/**
 ********************************************************************************
 * Copyright (c) 2015-2019 Robert Bosch GmbH and others.
 *
 * This program and the accompanying materials are made
 * available under the terms of the Eclipse Public License 2.0
 * which is available at https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     Robert Bosch GmbH - initial API and implementation
 ********************************************************************************
 */

package org.eclipse.app4mc.amalthea.model.util;

import java.math.BigInteger;
import java.util.List;

import org.eclipse.app4mc.amalthea.model.AmaltheaFactory;
import org.eclipse.app4mc.amalthea.model.AmaltheaServices;
import org.eclipse.app4mc.amalthea.model.Time;
import org.eclipse.app4mc.amalthea.model.TimeUnit;

public class TimeUtil {

	// Suppress default constructor
	private TimeUtil() {
		throw new IllegalStateException("Utility class");
	}

	/**
	 * Returns a list with all possible Units
	 * @return TimeUnit.VALUES
	 */
	public static List<TimeUnit> getTimeUnitList() {
		return AmaltheaServices.TIME_UNIT_LIST;
	}

	/**
	 * Converts a Time object to the given TimeUnit.
	 * Note: when convert from small unit to bigger unit, the function will round the number e.g 5200Ps = 5Ns
	 */
	public static Time convertToTimeUnit(Time time, TimeUnit unit) {
		if (time.getUnit() == unit) {
			// Units are the same, no conversion
			return time;
		}

		if (time.getUnit() == TimeUnit._UNDEFINED_ || unit == TimeUnit._UNDEFINED_ ) {
			return null;
		}

		Time newTime = AmaltheaFactory.eINSTANCE.createTime();

		List<TimeUnit> units = getTimeUnitList();
		int power = units.indexOf(time.getUnit()) - units.indexOf(unit);
		// Get the difference from the source TimeUnit to the destination TimeUnit as a factor
		double factor = Math.pow(1000, power);

		// Convert
		if(factor >= 1.0) {
			newTime.setValue(time.getValue().multiply(BigInteger.valueOf((long)factor)));
		} else {
			factor = 1 / factor;
			newTime.setValue(time.getValue().divide(BigInteger.valueOf((long)factor)));
		}
		newTime.setUnit(unit);

		return newTime;
	}
}