/*
 * This file is part of the Alitheia system, developed by the SQO-OSS
 * consortium as part of the IST FP6 SQO-OSS project, number 033331.
 *
 * Copyright 2010 - Organization for Free and Open Source Software,  
 *                 Athens, Greece.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials provided
 *       with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
package eu.sqooss.service.abstractmetric;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import eu.sqooss.service.db.DAObject;

/**
 * Declares a new Metric along with an activation type and a short description.
 * At compile time, the annotation is used to check whether a run() and
 * getResult() methods have been defined for each different activation type. At
 * runtime, it is used to automatically get metric declarations from the
 * annotated metric plug-in. 
 *  
 * @author Georgios Gousios <gousiosg@gmail.com>
 * @see eu.sqooss.service.abstractmetric.MetricDeclarations
 */
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE})
public @interface MetricDecl {

	/**
	 * The metric mnemonic, an (up to) 10 char String.
	 */
	String mnemonic();
	
	/**
	 * The metric description, a free form String.
	 */
	String descr();
	
    /**
     * A list of object types whose changes can activate the metric. By
     * convention, the first entry is the entity to which the metric results are
     * bound to.
     */
    Class<? extends DAObject>[] activators();
	
	/**
	 * A list of metrics that this metric depends upon.
	 */
	String[] dependencies() default {};
}
