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package org.apache.james.transport.matchers;

import org.apache.mailet.GenericMatcher;
import org.apache.mailet.Mail;
import org.apache.mailet.MailAddress;
import org.apache.oro.text.regex.MalformedPatternException;
import org.apache.oro.text.regex.Pattern;
import org.apache.oro.text.regex.Perl5Compiler;
import org.apache.oro.text.regex.Perl5Matcher;

import java.util.Collection;

import javax.mail.MessagingException;

/**
 * <P>Matches mails that are sent by a sender whose address matches a regular expression.</P>
 * <P>Is equivalent to the {@link RecipientIsRegex} matcher but matching on the sender.</P>
 * <P>Configuration string: a regular expression.</P>
 * <PRE><CODE>
 * <mailet match="SenderIsRegex=<regular-expression>" class="<any-class>">
 * </CODE></PRE>
 * <P>The example below will match any sender in the format user@log.anything</P>
 * <PRE><CODE>
 * <mailet match="SenderIsRegex=(.*)@log\.(.*)" class="<any-class>">
 * </mailet>
 * </CODE></PRE>
 * <P>Another example below will match any sender having some variations of the string
 * <I>mp3</I> inside the username part.</P>
 * <PRE><CODE>
 * <mailet match="SenderIsRegex=(.*)(mp3|emmepitre)(.*)@" class="<any-class>">
 * </mailet>
 * </CODE></PRE>
 *
 * @version CVS $Revision: 494012 $ $Date: 2007-01-08 11:23:58 +0100 (Mo, 08 Jan 2007) $
 * @since 2.2.0
 */
public class SenderIsRegex extends GenericMatcher {
    Pattern pattern   = null;

    public void init() throws MessagingException {
        String patternString = getCondition();
        if (patternString == null) {
            throw new MessagingException("Pattern is missing");
        }
        
        patternString = patternString.trim();
        Perl5Compiler compiler = new Perl5Compiler();
        try {
            pattern = compiler.compile(patternString, Perl5Compiler.READ_ONLY_MASK);
        } catch(MalformedPatternException mpe) {
            throw new MessagingException("Malformed pattern: " + patternString, mpe);
        }
    }

    public Collection match(Mail mail) {
        MailAddress mailAddress = mail.getSender();
        if (mailAddress == null) {
            return null;
        }
        String senderString = mailAddress.toString();
        Perl5Matcher matcher  = new Perl5Matcher();
        if (matcher.matches(senderString, pattern)) {
            return mail.getRecipients();
        }
        return null;
    }
}