import os.path, re

from twisted.python import log
from twisted.application import service
from twisted.internet import defer, reactor
from foolscap import Tub, eventual
from allmydata.util import idlib, iputil, observer
from allmydata.util.assertutil import _assert, precondition


# Just to get their versions:
import allmydata
import zfec
import foolscap

# group 1 will be addr (dotted quad string), group 3 if any will be portnum (string)
ADDR_RE=re.compile("^([1-9][0-9]*\.[1-9][0-9]*\.[1-9][0-9]*\.[1-9][0-9]*)(:([1-9][0-9]*))?$")

class Node(service.MultiService):
    # this implements common functionality of both Client nodes, Introducer 
    # nodes, and Vdrive nodes
    NODETYPE = "unknown NODETYPE"
    PORTNUMFILE = None
    CERTFILE = "node.pem"
    LOCAL_IP_FILE = "advertised_ip_addresses"
    NODEIDFILE = "my_nodeid"

    def __init__(self, basedir="."):
        service.MultiService.__init__(self)
        self.basedir = os.path.abspath(basedir)
        self._tub_ready_observerlist = observer.OneShotObserverList()
        certfile = os.path.join(self.basedir, self.CERTFILE)
        self.tub = Tub(certFile=certfile)
        self.tub.setOption("logLocalFailures", True)
        self.tub.setOption("logRemoteFailures", True)
        self.nodeid = idlib.a2b(self.tub.tubID)
        f = open(os.path.join(self.basedir, self.NODEIDFILE), "w")
        f.write(idlib.b2a(self.nodeid) + "\n")
        f.close()
        self.short_nodeid = self.tub.tubID[:4] # ready for printing
        assert self.PORTNUMFILE, "Your node.Node subclass must provide PORTNUMFILE"
        self._portnumfile = os.path.join(self.basedir, self.PORTNUMFILE)
        try:
            portnum = int(open(self._portnumfile, "rU").read())
        except EnvironmentError, ValueError:
            portnum = 0
        self.tub.listenOn("tcp:%d" % portnum)
        # we must wait until our service has started before we can find out
        # our IP address and thus do tub.setLocation, and we can't register
        # any services with the Tub until after that point
        self.tub.setServiceParent(self)

        AUTHKEYSFILEBASE = "authorized_keys."
        for f in os.listdir(self.basedir):
            if f.startswith(AUTHKEYSFILEBASE):
                keyfile = os.path.join(self.basedir, f)
                portnum = int(f[len(AUTHKEYSFILEBASE):])
                from allmydata import manhole
                m = manhole.AuthorizedKeysManhole(portnum, keyfile)
                m.setServiceParent(self)
                self.log("AuthorizedKeysManhole listening on %d" % portnum)

        self.log("Node constructed.  tahoe version: %s, foolscap version: %s, zfec version: %s" % (allmydata.__version__, foolscap.__version__, zfec.__version__,))

    def _startService(self):
        precondition(reactor.running)

        # note: this class can only be started and stopped once.
        service.MultiService.startService(self)
        d = defer.succeed(None)
        d.addCallback(lambda res: iputil.get_local_addresses_async())
        d.addCallback(self._setup_tub)
        d.addCallback(lambda res: self.tub_ready())
        def _ready(res):
            self.log("%s running" % self.NODETYPE)
            self._tub_ready_observerlist.fire(self)
            return self
        d.addCallback(_ready)

    def startService(self):
        foolscap.eventual.eventually(self._startService)

    def stopService(self):
        d = self._tub_ready_observerlist.when_fired()
        d.addCallback(lambda ignored_result: service.MultiService.stopService(self))
        return d
       
    def shutdown(self):
        """Shut down the node. Returns a Deferred that fires (with None) when
        it finally stops kicking."""
        return self.stopService()

    def log(self, msg):
        log.msg(self.short_nodeid + ": " + msg)

    def _setup_tub(self, local_addresses):
        # we can't get a dynamically-assigned portnum until our Tub is
        # running, which means after startService.
        l = self.tub.getListeners()[0]
        portnum = l.getPortnum()
        # record which port we're listening on, so we can grab the same one next time
        open(self._portnumfile, "w").write("%d\n" % portnum)

        local_addresses = [ "%s:%d" % (addr, portnum,) for addr in local_addresses ]

        addresses = []
        try:
            for addrline in open(os.path.join(self.basedir, self.LOCAL_IP_FILE), "rU"):
                mo = ADDR_RE.search(addrline)
                if mo:
                    (addr, dummy, aportnum,) = mo.groups()
                    if aportnum is None:
                        aportnum = portnum
                    addresses.append("%s:%d" % (addr, aportnum,))
        except EnvironmentError:
            pass

        addresses.extend(local_addresses)

        location = ",".join(addresses)
        self.log("Tub location set to %s" % location)
        self.tub.setLocation(location)
        return self.tub

    def tub_ready(self):
        # called when the Tub is available for registerReference
        pass

    def when_tub_ready(self):
        return self._tub_ready_observerlist.when_fired()

    def add_service(self, s):
        s.setServiceParent(self)
        return s