python-telegram-bot/telegram/utils/request.py

#!/usr/bin/env python
#
# A library that provides a Python interface to the Telegram Bot API
# Copyright (C) 2015-2020
# Leandro Toledo de Souza <devs@python-telegram-bot.org>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program 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 Lesser Public License for more details.
#
# You should have received a copy of the GNU Lesser Public License
# along with this program.  If not, see [http://www.gnu.org/licenses/].
"""This module contains methods to make POST and GET requests."""
import logging
import os
import socket
import sys
import warnings

try:
    import ujson as json
except ImportError:
    import json  # type: ignore[no-redef]

import certifi

try:
    import telegram.vendor.ptb_urllib3.urllib3 as urllib3
    import telegram.vendor.ptb_urllib3.urllib3.contrib.appengine as appengine
    from telegram.vendor.ptb_urllib3.urllib3.connection import HTTPConnection
    from telegram.vendor.ptb_urllib3.urllib3.util.timeout import Timeout
    from telegram.vendor.ptb_urllib3.urllib3.fields import RequestField
except ImportError:  # pragma: no cover
    try:
        import urllib3  # type: ignore[no-redef]
        import urllib3.contrib.appengine as appengine  # type: ignore[no-redef]
        from urllib3.connection import HTTPConnection  # type: ignore[no-redef]
        from urllib3.util.timeout import Timeout  # type: ignore[no-redef]
        from urllib3.fields import RequestField  # type: ignore[no-redef]
        warnings.warn('python-telegram-bot is using upstream urllib3. This is allowed but not '
                      'supported by python-telegram-bot maintainers.')
    except ImportError:
        warnings.warn(
            "python-telegram-bot wasn't properly installed. Please refer to README.rst on "
            "how to properly install.")
        raise


from telegram import (InputFile, TelegramError, InputMedia)
from telegram.error import (Unauthorized, NetworkError, TimedOut, BadRequest, ChatMigrated,
                            RetryAfter, InvalidToken, Conflict)

from telegram.utils.types import JSONDict
from typing import Any, Union


def _render_part(self: RequestField, name: str, value: str) -> str:
    """
    Monkey patch urllib3.urllib3.fields.RequestField to make it *not* support RFC2231 compliant
    Content-Disposition headers since telegram servers don't understand it. Instead just escape
    \\ and " and replace any \n and \r with a space.
    """
    value = value.replace(u'\\', u'\\\\').replace(u'"', u'\\"')
    value = value.replace(u'\r', u' ').replace(u'\n', u' ')
    return u'{}="{}"'.format(name, value)


RequestField._render_part = _render_part  # type: ignore

logging.getLogger('urllib3').setLevel(logging.WARNING)

USER_AGENT = 'Python Telegram Bot (https://github.com/python-telegram-bot/python-telegram-bot)'


class Request:
    """
    Helper class for python-telegram-bot which provides methods to perform POST & GET towards
    telegram servers.

    Args:
        con_pool_size (int): Number of connections to keep in the connection pool.
        proxy_url (str): The URL to the proxy server. For example: `http://127.0.0.1:3128`.
        urllib3_proxy_kwargs (dict): Arbitrary arguments passed as-is to `urllib3.ProxyManager`.
            This value will be ignored if proxy_url is not set.
        connect_timeout (int|float): The maximum amount of time (in seconds) to wait for a
            connection attempt to a server to succeed. None will set an infinite timeout for
            connection attempts. (default: 5.)
        read_timeout (int|float): The maximum amount of time (in seconds) to wait between
            consecutive read operations for a response from the server. None will set an infinite
            timeout. This value is usually overridden by the various ``telegram.Bot`` methods.
            (default: 5.)

