# (c) 2012-2014, Michael DeHaan <michael.dehaan@gmail.com>
#
# This file is part of Ansible
#
# Ansible 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.
#
# Ansible 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 Ansible.  If not, see <http://www.gnu.org/licenses/>.

# Make coding more python3-ish
from __future__ import (absolute_import, division, print_function)
__metaclass__ = type

import itertools
from six import string_types

from ansible.errors import AnsibleError
from ansible.playbook.attribute import FieldAttribute
from ansible.template import Templar

class Taggable:

    untagged = frozenset(['untagged'])
    _tags = FieldAttribute(isa='list', default=[], listof=(string_types,int))

    def __init__(self):
        super(Taggable, self).__init__()

    def _load_tags(self, attr, ds):
        if isinstance(ds, list):
            return ds
        elif isinstance(ds, basestring):
            return [ ds ]
        else:
            raise AnsibleError('tags must be specified as a list', obj=ds)

    def _get_attr_tags(self):
        '''
        Override for the 'tags' getattr fetcher, used from Base.
        '''
        tags = self._attributes['tags']
        if tags is None:
            tags = []
        if hasattr(self, '_get_parent_attribute'):
            tags = self._get_parent_attribute('tags', extend=True)
        return tags

    def evaluate_tags(self, only_tags, skip_tags, all_vars):
        ''' this checks if the current item should be executed depending on tag options '''

        should_run = True

        if self.tags:
            templar = Templar(loader=self._loader, variables=all_vars)
            tags = templar.template(self.tags)

            if not isinstance(tags, list):
                if tags.find(',') != -1:
                    tags = set(tags.split(','))
                else:
                    tags = set([tags])
            else:
                tags = set([i for i,_ in itertools.groupby(tags)])
        else:
            # this makes isdisjoint work for untagged
            tags = self.untagged

        if only_tags:

            should_run = False

            if 'always' in tags or 'all' in only_tags:
                 should_run = True
            elif not tags.isdisjoint(only_tags):
                should_run = True
            elif 'tagged' in only_tags and tags != self.untagged:
                should_run = True

        if should_run and skip_tags:

            # Check for tags that we need to skip
            if 'all' in skip_tags:
                if 'always' not in tags or 'always' in skip_tags:
                    should_run = False
            elif not tags.isdisjoint(skip_tags):
                should_run = False
            elif 'tagged' in skip_tags and tags != self.untagged:
                should_run = False

        return should_run
