"""

Scrapy Telnet Console extension

See documentation in docs/topics/telnetconsole.rst

"""

import pprint

import logging

from twisted.internet import protocol

try:

    from twisted.conch import manhole, telnet

    from twisted.conch.insults import insults

    TWISTED_CONCH_AVAILABLE = True

except ImportError:

    TWISTED_CONCH_AVAILABLE = False

from scrapy.exceptions import NotConfigured

from scrapy import signals

from scrapy.utils.trackref import print_live_refs

from scrapy.utils.engine import print_engine_status

from scrapy.utils.reactor import listen_tcp

try:

    import guppy

    hpy = guppy.hpy()

except ImportError:

    hpy = None

logger = logging.getLogger(__name__)

# signal to update telnet variables

# args: telnet_vars

update_telnet_vars = object()

class TelnetConsole(protocol.ServerFactory):

    def __init__(self, crawler):

        if not crawler.settings.getbool('TELNETCONSOLE_ENABLED'):

            raise NotConfigured

        if not TWISTED_CONCH_AVAILABLE:

            raise NotConfigured

        self.crawler = crawler

        self.noisy = False

        self.portrange = [int(x) for x in crawler.settings.getlist('TELNETCONSOLE_PORT')]

        self.host = crawler.settings['TELNETCONSOLE_HOST']

        self.crawler.signals.connect(self.start_listening, signals.engine_started)

        self.crawler.signals.connect(self.stop_listening, signals.engine_stopped)

    @classmethod

    def from_crawler(cls, crawler):

        return cls(crawler)

    def start_listening(self):

        self.port = listen_tcp(self.portrange, self.host, self)

        h = self.port.getHost()

        logger.debug("Telnet console listening on %(host)s:%(port)d",

                    {'host': h.host, 'port': h.port},

                    extra={'crawler': self.crawler})

    def stop_listening(self):

        self.port.stopListening()

    def protocol(self):

        telnet_vars = self._get_telnet_vars()

        return telnet.TelnetTransport(telnet.TelnetBootstrapProtocol,

            insults.ServerProtocol, manhole.Manhole, telnet_vars)

    def _get_telnet_vars(self):

        # Note: if you add entries here also update topics/telnetconsole.rst

        telnet_vars = {

            'engine': self.crawler.engine,

            'spider': self.crawler.engine.spider,

            'slot': self.crawler.engine.slot,

            'crawler': self.crawler,

            'extensions': self.crawler.extensions,

            'stats': self.crawler.stats,

            'settings': self.crawler.settings,

            'est': lambda: print_engine_status(self.crawler.engine),

            'p': pprint.pprint,

            'prefs': print_live_refs,

            'hpy': hpy,

            'help': "This is Scrapy telnet console. For more info see: " \

                "https://doc.scrapy.org/en/latest/topics/telnetconsole.html",

        }

        self.crawler.signals.send_catch_log(update_telnet_vars, telnet_vars=telnet_vars)

        return telnet_vars