx commands
        first extruder has index 0 */
    this->multiple_extruders = (*std::max_element(extruder_ids.begin(), extruder_ids.end())) > 0;
}

std::string GCodeWriter::preamble()
{
    std::ostringstream gcode;
    
    if (FLAVOR_IS_NOT(gcfMakerWare)) {
        gcode << "G90\n";
        gcode << "G21\n";
    }
    if (FLAVOR_IS(gcfRepRapSprinter) ||
        FLAVOR_IS(gcfRepRapFirmware) ||
        FLAVOR_IS(gcfMarlinLegacy) ||
        FLAVOR_IS(gcfMarlinFirmware) ||
        FLAVOR_IS(gcfTeacup) ||
        FLAVOR_IS(gcfRepetier) ||
        FLAVOR_IS(gcfSmoothie) ||
        FLAVOR_IS(gcfKlipper))
    {
        if (this->config.use_relative_e_distances) {
            gcode << "M83 ; use relative distances for extrusion\n";
        } else {
            gcode << "M82 ; use absolute distances for extrusion\n";
        }
        gcode << this->reset_e(true);
    }
    
    return gcode.str();
}

std::string GCodeWriter::postamble() const
{
    std::ostringstream gcode;
    if (FLAVOR_IS(gcfMachinekit))
          gcode << "M2 ; end of program\n";
    return gcode.str();
}

std::string GCodeWriter::set_temperature(unsigned int temperature, bool wait, int tool) const
{
    if (wait && (FLAVOR_IS(gcfMakerWare) || FLAVOR_IS(gcfSailfish)))
        return "";
    
    std::string code, comment;
    if (wait && FLAVOR_IS_NOT(gcfTeacup) && FLAVOR_IS_NOT(gcfRepRapFirmware)) {
        code = "M109";
        comment = "set nozzle temperature and wait for it to be reached";
    } else {
        if (FLAVOR_IS(gcfRepRapFirmware)) { // M104 is deprecated on RepRapFirmware
            code = "G10";
        } else {
            code = "M104";
        }
        comment = "set nozzle temperature";
    }
    
    std::ostringstream gcode;
    gcode << code << " ";
    if (FLAVOR_IS(gcfMach3) || FLAVOR_IS(gcfMachinekit)) {
        gcode << "P";
    } else {
        gcode << "S";
    }
    gcode << temperature;
    bool multiple_tools = this->multiple_extruders && ! m_single_extruder_multi_material;
    if (tool != -1 && (multiple_tools || FLAVOR_IS(gcfMakerWare) || FLAVOR_IS(gcfSailfish)) ) {
        if (FLAVOR_IS(gcfRepRapFirmware)) {
            gcode << " P" << tool;
        } else {
            gcode << " T" << tool;
        }
    }
    gcode << " ; " << comment << "\n";
    
    if ((FLAVOR_IS(gcfTeacup) || FLAVOR_IS(gcfRepRapFirmware)) && wait)
        gcode << "M116 ; wait for temperature to be reached\n";
    
    return gcode.str();
}

// BBS
std::string GCodeWriter::set_bed_temperature(int temperature, bool wait)
{
    if (temperature == m_last_bed_temperature && (! wait || m_last_bed_temperature_reached))
        return std::string();

    m_last_bed_temperature = temperature;
    m_last_bed_temperature_reached = wait;

    std::string code, comment;
    std::ostringstream gcode;

    if (wait) {
        code = "M190";
        comment = "set bed temperature and wait for it to be reached";
    }
    else {
        code = "M140";
        comment = "set bed temperature";
    }

    gcode << code << " S" << temperature << " ; " << comment << "\n";
    return gcode.str();
}

std::string GCodeWriter::set_acceleration(unsigned int acceleration)
{
    // Clamp the acceleration to the allowed maximum.
    if (m_max_acceleration > 0 && acceleration > m_max_acceleration)
        acceleration = m_max_acceleration;

