import asyncio
import concurrent.futures as pool
import subprocess

from functools import partial

from fastapi import HTTPException

from src.core.async_queue import AsyncQueue
from src.core.rabbitmq import get_messages
from src.core.redis_client import RedisClient
from src.core.result import Result, ResultTypeEnum
from src.exceptions.download_exceptions import SiteNotImplementedException
from src.parsers.MyMail.my_mail_parser import MyMailParser
from src.parsers.Yappy.yappy_parser import YappyParser
from src.parsers.base_parser import BaseParser


class MasterService:
    def __init__(self):
        self.loop = asyncio.get_event_loop()
        self.MAX_EXECUTOR_WORKERS = 8
        self.executor = pool.ProcessPoolExecutor(max_workers=self.MAX_EXECUTOR_WORKERS,
                                                 initializer=executor_initializer)
        self.queue = AsyncQueue()
        self.rabbit_consumer = get_messages
        self.currently_underway = {}  # contains currently in progress videos

    async def run(self):
        subprocess.run(
            "for pid in $(ps -ef | grep video_downloader_executor_process | awk '{print $2}'); do kill -9 $pid; done",
            shell=True, capture_output=True
        )

        tasks = [self.loop.create_task(self.create_workers()) for i in range(self.MAX_EXECUTOR_WORKERS + 1)]

        await asyncio.gather(self.rabbit_consumer(self.queue), *tasks)

    async def create_workers(self):
        while True:
            video_params = await self.queue.get()
            redis = RedisClient()
            await redis.del_task_from_queue_and_add_to_tasks(task=video_params)
            self.currently_underway[video_params['link']] = video_params
            download_task = self.loop.run_in_executor(self.executor, partial(
                MasterService.video_processing_executor, video_params=video_params
                )
            )

            result = await download_task
            await redis.del_task_from_tasks_and_add_to_task_done(task=video_params)
            # TODO process result
            self.queue.task_done()

    @staticmethod
    def video_download(video_params: dict):
        downloader: BaseParser | YappyParser | MyMailParser = MasterService.get_parser(video_params)
        try:
            result = downloader.video_download()
            return result
        except SiteNotImplementedException as ex:
            raise HTTPException(
                status_code=400,
                detail=ex.message
            )

    @staticmethod
    def get_parser(params: dict):
        parser_mapping = {
            "MyMailRu": MyMailParser(params),
            "base": BaseParser(params),
            "Yappy": YappyParser(params),
        }
        return parser_mapping[params["parser"]]

    @staticmethod
    def video_processing_executor(video_params: dict):
        try:
            MasterService.video_download(video_params=video_params)
            return Result(result_type=ResultTypeEnum.DONE)
        except Exception as ex:
            return Result(result_type=ResultTypeEnum.EXCEPTION, value=ex)
        # TODO upload to server


def executor_initializer():
    import setproctitle
    setproctitle.setproctitle(f'video_downloader_executor_process')
    return True