# vim: tabstop=4 shiftwidth=4 softtabstop=4

#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

from heat.common import exception
from heat.engine import watchrule
from heat.engine import resource
from heat.engine.properties import Properties

from heat.openstack.common import log as logging

logger = logging.getLogger(__name__)


class CloudWatchAlarm(resource.Resource):
    properties_schema = {'ComparisonOperator': {'Type': 'String',
                         'AllowedValues': ['GreaterThanOrEqualToThreshold',
                         'GreaterThanThreshold', 'LessThanThreshold',
                         'LessThanOrEqualToThreshold']},
                         'AlarmDescription': {'Type': 'String'},
                         'EvaluationPeriods': {'Type': 'String'},
                         'MetricName': {'Type': 'String'},
                         'Namespace': {'Type': 'String'},
                         'Period': {'Type': 'String'},
                         'Statistic': {'Type': 'String',
                                       'AllowedValues': ['SampleCount',
                                                         'Average',
                                                         'Sum',
                                                         'Minimum',
                                                         'Maximum']},
                         'AlarmActions': {'Type': 'List'},
                         'OKActions': {'Type': 'List'},
                         'Dimensions': {'Type': 'List'},
                         'InsufficientDataActions': {'Type': 'List'},
                         'Threshold': {'Type': 'String'},
                         'Units': {'Type': 'String',
                                   'AllowedValues': ['Seconds',
                                                     'Microseconds',
                                                     'Milliseconds',
                                                     'Bytes',
                                                     'Kilobytes',
                                                     'Megabytes',
                                                     'Gigabytes',
                                                     'Terabytes',
                                                     'Bits',
                                                     'Kilobits',
                                                     'Megabits',
                                                     'Gigabits',
                                                     'Terabits',
                                                     'Percent',
                                                     'Count',
                                                     'Bytes/Second',
                                                     'Kilobytes/Second',
                                                     'Megabytes/Second',
                                                     'Gigabytes/Second',
                                                     'Terabytes/Second',
                                                     'Bits/Second',
                                                     'Kilobits/Second',
                                                     'Megabits/Second',
                                                     'Gigabits/Second',
                                                     'Terabits/Second',
                                                     'Count/Second', None]}}

    strict_dependency = False
    update_allowed_keys = ('Properties',)
    # allow the properties that affect the watch calculation.
    # note: when using in-instance monitoring you can only change the
    # metric name if you re-configure the instance too.
    update_allowed_properties = ('ComparisonOperator', 'AlarmDescription',
                                 'EvaluationPeriods', 'Period', 'Statistic',
                                 'AlarmActions', 'OKActions', 'Units'
                                 'InsufficientDataActions', 'Threshold')

    def handle_create(self):
        wr = watchrule.WatchRule(context=self.context,
                                 watch_name=self.physical_resource_name(),
                                 rule=self.parsed_template('Properties'),
                                 stack_id=self.stack.id)
        wr.store()

    def handle_update(self, json_snippet, tmpl_diff, prop_diff):
        # If Properties has changed, update self.properties, so we
        # get the new values during any subsequent adjustment
        if prop_diff:
            self.properties = Properties(self.properties_schema,
                                         json_snippet.get('Properties', {}),
                                         self.stack.resolve_runtime_data,
                                         self.name)
            loader = watchrule.WatchRule.load
            wr = loader(self.context,
                        watch_name=self.physical_resource_name())

            wr.rule = self.parsed_template('Properties')
            wr.store()

    def handle_delete(self):
        try:
            wr = watchrule.WatchRule.load(
                self.context, watch_name=self.physical_resource_name())
            wr.destroy()
        except exception.NotFound:
            pass

    def FnGetRefId(self):
        return unicode(self.physical_resource_name())

    def physical_resource_name(self):
        return '%s-%s' % (self.stack.name, self.name)


def resource_mapping():
    return {
        'AWS::CloudWatch::Alarm': CloudWatchAlarm,
    }