platform/sensinact-core/src/main/java/org/eclipse/sensinact/gateway/core/method/Shortcut.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.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Stack;

import org.eclipse.sensinact.gateway.common.bundle.Mediator;
import org.eclipse.sensinact.gateway.common.primitive.InvalidValueException;

/**
 * Shortcut to a {@link Signature} of an {@link AccessMethod}
 * 
 * @author <a href="mailto:christophe.munilla@cea.fr">Christophe Munilla</a>
 */
public class Shortcut extends Signature {
	private final Map<Integer, Parameter> fixedParameters;
	private final Stack<Shortcut> shortucts;

	/**
	 * Constructor
	 * 
	 * @param type
	 *            the type of the {@link AccessMethod} associates to the shortcut to
	 *            instantiate
	 * @param parameterTypes
	 *            the array of parameter types of the shortcut to instantiate
	 * @param parameterNames
	 *            the array of parameter names of the shortcut to instantiate
	 * @param fixedParameters
	 *            the set of fixed {@link Parameter}s mapped to their index in the
	 *            method signature
	 * @throws InvalidValueException
	 */
	public Shortcut(Mediator mediator, AccessMethod.Type type, Class<?>[] parameterTypes, String[] parameterNames,
			Map<Integer, Parameter> fixedParameters) throws InvalidValueException {
		super(mediator, type, parameterTypes, parameterNames);
		this.fixedParameters = Collections.unmodifiableMap(fixedParameters);
		this.shortucts = new Stack<Shortcut>();
	}

	/**
	 * Constructor
	 * 
	 * @param methodType
	 *            the type of the associated {@link AccessMethod}
	 * @param responseType
	 *            the object type returned by the associated {@link AccessMethod}
	 * @param parameters
	 *            this Signature {@link Parameter}s array
	 * @param fixedParameters
	 *            the set of fixed {@link Parameter}s mapped to their index in the
	 *            method signature
	 */
	public Shortcut(Mediator mediator, String methodType, Parameter[] parameters,
			Map<Integer, Parameter> fixedParameters) {
		super(mediator, methodType, parameters);
		this.fixedParameters = Collections.unmodifiableMap(fixedParameters);
		this.shortucts = new Stack<Shortcut>();
	}

	/**
	 * Constructor
	 * 
	 * @param name
	 *            the type's name of the associated {@link AccessMethod}
	 * @param responseType
	 *            the object type returned by the associated {@link AccessMethod}
	 * @param parameters
	 *            this Signature {@link Parameter}s array
	 * @param fixedParameters
	 *            the set of fixed {@link Parameter}s mapped to their index in the
	 *            method signature
	 */
	public Shortcut(Mediator mediator, String name, AccessMethodResponse.Response returnedType, Parameter[] parameters,
			Map<Integer, Parameter> fixedParameters) {
		super(mediator, name, returnedType, parameters);
		this.fixedParameters = Collections.unmodifiableMap(fixedParameters);
		this.shortucts = new Stack<Shortcut>();
	}

	/**
	 * Pushes the Shortcut whose fixed parameters have to be used while building the
	 * object values array
	 * 
	 * @param shortcut
	 *            the Shortcut to push
	 */
	public void push(Shortcut shortcut) {
		if (shortcut == null) {
			return;
		}
		this.shortucts.push(shortcut);
	}

	/**
	 * Returns the map of this Shortcut fixed {@link Parameter}s
	 * 
	 * @return the map of this Shortcut fixed {@link Parameter}s
	 */
	public Map<Integer, Parameter> getFixedParameters() {
		return this.fixedParameters;
	}

	/**
	 * Returns the array of object values of this Shortcut's set of
	 * {@link Parameter}s after completion
	 * 
	 * @return the array of this Shortcut's {@link Parameter}s'object values
	 */
	@Override
	public Object[] values() {
		int position = 0;
		Map<Integer, Parameter> gathered = new HashMap<Integer, Parameter>();

		while (!this.shortucts.isEmpty()) {
			gathered.putAll(this.shortucts.pop().getFixedParameters());
		}
		gathered.putAll(this.fixedParameters);
		Object[] values = new Object[super.length() + gathered.size()];

		Iterator<Parameter> iterator = super.iterator();
		Parameter parameter = null;

		for (; position < values.length; position++) {
			parameter = gathered.get(position);
			if (parameter == null && iterator.hasNext()) {
				parameter = iterator.next();
			}
			values[position] = parameter.getValue();
		}
		return values;
	}

	/**
	 * @inheritDoc
	 * 
	 * @see Signature#clone()
	 */
	public Object clone() {
		return new Shortcut(super.mediator, super.name, super.returnedType, super.parameters, this.fixedParameters);
	}
}