# Copyright 1999-2021 Alibaba Group Holding Ltd.
#
# 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.

import json
from typing import List, Optional

from ....lib.aio import alru_cache
from ...web import web_api, MarsServiceWebAPIHandler, MarsWebAPIClientMixin
from ..core import SubtaskScheduleSummary
from .core import AbstractSchedulingAPI


class SchedulingWebAPIHandler(MarsServiceWebAPIHandler):
    _root_pattern = '/api/session/(?P<session_id>[^/]+)/scheduling'

    @alru_cache(cache_exceptions=False)
    async def _get_cluster_api(self):
        from ...cluster import ClusterAPI
        return await ClusterAPI.create(self._supervisor_addr)

    @alru_cache(cache_exceptions=False)
    async def _get_oscar_scheduling_api(self, session_id: str):
        from ..api import SchedulingAPI
        cluster_api = await self._get_cluster_api()
        [address] = await cluster_api.get_supervisors_by_keys([session_id])
        return await SchedulingAPI.create(session_id, address)

    @web_api('subtasks', method='get')
    async def get_subtask_schedule_summaries(self, session_id: str):
        oscar_api = await self._get_oscar_scheduling_api(session_id)
        task_id = self.get_argument('task_id', None) or None

        result = await oscar_api.get_subtask_schedule_summaries(task_id)
        self.write(json.dumps({
            summary.subtask_id: {
                "task_id": summary.task_id,
                "subtask_id": summary.subtask_id,
                "bands": [
                    {
                        "endpoint": band[0],
                        "band_name": band[1],
                    }
                    for band in summary.bands
                ],
                "is_finished": summary.is_finished,
                "is_cancelled": summary.is_cancelled,
            }
            for summary in result
        }))


web_handlers = {
    SchedulingWebAPIHandler.get_root_pattern(): SchedulingWebAPIHandler
}


class WebSchedulingAPI(AbstractSchedulingAPI, MarsWebAPIClientMixin):
    def __init__(self,
                 session_id: str,
                 address: str):
        self._session_id = session_id
        self._address = address.rstrip('/')

    async def get_subtask_schedule_summaries(
            self,
            task_id: Optional[str] = None
    ) -> List[SubtaskScheduleSummary]:
        task_id = task_id or ""
        path = f'{self._address}/api/session/{self._session_id}/scheduling/subtasks' \
               f'?task_id={task_id}'

        res = await self._request_url('GET', path)
        res_json = json.loads(res.body)

        return [
            SubtaskScheduleSummary(
                task_id=summary_json["task_id"],
                subtask_id=summary_json["subtask_id"],
                bands=[
                    (band_json["endpoint"], band_json["band_name"])
                    for band_json in summary_json["bands"]
                ],
                is_finished=summary_json["is_finished"],
                is_cancelled=summary_json["is_cancelled"],
            )
            for summary_json in res_json.values()
        ]
