# coding: utf-8
import random
import typing
from multiprocessing import Process
from multiprocessing.connection import Connection
from multiprocessing.connection import Pipe

from synergine2.base import BaseObject
from synergine2.config import Config
from synergine2.share import SharedDataManager

STOP = '__STOP__'

# global shared manager
shared_data = SharedDataManager()


# TODO: se jobs
class Job(object):
    pass


class Worker(object):
    def __init__(
        self,
        config: Config,
        real_job: typing.Callable[..., typing.Any],
    ) -> None:
        self.config = config

        local_read_pipe, local_write_pipe = Pipe(duplex=False)
        process_read_pipe, process_write_pipe = Pipe(duplex=False)

        self.local_read_pipe = local_read_pipe  # type: Connection
        self.local_write_pipe = local_write_pipe  # type: Connection
        self.process_read_pipe = process_read_pipe  # type: Connection
        self.process_write_pipe = process_write_pipe  # type: Connection

        self.real_job = real_job
        self.process = Process(
            target=self.work,
            args=(
                self.local_write_pipe,
                self.process_read_pipe,
            ),
            kwargs={'seed': random.random()},
            name='Worker',
        )
        self.db = None  # TODO delete
        self.process.start()

    def work(self, *args, **kwargs):
        seed_value = kwargs.pop('seed')
        random.seed(seed_value)
        try:
            while True:
                args = self.process_read_pipe.recv()
                if args == STOP:
                    return

                result = self.real_job(*args)
                self.local_write_pipe.send(result)
        except KeyboardInterrupt:
            return


class ProcessManager(BaseObject):
    def __init__(
            self,
            config: Config,
            process_count: int,
            job: typing.Callable[..., typing.Any],
    ) -> None:
        self.config = config
        self._process_count = process_count
        self.workers = []
        self.job = job

    @property
    def process_count(self) -> int:
        return self._process_count

    def start_workers(self) -> None:
        assert not self.workers
        for i in range(self._process_count):
            self.workers.append(Worker(self.config, self.job))

    def make_them_work(self, message: typing.Any) -> 'TODO':
        responses = []

        for worker_id, worker in enumerate(self.workers):
            worker.process_write_pipe.send((worker_id, self._process_count, message))

        for worker in self.workers:
            responses.append(worker.local_read_pipe.recv())

        return responses

    def terminate(self) -> None:
        for worker in self.workers:
            worker.process_write_pipe.send(STOP)

        for worker in self.workers:
            worker.process.join()