package example.timeestimation;

import gssim.schedframe.scheduling.ExecTask;

import java.util.Map;

import schedframe.Parameters;
import schedframe.PluginConfiguration;
import schedframe.events.scheduling.SchedulingEvent;
import schedframe.resources.units.PEUnit;
import schedframe.resources.units.ResourceUnit;
import schedframe.resources.units.ResourceUnitName;
import schedframe.resources.units.StandardResourceUnitName;


/**
 * 
 * @author Marcin Krystek
 *
 */
public class DefaultTimeEstimationPlugin implements schedframe.scheduling.plugin.estimation.ExecutionTimeEstimationPlugin{

	/*
	 * This method should return an estimation of time required to execute the task.
	 * Requested calculation should be done based on the resources allocated for the task,
	 * task description and task remaining length (in instructions).
	 * 
	 * Example implementation calculate the estimation based on cpu processing power.
	 * There is also a simple assumption, that cpu processing power is a linear function
	 * of number of allocated cpus and their speed.
	 */
	public double execTimeEstimation(SchedulingEvent event,
			Map<ResourceUnitName, ResourceUnit> allocatedResources,
			ExecTask task, double completionPercentage) {
		
		// collect all information necessary to do the calculation
		PEUnit peUnit = (PEUnit) allocatedResources.get(StandardResourceUnitName.PE);

		// obtain single pe speed
		int speed = peUnit.getSpeed();

		// number of used pe  
		int cnt = peUnit.getUsedAmount();

		double remainingLength =  task.getLength() * (1- completionPercentage);
		// do the calculation
		double execTime = (remainingLength / (cnt * speed));

		// if the result is very close to 0, but less then one millisecond then round this result to 0.001
		if (Double.compare(execTime, 0.001) < 0) {
			execTime = 0.001;
		}

		// time is measured in integer units, so get the nearest execTime int value.
		execTime = Math.ceil(execTime);
		return execTime;
	}

	public PluginConfiguration getConfiguration() {
		return null;
	}

	public String getName() {
		return "ExampleTimeEstimationPlugin";
	}

	public void init(Parameters parameters) {
	}

}