#!/usr//bin/env python
# vim: ts=8 sts=4 sw=4 expandtab
# Author: Douglas Clowes (dcl@ansto.gov.au) 2012-06-29
from twisted.internet.protocol import Protocol
from twisted.internet.protocol import ServerFactory
from galilcontroller import GalilController

class GalilProtocol(Protocol):
    """Protocol object used by the Twisted Infrastructure to handle connections
    """

    def __init__(self, thisDevice):
        print "GalilProtocol protocol ctor", thisDevice
        self.device = thisDevice
        self.term = "\r\n"

    def write(self, response):
        self.response = self.response + response

    def connectionMade(self):
        self.pdu = ""
        self.response = ""
        self.device.protocol = self
        self.factory.numProtocols = self.factory.numProtocols + 1
        print "connectionMade: connection number", self.factory.numProtocols
        if self.factory.numProtocols > 2:
            print "Too many connections - rejecting"
            self.transport.write("Too many connections, try later\r\n")
            self.transport.loseConnection()
        '''else:
            self.transport.write("Welcome connection %d\r\n" % self.factory.numProtocols)'''

    def connectionLost(self, reason):
        self.factory.numProtocols = self.factory.numProtocols - 1
        print "connectionLost: connections left", self.factory.numProtocols

    def dataReceived(self, data):
        #print "dataReceived - len:", len(data)
        last_was_cr = False
        for c in data:
            if  c == "\r" or c == ";" or c == "\n":
                if c == "\n" and last_was_cr:
                    continue
                last_was_cr = False
                if c == "\r":
                    last_was_cr = True
                if len(self.pdu) > 0:
                    #print "Request: ", self.pdu
                    the_response = self.device.dataReceived(self.pdu)
                    #print "Response:", the_response
                    for item in the_response:
                        self.write(item + self.term)
                    self.pdu = ""
                if c == ";":
                    if len(self.response) > 0 and self.response[-1] != ":":
                        self.response = self.response + ":"
                else:
                    if len(self.response) > 0:
                        if self.response[-1] == ";":
                            self.response = self.response[:-1]
                    if len(self.response) > 0 and self.response[-1] != ":":
                        self.response = self.response + ":"
                    if len(self.response) == 0:
                        self.response = self.response + ":"
                    if len(self.response) > 0:
                        #print "Protocol Response: %s" % self.response
                        self.transport.write(self.response)
                        self.response = ""
            else:
                self.pdu = self.pdu + c

class GalilFactory(ServerFactory):
    """Factory object used by the Twisted Infrastructure to create a Protocol
       object for incomming connections"""

    protocol = GalilProtocol

    def __init__(self, thePort):
        print "GalilFactory ctor: "
        self.port = thePort
        self.device = GalilController(thePort)
        self.numProtocols = 0

    def buildProtocol(self, addr):
        p = self.protocol(self.device)
        p.factory = self
        return p