    if (acceleration == 0 || acceleration == m_last_acceleration)
        return std::string();
    
    m_last_acceleration = acceleration;
    
    std::ostringstream gcode;
    if (FLAVOR_IS(gcfRepetier)) {
        // M201: Set max printing acceleration
        gcode << "M201 X" << acceleration << " Y" << acceleration;
        //BBS
        if (GCodeWriter::full_gcode_comment) gcode << " ; adjust acceleration";
        gcode << "\n";
        // M202: Set max travel acceleration
        gcode << "M202 X" << acceleration << " Y" << acceleration;
    } else if (FLAVOR_IS(gcfRepRapFirmware)) {
        // M204: Set default acceleration
        gcode << "M204 P" << acceleration;
    } else if (FLAVOR_IS(gcfMarlinFirmware)) {
        // This is new MarlinFirmware with separated print/retraction/travel acceleration.
        // Use M204 P, we don't want to override travel acc by M204 S (which is deprecated anyway).
        gcode << "M204 P" << acceleration;
    } else if (FLAVOR_IS(gcfKlipper)) {
        gcode << "SET_VELOCITY_LIMIT ACCEL=" << acceleration;
        if (this->config.accel_to_decel_enable) {
            gcode << " ACCEL_TO_DECEL=" << acceleration * this->config.accel_to_decel_factor / 100;
            if (GCodeWriter::full_gcode_comment)
                gcode << " ; adjust ACCEL_TO_DECEL";
        }
    } else
        gcode << "M204 S" << acceleration;

    //BBS
    if (GCodeWriter::full_gcode_comment) gcode << " ; adjust acceleration";
    gcode << "\n";
    
    return gcode.str();
}

std::string GCodeWriter::set_jerk_xy(double jerk)
{
    // Clamp the jerk to the allowed maximum.
    if (m_max_jerk > 0 && jerk > m_max_jerk)
        jerk = m_max_jerk;

    if (jerk < 0.01 || is_approx(jerk, m_last_jerk))
        return std::string();
    
    m_last_jerk = jerk;
    
    std::ostringstream gcode;
    if(FLAVOR_IS(gcfKlipper))
        gcode << "SET_VELOCITY_LIMIT SQUARE_CORNER_VELOCITY=" << jerk;
    else
        gcode << "M205 X" << jerk << " Y" << jerk;
      
    if (m_is_bbl_printers)
        gcode << std::setprecision(2) << " Z" << m_max_jerk_z << " E" << m_max_jerk_e;

    if (GCodeWriter::full_gcode_comment) gcode << " ; adjust jerk";
    gcode << "\n";

    return gcode.str();

}

std::string GCodeWriter::set_pressure_advance(double pa) const
{
    std::ostringstream gcode;
    if (pa < 0)
        return gcode.str();
    if(m_is_bbl_printers){
        //SoftFever: set L1000 to use linear model
        gcode << "M900 K" <<std::setprecision(4)<< pa << " L1000 M10 ; Override pressure advance value\n";
    }
    else{
        if (FLAVOR_IS(gcfKlipper))
            gcode << "SET_PRESSURE_ADVANCE ADVANCE=" << std::setprecision(4) << pa << "; Override pressure advance value\n";
        else if(FLAVOR_IS(gcfRepRapFirmware))
            gcode << ("M572 D0 S") << std::setprecision(4) << pa << "; Override pressure advance value\n";
        else
            gcode << "M900 K" <<std::setprecision(4)<< pa << "; Override pressure advance value\n";
    }
    return gcode.str();
}



std::string GCodeWriter::reset_e(bool force)
{
    if (FLAVOR_IS(gcfMach3)
        || FLAVOR_IS(gcfMakerWare)
        || FLAVOR_IS(gcfSailfish))
        return "";
    
    if (m_extruder != nullptr) {
        if (m_extruder->E() == 0. && ! force)
            return "";
        m_extruder->reset_E();
    }

