#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
#

import os, connection, session
from util import notify
from datatypes import RangedSet
from exceptions import VersionError, Closed
from logging import getLogger
from ops import Control
import sys
from qpid import sasl

log = getLogger("qpid.io.ctl")

class Delegate:

  def __init__(self, connection, delegate=session.client):
    self.connection = connection
    self.delegate = delegate

  def received(self, op):
    ssn = self.connection.attached.get(op.channel)
    if ssn is None:
      ch = connection.Channel(self.connection, op.channel)
    else:
      ch = ssn.channel

    if isinstance(op, Control):
      log.debug("RECV %s", op)
      getattr(self, op.NAME)(ch, op)
    elif ssn is None:
      ch.session_detached()
    else:
      ssn.received(op)

  def connection_close(self, ch, close):
    self.connection.close_code = (close.reply_code, close.reply_text)
    ch.connection_close_ok()
    raise Closed(close.reply_text)

  def connection_close_ok(self, ch, close_ok):
    self.connection.opened = False
    self.connection.closed = True
    notify(self.connection.condition)

  def connection_heartbeat(self, ch, hrt):
    pass

  def session_attach(self, ch, a):
    try:
      self.connection.attach(a.name, ch, self.delegate, a.force)
      ch.session_attached(a.name)
    except connection.ChannelBusy:
      ch.session_detached(a.name)
    except connection.SessionBusy:
      ch.session_detached(a.name)

  def session_attached(self, ch, a):
    notify(ch.session.condition)

  def session_detach(self, ch, d):
    #send back the confirmation of detachment before removing the
    #channel from the attached set; this avoids needing to hold the
    #connection lock during the sending of this control and ensures
    #that if the channel is immediately reused for a new session the
    #attach request will follow the detached notification.
    ch.session_detached(d.name)
    ssn = self.connection.detach(d.name, ch)

  def session_detached(self, ch, d):
    self.connection.detach(d.name, ch)

  def session_request_timeout(self, ch, rt):
    ch.session_timeout(rt.timeout);

  def session_command_point(self, ch, cp):
    ssn = ch.session
    ssn.receiver.next_id = cp.command_id
    ssn.receiver.next_offset = cp.command_offset

  def session_completed(self, ch, cmp):
    ch.session.sender.completed(cmp.commands)
    if cmp.timely_reply:
      ch.session_known_completed(cmp.commands)
    notify(ch.session.condition)

  def session_known_completed(self, ch, kn_cmp):
    ch.session.receiver.known_completed(kn_cmp.commands)

  def session_flush(self, ch, f):
    rcv = ch.session.receiver
    if f.expected:
      if rcv.next_id == None:
        exp = None
      else:
        exp = RangedSet(rcv.next_id)
      ch.session_expected(exp)
    if f.confirmed:
      ch.session_confirmed(rcv._completed)
    if f.completed:
      ch.session_completed(rcv._completed)

class Server(Delegate):

  def start(self):
    self.connection.read_header()
    # XXX
    self.connection.write_header(0, 10)
    connection.Channel(self.connection, 0).connection_start(mechanisms=["ANONYMOUS"])

  def connection_start_ok(self, ch, start_ok):
    ch.connection_tune(channel_max=65535)

  def connection_tune_ok(self, ch, tune_ok):
    pass

  def connection_open(self, ch, open):
    self.connection.opened = True
    ch.connection_open_ok()
    notify(self.connection.condition)

class Client(Delegate):

  ppid = 0
  try:
    ppid = os.getppid()
  except:
    pass

  PROPERTIES = {"product": "qpid python client",
                "version": "development",
                "platform": os.name,
                "qpid.client_process": os.path.basename(sys.argv[0]),
                "qpid.client_pid": os.getpid(),
                "qpid.client_ppid": ppid}

  def __init__(self, connection, username=None, password=None,
               mechanism=None, heartbeat=None, **kwargs):
    Delegate.__init__(self, connection)
    self.client_properties=Client.PROPERTIES.copy()
    self.client_properties.update(kwargs.get("client_properties",{}))
    ##
    ## self.acceptableMechanisms is the list of SASL mechanisms that the client is willing to
    ## use.  If it's None, then any mechanism is acceptable.
    ##
    self.acceptableMechanisms = None
    if mechanism:
      self.acceptableMechanisms = mechanism.split(" ")
    self.heartbeat = heartbeat
    self.username  = username
    self.password  = password

    self.sasl = sasl.Client()
    if username and len(username) > 0:
      self.sasl.setAttr("username", str(username))
    if password and len(password) > 0:
      self.sasl.setAttr("password", str(password))
    self.sasl.setAttr("service", str(kwargs.get("service", "qpidd")))
    if "host" in kwargs:
      self.sasl.setAttr("host", str(kwargs["host"]))
    if "min_ssf" in kwargs:
      self.sasl.setAttr("minssf", kwargs["min_ssf"])
    if "max_ssf" in kwargs:
      self.sasl.setAttr("maxssf", kwargs["max_ssf"])
    self.sasl.init()

  def start(self):
    # XXX
    cli_major = 0
    cli_minor = 10
    self.connection.write_header(cli_major, cli_minor)
    magic, _, _, major, minor = self.connection.read_header()
    if not (magic == "AMQP" and major == cli_major and minor == cli_minor):
      raise VersionError("client: %s-%s, server: %s-%s" %
                         (cli_major, cli_minor, major, minor))

  def connection_start(self, ch, start):
    mech_list = ""
    for mech in start.mechanisms:
      if (not self.acceptableMechanisms) or mech in self.acceptableMechanisms:
        mech_list += str(mech) + " "
    mech = None
    initial = None
    try:
      mech, initial = self.sasl.start(mech_list)
    except Exception, e:
      raise Closed(str(e))
    ch.connection_start_ok(client_properties=self.client_properties,
                           mechanism=mech, response=initial)

  def connection_secure(self, ch, secure):
    resp = None
    try:
      resp = self.sasl.step(secure.challenge)
    except Exception, e:
      raise Closed(str(e))
    ch.connection_secure_ok(response=resp)

  def connection_tune(self, ch, tune):
    ch.connection_tune_ok(heartbeat=self.heartbeat)
    ch.connection_open()
    self.connection.user_id = self.sasl.auth_username()
    self.connection.security_layer_tx = self.sasl

  def connection_open_ok(self, ch, open_ok):
    self.connection.security_layer_rx = self.sasl
    self.connection.opened = True
    notify(self.connection.condition)

  def connection_heartbeat(self, ch, hrt):
    ch.connection_heartbeat()
