/*
   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/>.
 */
/*
  simple sprayer simulator class
*/

#include "SIM_Sprayer.h"
#include "AP_HAL/AP_HAL.h"
#include "AP_Math/AP_Math.h"

#include <stdio.h>

using namespace SITL;

// table of user settable parameters
const AP_Param::GroupInfo Sprayer::var_info[] = {

    // @Param: ENABLE
    // @DisplayName: Gripper servo Sim enable/disable
    // @Description: Allows you to enable (1) or disable (0) the gripper servo simulation
    // @Values: 0:Disabled,1:Enabled
    // @User: Advanced
    AP_GROUPINFO("ENABLE", 0, Sprayer, sprayer_enable, 0),

    // @Param: PUMP
    // @DisplayName: Sprayer pump pin
    // @Description: The pin number that the Sprayer pump is connected to. (start at 1)
    // @Range: 0 15
    // @User: Advanced
    AP_GROUPINFO("PUMP", 1, Sprayer, sprayer_pump_pin, -1),

    // @Param: SPIN
    // @DisplayName: Sprayer spinner servo pin
    // @Description: The pin number that the Sprayer spinner servo is connected to. (start at 1)
    // @Range: 0 15
    // @User: Advanced
    AP_GROUPINFO("SPIN", 2, Sprayer, sprayer_spin_pin, -1),

    AP_GROUPEND
};

/*
  update sprayer state
 */
void Sprayer::update(const struct sitl_input &input)
{
    const int16_t pump_pwm = sprayer_pump_pin >= 1 ? input.servos[sprayer_pump_pin-1] : -1;
    const int16_t spinner_pwm = sprayer_spin_pin >= 1 ? input.servos[sprayer_spin_pin-1] : -1;
    const uint64_t now = AP_HAL::micros64();
    const float dt = (now - last_update_us) * 1.0e-6f;
    if (pump_pwm >= 0) {
        // update remaining payload
        if (capacity > 0) {
            const double delta = last_pump_output * pump_max_rate * dt;
            capacity -= delta;
            if (capacity < 0) {
                capacity = 0.0f;
            }
        }

        // update pump
        float pump_demand = (pump_pwm - 1000) * 0.001f;
        // ::fprintf(stderr, "pump_demand=%f\n", pump_demand);
        if (pump_demand < 0) { // never updated
            pump_demand = 0;
        }
        const float pump_max_change = pump_slew_rate / 100.0f * dt;
        last_pump_output =
            constrain_float(pump_demand, last_pump_output - pump_max_change, last_pump_output + pump_max_change);
        last_pump_output = constrain_float(last_pump_output, 0, 1);
    } else {
        last_pump_output = 0.0f;
    }
    // update spinner (if any)
    if (spinner_pwm >= 0) {
        const float spinner_demand = (spinner_pwm - 1000) * 0.001f;
        const float spinner_max_change = spinner_slew_rate * 0.01f * dt;
        last_spinner_output = constrain_float(spinner_demand,
                                              last_spinner_output - spinner_max_change,
                                              last_spinner_output + spinner_max_change);
        last_spinner_output = constrain_float(last_spinner_output, 0, 1);
    }

    if (should_report()) {
        printf("Remaining: %f litres\n", capacity);
        printf("Pump: %f l/s\n", last_pump_output * pump_max_rate);
        if (spinner_pwm >= 0) {
            printf("Spinner: %f rev/s\n", (last_spinner_output * spinner_max_rate) / 360.0f);
        }
        last_report_us = now;
    }
    last_update_us = now;
}

bool Sprayer::should_report()
{
    if (AP_HAL::micros64() - last_report_us < report_interval) {
        return false;
    }

    if (!is_zero(last_pump_output) || !is_zero(last_spinner_output)) {
        zero_report_done = false;
        return true;
    }

    if (!zero_report_done) {
        zero_report_done = true;
        return true;
    }

    return false;
}