/**
* Determines the set of {@link Message}s to be deleted from this <code>Conversation</code>.
* Assembles a new {@link PendingDelete} object encapsulating the data on the items to be deleted.
*
* <p>A message will be deleted unless:
*
* <ul>
* <li>The caller lacks {@link ACL#RIGHT_DELETE} permission on the <code>Message</code>.
* <li>The caller has specified a {@link MailItem.TargetConstraint} that explicitly excludes the
* <code>Message</code>.
* <li>The caller has specified the maximum change number they know about, and the
* (modification/content) change number on the <code>Message</code> is greater.
* </ul>
*
* As a result of all these constraints, no messages may actually be deleted.
*
* @throws ServiceException The following error codes are possible:
* <ul>
* <li><code>mail.MODIFY_CONFLICT</code> - if the caller specified a max change number and a
* modification check, and the modified change number of the <code>Message</code> is
* greater
* <li><code>service.FAILURE</code> - if there's a database failure fetching the message
* list
* </ul>
*/
@Override
PendingDelete getDeletionInfo() throws ServiceException {
PendingDelete info = new PendingDelete();
info.rootId = mId;
info.itemIds.add(getType(), mId);
if (mData.size == 0) return info;
List<Message> msgs = getMessages();
TargetConstraint tcon = mMailbox.getOperationTargetConstraint();
boolean excludeModify = false, excludeAccess = false;
for (Message child : msgs) {
// silently skip explicitly excluded messages, PERMISSION_DENIED messages, and MODIFY_CONFLICT
// messages
if (!TargetConstraint.checkItem(tcon, child)) continue;
else if (!child.canAccess(ACL.RIGHT_DELETE)) excludeAccess = true;
else if (!child.checkChangeID()) excludeModify = true;
else info.add(child.getDeletionInfo());
}
int totalDeleted = info.itemIds.size();
if (totalDeleted == 1) {
// if all messages have been excluded, some for "error" reasons, throw an exception
if (excludeAccess)
throw ServiceException.PERM_DENIED("you do not have sufficient permissions");
if (excludeModify) throw MailServiceException.MODIFY_CONFLICT();
}
if (totalDeleted != msgs.size() + 1) info.incomplete = true;
return info;
}
