001/*
002 * SPDX-License-Identifier: Apache-2.0
003 *
004 * Copyright 2024-2026 The Enola <https://enola.dev> Authors
005 *
006 * Licensed under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 *     https://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package dev.enola.common.io.resource.convert;
019
020import com.google.common.net.MediaType;
021
022import dev.enola.common.io.resource.AbstractResource;
023import dev.enola.common.io.resource.ReadableResource;
024import dev.enola.common.io.resource.WritableResource;
025
026import java.io.IOException;
027import java.nio.charset.Charset;
028
029/**
030 * Copies all characters from the input into the output resource.
031 *
032 * <p>Depending on their respective {@link MediaType#charset()}, this may change the text encoding!
033 */
034public class CharResourceConverter implements CatchingResourceConverter {
035
036    @Override
037    public boolean convertIntoThrows(ReadableResource from, WritableResource into)
038            throws IOException {
039        // TODO Test if this couldn't just be written as: (and delete private helpers)
040        // if (!from.mediaType().charset().equals(into.mediaType().charset()) {
041        if (hasCharset(from) && hasCharset(into) && !charset(from).equals(charset(into))) {
042            from.charSource().copyTo(into.charSink());
043            return true;
044        } else {
045            return false;
046        }
047    }
048
049    private boolean hasCharset(AbstractResource resource) {
050        return resource.mediaType().charset().isPresent();
051    }
052
053    private Charset charset(AbstractResource resource) {
054        return resource.mediaType().charset().get();
055    }
056}