#!/usr/bin/python
#
# sfive
#
# sfive - spreadspace streaming statistics suite is a generic
# statistic collection tool for streaming server infrastuctures.
# The system collects and stores meta data like number of views
# and throughput from a number of streaming servers and stores
# it in a global data store.
# The data acquisition is designed to be generic and extensible in
# order to support different streaming software.
# sfive also contains tools and applications to filter and visualize
# live and recorded data.
#
#
# Copyright (C) 2014 Christian Pointner <equinox@spreadspace.org>
#                    Markus Grueneis <gimpf@gimpf.org>
#
# This file is part of sfive.
#
# sfive is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 3
# as published by the Free Software Foundation.
#
# sfive is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with sfive. If not, see <http://www.gnu.org/licenses/>.
#

from errno import EINTR, EMSGSIZE, EAGAIN, EWOULDBLOCK, ECONNREFUSED, ENOBUFS
from twisted.internet import protocol, unix, reactor, task
from twisted.internet.protocol import Protocol
from twisted.internet.defer import Deferred
from twisted.web.client import Agent
from twisted.web.http_headers import Headers
import socket
from time import sleep

import re
import simplejson as json
import datetime
import time
import dateutil.parser

_MAX_PACKET_SIZE = 65536 # in bytes

__version__ = "$Rev$"


class SFiveNGXluaProto(Protocol):
    def __init__(self, finished, fetcher):
        self.data = ''
        self.finished = finished
        self._fetcher = fetcher
        print 'SFive: started receiving log data'

    def dataReceived(self, bytes):
        self.data += bytes
        lines = self.data.splitlines(True)
        if len(lines) > 0:
            if '\n' not in lines[-1] and '\r' not in lines[-1]:
                self.data = lines[-1]
                del lines[-1]
            else:
                self.data = ''

            if len(lines) > 0:
                for line in lines:
                    self._fetcher.updateData(json.loads(line))

    def connectionLost(self, reason):
        print 'SFive: finished receiving log data:', reason.getErrorMessage()
        self._fetcher.close()


class SFivePort(unix.ConnectedDatagramPort):

    def __init__(self, addr, proto, maxPacketSize=8192, mode=0666, bindAddress=None, reactor=None):
        unix.ConnectedDatagramPort.__init__(self, addr, proto, maxPacketSize, mode, bindAddress, reactor)

    def write(self, data):
        try:
            return self.socket.send(data)
        except socket.error, se:
            no = se.args[0]
            if no == EINTR:
                return self.write(data)
            elif no == EMSGSIZE:
                raise error.MessageLengthError, "message too long"
            elif no == ECONNREFUSED:
                self.protocol.connectionRefused()
            elif no == EAGAIN:
            # the send buffer seems to be full - let's wait a little while...
            # this is not really a good solution but better than the aproach
            # of twisted which just drops the datagram...
                sleep(0.01)
                return self.write(data)
            else:
                raise

class SFiveProto(protocol.ConnectedDatagramProtocol):

    def __init__(self, fetcher):
        self._fetcher = fetcher

    def startProtocol(self):
        self._fetcher.socketReady()

    def datagramReceived(self, data):
        print 'SFive: received datagram: "%s" (will get ignored)' % (data)

    def connectionFailed(self, failure):
        print 'SFive: connection failed: %s' % (failure.getErrorMessage())
        self._fetcher.socketError()

    def sendDatagram(self, data):
        try:
            return self.transport.write(data)
        except socket.error as err:
            print 'SFive: sending datagram failed: %s' % (err)
            self._fetcher.socketError()


class ClientList:

    def __init__(self):
        self._clients = { }

    def clear(self):
        self._clients = { }

    def getCnt(self):
        return len(self._clients)

    def getBytesSent(self):
        sum = 0
        for val in self._clients.itervalues():
            sum += val['bytes-sent']

        return sum

    def values(self):
        return self._clients.itervalues()

    def update(self, logdata):
        key = '%(client)s/%(ua)s' % logdata
        if key in self._clients.keys():
            self._clients[key]['bytes-sent'] += logdata['bytes-sent']
        else:
            self._clients[key] = { 'ip': logdata['client'],
                                   'user-agent': logdata['ua'],
                                   'bytes-sent': logdata['bytes-sent'] }


