dhiltonp

//!
//! Copyright 2016 David Hilton
//! All rights reserved.
//! Redistribution and use in source and binary forms, with or without
//! modification, are permitted provided that the following conditions are met:
//!     * Redistributions of source code must retain the above copyright
//!       notice, this list of conditions and the following disclaimer.
//!     * Redistributions in binary form must reproduce the above copyright
//!       notice, this list of conditions and the following disclaimer in the
//!       documentation and/or other materials provided with the distribution.
//!     * Neither the name of the <organization> nor the
//!       names of its contributors may be used to endorse or promote products
//!       derived from this software without specific prior written permission.
//!
//! THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
//! ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
//! WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
//! DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
//! DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
//! (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
//! LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
//! ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
//! (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
//! SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//!

using Toybox.System;
using Toybox.Time;
using Toybox.Timer;
using Toybox.Sensor;
using Toybox.Math;

class HRPoller {
    var rhr = 50;
    var mhr = 185;
    var hr_range;
    var max_sample_rate = 600;
    var min_sample_rate = 60;

    var enhanced_rhr_detection = true;

    var poll_timer;
    var hr_active = false;
    var last_update = 0; // time from epoch, I'm guessing. Should first update next run.
    var next_update = 0; // now!

    var last_rhr_time = 0;
    var enhanced_rhr_active = false;

    function start() {
        // load poll frequency settings

        // From AccelMagView.mc
        poll_timer = new Timer.Timer();
        poll_timer.start( method(:update), 1000, true );
        System.println("HRPoller started");
    }

    function stop() {
        // save poll frequency settings
        // turn off HR requesting, if active
        System.println("HRPoller stopped");
    }

    function update() {
        //System.println("HRPoller updating");
        var hr_range = mhr - rhr;
        var now = Time.now().value();
        var sensor_on_before_read = 30;

        if (!hr_active && now - last_update > next_update - sensor_on_before_read) {
            // turn on sensor, set callback
            System.println("turning on sensor");
            Sensor.setEnabledSensors( [Sensor.SENSOR_HEARTRATE] );
            hr_active = true;
            return;
        }

        if(hr_active && now - last_update > next_update) {
            last_update = now;

            // do we have a stable value?
            // read value, store, calculate callback time, maybe turn off sensor
            var hr = Sensor.getInfo().heartRate;

            // TODO: observe enhanced RHR calculation
            // if it's been over about 2 hours since the last long RHR check,
            //  and HR is low, stay on for a bit.
            if (now - last_rhr_time > 7000 && hr < rhr*1.1) {
                System.println("enhanced rhr");
                next_update = 5*60;
                last_rhr_time = now;
                return; // read again in 3 minutes from now; in the meantime, the system will record HR
            } else {
                next_update = min_sample_rate*Math.pow((max_sample_rate/min_sample_rate),
                                  (mhr-hr)/hr_range.toFloat());
            }
            System.println(hr.toString()+"hr: next update in "+next_update.toString());

            // leave sensor on?
            if(next_update > sensor_on_before_read*1.5) {
                // garmin sensor app turns on the sensor for 2minutes; this seems excessive?
                // It turns on for 20+ seconds when doing a regular update. Maybe 30s?
                Sensor.setEnabledSensors( [] );
                hr_active = false;
            }

            return;
        }
    }
}