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 * 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   *
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 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       *
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package org.apache.james.transport.matchers;

import java.util.Collection;
import java.util.Map;
import java.util.stream.Stream;

import javax.mail.MessagingException;

import org.apache.james.core.Domain;
import org.apache.james.core.MailAddress;
import org.apache.mailet.Mail;
import org.apache.mailet.base.GenericMatcher;

import com.github.steveash.guavate.Guavate;

/**
 * Matches mail to Domains which are local
 * .
 */
public class HostIsLocal extends GenericMatcher {
    @Override
    public Collection<MailAddress> match(Mail mail) throws MessagingException {
        return recipientsByDomains(mail)
            .flatMap(this::hasLocalDomain)
            .collect(Guavate.toImmutableList());
    }

    private Stream<MailAddress> hasLocalDomain(Map.Entry<Domain, Collection<MailAddress>> entry) {
        if (getMailetContext().isLocalServer(entry.getKey())) {
            return entry.getValue().stream();
        }
        return Stream.empty();
    }

    private Stream<Map.Entry<Domain, Collection<MailAddress>>> recipientsByDomains(Mail mail) {
        return mail.getRecipients()
            .stream()
            .collect(Guavate.toImmutableListMultimap(MailAddress::getDomain))
            .asMap()
            .entrySet()
            .stream();
    }
}
