content: from __future__ import annotations
  
  import socket
  import ssl as ssl_module
  import threading
  import warnings
  from collections.abc import Sequence
  from typing import Any, Callable, Literal, TypeVar, cast
  
  from ..client import ClientProtocol
  from ..datastructures import HeadersLike
  from ..exceptions import InvalidProxyMessage, InvalidProxyStatus, ProxyError
  from ..extensions.base import ClientExtensionFactory
  from ..extensions.permessage_deflate import enable_client_permessage_deflate
  from ..headers import validate_subprotocols
  from ..http11 import USER_AGENT, Response
  from ..protocol import CONNECTING, Event
  from ..proxy import Proxy, get_proxy, parse_proxy, prepare_connect_request
  from ..streams import StreamReader
  from ..typing import BytesLike, LoggerLike, Origin, Subprotocol
  from ..uri import WebSocketURI, parse_uri
  from .connection import Connection
  from .utils import Deadline
  
  
  __all__ = ["connect", "unix_connect", "ClientConnection"]
  
  
  class ClientConnection(Connection):
      """
      :mod:`threading` implementation of a WebSocket client connection.
  
      :class:`ClientConnection` provides :meth:`recv` and :meth:`send` methods for
      receiving and sending messages.
  
      It supports iteration to receive messages::
  
          for message in websocket:
              process(message)
  
      The iterator exits normally when the connection is closed with code
      1000 (OK) or 1001 (going away) or without a close code. It raises a
      :exc:`~websockets.exceptions.ConnectionClosedError` when the connection is
      closed with any other code.
  
      The ``ping_interval``, ``ping_timeout``, ``close_timeout``, and
      ``max_queue`` arguments have the same meaning as in :func:`connect`.
  
      Args:
          socket: Socket connected to a WebSocket server.
          protocol: Sans-I/O connection.
  
      """
  
      def __init__(
          self,
          socket: socket.socket,
          protocol: ClientProtocol,
          *,
          ping_interval: float | None = 20,
          ping_timeout: float | None = 20,
          close_timeout: float | None = 10,
          max_queue: int | None | tuple[int | None, int | None] = 16,
      ) -> None:
          self.protocol: ClientProtocol
          self.response_rcvd = threading.Event()
          super().__init__(
              socket,
              protocol,
              ping_interval=ping_interval,
              ping_timeout=ping_timeout,
              close_timeout=close_timeout,
              max_queue=max_queue,
          )
  
      def handshake(
          self,
          additional_headers: HeadersLike | None = None,
          user_agent_header: str | None = USER_AGENT,
          timeout: float | None = None,
      ) -> None:
          """
          Perform the opening handshake.
  
          """
          with self.send_context(expected_state=CONNECTING):
              self.request = self.protocol.connect()
              if additional_headers is not None:
                  self.request.headers.update(additional_headers)
              if user_agent_header is not None:
                  self.request.headers.setdefault("User-Agent", user_agent_header)
              self.protocol.send_request(self.request)
  
          if not self.response_rcvd.wait(timeout):
              raise TimeoutError("timed out while waiting for handshake response")
  
          # self.protocol.handshake_exc is set when the connection is lost before
          # receiving a response, when the response cannot be parsed, or when the
          # response fails the handshake.
  
          if self.protocol.handshake_exc is not None:
              raise self.protocol.handshake_exc
  
      def process_event(self, event: Event) -> None:
          """
          Process one incoming event.
  
          """
          # First event - handshake response.
          if self.response is None:
              assert isinstance(event, Response)
              self.response = event
              self.response_rcvd.set()
          # Later events - frames.
          else:
              super().process_event(event)
  
      def recv_events(self) -> None:
          """
          Read incoming data from the socket and process events.
  
          """
          try:
              super().recv_events()
          finally:
              # If the connection is closed during the handshake, unblock it.
              self.response_rcvd.set()
  
  
  def connect(
      uri: str,
      *,
      # TCP/TLS
      sock: socket.socket | None = None,
      ssl: ssl_module.SSLContext | None = None,
      server_hostname: str | None = None,
      # WebSocket
      origin: Origin | None = None,
      extensions: Sequence[ClientExtensionFactory] | None = None,
      subprotocols: Sequence[Subprotocol] | None = None,
      compression: str | None = "deflate",
      # HTTP
      additional_headers: HeadersLike | None = None,
      user_agent_header: str | None = USER_AGENT,
      proxy: str | Literal[True] | None = True,
      proxy_ssl: ssl_module.SSLContext | None = None,
      proxy_server_hostname: str | None = None,
      # Timeouts
      open_timeout: float | None = 10,
      ping_interval: float | None = 20,
      ping_timeout: float | None = 20,
      close_timeout: float | None = 10,
      # Limits
      max_size: int | None | tuple[int | None, int | None] = 2**20,
      max_queue: int | None | tuple[int | None, int | None] = 16,
      # Logging
      logger: LoggerLike | None = None,
      # Escape hatch for advanced customization
      create_connection: type[ClientConnection] | None = None,
      **kwargs: Any,
  ) -> ClientConnection:
      """
      Connect to the WebSocket server at ``uri``.
  