    if (! this->config.use_relative_e_distances) {
        std::ostringstream gcode;
        gcode << "G92 E0";
        //BBS
        if (GCodeWriter::full_gcode_comment) gcode << " ; reset extrusion distance";
        gcode << "\n";
        return gcode.str();
    } else {
        return "";
    }
}

std::string GCodeWriter::update_progress(unsigned int num, unsigned int tot, bool allow_100) const
{
    if (FLAVOR_IS_NOT(gcfMakerWare) && FLAVOR_IS_NOT(gcfSailfish))
        return "";
    
    unsigned int percent = (unsigned int)floor(100.0 * num / tot + 0.5);
    if (!allow_100) percent = std::min(percent, (unsigned int)99);
    
    std::ostringstream gcode;
    gcode << "M73 P" << percent;
    //BBS
    if (GCodeWriter::full_gcode_comment) gcode << " ; update progress";
    gcode << "\n";
    return gcode.str();
}

std::string GCodeWriter::toolchange_prefix() const
{
    return FLAVOR_IS(gcfMakerWare) ? "M135 T" :
           FLAVOR_IS(gcfSailfish)  ? "M108 T" : "T";
}

std::string GCodeWriter::toolchange(unsigned int extruder_id)
{
    // set the new extruder
	auto it_extruder = Slic3r::lower_bound_by_predicate(m_extruders.begin(), m_extruders.end(), [extruder_id](const Extruder &e) { return e.id() < extruder_id; });
    assert(it_extruder != m_extruders.end() && it_extruder->id() == extruder_id);
    m_extruder = &*it_extruder;

    // return the toolchange command
    // if we are running a single-extruder setup, just set the extruder and return nothing
    std::ostringstream gcode;
    if (this->multiple_extruders) {
        gcode << this->toolchange_prefix() << extruder_id;
        //BBS
        if (GCodeWriter::full_gcode_comment)
            gcode << " ; change extruder";
        gcode << "\n";
        gcode << this->reset_e(true);
    }
    return gcode.str();
}

std::string GCodeWriter::set_speed(double F, const std::string &comment, const std::string &cooling_marker)
{
    assert(F > 0.);
    assert(F < 100000.);
    
    m_current_speed = F;
    GCodeG1Formatter w;
    w.emit_f(F);
    //BBS
    w.emit_comment(GCodeWriter::full_gcode_comment, comment);
    w.emit_string(cooling_marker);
    return w.string();
}

std::string GCodeWriter::travel_to_xy(const Vec2d &point, const std::string &comment)
{
    m_pos(0) = point(0);
    m_pos(1) = point(1);

    this->set_current_position_clear(true);
    //BBS: take plate offset into consider
    Vec2d point_on_plate = { point(0) - m_x_offset, point(1) - m_y_offset };
    
    GCodeG1Formatter w;
    w.emit_xy(point_on_plate);
    auto speed = m_is_first_layer
        ? this->config.get_abs_value("initial_layer_travel_speed") : this->config.travel_speed.value;
    w.emit_f(speed * 60.0);
    //BBS
    w.emit_comment(GCodeWriter::full_gcode_comment, comment);
    return w.string();
}

std::string GCodeWriter::travel_to_xyz(const Vec3d &point, const std::string &comment)
{
    // FIXME: This function was not being used when travel_speed_z was separated (bd6badf).
    // Calculation of feedrate was not updated accordingly. If you want to use
    // this function, fix it first.
    //std::terminate();

