platform/sensinact-core/src/main/java/org/eclipse/sensinact/gateway/core/method/SubscriptionMode.java

/*
* Copyright (c) 2020 Kentyou.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
*    Kentyou - initial API and implementation
 */
package org.eclipse.sensinact.gateway.core.method;

import java.util.Vector;

import org.eclipse.sensinact.gateway.util.JSONUtils;

/**
 * handled subscription mode
 * 
 * @author <a href="mailto:christophe.munilla@cea.fr">Christophe Munilla</a>
 */
public enum SubscriptionMode {
	NONE((byte) 0x00), ON_CHANGE((byte) 0x01), SCHEDULED((byte) 0x02), CONDITIONAL((byte) 0x04), BUFFERIZED(
			(byte) 0x08), TIMED_OUT((byte) 0x10);

	protected final byte mode;

	/**
	 * Constructor
	 * 
	 * @param mode
	 *            byte identifier of the mode
	 */
	SubscriptionMode(byte mode) {
		this.mode = mode;
	}

	/**
	 * Returns true if the SubscriptionMode passed as parameter is present in the
	 * byte value representation of specified mode(s)
	 * 
	 * @param mode
	 *            byte value representation of subscription mode(s)
	 * @param subscriptionMode
	 *            the subscription mode to check the presence
	 * 
	 * @return
	 */
	public static boolean contains(byte mode, SubscriptionMode subscriptionMode) {
		return (mode & subscriptionMode.mode) == subscriptionMode.mode;
	}

	/**
	 * Builds and returns the byte value representation of the
	 * {@link SubscriptionMode}s array passed as parameter
	 * 
	 * @param modes
	 *            the array of {@link SubscriptionMode}s to build the byte value
	 *            representation of
	 * @return the byte value representation of the specified
	 *         {@link SubscriptionMode}s
	 */
	public static byte valueOf(SubscriptionMode[] modes) {
		byte mode = NONE.mode;
		int index = 0;
		int length = modes == null ? 0 : modes.length;
		for (; index < length; index++) {
			mode |= modes[index].mode;
		}
		return mode;
	}

	/**
	 * Converts the byte value passed as parameter into the array of
	 * {@link SubscriptionMode}s whose byte values composed the specified one
	 * 
	 * @param mode
	 *            the byte value representation to convert
	 * @return the {@link SubscriptionMode}s array based on the specified byte value
	 *         representation
	 */
	public static SubscriptionMode[] valueOf(byte mode) {
		SubscriptionMode[] modes = SubscriptionMode.values();

		Vector<SubscriptionMode> contained = new Vector<SubscriptionMode>();

		int index = 0;
		int length = modes == null ? 0 : modes.length;

		for (; index < length; index++) {
			if (SubscriptionMode.contains(mode, modes[index])) {
				contained.add(modes[index]);
			}
		}
		return contained.toArray(new SubscriptionMode[contained.size()]);
	}

	/**
	 * Returns the JSON formated String description of the array of
	 * {@link SubscriptionMode}s passed as parameter using its processed byte value
	 * representation
	 */
	public static String getJSON(SubscriptionMode[] modes) {
		StringBuilder buffer = new StringBuilder();
		buffer.append(JSONUtils.QUOTE);
		buffer.append("subscriptionMode");
		buffer.append(JSONUtils.QUOTE);
		buffer.append(JSONUtils.COLON);
		buffer.append(SubscriptionMode.valueOf(modes));
		return buffer.toString();
	}
}