#
# 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.
#

"""
An AQMP client implementation that uses a custom delegate for
interacting with the server.
"""

import os, threading
from peer import Peer, Channel, Closed
from delegate import Delegate
from connection08 import Connection, Frame, connect
from spec08 import load
from queue import Queue
from reference import ReferenceId, References


class Client:

  def __init__(self, host, port, spec = None, vhost = None):
    self.host = host
    self.port = port
    if spec:
      self.spec = spec
    else:
      from specs_config import amqp_spec_0_9
      self.spec = load(amqp_spec_0_9)
    self.structs = StructFactory(self.spec)
    self.sessions = {}

    self.mechanism = None
    self.response = None
    self.locale = None

    self.vhost = vhost
    if self.vhost == None:
      self.vhost = "/"

    self.queues = {}
    self.lock = threading.Lock()

    self.closed = False
    self.reason = None
    self.started = threading.Event()

  def wait(self):
    self.started.wait()
    if self.closed:
      raise Closed(self.reason)

  def queue(self, key):
    self.lock.acquire()
    try:
      try:
        q = self.queues[key]
      except KeyError:
        q = Queue(0)
        self.queues[key] = q
    finally:
      self.lock.release()
    return q

  def start(self, response, mechanism="AMQPLAIN", locale="en_US", tune_params=None):
    self.mechanism = mechanism
    self.response = response
    self.locale = locale
    self.tune_params = tune_params

    self.socket = connect(self.host, self.port)
    self.conn = Connection(self.socket, self.spec)
    self.peer = Peer(self.conn, ClientDelegate(self), Session)

    self.conn.init()
    self.peer.start()
    self.wait()
    self.channel(0).connection_open(self.vhost)

  def channel(self, id):
    self.lock.acquire()
    try:
      ssn = self.peer.channel(id)
      ssn.client = self
      self.sessions[id] = ssn
    finally:
      self.lock.release()
    return ssn

  def session(self):
    self.lock.acquire()
    try:
      id = None
      for i in xrange(1, 64*1024):
        if not self.sessions.has_key(i):
          id = i
          break
    finally:
      self.lock.release()
    if id == None:
      raise RuntimeError("out of channels")
    else:
      return self.channel(id)

  def close(self):
    self.socket.close()

class ClientDelegate(Delegate):

  def __init__(self, client):
    Delegate.__init__(self)
    self.client = client

  def connection_start(self, ch, msg):
    msg.start_ok(mechanism=self.client.mechanism,
                 response=self.client.response,
                 locale=self.client.locale)

  def connection_tune(self, ch, msg):
    if self.client.tune_params:
      #todo: just override the params, i.e. don't require them
      #      all to be included in tune_params
      msg.tune_ok(**self.client.tune_params)
    else:
      msg.tune_ok(*msg.frame.args)
    self.client.started.set()

  def message_transfer(self, ch, msg):
    self.client.queue(msg.destination).put(msg)

  def message_open(self, ch, msg):
    ch.references.open(msg.reference)

  def message_close(self, ch, msg):
    ch.references.close(msg.reference)

  def message_append(self, ch, msg):
    ch.references.get(msg.reference).append(msg.bytes)

  def message_acquired(self, ch, msg):
    ch.control_queue.put(msg)

  def basic_deliver(self, ch, msg):
    self.client.queue(msg.consumer_tag).put(msg)

  def channel_pong(self, ch, msg):
    msg.ok()

  def channel_close(self, ch, msg):
    ch.closed(msg)

  def session_ack(self, ch, msg):
    pass

  def session_closed(self, ch, msg):
    ch.closed(msg)

  def connection_close(self, ch, msg):
    self.client.peer.closed(msg)

  def execution_complete(self, ch, msg):
    ch.completion.complete(msg.cumulative_execution_mark)

  def execution_result(self, ch, msg):
    future = ch.futures[msg.command_id]
    future.put_response(ch, msg.data)

  def closed(self, reason):
    self.client.closed = True
    self.client.reason = reason
    self.client.started.set()

class StructFactory:

  def __init__(self, spec):
    self.spec = spec
    self.factories = {}

  def __getattr__(self, name):
    if self.factories.has_key(name):
      return self.factories[name]
    elif self.spec.domains.byname.has_key(name):
      f = lambda *args, **kwargs: self.struct(name, *args, **kwargs)
      self.factories[name] = f
      return f
    else:
      raise AttributeError(name)

  def struct(self, name, *args, **kwargs):
    return self.spec.struct(name, *args, **kwargs)

class Session(Channel):

  def __init__(self, *args):
    Channel.__init__(self, *args)
    self.references = References()
    self.client = None

  def open(self):
    self.session_open()

  def close(self):
    self.session_close()
    self.client.lock.acquire()
    try:
      del self.client.sessions[self.id]
    finally:
      self.client.lock.release()