    /*  If target Z is lower than current Z but higher than nominal Z we
        don't perform the Z move but we only move in the XY plane and
        adjust the nominal Z by reducing the lift amount that will be 
        used for unlift. */
        // BBS
    Vec3d dest_point = point;
    auto travel_speed =
        m_is_first_layer ? this->config.get_abs_value("initial_layer_travel_speed") : this->config.travel_speed.value;
    //BBS: a z_hop need to be handle when travel
    if (std::abs(m_to_lift) > EPSILON) {
        assert(std::abs(m_lifted) < EPSILON);
        //BBS: don't need to do real lift if the current position is absolutely same with target.
        //This ususally happens when the last extrusion line is short and the end of wipe position
        //is same with the traget point by chance.
        if ((!this->is_current_position_clear() || m_pos != dest_point) &&
            m_to_lift + m_pos(2) > point(2)) {
            m_lifted = m_to_lift + m_pos(2) - point(2);
            dest_point(2) = m_to_lift + m_pos(2);
        }
        m_to_lift = 0.;

        std::string slop_move;
        //BBS: minus plate offset
        Vec3d source = { m_pos(0) - m_x_offset, m_pos(1) - m_y_offset, m_pos(2) };
        Vec3d target = { dest_point(0) - m_x_offset, dest_point(1) - m_y_offset, dest_point(2) };
        Vec3d delta = target - source;
        Vec2d delta_no_z = { delta(0), delta(1) };
        //BBS: don'need slope travel because we don't know where is the source position the first time
        //BBS: Also don't need to do slope move or spiral lift if x-y distance is absolute zero
        if (delta(2) > 0 && delta_no_z.norm() != 0.0f)    {
            //BBS: SpiralLift
            if (m_to_lift_type == LiftType::SpiralLift && this->is_current_position_clear()) {
                //BBS: todo: check the arc move all in bed area, if not, then use lazy lift
                double radius = delta(2) / (2 * PI * atan(GCodeWriter::slope_threshold));
                Vec2d ij_offset = radius * delta_no_z.normalized();
                ij_offset = { -ij_offset(1), ij_offset(0) };
                slop_move = this->_spiral_travel_to_z(target(2), ij_offset, "spiral lift Z");
            }
            //BBS: LazyLift
            else if (m_to_lift_type == LiftType::LazyLift &&
                this->is_current_position_clear() && 
                atan2(delta(2), delta_no_z.norm()) < GCodeWriter::slope_threshold) {
                //BBS: check whether we can make a travel like
                //   _____
                //  /       to make the z list early to avoid to hit some warping place when travel is long.
                Vec2d temp = delta_no_z.normalized() * delta(2) / tan(GCodeWriter::slope_threshold);
                Vec3d slope_top_point = Vec3d(temp(0), temp(1), delta(2)) + source;
                GCodeG1Formatter w0;
                w0.emit_xyz(slope_top_point);
                w0.emit_f(travel_speed * 60.0);
                //BBS
                w0.emit_comment(GCodeWriter::full_gcode_comment, comment);
                slop_move = w0.string();
            }
            else if (m_to_lift_type == LiftType::NormalLift) {
                slop_move = _travel_to_z(target.z(), "normal lift Z");
            }
        }

        std::string xy_z_move;
        {
            GCodeG1Formatter w0;
            if (this->is_current_position_clear()) {
                w0.emit_xyz(target);
                w0.emit_f(travel_speed * 60.0);
                w0.emit_comment(GCodeWriter::full_gcode_comment, comment);
                xy_z_move = w0.string();
            }
            else {
                w0.emit_xy(Vec2d(target.x(), target.y()));
                w0.emit_f(travel_speed * 60.0);
                w0.emit_comment(GCodeWriter::full_gcode_comment, comment);
                xy_z_move = w0.string() + _travel_to_z(target.z(), comment);
            }
        }
        m_pos = dest_point;
        this->set_current_position_clear(true);
        return slop_move + xy_z_move;
    }
    else if (!this->will_move_z(point(2))) {
        double nominal_z = m_pos(2) - m_lifted;
        m_lifted -= (point(2) - nominal_z);
        // In case that z_hop == layer_height we could end up with almost zero in_m_lifted
        // and a retract could be skipped
        if (std::abs(m_lifted) < EPSILON)
            m_lifted = 0.;
        //BBS
        this->set_current_position_clear(true);
        return this->travel_to_xy(to_2d(point));
    }
    else {
        /*  In all the other cases, we perform an actual XYZ move and cancel
            the lift. */
        m_lifted = 0;
    }
    
