001/* -*- mode: Java; c-basic-offset: 2; indent-tabs-mode: nil; coding: utf-8-unix -*-
002 *
003 * Copyright © 2024–2025 microBean™.
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
006 * the License. You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
011 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
012 * specific language governing permissions and limitations under the License.
013 */
014package org.microbean.bean;
015
016import java.lang.constant.ClassDesc;
017import java.lang.constant.Constable;
018import java.lang.constant.ConstantDesc;
019import java.lang.constant.DynamicConstantDesc;
020import java.lang.constant.MethodHandleDesc;
021
022import java.util.List;
023import java.util.Optional;
024
025import javax.lang.model.type.TypeMirror;
026
027import org.microbean.attributes.Attributed;
028import org.microbean.attributes.Attributes;
029
030import org.microbean.constant.Constables;
031
032import static java.lang.constant.ConstantDescs.BSM_INVOKE;
033import static java.lang.constant.ConstantDescs.CD_List;
034import static java.util.Arrays.asList;
035
036/**
037 * A pairing of a {@link TypeMirror} with a {@link List} of {@link Attributes}s.
038 *
039 * @param type a {@link TypeMirror}
040 *
041 * @param attributes a {@link List} of {@link Attributes}s
042 *
043 * @author <a href="https://about.me/lairdnelson" target="_top">Laird Nelson</a>
044 */
045public final record AttributedType(TypeMirror type, List<Attributes> attributes) implements Attributed, Constable {
046
047  /**
048   * Creates a new {@link AttributedType}.
049   *
050   * @param type a {@link TypeMirror}; must not be {@code null}; must be a {@linkplain
051   * javax.lang.model.type.TypeKind#isPrimitive() primitive}, {@linkplain javax.lang.model.type.TypeKind#ARRAY array} or
052   * {@linkplain javax.lang.model.type.TypeKind#DECLARED declared} type
053   *
054   * @param attributes an array of {@link Attributes}; may be {@code null}
055   *
056   * @exception NullPointerException if {@code type} is {@code null}
057   *
058   * @exception IllegalArgumentException if {@code type} is the wrong kind of type
059   */
060  public AttributedType(final TypeMirror type, final Attributes... attributes) {
061    this(type, attributes == null || attributes.length <= 0 ? List.of() : asList(attributes));
062  }
063
064  /**
065   * Creates a new {@link AttributedType}.
066   *
067   * @param type a {@link TypeMirror}; must not be {@code null}; must be a {@linkplain
068   * javax.lang.model.type.TypeKind#isPrimitive() primitive}, {@linkplain javax.lang.model.type.TypeKind#ARRAY array} or
069   * {@linkplain javax.lang.model.type.TypeKind#DECLARED declared} type
070   *
071   * @param attributes a {@link List} of {@link Attributes}; must not be {@code null}
072   *
073   * @exception NullPointerException if either argument is {@code null}
074   *
075   * @exception IllegalArgumentException if {@code type} is the wrong kind of type
076   */
077  public AttributedType {
078    switch (type.getKind()) {
079    case ARRAY, BOOLEAN, BYTE, CHAR, DECLARED, DOUBLE, FLOAT, INT, LONG, SHORT:
080      break;
081    case ERROR, EXECUTABLE, INTERSECTION, MODULE, NONE, NULL, OTHER, PACKAGE, TYPEVAR, UNION, VOID, WILDCARD:
082    default:
083      throw new IllegalArgumentException("type: " + type);
084    }
085    attributes = List.copyOf(attributes);
086  }
087
088  /**
089   * Creates a new {@link AttributedType}.
090   *
091   * @param type a {@link TypeMirror}; must not be {@code null}; must be a {@linkplain
092   * javax.lang.model.type.TypeKind#isPrimitive() primitive}, {@linkplain javax.lang.model.type.TypeKind#ARRAY array} or
093   * {@linkplain javax.lang.model.type.TypeKind#DECLARED declared} type
094   *
095   * @exception NullPointerException if {@code type} is {@code null}
096   *
097   * @exception IllegalArgumentException if {@code type} is the wrong kind of type
098   */
099  public AttributedType(final TypeMirror type) {
100    this(type, List.of());
101  }
102
103  /**
104   * Returns an {@link Optional} containing a {@link ConstantDesc} describing this {@link AttributedType}, or an
105   * {@linkplain Optional#isEmpty() empty <code>Optional</code>} if it could not be described.
106   *
107   * @return an {@link Optional} containing a {@link ConstantDesc} describing this {@link AttributedType}, or an
108   * {@linkplain Optional#isEmpty() empty <code>Optional</code>} if it could not be describe; never {@code null}
109   */
110  @Override // Constable
111  public Optional<? extends ConstantDesc> describeConstable() {
112    return this.type() instanceof Constable t ? t.describeConstable() : Optional.<ConstantDesc>empty()
113      .flatMap(typeDesc -> Constables.describeConstable(this.attributes())
114               .map(attributesDesc -> DynamicConstantDesc.of(BSM_INVOKE,
115                                                             MethodHandleDesc.ofConstructor(ClassDesc.of(this.getClass().getName()),
116                                                                                            ClassDesc.of(TypeMirror.class.getName()),
117                                                                                            CD_List),
118                                                             typeDesc,
119                                                             attributesDesc)));
120  }
121
122  /**
123   * Returns an {@link AttributedType} comprising the supplied arguments.
124   *
125   * @param type a {@link TypeMirror}; must not be {@code null}; must be a {@linkplain
126   * javax.lang.model.type.TypeKind#isPrimitive() primitive}, {@linkplain javax.lang.model.type.TypeKind#ARRAY array} or
127   * {@linkplain javax.lang.model.type.TypeKind#DECLARED declared} type
128   *
129   * @param attributes an array of {@link Attributes}; may be {@code null}
130   *
131   * @return a non-{@code null} {@link AttributedType}
132   *
133   * @exception NullPointerException if {@code type} is {@code null}
134   *
135   * @exception IllegalArgumentException if {@code type} is the wrong kind of type
136   */
137  public static final AttributedType of(final TypeMirror type, Attributes... attributes) {
138    return new AttributedType(type, attributes == null || attributes.length <= 0 ? List.of() : asList(attributes));
139  }
140
141}