ChainedAdderReference.java

/*
 * Copyright 2023 Terminal Utils Authors
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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 net.morimekta.terminal.args.reference;

import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.util.Collection;
import java.util.function.Supplier;

/**
 * Adder reference that chains through a settable reference, creating the
 * collection if it does not yet exist.
 */
public class ChainedAdderReference implements AdderReference {
    private final SettableReference            chained;
    private final Class<?>                     itemType;
    private final Supplier<Collection<Object>> mkCollection;

    public ChainedAdderReference(
            SettableReference chained,
            Class<?> itemType,
            Supplier<Collection<Object>> mkCollection) {
        this.chained = chained;
        this.itemType = itemType;
        this.mkCollection = mkCollection;
    }

    @Override
    public void add(Object value) {
        @SuppressWarnings("unchecked")
        var collection = (Collection<Object>) chained.get();
        if (collection == null) {
            collection = mkCollection.get();
            chained.set(collection);
        }
        collection.add(value);
    }

    @Override
    public Class<?> getItemType() {
        return itemType;
    }

    @Override
    public String getName() {
        return chained.getName();
    }

    @Override
    public String getUsage() {
        return "Add value to " + getName();
    }

    @Override
    public Object get() {
        return chained.get();
    }

    @Override
    public boolean isAnnotationPresent(Class<? extends Annotation> annotation) {
        return chained.isAnnotationPresent(annotation);
    }

    @Override
    public <A extends Annotation> A getAnnotation(Class<A> annotation) {
        return chained.getAnnotation(annotation);
    }

    @Override
    public Class<?> getType() {
        return chained.getType();
    }

    @Override
    public Type getGenericType() {
        return chained.getGenericType();
    }
}