    //BBS: take plate offset into consider
    Vec3d point_on_plate = { dest_point(0) - m_x_offset, dest_point(1) - m_y_offset, dest_point(2) };
    std::string out_string;
    GCodeG1Formatter w;
    if (!this->is_current_position_clear())
    {
        //force to move xy first then z after filament change
        w.emit_xy(Vec2d(point_on_plate.x(), point_on_plate.y()));
        w.emit_f(this->config.travel_speed.value * 60.0);
        w.emit_comment(GCodeWriter::full_gcode_comment, comment);
        out_string = w.string() + _travel_to_z(point_on_plate.z(), comment);
    } else {
        GCodeG1Formatter w;
        w.emit_xyz(point_on_plate);
        w.emit_f(this->config.travel_speed.value * 60.0);
        w.emit_comment(GCodeWriter::full_gcode_comment, comment);
        out_string = w.string();
    }

    m_pos = dest_point;
    this->set_current_position_clear(true);
    return out_string;
}

std::string GCodeWriter::travel_to_z(double z, const std::string &comment)
{
    /*  If target Z is lower than current Z but higher than nominal Z
        we don't perform the move but we only adjust the nominal Z by
        reducing the lift amount that will be used for unlift. */
    if (!this->will_move_z(z)) {
        double nominal_z = m_pos(2) - m_lifted;
        m_lifted -= (z - nominal_z);
        if (std::abs(m_lifted) < EPSILON)
            m_lifted = 0.;
        return "";
    }
    
    /*  In all the other cases, we perform an actual Z move and cancel
        the lift. */
    m_lifted = 0;
    return this->_travel_to_z(z, comment);
}

std::string GCodeWriter::_travel_to_z(double z, const std::string &comment)
{
    m_pos(2) = z;

    double speed = this->config.travel_speed_z.value;
    if (speed == 0.) {
        speed = m_is_first_layer ? this->config.get_abs_value("initial_layer_travel_speed")
                                 : this->config.travel_speed.value;
    }
    
    GCodeG1Formatter w;
    w.emit_z(z);
    w.emit_f(speed * 60.0);
    //BBS
    w.emit_comment(GCodeWriter::full_gcode_comment, comment);
    return w.string();
}

std::string GCodeWriter::_spiral_travel_to_z(double z, const Vec2d &ij_offset, const std::string &comment)
{
    m_pos(2) = z;

    double speed = this->config.travel_speed_z.value;
    if (speed == 0.) {
        speed = m_is_first_layer ? this->config.get_abs_value("initial_layer_travel_speed")
                                 : this->config.travel_speed.value;
    }
    
    std::string output = "G17\n";
    GCodeG2G3Formatter w(true);
    w.emit_z(z);
    w.emit_ij(ij_offset);
    w.emit_string(" P1 ");
    w.emit_f(speed * 60.0);
    w.emit_comment(GCodeWriter::full_gcode_comment, comment);
    return output + w.string();
}

bool GCodeWriter::will_move_z(double z) const
{
    /* If target Z is lower than current Z but higher than nominal Z
        we don't perform an actual Z move. */
    if (m_lifted > 0) {
        double nominal_z = m_pos(2) - m_lifted;
        if (z >= nominal_z && z <= m_pos(2))
            return false;
    }
    // BBS.
    // Dont move z if it is the same as target z
    else if (std::abs(m_pos(2) - z) < EPSILON) {
        return false;
    }
    return true;
}

std::string GCodeWriter::extrude_to_xy(const Vec2d &point, double dE, const std::string &comment, bool force_no_extrusion)
{
    m_pos(0) = point(0);
    m_pos(1) = point(1);
    if(std::abs(dE) <= std::numeric_limits<double>::epsilon())
        force_no_extrusion = true;
    
    if (!force_no_extrusion)
        m_extruder->extrude(dE);

    //BBS: take plate offset into consider
    Vec2d point_on_plate = { point(0) - m_x_offset, point(1) - m_y_offset };

