/*
 *    GeoAPI - Java interfaces for OGC/ISO standards
 *    Copyright © 2022-2024 Open Geospatial Consortium, Inc.
 *    http://www.geoapi.org
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */
package org.opengis.metadata.quality;

import java.util.Map;
import java.util.Set;
import java.util.List;
import java.util.Collection;
import java.util.Optional;
import org.opengis.util.CodeList;
import org.opengis.annotation.UML;
import org.opengis.referencing.operation.Matrix;
import org.opengis.geoapi.internal.Vocabulary;

import static org.opengis.annotation.Obligation.*;
import static org.opengis.annotation.Specification.*;


/**
 * Structure for reporting a complex data quality result.
 *
 * @author  Alexis Gaillard (Geomatys)
 * @author  Martin Desruisseaux (Geomatys)
 * @version 3.1
 * @since   3.1
 */
@Vocabulary(capacity=6, parameters=1)
@UML(identifier="DQM_ValueStructure", specification=ISO_19157)
public final class ValueStructure extends CodeList<ValueStructure> {
    /**
     * Serial number for compatibility with different versions.
     */
    private static final long serialVersionUID = 455647811714853262L;

    /**
     * Finite, unordered collection of related items that may be repeated.
     * The corresponding Java type is {@link java.util.Collection}.
     */
    @UML(identifier="bag", obligation=CONDITIONAL, specification=ISO_19157)
    public static final ValueStructure BAG = new ValueStructure("BAG", Collection.class);

    /**
     * Unordered collection of related items with no repetition.
     * The corresponding Java type is {@link java.util.Set}.
     */
    @UML(identifier="set", obligation=CONDITIONAL, specification=ISO_19157)
    public static final ValueStructure SET = new ValueStructure("SET", Set.class);

    /**
     * Finite, ordered collection of related items that may be repeated.
     * The corresponding Java type is {@link java.util.List}.
     */
    @UML(identifier="sequence", obligation=CONDITIONAL, specification=ISO_19157)
    public static final ValueStructure SEQUENCE = new ValueStructure("SEQUENCE", List.class);

    /**
     * An arrangement of data in which each item may be identified by means of arguments or keys.
     * The corresponding Java type is {@link java.util.Map}.
     */
    @UML(identifier="table", obligation=CONDITIONAL, specification=ISO_19157)
    public static final ValueStructure TABLE = new ValueStructure("TABLE", Map.class);

    /**
     * Rectangular array of numbers.
     * The corresponding Java type is {@link org.opengis.referencing.operation.Matrix}.
     */
    @UML(identifier="matrix", obligation=CONDITIONAL, specification=ISO_19157)
    public static final ValueStructure MATRIX = new ValueStructure("MATRIX", Matrix.class);

    /**
     * Feature that acts as a function to return values from its range
     * for any direct position within its spatial, temporal or spatiotemporal domain.
     */
    @UML(identifier="coverage", obligation=CONDITIONAL, specification=ISO_19157)
    public static final ValueStructure COVERAGE = new ValueStructure("COVERAGE");

    /**
     * The values in the order they should be tested by {@link #valueOf(Class)}.
     * In particular, {@link #SEQUENCE} and {@link #SET} shall be tested before {@link #BAG}.
     */
    private static final ValueStructure[] PREDEFINED = {SEQUENCE, SET, TABLE, BAG, MATRIX};

    /**
     * Base Java type for objects storing this kind of structure, or {@code null} if unspecified.
     */
    private final Class<?> type;

    /**
     * Constructs an element of the given name.
     *
     * This is invoked by reflection by {@link #valueOf(Class, String)}
     * when a new code needs to be created. This is indirectly required
     * for {@link #valueOf(String)} implementation.
     *
     * @param name  the name of the new element. This name shall not be in use by another element of this type.
     */
    private ValueStructure(final String name) {
        super(name);
        type = null;
    }

    /**
     * Constructs an element of the given name.
     *
     * @param name  the name of the new element. This name shall not be in use by another element of this type.
     * @param type  base Java interface for objects storing this kind of structure.
     */
    private ValueStructure(final String name, final Class<?> type) {
        super(name);
        this.type = type;
    }

    /**
     * Returns the list of {@code ValueStructure}s.
     *
     * @return the list of codes declared in the current JVM.
     */
    public static ValueStructure[] values() {
        return values(ValueStructure.class);
    }

    /**
     * Returns the list of codes of the same kind as this code list element.
     * Invoking this method is equivalent to invoking {@link #values()}, except that
     * this method can be invoked on an instance of the parent {@code CodeList} class.
     *
     * @return all code {@linkplain #values() values} for this code list.
     */
    @Override
    public ValueStructure[] family() {
        return values();
    }

    /**
     * Returns the structure that matches the given string, or returns a new one if none match it.
     * This methods returns the first instance (in declaration order) for which the {@linkplain #name() name}
     * is {@linkplain String#equalsIgnoreCase(String) equals, ignoring case}, to the given name.
     * If no existing instance is found, then a new one is created for the given name.
     *
     * @param  code  the name of the code to fetch or to create.
     * @param  type  Java type corresponding to the value, or {@code null} if unspecified.
     *               This is used only if a new code list element is created.
     * @return a code matching the given name.
     */
    public static ValueStructure valueOf(String code, final Class<?> type) {
        return valueOf(ValueStructure.class, code, (name) -> new ValueStructure(name, type)).get();
    }

    /**
     * Returns the structure corresponding to the given class.
     * The mapping between Java type and {@code ValueStructure} code list is as below:
     *
     * <table class="ogc">
     *   <caption>Mapping from Java type to {@code ValueStructure}</caption>
     *   <tr><th>Java or GeoAPI type</th>                              <th>Code list value</th></tr>
     *   <tr><td>{@link java.util.Collection}</td>                     <td>{@link #BAG}</td></tr>
     *   <tr><td>{@link java.util.Set}</td>                            <td>{@link #SET}</td></tr>
     *   <tr><td>{@link java.util.List}</td>                           <td>{@link #SEQUENCE}</td></tr>
     *   <tr><td>{@link java.util.Map}</td>                            <td>{@link #TABLE}</td></tr>
     *   <tr><td>{@link org.opengis.referencing.operation.Matrix}</td> <td>{@link #MATRIX}</td></tr>
     * </table>
     *
     * @param  type  the Java type for which to get a structure, or {@code null} if unknown.
     * @return structure for the given type, or an empty value if there is no value for the given type.
     */
    public static Optional<ValueStructure> valueOf(final Class<?> type) {
        if (type != null) {
            for (final ValueStructure value : PREDEFINED) {
                if (value.type.isAssignableFrom(type)) {
                    return Optional.of(value);
                }
            }
        }
        return Optional.empty();
    }

    /**
     * Returns the Java type corresponding to this code list value.
     * The Java type is documented in each code list value.
     *
     * @departure integration
     *   Added for integration with the Java language.
     *
     * @return the Java type for this code list value.
     */
    public Optional<Class<?>> toJavaType() {
        return Optional.ofNullable(type);
    }
}