"""Email proxy for Avaya's Voicemail Pro (which embeds G-Lock's EasyMail Pro).

Voicemail Pro has the capability to send email alerts when a voicemail
message is left in a given voicemail box. We use this capability at Amor
Ministries, for example, to run an "emergency extension"--if one of our
customers has an emergency after hours, they can leave a voicemail message
in this box, and various people will be paged to address the issue.

Unfortunately, the emails that Voicemail Pro sends out don't follow
RFC 821, which requires "MAIL FROM" before "DATA". This causes Exim,
which requires spec compliance, to choke. This module runs as an SMTP
proxy, fixing up the email from Voicemail Pro and forwarding it on to
a designated recipient. It only runs on localhost for security reasons.
"""

def log_error():
    import traceback
    f = open(r"C:\diefile.txt", "wb")
    traceback.print_exc(file=f)
    f.close()


try:
    import asyncore
    import smtpd
    import threading

    import win32serviceutil
    import win32service
    import win32event
    import servicemanager


    class win32log:
        
        def write(self, msg):
            servicemanager.LogInfoMsg('%s (%s): %s'
                                      % (SMTPProxyService._svc_name_,
                                         SMTPProxyService._svc_display_name_,
                                         msg))
        
        def flush(self): pass
    win32log = win32log()

    ##smtpd.DEBUGSTREAM = win32log


    class VoicemailProProxy(smtpd.PureProxy):
        def process_message(self, peer, mailfrom, rcpttos, data):
            # Fixup the mailfrom;
            # Exim requires that it contain a domain, but it's coming through as "Voicemail2".
            refused = self._deliver("vemergency@amor.org", rcpttos, data)
            
            # TBD: what to do with refused addresses?
            win32log.write("Delivery results: %s" % repr(refused))
            return refused


    class SMTPProxyService(win32serviceutil.ServiceFramework):
        
        _svc_name_ = "vmpropager3"
        _svc_display_name_ = "Voicemail Pro Email Fixup 3"
        
        def __init__(self, args, *a, **kw):
            try:
                servicemanager.LogInfoMsg("entering init")
                win32serviceutil.ServiceFramework.__init__(self, args)
                servicemanager.LogInfoMsg("framework inited")
                # create an event that SvcDoRun can wait on and SvcStop can set.
                self.hWaitStop = win32event.CreateEvent(None, 0, 0, None)
                servicemanager.LogInfoMsg("event created")
                # create our proxy instance
                self.proxy = VoicemailProProxy(("localhost", 25), ("192.168.0.6", 25))
                servicemanager.LogInfoMsg("proxy created")
            except:
                log_error()
                raise
        
        def SvcDoRun(self):
            # log a service started message
            servicemanager.LogMsg(
                servicemanager.EVENTLOG_INFORMATION_TYPE,
                servicemanager.PYS_SERVICE_STARTED,
                (self._svc_name_, ' (%s)' % self._svc_display_name_))
            
            # Start the SMTP proxy listener loop in a separate thread
            t = threading.Thread(None, asyncore.loop)
            t.start()
            
            # Wait for a service stop request.
            win32event.WaitForSingleObject(self.hWaitStop, win32event.INFINITE)
            
            # signal stop and wait for the SMTP thread to stop
            self.proxy.close()
            t.join()
            
            # log a service stopped message
            servicemanager.LogMsg(
                servicemanager.EVENTLOG_INFORMATION_TYPE,
                servicemanager.PYS_SERVICE_STOPPED,
                (self._svc_name_, ' (%s) ' % self._svc_display_name_))
        
        def SvcStop(self):
            self.ReportServiceStatus(win32service.SERVICE_STOP_PENDING)
            win32event.SetEvent(self.hWaitStop)
        SvcShutdown = SvcStop


    if __name__ == '__main__':
        import sys
        if sys.argv[1:] == ['test']:
            p = VoicemailProProxy(("localhost", 25), ("192.168.0.6", 25))
            try:
                asyncore.loop()
            except KeyboardInterrupt:
                p.close()
        else:
            print "handling command line"
            win32serviceutil.HandleCommandLine(SMTPProxyService)
    else:
        # Don't use sys.stdout
        import win32traceutil
except:
    log_error()
    raise