    GCodeG1Formatter w;
    w.emit_xy(point_on_plate);
    if (!force_no_extrusion)
        w.emit_e(m_extruder->E());
    //BBS
    w.emit_comment(GCodeWriter::full_gcode_comment, comment);
    return w.string();
}

//BBS: generate G2 or G3 extrude which moves by arc
//point is end point which means X and Y axis
//center_offset is I and J axis
std::string GCodeWriter::extrude_arc_to_xy(const Vec2d& point, const Vec2d& center_offset, double dE, const bool is_ccw, const std::string& comment, bool force_no_extrusion)
{
    m_pos(0) = point(0);
    m_pos(1) = point(1);
    if (!force_no_extrusion)
        m_extruder->extrude(dE);

    Vec2d point_on_plate = { point(0) - m_x_offset, point(1) - m_y_offset };

    GCodeG2G3Formatter w(is_ccw);
    w.emit_xy(point_on_plate);
    w.emit_ij(center_offset);
    if (!force_no_extrusion)
        w.emit_e(m_extruder->E());
    //BBS
    w.emit_comment(GCodeWriter::full_gcode_comment, comment);
    return w.string();
}

std::string GCodeWriter::extrude_to_xyz(const Vec3d &point, double dE, const std::string &comment, bool force_no_extrusion)
{
    m_pos = point;
    m_lifted = 0;
    if (!force_no_extrusion)
        m_extruder->extrude(dE);
    
    //BBS: take plate offset into consider
    Vec3d point_on_plate = { point(0) - m_x_offset, point(1) - m_y_offset, point(2) };

    GCodeG1Formatter w;
    w.emit_xyz(point_on_plate);
    if (!force_no_extrusion)
        w.emit_e(m_extruder->E());
    //BBS
    w.emit_comment(GCodeWriter::full_gcode_comment, comment);
    return w.string();
}

std::string GCodeWriter::retract(bool before_wipe)
{
    double factor = before_wipe ? m_extruder->retract_before_wipe() : 1.;
    assert(factor >= 0. && factor <= 1. + EPSILON);
    return this->_retract(
        factor * m_extruder->retraction_length(),
        factor * m_extruder->retract_restart_extra(),
        "retract"
    );
}

std::string GCodeWriter::retract_for_toolchange(bool before_wipe)
{
    double factor = before_wipe ? m_extruder->retract_before_wipe() : 1.;
    assert(factor >= 0. && factor <= 1. + EPSILON);
    return this->_retract(
        factor * m_extruder->retract_length_toolchange(),
        factor * m_extruder->retract_restart_extra_toolchange(),
        "retract for toolchange"
    );
}

std::string GCodeWriter::_retract(double length, double restart_extra, const std::string &comment)
{
    /*  If firmware retraction is enabled, we use a fake value of 1
    since we ignore the actual configured retract_length which
    might be 0, in which case the retraction logic gets skipped. */
    if (this->config.use_firmware_retraction)
        length = 1;

    std::string gcode;
    if (double dE = m_extruder->retract(length, restart_extra);  dE != 0) {
        if (this->config.use_firmware_retraction) {
            gcode = FLAVOR_IS(gcfMachinekit) ? "G22 ; retract\n" : "G10 ; retract\n";
        }
        else {
            // BBS
            GCodeG1Formatter w;
            w.emit_e(m_extruder->E());
            w.emit_f(m_extruder->retract_speed() * 60.);
            // BBS
            w.emit_comment(GCodeWriter::full_gcode_comment, comment);
            gcode = w.string();
        }
    }
    
    if (FLAVOR_IS(gcfMakerWare))
        gcode += "M103 ; extruder off\n";

    return gcode;
}

std::string GCodeWriter::unretract()
{
    std::string gcode;
    
    if (FLAVOR_IS(gcfMakerWare))
        gcode = "M101 ; extruder on\n";
    
