'''
mailbox_state.py - The module contains the MailboxState class.

Copyright (c) 2012 Intra2net AG
Author: Plamen Dimitrov

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 3 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.
'''

class MailboxState:
    """This class is responsible for containing and updating a mailbox data."""

    # class attributes
    # string with quotation marks for the mailbox name
    name = None
    # string for the mailbox uidvalidity
    uidvalidity = None
    # string for user owning the mailbox
    owner = None
    # list of bytes for last cached mail uids
    uids = None
    # tolerance with which the mailbox was synced
    tolerance = None
    # boolean flag for committing state changes
    needs_save = None
    # integer for found date conflicts
    date_conflicts = None
    # integer for found messages with missing received headers
    no_received_field = None
    # unique key for a mailbox
    key = None

    def __init__(self, name, uidvalidity, owner):
        self.name = name
        self.uidvalidity = uidvalidity
        self.owner = owner

        self.uids = []
        self.tolerance = 0
        self.needs_save = False

        self.date_conflicts = 0
        self.no_received_field = 0

        #special key to ensure better mailbox uniqueness
        self.key = self.name.strip('"') + self.uidvalidity

        return

    def __getstate__(self):
        """Prepares the MailboxState instance for pickling."""
        changed_dict = self.__dict__.copy()
        # remove the following attributes for pickling
        del changed_dict['needs_save']
        del changed_dict['date_conflicts']
        del changed_dict['no_received_field']
        return changed_dict

    def __setstate__(self, dict):
        """Prepares the MailboxState instance for unpickling."""
        self.name = dict["name"]
        self.uidvalidity = dict["uidvalidity"]
        self.owner = dict["owner"]

        self.uids = dict["uids"]
        self.tolerance = dict["tolerance"]
        self.needs_save = False

        self.date_conflicts = 0
        self.no_received_field = 0
        
        self.key = dict["key"]
        
        return    

    def __str__(self):
        """Makes the class printable."""
        return self.key

    def synchronize(self, list_ids, tolerance):
        """Adds new messages to the cache and returns a list of them.
        Confirm the changes to a mailbox to finally save it."""
        new_ids = []
        # cache is invalid if mailbox is synced with different tolerance
        if(len(self.uids)==0 or tolerance != self.tolerance):
            new_ids = list_ids
            self.tolerance = tolerance
        else:
            for uid in list_ids:
                try:
                    self.uids.index(uid)
                except ValueError:
                    new_ids.append(uid)
        # update this mailbox potential uids
        self.uids = list_ids
        return new_ids

    def confirm_change(self):
        """Confirm the chages to the cached mailbox and specify used tolerance."""
        self.needs_save = True
        return