# Gmail IMAP folder support
# Copyright (C) 2008 Riccardo Murri <riccardo.murri@gmail.com>
# Copyright (C) 2002-2007 John Goerzen <jgoerzen@complete.org>
#
#    This program is free software; you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation; either version 2 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program; if not, write to the Free Software
#    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA

"""Folder implementation to support features of the Gmail IMAP server.
"""

from IMAP import IMAPFolder
import imaplib
from offlineimap import imaputil, imaplibutil
from copy import copy


class GmailFolder(IMAPFolder):
    """Folder implementation to support features of the Gmail IMAP server.
    Specifically, deleted messages are moved to folder `Gmail.TRASH_FOLDER`
    (by default: ``[Gmail]/Trash``) prior to expunging them, since
    Gmail maps to IMAP ``EXPUNGE`` command to "remove label".

    For more information on the Gmail IMAP server:
      http://mail.google.com/support/bin/answer.py?answer=77657&topic=12815
    """

    def __init__(self, imapserver, name, visiblename, accountname, repository):
        self.realdelete = repository.getrealdelete(name)
        self.trash_folder = repository.gettrashfolder(name)
        #: Gmail will really delete messages upon EXPUNGE in these folders
        self.real_delete_folders =  [ self.trash_folder, repository.getspamfolder() ]
        IMAPFolder.__init__(self, imapserver, name, visiblename, \
                            accountname, repository)

    def deletemessages_noconvert(self, uidlist):
        uidlist = [uid for uid in uidlist if uid in self.messagelist]
        if not len(uidlist):
            return        

        if self.realdelete and not (self.getname() in self.real_delete_folders):
            # IMAP expunge is just "remove label" in this folder,
            # so map the request into a "move into Trash"

            imapobj = self.imapserver.acquireconnection()
            try:
                imapobj.select(self.getfullname())
                result = imapobj.uid('copy',
                                     imaputil.listjoin(uidlist),
                                     self.trash_folder)
                assert result[0] == 'OK', \
                       "Bad IMAPlib result: %s" % result[0]
            finally:
                self.imapserver.releaseconnection(imapobj)
            for uid in uidlist:
                del self.messagelist[uid]
        else:
            IMAPFolder.deletemessages_noconvert(self, uidlist)
            
    def processmessagesflags(self, operation, uidlist, flags):
        # XXX: the imapobj.myrights(...) calls dies with an error
        # report from Gmail server stating that IMAP command
        # 'MYRIGHTS' is not implemented.  So, this
        # `processmessagesflags` is just a copy from `IMAPFolder`,
        # with the references to `imapobj.myrights()` deleted This
        # shouldn't hurt, however, Gmail users always have full
        # control over all their mailboxes (apparently).
        if len(uidlist) > 101:
            # Hack for those IMAP ervers with a limited line length
            self.processmessagesflags(operation, uidlist[:100], flags)
            self.processmessagesflags(operation, uidlist[100:], flags)
            return
        
        imapobj = self.imapserver.acquireconnection()
        try:
            imapobj.select(self.getfullname())
            r = imapobj.uid('store',
                            imaputil.listjoin(uidlist),
                            operation + 'FLAGS',
                            imaputil.flagsmaildir2imap(flags))
            assert r[0] == 'OK', 'Error with store: ' + '. '.join(r[1])
            r = r[1]
        finally:
            self.imapserver.releaseconnection(imapobj)

        needupdate = copy(uidlist)
        for result in r:
            if result == None:
                # Compensate for servers that don't return anything from
                # STORE.
                continue
            attributehash = imaputil.flags2hash(imaputil.imapsplit(result)[1])
            if not ('UID' in attributehash and 'FLAGS' in attributehash):
                # Compensate for servers that don't return a UID attribute.
                continue
            flags = attributehash['FLAGS']
            uid = long(attributehash['UID'])
            self.messagelist[uid]['flags'] = imaputil.flagsimap2maildir(flags)
            try:
                needupdate.remove(uid)
            except ValueError:          # Let it slide if it's not in the list
                pass
        for uid in needupdate:
            if operation == '+':
                for flag in flags:
                    if not flag in self.messagelist[uid]['flags']:
                        self.messagelist[uid]['flags'].append(flag)
                    self.messagelist[uid]['flags'].sort()
            elif operation == '-':
                for flag in flags:
                    if flag in self.messagelist[uid]['flags']:
                        self.messagelist[uid]['flags'].remove(flag)