#!/usr/bin/env python

#
# 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
import getopt
import sys
import socket
import qpid
import uuid
from threading       import Condition
from qpid.management import managementClient
from qpid.peer       import Closed
from qpid.connection import Connection
from qpid.util       import connect
from time            import sleep

defspecpath  = "/usr/share/amqp/amqp.0-10.xml"
specpath     = defspecpath
host         = "localhost"

def Usage ():
    print "Usage:  qpid-queue-stats [OPTIONS]"
    print
    print "Options:"
    print "    -a <broker-addr>     default: localhost"
    print "         broker-addr is in the form:   hostname | ip-address [:<port>]"
    print "         ex:  localhost, 10.1.1.7:10000, broker-host:10000"
    print "    -s <amqp-spec-file>  default:", defspecpath
    print
    sys.exit (1)

class Broker:
    def __init__ (self, text):
        colon = text.find (":")
        if colon == -1:
            host = text
            self.port = 5672
        else:
            host = text[:colon]
            self.port = int (text[colon+1:])
        self.host = socket.gethostbyname (host)

    def name (self):
        return self.host + ":" + str (self.port)

class mgmtObject (object):
  """ Generic object that holds the contents of a management object with its
      attributes set as object attributes. """

  def __init__ (self, classKey, timestamps, row):
    self.classKey   = classKey
    self.timestamps = timestamps
    for cell in row:
      setattr (self, cell[0], cell[1])



class BrokerManager:
    def __init__ (self):
        self.dest    = None
        self.src     = None
        self.broker  = None
        self.objects = {}

    def SetBroker (self, broker):
        self.broker = broker

    def ConnectToBroker (self):
        try:
            self.spec     = qpid.spec.load (specpath)
            self.conn     = Connection (connect (self.broker.host, self.broker.port), self.spec)
            self.conn.start ()
            self.mclient  = managementClient (self.spec, None, self.configCb, self.instCb)
            self.mchannel = self.mclient.addChannel (self.conn.session(str(uuid.uuid4())))
        except socket.error, e:
            print "Connect Error:", e
            exit (1)

    def configCb (self, context, classKey, row, timestamps):
        className = classKey[1]
        if className != "queue":
            return

        obj = mgmtObject (classKey, timestamps, row)
        if obj.id not in self.objects:
            self.objects[obj.id] = (obj.name, None, None)

    def instCb (self, context, classKey, row, timestamps):
        className = classKey[1]
        if className != "queue":
            return

        obj = mgmtObject (classKey, timestamps, row)
        if obj.id not in self.objects:
            return

        (name, first, last) = self.objects[obj.id]
        if first == None:
            self.objects[obj.id] = (name, obj, None)
            return

        if last == None:
            lastSample = first
        else:
            lastSample = last

        self.objects[obj.id] = (name, first, obj)

        deltaTime   = float (obj.timestamps[0] - lastSample.timestamps[0])
        enqueueRate = float (obj.msgTotalEnqueues - lastSample.msgTotalEnqueues) / (deltaTime / 1000000000.0)
        dequeueRate = float (obj.msgTotalDequeues - lastSample.msgTotalDequeues) / (deltaTime / 1000000000.0)
        print "%-41s%10.2f%10d..%-10d%13.2f%13.2f" % \
            (name, deltaTime / 1000000000, obj.msgDepthLow, obj.msgDepthHigh, enqueueRate, dequeueRate)


    def Overview (self):
        self.ConnectToBroker ()
        print "Queue Name                                     Sec       Depth Range          Enq Rate     Deq Rate"
        print "==================================================================================================="
        while True:
            sleep (1)

##
## Main Program
##

try:
    (optlist, cargs) = getopt.getopt (sys.argv[1:], "s:a:")
except:
    Usage ()

for opt in optlist:
    if opt[0] == "-s":
        specpath = opt[1]
    if opt[0] == "-a":
        host = opt[1]

nargs = len (cargs)
bm  = BrokerManager ()
bm.SetBroker (Broker (host))
bm.Overview ()