# Copyright (C) 2005-2012 Aaron Bentley <abentley@panoramicfeedback.com>
#                         Chris Ball <cjb@laptop.org>
#                         Gianluca Montecchi <gian@grys.it>
#                         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.bugdir
import libbe.bug
import libbe.command
import libbe.command.util
import libbe.storage

import libbe.diff

class Diff (libbe.command.Command):
    __doc__ = """Compare bug reports with older tree

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

    >>> original = bd.storage.commit('Original status')
    >>> bug = bd.bug_from_uuid('a')
    >>> bug.status = 'closed'
    >>> changed = bd.storage.commit('Closed bug a')
    >>> ret = ui.run(cmd, args=[original])
    Modified bugs:
      abc/a:cm: Bug A
        Changed bug settings:
          status: open -> closed
    >>> ret = ui.run(cmd, {'subscribe':'%(bugdir_id)s:mod', 'uuids':True}, [original])
    a
    >>> bd.storage.versioned = False
    >>> ret = ui.run(cmd, args=[original])
    Traceback (most recent call last):
      ...
    UserError: This repository is not revision-controlled.
    >>> ui.cleanup()
    >>> bd.cleanup()
    """ % {'bugdir_id':libbe.diff.BUGDIR_ID}
    name = 'diff'

    def __init__(self, *args, **kwargs):
        libbe.command.Command.__init__(self, *args, **kwargs)
        self.options.extend([
                libbe.command.Option(name='repo', short_name='r',
                    help='Compare with repository in REPO instead'
                         ' of the current repository.',
                    arg=libbe.command.Argument(
                        name='repo', metavar='REPO',
                        completion_callback=libbe.command.util.complete_path)),
                libbe.command.Option(name='subscribe', short_name='s',
                    help='Only print changes matching SUBSCRIPTION, '
                    'subscription is a comma-separated list of ID:TYPE '
                    'tuples.  See `be subscribe --help` for descriptions '
                    'of ID and TYPE.',
                    arg=libbe.command.Argument(
                        name='subscribe', metavar='SUBSCRIPTION')),
                libbe.command.Option(name='uuids', short_name='u',
                    help='Only print the changed bug UUIDS.'),
                ])
        self.args.extend([
                libbe.command.Argument(
                    name='revision', metavar='REVISION', default=None,
                    optional=True)
                ])

    def _run(self, **params):
        try:
            subscriptions = libbe.diff.subscriptions_from_string(
                params['subscribe'])
        except ValueError as e:
            raise libbe.command.UserError(e.msg)
        bugdirs = self._get_bugdirs()
        for uuid,bugdir in sorted(bugdirs.items()):
            self.diff(bugdir, subscriptions, params=params)


    def diff(self, bugdir, subscriptions, params):
        if params['repo'] is None:
            if bugdir.storage.versioned == False:
                raise libbe.command.UserError(
                    'This repository is not revision-controlled.')
            if params['revision'] is None: # get the most recent revision
                params['revision'] = bugdir.storage.revision_id(-1)
            old_bd = libbe.bugdir.RevisionedBugDir(bugdir, params['revision'])
        else:
            old_storage = libbe.storage.get_storage(params['repo'])
            old_storage.connect()
            old_bd_current = libbe.bugdir.BugDir(old_storage, from_disk=True)
            if params['revision'] is None: # use the current working state
                old_bd = old_bd_current
            else:
                if old_bd_current.storage.versioned == False:
                    raise libbe.command.UserError(
                        '{} is not revision-controlled.'.format(
                            bugdir.storage.repo))
                old_bd = libbe.bugdir.RevisionedBugDir(old_bd_current,revision)
        d = libbe.diff.Diff(old_bd, bugdir)
        tree = d.report_tree(subscriptions)

        if params['uuids'] == True:
            uuids = []
            bugs = tree.child_by_path('/bugs')
            for bug_type in bugs:
                uuids.extend([bug.name for bug in bug_type])
            print('\n'.join(uuids), file=self.stdout)
        else :
            rep = tree.report_string()
            if rep is not None:
                print(rep, file=self.stdout)
        return 0

    def _long_help(self):
        return """
Uses the storage backend to compare the current tree with a previous
tree, and prints a pretty report.  If REVISION is given, it is a
specifier for the particular previous tree to use.  Specifiers are
specific to their storage backend.

Besides the standard summary output, you can use the options to output
UUIDS for the different categories.  This output can be used as the
input to 'be show' to get an understanding of the current status.
"""