    if (double dE = m_extruder->unretract(); dE != 0) {
        if (this->config.use_firmware_retraction) {
            gcode += FLAVOR_IS(gcfMachinekit) ? "G23 ; unretract\n" : "G11 ; unretract\n";
            gcode += this->reset_e();
        }
        else {
            //BBS
            // use G1 instead of G0 because G0 will blend the restart with the previous travel move
            GCodeG1Formatter w;
            w.emit_e(m_extruder->E());
            w.emit_f(m_extruder->deretract_speed() * 60.);
            //BBS
            w.emit_comment(GCodeWriter::full_gcode_comment, " ; unretract");
            gcode += w.string();
        }
    }
    
    return gcode;
}

/*  If this method is called more than once before calling unlift(),
    it will not perform subsequent lifts, even if Z was raised manually
    (i.e. with travel_to_z()) and thus _lifted was reduced. */
std::string GCodeWriter::lift(LiftType lift_type, bool spiral_vase)
{
    // check whether the above/below conditions are met
    double target_lift = 0;
    {
        double above = this->config.retract_lift_above.get_at(m_extruder->id());
        double below = this->config.retract_lift_below.get_at(m_extruder->id());
        if (m_pos(2) >= above && (below == 0 || m_pos(2) <= below))
            target_lift = this->config.z_hop.get_at(m_extruder->id());
    }
    // BBS
    if (m_lifted == 0 && m_to_lift == 0 && target_lift > 0) {
        if (spiral_vase) {
            m_lifted = target_lift;
            return this->_travel_to_z(m_pos(2) + target_lift, "lift Z");
        }
        else {
            m_to_lift = target_lift;
            m_to_lift_type = lift_type;
        }
    }
    return "";
}

std::string GCodeWriter::unlift()
{
    std::string gcode;
    if (m_lifted > 0) {
        gcode += this->_travel_to_z(m_pos(2) - m_lifted, "restore layer Z");
        m_lifted = 0;
    }
    m_to_lift = 0.;
    return gcode;
}

std::string GCodeWriter::set_fan(const GCodeFlavor gcode_flavor, unsigned int speed)
{
    std::ostringstream gcode;
    if (speed == 0) {
        switch (gcode_flavor) {
        case gcfTeacup:
            gcode << "M106 S0"; break;
        case gcfMakerWare:
        case gcfSailfish:
            gcode << "M127";    break;
        default:
            gcode << "M106 S0";    break;
        }
        if (GCodeWriter::full_gcode_comment)
            gcode << " ; disable fan";
        gcode << "\n";
    } else {
        switch (gcode_flavor) {
        case gcfMakerWare:
        case gcfSailfish:
            gcode << "M126";    break;
        case gcfMach3:
        case gcfMachinekit:
            gcode << "M106 P" << static_cast<unsigned int>(255.5 * speed / 100.0); break;
        default:
            gcode << "M106 S" << static_cast<unsigned int>(255.5 * speed / 100.0); break;
        }
        if (GCodeWriter::full_gcode_comment) 
            gcode << " ; enable fan";
        gcode << "\n";
    }
    return gcode.str();
}

std::string GCodeWriter::set_fan(unsigned int speed) const
{
    //BBS
    return GCodeWriter::set_fan(this->config.gcode_flavor, speed);
}

//BBS: set additional fan speed for BBS machine only
std::string GCodeWriter::set_additional_fan(unsigned int speed)
{
    std::ostringstream gcode;

    gcode << "M106 " << "P2 " << "S" << (int)(255.0 * speed / 100.0);
    if (GCodeWriter::full_gcode_comment) {
        if (speed == 0)
            gcode << " ; disable additional fan ";
        else
            gcode << " ; enable additional fan ";
    }
    gcode << "\n";
    return gcode.str();
}

void GCodeWriter::add_object_start_labels(std::string& gcode)
{
    if (!m_gcode_label_objects_start.empty()) {
        gcode += m_gcode_label_objects_start;
        m_gcode_label_objects_start = "";
    }
}

void GCodeWriter::add_object_end_labels(std::string& gcode)
{
    if (!m_gcode_label_objects_end.empty()) {
        gcode += m_gcode_label_objects_end;
        m_gcode_label_objects_end = "";