    """

    def __init__(self,
                 con_pool_size: int = 1,
                 proxy_url: str = None,
                 urllib3_proxy_kwargs: JSONDict = None,
                 connect_timeout: float = 5.,
                 read_timeout: float = 5.):
        if urllib3_proxy_kwargs is None:
            urllib3_proxy_kwargs = dict()

        self._connect_timeout = connect_timeout

        sockopts = HTTPConnection.default_socket_options + [
            (socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)]

        # TODO: Support other platforms like mac and windows.
        if 'linux' in sys.platform:
            sockopts.append((socket.IPPROTO_TCP,
                             socket.TCP_KEEPIDLE, 120))  # pylint: disable=no-member
            sockopts.append((socket.IPPROTO_TCP,
                             socket.TCP_KEEPINTVL, 30))  # pylint: disable=no-member
            sockopts.append((socket.IPPROTO_TCP,
                             socket.TCP_KEEPCNT, 8))  # pylint: disable=no-member

        self._con_pool_size = con_pool_size

        kwargs = dict(
            maxsize=con_pool_size,
            cert_reqs='CERT_REQUIRED',
            ca_certs=certifi.where(),
            socket_options=sockopts,
            timeout=urllib3.Timeout(
                connect=self._connect_timeout, read=read_timeout, total=None))

        # Set a proxy according to the following order:
        # * proxy defined in proxy_url (+ urllib3_proxy_kwargs)
        # * proxy set in `HTTPS_PROXY` env. var.
        # * proxy set in `https_proxy` env. var.
        # * None (if no proxy is configured)

        if not proxy_url:
            proxy_url = os.environ.get('HTTPS_PROXY') or os.environ.get('https_proxy')

        self._con_pool: Union[urllib3.PoolManager, appengine.AppEngineManager,
                              'SOCKSProxyManager',  # noqa: F821
                              urllib3.ProxyManager] = None  # type: ignore
        if not proxy_url:
            if appengine.is_appengine_sandbox():
                # Use URLFetch service if running in App Engine
                self._con_pool = appengine.AppEngineManager()
            else:
                self._con_pool = urllib3.PoolManager(**kwargs)
        else:
            kwargs.update(urllib3_proxy_kwargs)
            if proxy_url.startswith('socks'):
                try:
                    from telegram.vendor.ptb_urllib3.urllib3.contrib.socks import SOCKSProxyManager
                except ImportError:
                    raise RuntimeError('PySocks is missing')
                self._con_pool = SOCKSProxyManager(proxy_url, **kwargs)
            else:
                mgr = urllib3.proxy_from_url(proxy_url, **kwargs)
                if mgr.proxy.auth:
                    # TODO: what about other auth types?
                    auth_hdrs = urllib3.make_headers(proxy_basic_auth=mgr.proxy.auth)
                    mgr.proxy_headers.update(auth_hdrs)

                self._con_pool = mgr

    @property
    def con_pool_size(self) -> int:
        """The size of the connection pool used."""
        return self._con_pool_size

    def stop(self) -> None:
        self._con_pool.clear()  # type: ignore

    @staticmethod
    def _parse(json_data: bytes) -> Union[JSONDict, bool]:
        """Try and parse the JSON returned from Telegram.

        Returns:
            dict: A JSON parsed as Python dict with results - on error this dict will be empty.

        """

        decoded_s = json_data.decode('utf-8', 'replace')
        try:
            data = json.loads(decoded_s)
        except ValueError:
            raise TelegramError('Invalid server response')

        if not data.get('ok'):  # pragma: no cover
            description = data.get('description')
            parameters = data.get('parameters')
            if parameters:
                migrate_to_chat_id = parameters.get('migrate_to_chat_id')
                if migrate_to_chat_id:
                    raise ChatMigrated(migrate_to_chat_id)
                retry_after = parameters.get('retry_after')
                if retry_after:
                    raise RetryAfter(retry_after)
            if description:
                return description

        return data['result']

    def _request_wrapper(self, *args: Any, **kwargs: Any) -> bytes:
        """Wraps urllib3 request for handling known exceptions.

        Args:
            args: unnamed arguments, passed to urllib3 request.
            kwargs: keyword arguments, passed tp urllib3 request.

        Returns:
            bytes: A non-parsed JSON text.

