# Copyright (C) 2009-2012 Chris Ball <cjb@laptop.org>
#                         W. Trevor King <wking@tremily.us>
#
# This file is part of Bugs Everywhere.
#
# Bugs Everywhere 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.
#
# Bugs Everywhere 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
# Bugs Everywhere.  If not, see <http://www.gnu.org/licenses/>.

import libbe
import libbe.command
import libbe.command.util
import libbe.util.utility


DUE_TAG = 'DUE:'


class Due (libbe.command.Command):
    """Set bug due dates

    >>> import sys
    >>> import libbe.bugdir
    >>> bd = libbe.bugdir.SimpleBugDir(memory=False)
    >>> io = libbe.command.StringInputOutput()
    >>> io.stdout = sys.stdout
    >>> ui = libbe.command.UserInterface(io=io)
    >>> ui.storage_callbacks.set_storage(bd.storage)
    >>> cmd = Due(ui=ui)

    >>> ret = ui.run(cmd, args=['/a'])
    No due date assigned.
    >>> ret = ui.run(cmd, args=['/a', 'Thu, 01 Jan 1970 00:00:00 +0000'])
    >>> ret = ui.run(cmd, args=['/a'])
    Thu, 01 Jan 1970 00:00:00 +0000
    >>> ret = ui.run(cmd, args=['/a', 'none'])
    >>> ret = ui.run(cmd, args=['/a'])
    No due date assigned.
    >>> ui.cleanup()
    >>> bd.cleanup()
    """
    name = 'due'

    def __init__(self, *args, **kwargs):
        libbe.command.Command.__init__(self, *args, **kwargs)
        self.args.extend([
                libbe.command.Argument(
                    name='bug-id', metavar='BUG-ID',
                    completion_callback=libbe.command.util.complete_bug_id),
                libbe.command.Argument(
                    name='due', metavar='DUE', optional=True),
                ])

    def _run(self, **params):
        bugdirs = self._get_bugdirs()
        bugdir,bug,comment = (
            libbe.command.util.bugdir_bug_comment_from_user_id(
                bugdirs, params['bug-id']))
        if params['due'] is None:
            due_time = get_due(bug)
            if due_time is None:
                print('No due date assigned.', file=self.stdout)
            else:
                print(libbe.util.utility.time_to_str(due_time), file=self.stdout)
        else:
            if params['due'] == 'none':
                remove_due(bug)
            else:
                due_time = libbe.util.utility.str_to_time(params['due'])
                set_due(bug, due_time)

    def _long_help(self):
        return """
If no DATE is specified, the bug's current due date is printed.  If
DATE is specified, it will be assigned to the bug.
"""

# internal helper functions

def _generate_due_string(time):
    return "%s%s" % (DUE_TAG, libbe.util.utility.time_to_str(time))

def _parse_due_string(string):
    assert string.startswith(DUE_TAG)
    return libbe.util.utility.str_to_time(string[len(DUE_TAG):])

# functions exposed to other modules

def get_due(bug):
    matched = []
    for line in bug.extra_strings:
        if line.startswith(DUE_TAG):
            matched.append(_parse_due_string(line))
    if len(matched) == 0:
        return None
    if len(matched) > 1:
        raise Exception('Several due dates for %s?:\n  %s'
                        % (bug.uuid, '\n  '.join(matched)))
    return matched[0]

def remove_due(bug):
    estrs = bug.extra_strings
    for due_str in [s for s in estrs if s.startswith(DUE_TAG)]:
        estrs.remove(due_str)
    bug.extra_strings = estrs # reassign to notice change

def set_due(bug, time):
    remove_due(bug)
    estrs = bug.extra_strings
    estrs.append(_generate_due_string(time))
    bug.extra_strings = estrs # reassign to notice change