/*$************************************************************************************************
 **
 ** $Id: ParameterValueGroup.java 831 2006-05-01 00:27:23Z Desruisseaux $
 **
 ** $URL: http://svn.code.sf.net/p/geoapi/code/branches/2.0.x/geoapi/src/main/java/org/opengis/parameter/ParameterValueGroup.java $
 **
 ** Copyright (C) 2003-2005 Open GIS Consortium, Inc.
 ** All Rights Reserved. http://www.opengis.org/legal/
 **
 *************************************************************************************************/
package org.opengis.parameter;

// J2SE dependencies
import java.util.List;

// OpenGIS dependencies
import org.opengis.metadata.Identifier;  // For javadoc

// Annotations
import org.opengis.annotation.UML;
import org.opengis.annotation.Extension;
import static org.opengis.annotation.Obligation.*;
import static org.opengis.annotation.Specification.*;


/**
 * A group of related parameter values. The same group can be repeated more than once in an
 * {@linkplain org.opengis.referencing.operation.Operation operation} or higher level {@code ParameterValueGroup},
 * if those instances contain different values of one or more {@link ParameterValue}s which suitably
 * distinquish among those groups.
 * 
 * @version Abstract specification 2.0
 * @author ISO/DIS 19111
 * @author Martin Desruisseaux (IRD)
 * @author Jody Garnett (Refractions Research)
 * @since GeoAPI 1.0
 *
 * @see ParameterDescriptorGroup
 * @see ParameterValue
 */
@UML(identifier="CC_ParameterValueGroup", specification=ISO_19111)
public interface ParameterValueGroup extends GeneralParameterValue {
    /**
     * The abstract definition of this group of parameters.
     *
     * @rename Renamed getDescriptor() because getGroup() seems too
     *         restrictive, misleading (this method returns an abstract definition of a group
     *         of parameters, not the actual group), and for consistency with usage in other
     *         Java extensions (e.g.
     *         {@link javax.media.jai.ParameterList.html#getParameterListDescriptor ParameterList}).
     */
/// @UML(identifier="valuesOfGroup", obligation=MANDATORY, specification=ISO_19111)
/// ParameterDescriptorGroup getDescriptor();

    /**
     * Returns the values in this group. The returned list may or may not be unmodifiable;
     * this is implementation-dependent. However, if some aspects of this list are modifiable,
     * then any modification shall be reflected back into this {@code ParameterValueGroup}.
     * More specifically:
     *
     * 

     *   
If the list supports the {@link List#add(Object) add} operation, then it should
     *       ensure that the added {@linkplain GeneralParameterValue general parameter value} is
     *       valid and can be added to this group.
     *       An {@link InvalidParameterCardinalityException} (or any other appropriate exception)
     *       shall be thrown if it is not the case.
     *   
The list may also supports the {@link List#remove(Object) remove} operation as a
     *       way to remove parameter created by the {@link #parameter} method.
     * 
     */
    @UML(identifier="includesValue", obligation=MANDATORY, specification=ISO_19111)
    List values();

    /**
     * Returns the value in this group for the specified {@linkplain Identifier#getCode
     * identifier code}. If no {@linkplain ParameterValue parameter value} is found but
     * a {@linkplain ParameterDescriptor parameter descriptor} is found (which may occurs
     * if the parameter is optional, i.e. {@linkplain ParameterDescriptor#getMinimumOccurs
     * minimumOccurs} == 0), then a {@linkplain ParameterValue parameter value} is
     * automatically created and initialized to its {@linkplain ParameterDescriptor#getDefaultValue
     * default value} (if any).
     *
     * 
This convenience method provides a way to get and set parameter values by name. For
     * example the following idiom fetches a floating point value for the
     * "false_easting" parameter:
     *
     * 

     * double value = parameter("false_easting").{@linkplain ParameterValue#doubleValue() doubleValue()};
     * 
     *
     * 
This method do not search recursively in subgroups. This is because more than one
     * subgroup may exist for the same {@linkplain ParameterDescriptorGroup descriptor}.
     * The user must {@linkplain #groups query all subgroups} and select explicitly the
     * appropriate one to use.
     *
     * @param  name The case insensitive {@linkplain Identifier#getCode identifier code} of the
     *              parameter to search for. 
     * @return The parameter value for the given identifier code.
     * @throws ParameterNotFoundException if there is no parameter value for the given identifier code.
     */
    @Extension
    ParameterValue parameter(String name) throws ParameterNotFoundException;

    /**
     * Returns all subgroups with the specified name. This method do not create new groups.
     * If the requested group is optional (i.e.
     * {@linkplain ParameterDescriptor#getMinimumOccurs minimumOccurs} == 0)
     * and no value were defined previously, then this method returns an empty set.
     *
     * @param  name The case insensitive {@linkplain Identifier#getCode identifier code} of the
     *              parameter group to search for.
     * @return The set of all parameter group for the given identifier code.
     * @throws ParameterNotFoundException if no {@linkplain ParameterDescriptorGroup descriptor}
     *         was found for the given name.
     */
    @Extension
    List groups(String name) throws ParameterNotFoundException;

    /**
     * Create a new group of the specified name. The specified name must be the
     * {@linkplain Identifier#getCode identifier code} of a {@linkplain ParameterDescriptorGroup
     * descriptor group}.
     *
     * @param  name The case insensitive {@linkplain Identifier#getCode identifier code} of the
     *              parameter group to create.
     * @return A newly created parameter group for the given identifier code.
     * @throws ParameterNotFoundException if no {@linkplain ParameterDescriptorGroup descriptor}
     *         was found for the given name.
     * @throws IllegalStateException if this parameter group already contains the
     *         {@linkplain ParameterDescriptorGroup#getMaximumOccurs maximum number of occurences}
     *         of subgroups of the given name.
     */
    @Extension
    ParameterValueGroup addGroup(String name) throws ParameterNotFoundException, IllegalStateException;

    /**
     * Returns a copy of this group of parameter values.
     * Included parameter values and subgroups are cloned recursively.
     *
     * @return A copy of this group of parameter values.
     */
    /*{ParameterValueGroup}*/ Object clone();
}