#!/usr/bin/env python
# -*- coding: UTF-8 -*-
"""
@Project ：IoD_data_analysis_tool
@File    ：producer_consumer.py
@IDE     ：PyCharm
@Author  ：rengengchen
@Time    ：2022/8/5 11:53
"""
import multiprocessing
from typing import Iterable, Callable

from tqdm import tqdm


class Stop:
    pass


class AbstractPCConcurrencySystem:
    """
    @todo 对启动进程的维护
    @todo 进程数量
    """

    def __init__(self, num_producer: int = 1, num_consumer: int = 1, num_callback: int = 0,
                 len_task_queue: int = 0, len_result_queue: int = 0, len_callback_queue: int = 0,
                 producer_lock=None, consumer_lock=None, callback_lock=None,
                 meta=None, enable_progressbar=False, num_total_result=None):
        self.task_queue = multiprocessing.Queue(len_task_queue)

        self.num_producer = num_producer
        self.num_consumer = num_consumer
        self.num_callback = num_callback
        self.producer_lock = producer_lock or multiprocessing.Lock()
        self.consumer_lock = consumer_lock or multiprocessing.Lock()
        self.meta = meta
        self.enable_progressbar = enable_progressbar
        if enable_progressbar and self.num_callback == 0:
            self.num_callback = 1
        self.result_queue = multiprocessing.Queue(len_result_queue)
        if self.num_callback:
            self.callback_lock = callback_lock or multiprocessing.Lock()
        self.num_total_result = num_total_result
        self.callback_queue = multiprocessing.Queue(len_callback_queue)

    def get_result(self):
        return self.callback_queue.get()

    def produce(self):
        """
        Must return an iterable object or a Stop object.
        """
        raise NotImplementedError

    def consume(self, consumer_params):
        """
        @return: task result or Stop()
        """
        raise NotImplementedError

    def callback(self, result):
        return result

    def _produce(self):
        producer = self.produce()
        if isinstance(producer, Iterable):
            for params in producer:
                self.task_queue.put(params, block=True)
            stop = Stop()
            for _ in range(self.num_consumer):
                self.task_queue.put(stop, block=True)
        elif isinstance(producer, Callable):
            while True:
                task = producer()
                if isinstance(task, Stop):
                    break
                self.task_queue.put(task, block=True)

    def _consume(self):
        consumer_params = self.task_queue.get(block=True)
        while not isinstance(consumer_params, Stop):
            info = self.consume(consumer_params)
            self.result_queue.put(info)
            consumer_params = self.task_queue.get(block=True)
        self.result_queue.put(Stop())

    def _callback(self):
        if self.enable_progressbar:
            bar = tqdm(total=self.num_total_result)
        over_flag = 0
        while over_flag < self.num_consumer:
            result = self.result_queue.get(block=True)
            if isinstance(result, Stop):
                over_flag += 1
            else:
                callback = self.callback(result)
                self.callback_queue.put(callback)
                if self.enable_progressbar:
                    bar.update(1)
        else:
            if self.enable_progressbar:
                bar.close()

    def run(self):
        consumers = []
        callbackers = []
        # 创建并启动生产者
        for i in range(self.num_producer):
            multiprocessing.Process(target=self._produce, name=f'producer_{i}').start()
        # 创建并启动消费者
        for i in range(self.num_consumer):
            p = multiprocessing.Process(target=self._consume, name=f'consumer_{i}')
            consumers.append(p)
            p.start()
        # 处理结果
        if self.num_callback:
            for i in range(self.num_callback):
                p = multiprocessing.Process(target=self._callback, name=f'callback_{i}')
                callbackers.append(p)
                p.start()
        return self

    def close(self):
        self.task_queue.close()
        self.result_queue.close()
        self.callback_queue.close()