FFTDrawer/app/src/main/java/com/feemers/android/fftdrawer/SignalProcessing/DetectorTimedomain.java

package com.feemers.android.fftdrawer.SignalProcessing;

import android.util.Log;
import android.util.Pair;

import java.util.ArrayList;

public class DetectorTimedomain extends DetectorImpl {
    private boolean m_calculate_amplitude;
    private int m_threshold_cnt;
    private int m_sample_cnt;

    public DetectorTimedomain(int windowSize) {
        super(windowSize);
        Log.d("DetectorTimedomain", "DetectorTimedomain() - Constructor called");
        m_calculate_amplitude = false;
        m_threshold_cnt = 0;
        m_sample_cnt = 0;
    }

    @Override
    public void onNewSample(double sample) {
        super.onNewSample(sample);
        check_for_earthquake(sample);
    }

    public void check_for_earthquake(double sample)
    {
        // This method checks if threshold was exceeded and calculates the amplitude if enough values are available
        // Possible combinitions of the return values:
        // 1: false, 0.0   -> Threshold wasn't exceeded
        // 2: true, 0.0   -> Threshold was exceeded, but no value for amplitude is available yet (because m_buffer isn't filled yet)
        // 3: true, amplitude   -> Threshold was exceeded and a value for amplitude is available
        //TODO: find better solution for returning the results -> temp solution: No return-values but printing to logcat instead. Use Notifier later.

        Pair<Boolean, Double> return_pair = new Pair<Boolean, Double>(false, 0.0);
        if ((sample > m_threshold) && !(m_calculate_amplitude)) {
            Log.d("DetectorTimedomain", "threshold was exceeded. threshold: " + m_threshold); //TODO: send this info with notifier instead
            m_threshold_cnt++;
            // Later: add Logger entry
            m_calculate_amplitude = true;
            m_buffer = new ArrayList<>(); //resetting to an empty ArrayList
        }

        if (m_calculate_amplitude) {
            if (m_sample_cnt >= m_buffer_SIZE) {
                //Vector sensor_samples is filled -> determine amplitude
                double amplitude = calculate_maximum(m_buffer);
                m_sample_cnt = 0;
                m_calculate_amplitude = false;
                Log.d("DetectorTimedomain", "Maximum calculated: " + amplitude); //TODO: send this message with notifier instead
                return_pair = new Pair<Boolean, Double>(true, amplitude);
                // Later: add Logger entry
            } else {
                m_buffer.add(sample);
                m_sample_cnt++;
                return_pair = new Pair<Boolean, Double>(true, 0.0);
            }
        }
        m_Notifier.sendEvent();
        //return return_pair;
    }

    private double calculate_maximum(ArrayList<Double> samples) {
        double maximum = 0;
        for (double sample : samples) {
            if (maximum < sample)
                maximum = sample;
        }
        return maximum;
    }
}