        Raises:
            TelegramError

        """
        # Make sure to hint Telegram servers that we reuse connections by sending
        # "Connection: keep-alive" in the HTTP headers.
        if 'headers' not in kwargs:
            kwargs['headers'] = {}
        kwargs['headers']['connection'] = 'keep-alive'
        # Also set our user agent
        kwargs['headers']['user-agent'] = USER_AGENT

        try:
            resp = self._con_pool.request(*args, **kwargs)
        except urllib3.exceptions.TimeoutError:
            raise TimedOut()
        except urllib3.exceptions.HTTPError as error:
            # HTTPError must come last as its the base urllib3 exception class
            # TODO: do something smart here; for now just raise NetworkError
            raise NetworkError('urllib3 HTTPError {}'.format(error))

        if 200 <= resp.status <= 299:
            # 200-299 range are HTTP success statuses
            return resp.data

        try:
            message = str(self._parse(resp.data))
        except ValueError:
            message = 'Unknown HTTPError'

        if resp.status in (401, 403):
            raise Unauthorized(message)
        elif resp.status == 400:
            raise BadRequest(message)
        elif resp.status == 404:
            raise InvalidToken()
        elif resp.status == 409:
            raise Conflict(message)
        elif resp.status == 413:
            raise NetworkError('File too large. Check telegram api limits '
                               'https://core.telegram.org/bots/api#senddocument')

        elif resp.status == 502:
            raise NetworkError('Bad Gateway')
        else:
            raise NetworkError('{} ({})'.format(message, resp.status))

    def post(self,
             url: str,
             data: JSONDict,
             timeout: float = None) -> Union[JSONDict, bool]:
        """Request an URL.

        Args:
            url (:obj:`str`): The web location we want to retrieve.
            data (dict[str, str|int], optional): A dict of key/value pairs.
            timeout (:obj:`int` | :obj:`float`, optional): If this value is specified, use it as
                the read timeout from the server (instead of the one specified during creation of
                the connection pool).

        Returns:
          A JSON object.

        """
        urlopen_kwargs = {}

        if timeout is not None:
            urlopen_kwargs['timeout'] = Timeout(read=timeout, connect=self._connect_timeout)

        if data is None:
            data = {}

        # Are we uploading files?
        files = False

        for key, val in data.copy().items():
            if isinstance(val, InputFile):
                # Convert the InputFile to urllib3 field format
                data[key] = val.field_tuple
                files = True
            elif isinstance(val, (float, int)):
                # Urllib3 doesn't like floats it seems
                data[key] = str(val)
            elif key == 'media':
                # One media or multiple
                if isinstance(val, InputMedia):
                    # Attach and set val to attached name
                    data[key] = val.to_json()
                    if isinstance(val.media, InputFile):  # type: ignore
                        data[val.media.attach] = val.media.field_tuple  # type: ignore
                else:
                    # Attach and set val to attached name for all
                    media = []
                    for m in val:
                        media_dict = m.to_dict()
                        media.append(media_dict)
                        if isinstance(m.media, InputFile):
                            data[m.media.attach] = m.media.field_tuple
                            # if the file has a thumb, we also need to attach it to the data
                            if "thumb" in media_dict:
                                data[m.thumb.attach] = m.thumb.field_tuple
                    data[key] = json.dumps(media)
                files = True

        # Use multipart upload if we're uploading files, otherwise use JSON
        if files:
            result = self._request_wrapper('POST', url, fields=data, **urlopen_kwargs)
        else:
            result = self._request_wrapper('POST', url,
                                           body=json.dumps(data).encode('utf-8'),
                                           headers={'Content-Type': 'application/json'},
                                           **urlopen_kwargs)

        return self._parse(result)

    def retrieve(self, url: str, timeout: float = None) -> bytes:
        """Retrieve the contents of a file by its URL.

        Args:
            url (:obj:`str`): The web location we want to retrieve.
            timeout (:obj:`int` | :obj:`float`): If this value is specified, use it as the read
                timeout from the server (instead of the one specified during creation of the
                connection pool).

        """
        urlopen_kwargs = {}
        if timeout is not None:
            urlopen_kwargs['timeout'] = Timeout(read=timeout, connect=self._connect_timeout)

        return self._request_wrapper('GET', url, **urlopen_kwargs)

    def download(self, url: str, filename: str, timeout: float = None) -> None:
        """Download a file by its URL.

        Args:
            url (str): The web location we want to retrieve.
            timeout (:obj:`int` | :obj:`float`): If this value is specified, use it as the read
                timeout from the server (instead of the one specified during creation of the
                connection pool).
            filename (:obj:`str`): The filename within the path to download the file.

        """
        buf = self.retrieve(url, timeout=timeout)
        with open(filename, 'wb') as fobj:
            fobj.write(buf)