class NGXLuaFetcher():
    """Class to import live log data produced by s5-nginx.lua into the spreadspace streaming statistic suite"""

    def __init__(self, properties):
        print 'SFive: nginx-lua fetcher loaded'

        self._socket = properties['socket']
        self._hostname = properties['hostname']
        self._content_id = None
        self._format = None
        self._quality = None
        self._duration = properties['duration']
        self._tags = properties['tags']
        self._url = properties['url']
        self._initStreamerIds(properties['streamer-ids'])

        self._proto = None
        self._conn = None
        self._connected = False
        self._url_re = re.compile(properties['nameformat'])
        self._looper = None
        self._start_time = None

    def _initStreamerIds(self, streamer):
        print 'SFive: will look for the following streamer ids:'
        self._streamer = {}
        cs = {}
        fs = {}
        qs = {}
        for s in streamer:
            parts = s.split('/')
            if len(parts) != 3:
                raise ValueError('invalid streamer descriptipn "%s": must consist of 3 parts seperated by a /' % s)
            scs = parts[0].split(',')
            sfs = parts[1].split(',')
            sqs = parts[2].split(',')
            for c in scs:
                cs[c] = 1
                if c not in self._streamer:
                    self._streamer[c] = {}
                for f in sfs:
                    fs[f] = 1
                    if f not in self._streamer[c]:
                        self._streamer[c][f] = {}
                    for q in sqs:
                        qs[q] = 1
                        if q not in self._streamer[c][f]:
                            self._streamer[c][f][q] = ClientList()
                        print '  %s / %s / %s' % (c, f, q)

        if len(cs.keys()) == 1:
            self._content_id = cs.keys()[0]
            print 'SFive: only one content-id detected "%s" - will include it in init messages only' % self._content_id

        if len(fs.keys()) == 1:
            self._format = fs.keys()[0]
            print 'SFive: only one format detected "%s" - will include it in init messages only' % self._format

        if len(qs.keys()) == 1:
            self._quality = qs.keys()[0]
            print 'SFive: only one quality detected "%s" - will include it in init messages only' % self._quality



    def run(self):
        self._initFetch()
        # try to be aligned with current time
        # this will eventually get out of sync but for now this is good enough
        offset = self._duration - (time.time() % self._duration)
        print 'SFive: %sZ -> will wait %0.2f seconds before starting looper (alignment)' % (datetime.datetime.utcnow().isoformat('T'), offset)
        self._looper = task.LoopingCall(self._sendUpdates)
        reactor.callLater(offset, self._startLooper)
        reactor.callWhenRunning(self._initSocket)
        reactor.run()

    def _startLooper(self):
        self._start_time = datetime.datetime.utcnow().replace(microsecond=0)
        self._looper.start(self._duration, False)
        print 'SFive: looper started at %sZ' % (self._start_time.isoformat('T'))

    def _sendUpdates(self):
        for c in self._streamer.keys():
            for f in self._streamer[c].keys():
                for q in self._streamer[c][f].keys():
                    if self._connected:
                        self._sendDataset(self._start_time, self._duration, c, f, q)
                    self._streamer[c][f][q].clear()

        self._start_time = datetime.datetime.utcnow().replace(microsecond=0)

    def _initFetch(self):
        print "SFive: trying to fetch from '%s'" % self._url
        agent = Agent(reactor)
        d = agent.request('GET', self._url, Headers({'User-Agent': ['SFive nginx-lua fetcher']}), None)
        d.addCallback(self._httpResponse)
        d.addBoth(self.close)

    def _httpResponse(self, response):
        print 'SFive: got response from %s: %d %s' % (self._url, response.code, response.phrase)
        finished = Deferred()
        response.deliverBody(SFiveNGXluaProto(finished, self))
        return finished

    def updateData(self, data):
        try:
            m = re.match(self._url_re, data['url'])
            if not m:
                return
            streamerid = m.groupdict()
        except re.error as e:
            print 'SFive: regex error: %s' % (e)

        try:
            if data['status'] == 200 or data['status'] == 206:
                ts = dateutil.parser.parse(data['time'])
                ts = (ts - ts.utcoffset()).replace(tzinfo=None)
                if self._start_time and ts >= self._start_time:
                    self._streamer[streamerid['content']][streamerid['format']][streamerid['quality']].update(data)

