# -*- coding: utf-8 -*-
# Copyright 2014 Objectif Libre
#
#    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.
#
# @author: Stéphane Albert
#
import datetime
import decimal

import pecan
from pecan import rest
from wsme import types as wtypes
import wsmeext.pecan as wsme_pecan

from cloudkitty.api.v1.datamodels import storage as storage_models
from cloudkitty.common import policy
from cloudkitty import storage
from cloudkitty import utils as ck_utils


class DataFramesController(rest.RestController):
    """REST Controller to access stored data frames."""

    @wsme_pecan.wsexpose(storage_models.DataFrameCollection,
                         datetime.datetime,
                         datetime.datetime,
                         wtypes.text,
                         wtypes.text)
    def get_all(self, begin=None, end=None, tenant_id=None,
                resource_type=None):
        """Return a list of rated resources for a time period and a tenant.

        :param begin: Start of the period
        :param end: End of the period
        :param tenant_id: UUID of the tenant to filter on.
        :param resource_type: Type of the resource to filter on.
        :return: Collection of DataFrame objects.
        """

        policy.authorize(pecan.request.context, 'storage:list_data_frames', {})

        backend = pecan.request.storage_backend
        dataframes = []
        group_filters = {'project_id': tenant_id} if tenant_id else None

        if begin:
            begin = ck_utils.dt2ts(begin)
        if end:
            end = ck_utils.dt2ts(end)
        try:
            resp = backend.retrieve(
                begin, end,
                group_filters=group_filters,
                metric_types=resource_type,
                paginate=False)
        except storage.NoTimeFrame:
            return storage_models.DataFrameCollection(dataframes=[])
        for frame in resp['dataframes']:
            for service, data_list in frame['usage'].items():
                frame_tenant = None
                resources = []
                for data in data_list:
                    # This means we use a v1 storage backend
                    if 'desc' in data.keys():
                        desc = data['desc']
                    else:
                        desc = data['metadata'].copy()
                        desc.update(data.get('groupby', {}))
                    price = decimal.Decimal(str(data['rating']['price']))
                    resource = storage_models.RatedResource(
                        service=service,
                        desc=desc,
                        volume=data['vol']['qty'],
                        rating=price)
                    if frame_tenant is None:
                        frame_tenant = data['scope_id']
                    resources.append(resource)
                dataframe = storage_models.DataFrame(
                    begin=ck_utils.iso2dt(frame['period']['begin']),
                    end=ck_utils.iso2dt(frame['period']['end']),
                    tenant_id=frame_tenant,
                    resources=resources)
                dataframes.append(dataframe)
        return storage_models.DataFrameCollection(dataframes=dataframes)


class StorageController(rest.RestController):
    """REST Controller to access stored data."""

    dataframes = DataFramesController()