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package org.apache.james.mailbox.store.search.comparator;

import java.io.StringReader;
import java.util.Comparator;
import java.util.Date;
import java.util.List;

import org.apache.james.mailbox.store.mail.model.Header;
import org.apache.james.mailbox.store.mail.model.Message;
import org.apache.james.mime4j.field.datetime.DateTime;
import org.apache.james.mime4j.field.datetime.parser.DateTimeParser;
import org.apache.james.mime4j.field.datetime.parser.ParseException;

/**
 * {@link Comparator} which works like stated in RFC5256 2.2 Sent Date
 *
 */
public class SentDateComparator implements Comparator<Message<?>>{



    private final static Comparator<Message<?>> SENTDATE = new SentDateComparator(false);
    private final static Comparator<Message<?>> REVERSE_SENTDATE = new ReverseComparator(new SentDateComparator(true));
    
    private final boolean reverse;

    public SentDateComparator(boolean reverse) {
        this.reverse = reverse;
    }
    
    @Override
    public int compare(Message<?> o1, Message<?> o2) {
        Date date1 = getSentDate(o1);
        Date date2 = getSentDate(o2);
        int i = date1.compareTo(date2);
        
        // sent date was the same so use the uid as tie-breaker
        if (i == 0) {
            return UidComparator.uid(reverse).compare(o1, o2);
        }
        return 0;
    }
    
    private Date getSentDate(Message<?> message) {
        final List<Header> headers = message.getHeaders();
        for (Header header:headers) {
            final String name = header.getFieldName();
            if ("Date".equalsIgnoreCase(name)) {
                final String value = header.getValue();
                    final StringReader reader = new StringReader(value);
                    try {
                        DateTime dateTime = new DateTimeParser(reader).parseAll();
                        return dateTime.getDate();
                    } catch (ParseException e) {
                        break;
                    }
                
            }
        }
        return message.getInternalDate();
    }
    
    public static Comparator<Message<?>> sentDate(boolean reverse){
        if (reverse) {
            return REVERSE_SENTDATE;
        } else {
            return SENTDATE;
        }
    }

}

@@ -3119,24 +3119,145 @@
 eption e) %7B%0A
+                        // if we can not parse the date header we should break here and use the internaldate as fallback%0A
             

Add a comment. See MAILBOX-78