        // Orca: reset E so that e value remain correct after skipping the object
        // ref to: https://github.com/SoftFever/OrcaSlicer/pull/205/commits/7f1fe0bd544077626080aa1a9a0576aa735da1a4#r1083470162
        if (!this->config.use_relative_e_distances)
            gcode += reset_e(true);
    }
}

void GCodeWriter::add_object_change_labels(std::string& gcode)
{
    add_object_end_labels(gcode);
    add_object_start_labels(gcode);
}

void GCodeFormatter::emit_axis(const char axis, const double v, size_t digits) {
    assert(digits <= 9);
    static constexpr const std::array<int, 10> pow_10{1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000};
    *ptr_err.ptr++ = ' '; *ptr_err.ptr++ = axis;

    char *base_ptr = this->ptr_err.ptr;
    auto  v_int    = int64_t(std::round(v * pow_10[digits]));
    // Older stdlib on macOS doesn't support std::from_chars at all, so it is used boost::spirit::karma::generate instead of it.
    // That is a little bit slower than std::to_chars but not much.
#ifdef __APPLE__
    boost::spirit::karma::generate(this->ptr_err.ptr, boost::spirit::karma::int_generator<int64_t>(), v_int);
#else
    // this->buf_end minus 1 because we need space for adding the extra decimal point.
    this->ptr_err = std::to_chars(this->ptr_err.ptr, this->buf_end - 1, v_int);
#endif
    size_t writen_digits = (this->ptr_err.ptr - base_ptr) - (v_int < 0 ? 1 : 0);
    if (writen_digits < digits) {
        // Number is smaller than 10^digits, so that we will pad it with zeros.
        size_t remaining_digits = digits - writen_digits;
        // Move all newly inserted chars by remaining_digits to allocate space for padding with zeros.
        for (char *from_ptr = this->ptr_err.ptr - 1, *to_ptr = from_ptr + remaining_digits; from_ptr >= this->ptr_err.ptr - writen_digits; --to_ptr, --from_ptr)
            *to_ptr = *from_ptr;

        memset(this->ptr_err.ptr - writen_digits, '0', remaining_digits);
        this->ptr_err.ptr += remaining_digits;
    }

    // Move all newly inserted chars by one to allocate space for a decimal point.
    for (char *to_ptr = this->ptr_err.ptr, *from_ptr = to_ptr - 1; from_ptr >= this->ptr_err.ptr - digits; --to_ptr, --from_ptr)
        *to_ptr = *from_ptr;

    *(this->ptr_err.ptr - digits) = '.';
    for (size_t i = 0; i < digits; ++i) {
        if (*this->ptr_err.ptr != '0')
            break;
        this->ptr_err.ptr--;
    }
    if (*this->ptr_err.ptr == '.')
        this->ptr_err.ptr--;
    if ((this->ptr_err.ptr + 1) == base_ptr || *this->ptr_err.ptr == '-')
        *(++this->ptr_err.ptr) = '0';
    this->ptr_err.ptr++;

#if 0 // #ifndef NDEBUG
    {
        // Verify that the optimized formatter produces the same result as the standard sprintf().
        double v1 = atof(std::string(base_ptr, this->ptr_err.ptr).c_str());
        char buf[2048];
        sprintf(buf, "%.*lf", int(digits), v);
        double v2 = atof(buf);
        // Numbers may differ when rounding at exactly or very close to 0.5 due to numerical issues when scaling the double to an integer.
        // Thus the complex assert.
//        assert(v1 == v2);
        assert(std::abs(v1 - v) * pow_10[digits] < 0.50001);
        assert(std::abs(v2 - v) * pow_10[digits] < 0.50001);
    }
#endif // NDEBUG
}

} // namespace Slic3r
