package net.iponweb.disthene.reader.graphite.functions;
import net.iponweb.disthene.reader.beans.TimeSeries;
import net.iponweb.disthene.reader.exceptions.EvaluationException;
import net.iponweb.disthene.reader.exceptions.InvalidArgumentException;
import net.iponweb.disthene.reader.exceptions.TimeSeriesNotAlignedException;
import net.iponweb.disthene.reader.graphite.Target;
import net.iponweb.disthene.reader.graphite.evaluation.TargetEvaluator;
import net.iponweb.disthene.reader.utils.CollectionUtils;
import net.iponweb.disthene.reader.utils.DateTimeUtils;
import net.iponweb.disthene.reader.utils.TimeSeriesUtils;
import java.util.*;
/**
* @author Andrei Ivanov
*/
public class MovingAverageFunction extends DistheneFunction {
public MovingAverageFunction(String text) {
super(text, "movingAverage");
}
@Override
public List<TimeSeries> evaluate(TargetEvaluator evaluator) throws EvaluationException {
List<TimeSeries> processedArguments = new ArrayList<>();
processedArguments.addAll(evaluator.eval((Target) arguments.get(0)));
if (processedArguments.size() == 0) return new ArrayList<>();
if (!TimeSeriesUtils.checkAlignment(processedArguments)) {
throw new TimeSeriesNotAlignedException();
}
int step = processedArguments.get(0).getStep();
int length = processedArguments.get(0).getValues().length;
// need to get window in number of data points
long window;
if (arguments.get(1) instanceof Double) {
window = ((Double) arguments.get(1)).longValue();
} else {
long offset = Math.abs(DateTimeUtils.parseTimeOffset((String) arguments.get(1)));
window = offset / step;
}
List<TimeSeries> bootstrapped = evaluator.bootstrap((Target) arguments.get(0), processedArguments, window * step);
if (bootstrapped.size() == 0) return new ArrayList<>();
int bootstrappedLength = bootstrapped.get(0).getValues().length;
for (int i = 0; i < processedArguments.size(); i++) {
Queue<Double> queue = new LinkedList<>();
Double[] values = new Double[bootstrappedLength];
TimeSeries bts = bootstrapped.get(i);
for (int j = 0; j < bootstrappedLength; j++) {
if (queue.size() == 0) {
values[j] = bts.getValues()[j];
} else {
values[j] = CollectionUtils.average(queue);
}
if (bts.getValues()[j] != null) {
queue.offer(bts.getValues()[j]);
}
if (queue.size() > window) {
queue.remove();
}
}
processedArguments.get(i).setValues(Arrays.copyOfRange(values, bootstrappedLength - length, bootstrappedLength));
processedArguments.get(i).setName("movingAverage(" + processedArguments.get(i).getName() + "," + window + ")");
}
return processedArguments;
}
@Override
public void checkArguments() throws InvalidArgumentException {
if (arguments.size() != 2) throw new InvalidArgumentException("movingAverage: number of arguments is " + arguments.size() + ". Must be two.");
if (!(arguments.get(0) instanceof Target)) throw new InvalidArgumentException("movingAverage: argument is " + arguments.get(0).getClass().getName() + ". Must be series");
if (!(arguments.get(1) instanceof Double) && !(arguments.get(1) instanceof String)) throw new InvalidArgumentException("movingAverage: argument is " + arguments.get(1).getClass().getName() + ". Must be a number or a string");
}
}