/*
 * 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 org.eclipse.aether.internal.impl.transport.http;

import javax.inject.Inject;
import javax.inject.Named;
import javax.inject.Singleton;

import java.util.Map;
import java.util.function.Function;

import org.eclipse.aether.spi.connector.transport.http.ChecksumExtractor;
import org.eclipse.aether.spi.connector.transport.http.ChecksumExtractorStrategy;

import static java.util.Objects.requireNonNull;

/**
 * Checksum extractor.
 */
@Singleton
@Named
public final class DefaultChecksumExtractor implements ChecksumExtractor {
    private final Map<String, ChecksumExtractorStrategy> strategies;

    @Inject
    public DefaultChecksumExtractor(Map<String, ChecksumExtractorStrategy> strategies) {
        this.strategies = requireNonNull(strategies, "strategies");
    }

    @Override
    public Map<String, String> extractChecksums(Function<String, String> headerGetter) {
        for (ChecksumExtractorStrategy strategy : strategies.values()) {
            Map<String, String> extracted = strategy.extractChecksums(headerGetter);
            if (extracted != null && !extracted.isEmpty()) {
                return extracted;
            }
        }
        return null;
    }
}
