# Copyright 2014  Lars Wirzenius
#
# 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.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# =*= License: GPL-3+ =*=


import mailbox
import os

import distixlib


class CannotLoadTicketError(distixlib.StructuredError):

    msg = "Can't load ticket from {directory}: {errno}: {strerror}"


class TicketLoader(object):

    def load_from_directory(self, dirname):
        metadata_filename = os.path.join(dirname, 'ticket.yaml')

        try:
            metadata = self._load_metadata(metadata_filename)
        except distixlib.CannotLoadMetadataError as e:
            raise CannotLoadTicketError(
                directory=dirname,
                errno=e.kwargs['errno'],
                strerror=e.kwargs['strerror'])

        ticket = distixlib.Ticket()
        ticket.set_ticket_metadata(metadata)
        self._add_messages_to_ticket(ticket, self._load_messages(dirname))
        ticket.make_clean()
        return ticket

    def _load_metadata(self, filename):  # pragma: no cover
        metadata_loader = distixlib.MetadataLoader()
        return metadata_loader.load_from_file(filename)

    def _load_messages(self, dirname):  # pragma: no cover
        maildir_name = os.path.join(dirname, 'Maildir')
        maildir = mailbox.Maildir(maildir_name, factory=None)
        return maildir.values()

    def _add_messages_to_ticket(self, ticket, messages):
        for message in messages:  # pragma: no cover
            ticket.add_message(message)