#! /usr/bin/python
#
# Author: Rodney Dawes <rodney.dawes@canonical.com>
#
# Copyright 2009 Canonical Ltd.
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU General Public License version 3, as published
# by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranties of
# MERCHANTABILITY, SATISFACTORY QUALITY, 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/>.

from __future__ import with_statement

import os
import sys

from xdg.BaseDirectory import xdg_cache_home

from threading import Thread

from launchpadlib.launchpad import Launchpad, EDGE_SERVICE_ROOT
from launchpadlib.credentials import Credentials

class MSMain(object):

    def __init__(self, project):
        self.project = project

        self.cachedir = os.path.join(xdg_cache_home, "lptools")
        if not os.path.isdir(self.cachedir):
            os.makedirs(self.cachedir)

        self.launchpad = None
        self.thread = None
        self.buffer = []

    def __start_calendar(self):
        self.buffer.append("BEGIN:VCALENDAR")
        self.buffer.append("VERSION:2.0")
        self.buffer.append("PRODID:-//Canonical/lptools/NONSGML v1.0//EN")

    def __end_calendar(self):
        self.buffer.append("END:VCALENDAR")

    def __convert_to_ical(self, item):
        for milestone in item.all_milestones:
            if not milestone.date_targeted:
                continue
            self.buffer.append("BEGIN:VEVENT")
            date = milestone.date_targeted.strftime("%Y%m%dT%H%M%SZ")
            self.buffer.append("DTSTART:%s" % date)
            self.buffer.append("SUMMARY:%s" % milestone.name)
            self.buffer.append("END:VEVENT")

    def __login_and_go(self):
        credsfile = os.path.join(self.cachedir, "credentials")

        if os.path.exists(credsfile):
            creds = Credentials()

            with file(credsfile) as f:
                creds.load(f)
                self.launchpad = Launchpad(creds, EDGE_SERVICE_ROOT)
        else:
            self.launchpad = Launchpad.get_token_and_login(
                'lptools',
                EDGE_SERVICE_ROOT,
                self.cachedir)
            with file(credsfile, "w") as f:
                self.launchpad.credentials.save(f)

        self.__start_calendar()
        try:
            lp_project = self.launchpad.project_groups[self.project]
        except KeyError:
            lp_project = self.launchpad.projects[self.project]
        finally:
            self.__convert_to_ical(lp_project)
            self.__end_calendar()
            print self.calendar()

    def run(self):
        self.thread = Thread(target=self.__login_and_go).start()

    def stop(self):
        self.thread.join()

    def calendar(self):
        return "\n".join(self.buffer)

if __name__ == "__main__":
    try:
        project = sys.argv[1]
    except IndexError:
        print "Usage: %s <project>" % sys.argv[0]
        exit(1)

    try:
        mt = MSMain(project=sys.argv[1])
        mt.run()
    except KeyboardInterrupt:
        mt.stop()