# -*- coding: utf-8 -*-

'''
author:    Jimmy
contact:   234390130@qq.com
file:     eventEngine.py
time:     2017/8/25 上午10:06
description: 多進程異步事件驅(qū)動引擎

'''

__author__ = 'Jimmy'


from multiprocessing import Process, Queue


class EventEngine(object):
  # 初始化事件事件驅(qū)動引擎
  def __init__(self):
    #保存事件列表
    self.__eventQueue = Queue()
    #引擎開關
    self.__active = False
    #事件處理字典{'event1': [handler1,handler2] , 'event2':[handler3, ...,handler4]}
    self.__handlers = {}
    #保存事件處理進程池
    self.__processPool = []
    #事件引擎主進程
    self.__mainProcess = Process(target=self.__run)


  #執(zhí)行事件循環(huán)
  def __run(self):
    while self.__active:
      #事件隊列非空
      if not self.__eventQueue.empty():
        #獲取隊列中的事件 超時1秒
        event = self.__eventQueue.get(block=True ,timeout=1)
        #執(zhí)行事件
        self.__process(event)
      else:
        # print('無任何事件')
        pass


  #執(zhí)行事件
  def __process(self, event):
    if event.type in self.__handlers:
      for handler in self.__handlers[event.type]:
        #開一個進程去異步處理
        p = Process(target=handler, args=(event, ))
        #保存到進程池
        self.__processPool.append(p)
        p.start()


  #開啟事件引擎
  def start(self):
    self.__active = True
    self.__mainProcess.start()


  #暫停事件引擎
  def stop(self):
    """停止"""
    # 將事件管理器設為停止
    self.__active = False
    # 等待事件處理進程退出
    for p in self.__processPool:
      p.join()
    self.__mainProcess.join()


  #終止事件引擎
  def terminate(self):
    self.__active = False
    #終止所有事件處理進程
    for p in self.__processPool:
      p.terminate()
    self.__mainProcess.join()


  #注冊事件
  def register(self, type, handler):
    """注冊事件處理函數(shù)監(jiān)聽"""
    # 嘗試獲取該事件類型對應的處理函數(shù)列表，若無則創(chuàng)建
    try:
      handlerList = self.__handlers[type]
    except KeyError:
      handlerList = []
      self.__handlers[type] = handlerList

    # 若要注冊的處理器不在該事件的處理器列表中，則注冊該事件
    if handler not in handlerList:
      handlerList.append(handler)


  def unregister(self, type, handler):
    """注銷事件處理函數(shù)監(jiān)聽"""
    # 嘗試獲取該事件類型對應的處理函數(shù)列表，若無則忽略該次注銷請求
    try:
      handlerList = self.__handlers[type]

      # 如果該函數(shù)存在于列表中，則移除
      if handler in handlerList:
        handlerList.remove(handler)

      # 如果函數(shù)列表為空，則從引擎中移除該事件類型
      if not handlerList:
        del self.__handlers[type]
    except KeyError:
      pass


  def sendEvent(self, event):
    #發(fā)送事件 像隊列里存入事件
    self.__eventQueue.put(event)


class Event(object):
  #事件對象
  def __init__(self, type =None):
    self.type = type
    self.dict = {}



#測試
if __name__ == '__main__':
  import time
  EVENT_ARTICAL = "Event_Artical"

  # 事件源 公眾號
  class PublicAccounts:
    def __init__(self, eventManager):
      self.__eventManager = eventManager

    def writeNewArtical(self):
      # 事件對象，寫了新文章
      event = Event(EVENT_ARTICAL)
      event.dict["artical"] = u'如何寫出更優(yōu)雅的代碼\n'
      # 發(fā)送事件
      self.__eventManager.sendEvent(event)
      print(u'公眾號發(fā)送新文章\n')


  # 監(jiān)聽器 訂閱者
  class ListenerTypeOne:
    def __init__(self, username):
      self.__username = username

    # 監(jiān)聽器的處理函數(shù) 讀文章
    def ReadArtical(self, event):
      print(u'%s 收到新文章' % self.__username)
      print(u'%s 正在閱讀新文章內(nèi)容：%s' % (self.__username, event.dict["artical"]))


  class ListenerTypeTwo:
    def __init__(self, username):
      self.__username = username

    # 監(jiān)聽器的處理函數(shù) 讀文章
    def ReadArtical(self, event):
      print(u'%s 收到新文章 睡3秒再看' % self.__username)
      time.sleep(3)
      print(u'%s 正在閱讀新文章內(nèi)容：%s' % (self.__username, event.dict["artical"]))


  def test():
    listner1 = ListenerTypeOne("thinkroom") # 訂閱者1
    listner2 = ListenerTypeTwo("steve") # 訂閱者2

    ee = EventEngine()

    # 綁定事件和監(jiān)聽器響應函數(shù)(新文章)
    ee.register(EVENT_ARTICAL, listner1.ReadArtical)
    ee.register(EVENT_ARTICAL, listner2.ReadArtical)
    for i in range(0, 20):
      listner3 = ListenerTypeOne("Jimmy") # 訂閱者X
      ee.register(EVENT_ARTICAL, listner3.ReadArtical)

    ee.start()

    #發(fā)送事件
    publicAcc = PublicAccounts(ee)
    publicAcc.writeNewArtical()

  test()