/*
 * Copyright (C) The Apache Software Foundation. All rights reserved.
 *
 * This software is published under the terms of the Apache Software License
 * version 1.1, a copy of which has been included with this distribution in
 * the LICENSE file.
 */
package org.apache.james.mailrepository;

import org.apache.james.core.MailImpl;
import org.apache.james.services.SpoolRepository;
import org.apache.mailet.Mail;

import java.util.ConcurrentModificationException;
import java.util.Iterator;

/**
 * Implementation of a MailRepository on a FileSystem.
 *
 * Requires a configuration element in the .conf.xml file of the form:
 *       <repository
 *           class="org.apache.james.mailrepository.FileMemMailRepository">
 *         <protocols>
 *           <protocol>filemem</protocol>
 *         </protocols>
 *         <types>
 *           <type>MAIL</type>
 *         </types>
 *       </repository>
 *       <repository
 *           class="org.apache.james.mailrepository.FileMemSpoolRepository">
 *         <protocols>
 *           <protocol>filemem</protocol>
 *         </protocols>
 *         <types>
 *           <type>SPOOL</type>
 *         </types>
 *       </repository>
 * and in the spoolrepository section of the form
 *      <repository destinationURL="filemem://none/"
 *           type="SPOOL"
 *           destination="${path-to-root-dir-for-repository/">
 *       </repository>
 * Requires a logger called MailRepository.
 *
 * @version 1.0.0, 24/04/1999
 * @author  Federico Barbieri <scoobie@pop.systemy.it>
 * @author Charles Benett <charles@benett1.demon.co.uk>
 */
public class FileMemSpoolRepository
    extends FileMemMailRepository
    implements SpoolRepository {

    public synchronized String accept() {
    	if (DEEP_DEBUG) {
            getLogger().debug("Method accept() called");
        }
        while (true) {
            try {
                for(Iterator it = list(); it.hasNext(); ) {

                    String s = it.next().toString();
                    if (DEEP_DEBUG) {
                        getLogger().debug("Found item " + s
                                                      + " in spool.");
                    }
                    if (lock(s)) {
                        if (DEEP_DEBUG) {
                            getLogger().debug("accept() has locked: "
                                                          + s);
                        }
                        return s;
                    }
                }

                wait();
            } catch (InterruptedException ignored) {
            	if (DEEP_DEBUG) {
                  getLogger().debug("FileMemSpoolRepository accept() catch InterruptionException");
                }
                return "";
            } catch (ConcurrentModificationException ignoredAlso) {
               // Should never get here now that list methods clones keyset for iterator
            }
        }
    }

    public synchronized String accept(long delay) {
	    if (DEEP_DEBUG) {
            getLogger().debug("Method accept(delay) called");
        }
        while (true) {
            long youngest = 0;
            for (Iterator it = list(); it.hasNext(); ) {
                String s = it.next().toString();
		        if (DEEP_DEBUG) {
                    getLogger().debug("Found item " + s
                                                  + " in spool.");
                }
                if (lock(s)) {
		            if (DEEP_DEBUG) {
                        getLogger().debug("accept(delay) has"
                                                      + " locked: "  + s);
                    }
                    //We have a lock on this object... let's grab the message
                    //  and see if it's a valid time.
                    MailImpl mail = retrieve(s);
                    if (mail.getState().equals(Mail.ERROR)) {
                        //Test the time...
                        long timeToProcess = delay + mail.getLastUpdated().getTime();
                        if (System.currentTimeMillis() > timeToProcess) {
                            //We're ready to process this again
                            return s;
                        } else {
                            //We're not ready to process this.
                            if (youngest == 0 || youngest > timeToProcess) {
                                //Mark this as the next most likely possible mail to process
                                youngest = timeToProcess;
                            }
                        }
                    } else {
                        //This mail is good to go... return the key
                        return s;
                    }
                }
            }
            //We did not find any... let's wait for a certain amount of time
            try {
                if (youngest == 0) {
                    wait();
                } else {
                    wait(youngest - System.currentTimeMillis());
                }
            } catch (InterruptedException ignored) {
                if (DEEP_DEBUG) {
                  getLogger().debug("FileMemSpoolRepository accept(delay) catch InterruptionException");
                }
                return "";
            } catch (ConcurrentModificationException ignoredAlso) {
               // Should never get here now that list methods clones keyset for iterator
            }
        }
    }
}