"""
A windows service wrapper for the py.execnet socketserver.

To use, run:
 python socketserverservice.py register
 net start ExecNetSocketServer
"""

import sys
import os
import time
import win32serviceutil
import win32service
import win32event
import win32evtlogutil
import servicemanager
import threading
import socketserver


appname = 'ExecNetSocketServer'


class SocketServerService(win32serviceutil.ServiceFramework):
    _svc_name_ = appname
    _svc_display_name_ = "%s" % appname
    _svc_deps_ = ["EventLog"]
    def __init__(self, args):
        # The exe-file has messages for the Event Log Viewer.
        # Register the exe-file as event source.
        #
        # Probably it would be better if this is done at installation time,
        # so that it also could be removed if the service is uninstalled.
        # Unfortunately it cannot be done in the 'if __name__ == "__main__"'
        # block below, because the 'frozen' exe-file does not run this code.
        #
        win32evtlogutil.AddSourceToRegistry(self._svc_display_name_,
                                            servicemanager.__file__,
                                            "Application")
        win32serviceutil.ServiceFramework.__init__(self, args)
        self.hWaitStop = win32event.CreateEvent(None, 0, 0, None)
        self.WAIT_TIME = 1000 # in milliseconds


    def SvcStop(self):
        self.ReportServiceStatus(win32service.SERVICE_STOP_PENDING)
        win32event.SetEvent(self.hWaitStop)


    def SvcDoRun(self):
        # Redirect stdout and stderr to prevent "IOError: [Errno 9] 
        # Bad file descriptor". Windows services don't have functional
        # output streams. 
        sys.stdout = sys.stderr = open('nul', 'w')

        # Write a 'started' event to the event log...
        win32evtlogutil.ReportEvent(self._svc_display_name_,
                                    servicemanager.PYS_SERVICE_STARTED,
                                    0, # category
                                    servicemanager.EVENTLOG_INFORMATION_TYPE,
                                    (self._svc_name_, ''))
        print("Begin: %s" % (self._svc_display_name_))

        hostport = ':8888'
        print('Starting py.execnet SocketServer on %s' % hostport)
        serversock = socketserver.bind_and_listen(hostport)
        thread = threading.Thread(target=socketserver.startserver, 
                                    args=(serversock,),
                                    kwargs={'loop':True})
        thread.setDaemon(True)
        thread.start()

        # wait to be stopped or self.WAIT_TIME to pass
        while True:
            result = win32event.WaitForSingleObject(self.hWaitStop,
                    self.WAIT_TIME)
            if result == win32event.WAIT_OBJECT_0:
                break
                
        # write a 'stopped' event to the event log.
        win32evtlogutil.ReportEvent(self._svc_display_name_,
                                    servicemanager.PYS_SERVICE_STOPPED,
                                    0, # category
                                    servicemanager.EVENTLOG_INFORMATION_TYPE,
                                    (self._svc_name_, ''))
        print("End: %s" % appname)


if __name__ == '__main__':
    # Note that this code will not be run in the 'frozen' exe-file!!!
    win32serviceutil.HandleCommandLine(SocketServerService)