        except KeyError as e:
            print 'SFive: %s - ignoring dataset' % (e)
        except ValueError as e:
            print 'SFive: %s - ignoring dataset' % (e)

    def close(self):
        if self._conn and self._connected:
            self._conn.stopListening()
        self._connected = False
        if reactor.running:
            reactor.stop()



    def _initSocket(self):
        print 'SFive: trying to connect to %s...' % (self._socket)
        self._connected = False
        self._proto = SFiveProto(self)
        self._conn = SFivePort(self._socket, self._proto, _MAX_PACKET_SIZE, 0o666, None, reactor)
        self._conn.startListening()

    def socketReady(self):
        print 'SFive: connection to sfive hub established'
        self._connected = True
        self._sendInit()
        # TODO: start callback every self._duration seconds

    def socketError(self):
        print 'SFive: connection to sfive hub lost - trying reconnect'
        if self._conn and self._connected:
            self._conn.stopListening()
        self._connected = False
        reactor.callLater(3, self._initSocket)

    def _sendInit(self):
        initdata = { "version": 1, "hostname": self._hostname,
                     "streamer-id" : { },
                     "tags": self._tags }
        if self._content_id:
            initdata["streamer-id"]["content-id"] = self._content_id
        if self._format:
            initdata["streamer-id"]["format"] = self._format
        if self._quality:
            initdata["streamer-id"]["quality"] = self._quality
        if len(initdata["streamer-id"].keys()) == 0:
            del initdata["streamer-id"]

        self._proto.sendDatagram('%s\n' % (json.dumps(initdata)));

    def _sendDataset(self, timestamp, duration, content_id, format, quality):
        clients = self._streamer[content_id][format][quality]
        data = { "start-time": timestamp.isoformat('T') + 'Z',
                 "duration-ms": duration * 1000,
                 "streamer-id": { },
                 "data": {
                   "clients": list(clients.values()),
                   "client-count": clients.getCnt(),
                   "bytes-sent": clients.getBytesSent()
                 }
               }
        if not self._content_id:
            data["streamer-id"]["content-id"] = content_id
        if not self._format:
            data["streamer-id"]["format"] = format
        if not self._quality:
            data["streamer-id"]["quality"] = quality
        if len(data["streamer-id"].keys()) == 0:
            del data["streamer-id"]

        self._proto.sendDatagram('%s\n' % (json.dumps(data)));


if __name__ == '__main__':
    import argparse

    parser = argparse.ArgumentParser(description='SFive nginx-lua log line fetcher')
    parser.add_argument('--socket', '-s', dest='socket', required=True,
                        help='the path to the data socket of the local SFive hub')
    parser.add_argument('--hostname', '-n', dest='hostname', required=True,
                        help='the hostname of the machine')
    parser.add_argument('--duration', '-d', dest='duration', required=False,
                        help='time (in seconds) between updates; defaults to 15')
    parser.add_argument('--tag', '-t', dest='tags', action='append',
                        help='tag to be added to the statistic data, can be invoked several times')
    parser.add_argument('--streamer-id', '-S', dest='streamer-ids', action='append',
                        help='a streamer description like <content-id1>[,<content-id2>]/<format1>[,<format2>]/<quality>[,<quality>[,<quality]], can be invoked several times')
    parser.add_argument('--url', '-u', dest='url', required=False,
                        help='the url of the nginx sfive exporert, default http://localhost/sfive')
    parser.add_argument('--nameformat', '-F', dest='nameformat', required=False,
                        help='a regular expression (must contain named matches for content, format, quality)')
    args = vars(parser.parse_args())
    if not args['tags']:
        args['tags'] = []
    if not args['duration']:
        args['duration'] = 15
    else:
        args['duration'] = int(args['duration'])
    if not args['url']:
        args['url'] = 'http://localhost/sfive'
    if not args['nameformat']:
        args['nameformat'] = '/[^/]+/(?P<format>hls|dash)/(?P<content>.+)-(?P<quality>[^-]+)/.*'
    if not args['streamer-ids']:
        print 'SFive: you have to specify at least one streamer-id!'
        exit(-1)

    fetcher = NGXLuaFetcher(args)
    fetcher.run()