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package org.apache.james.mailetcontainer.impl.matchers;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Optional;

import javax.mail.MessagingException;

import org.apache.james.core.MailAddress;
import org.apache.mailet.Mail;
import org.apache.mailet.Matcher;

import com.google.common.collect.Lists;

/**
 * This is the Not CompositeMatcher - consider what wasn't in the result set
 * of each child matcher. Of course it is easier to understand if it only
 * includes one matcher in the composition, the normal recommended use. @See
 * CompositeMatcher interface.
 *
 * @return Collection of Recipients from the Negated composition of the child
 *         Matcher(s).
 */
public class Not extends GenericCompositeMatcher {

    @Override
    public Collection<MailAddress> match(Mail mail) throws MessagingException {
        Collection<MailAddress> finalResult = Optional.ofNullable(Lists.newArrayList(mail.getRecipients())).orElse(new ArrayList<>());
        for (Matcher matcher : getMatchers()) {
            Collection<MailAddress> matcherResult = matcher.match(mail);
            if (matcherResult != null) {
                finalResult.removeAll(matcherResult);
            }
        }
        return finalResult;
    }
}