      This function returns a :class:`ClientConnection` instance, which you can
      use to send and receive messages.
  
      :func:`connect` may be used as a context manager::
  
          from websockets.sync.client import connect
  
          with connect(...) as websocket:
              ...
  
      The connection is closed automatically when exiting the context.
  
      Args:
          uri: URI of the WebSocket server.
          sock: Preexisting TCP socket. ``sock`` overrides the host and port
              from ``uri``. You may call :func:`socket.create_connection` to
              create a suitable TCP socket.
          ssl: Configuration for enabling TLS on the connection.
          server_hostname: Host name for the TLS handshake. ``server_hostname``
              overrides the host name from ``uri``.
          origin: Value of the ``Origin`` header, for servers that require it.
          extensions: List of supported extensions, in order in which they
              should be negotiated and run.
          subprotocols: List of supported subprotocols, in order of decreasing
              preference.
          compression: The "permessage-deflate" extension is enabled by default.
              Set ``compression`` to :obj:`None` to disable it. See the
              :doc:`compression guide <../../topics/compression>` for details.
          additional_headers (HeadersLike | None): Arbitrary HTTP headers to add
              to the handshake request.
          user_agent_header: Value of  the ``User-Agent`` request header.
              It defaults to ``"Python/x.y.z websockets/X.Y"``.
              Setting it to :obj:`None` removes the header.
          proxy: If a proxy is configured, it is used by default. Set ``proxy``
              to :obj:`None` to disable the proxy or to the address of a proxy
              to override the system configuration. See the :doc:`proxy docs
              <../../topics/proxies>` for details.
          proxy_ssl: Configuration for enabling TLS on the proxy connection.
          proxy_server_hostname: Host name for the TLS handshake with the proxy.
              ``proxy_server_hostname`` overrides the host name from ``proxy``.
          open_timeout: Timeout for opening the connection in seconds.
              :obj:`None` disables the timeout.
          ping_interval: Interval between keepalive pings in seconds.
              :obj:`None` disables keepalive.
          ping_timeout: Timeout for keepalive pings in seconds.
              :obj:`None` disables timeouts.
          close_timeout: Timeout for closing the connection in seconds.
              :obj:`None` disables the timeout.
          max_size: Maximum size of incoming messages in bytes.
              :obj:`None` disables the limit. You may pass a ``(max_message_size,
              max_fragment_size)`` tuple to set different limits for messages and
              fragments when you expect long messages sent in short fragments.
          max_queue: High-water mark of the buffer where frames are received.
              It defaults to 16 frames. The low-water mark defaults to ``max_queue
              // 4``. You may pass a ``(high, low)`` tuple to set the high-water
              and low-water marks. If you want to disable flow control entirely,
              you may set it to ``None``, although that's a bad idea.
          logger: Logger for this client.
              It defaults to ``logging.getLogger("websockets.client")``.
              See the :doc:`logging guide <../../topics/logging>` for details.
          create_connection: Factory for the :class:`ClientConnection` managing
              the connection. Set it to a wrapper or a subclass to customize
              connection handling.
  
      Any other keyword arguments are passed to :func:`~socket.create_connection`.
  
      Raises:
          InvalidURI: If ``uri`` isn't a valid WebSocket URI.
          OSError: If the TCP connection fails.
          InvalidHandshake: If the opening handshake fails.
          TimeoutError: If the opening handshake times out.
  
      """
  
      # Process parameters
  
      # Backwards compatibility: ssl used to be called ssl_context.
      if ssl is None and "ssl_context" in kwargs:
          ssl = kwargs.pop("ssl_context")
          warnings.warn(  # deprecated in 13.0 - 2024-08-20
              "ssl_context was renamed to ssl",
              DeprecationWarning,
          )
  
      ws_uri = parse_uri(uri)
      if not ws_uri.secure and ssl is not None:
          raise ValueError("ssl argument is incompatible with a ws:// URI")
  
      # Private APIs for unix_connect()
      unix: bool = kwargs.pop("unix", False)
      path: str | None = kwargs.pop("path", None)
  
      if unix:
          if path is None and sock is None:
              raise ValueError("missing path argument")
          elif path is not None and sock is not None:
              raise ValueError("path and sock arguments are incompatible")
  
      if subprotocols is not None:
          validate_subprotocols(subprotocols)
  
      if compression == "deflate":
          extensions = enable_client_permessage_deflate(extensions)
      elif compression is not None:
          raise ValueError(f"unsupported compression: {compression}")
  
      if unix:
          proxy = None
      if sock is not None:
          proxy = None
      if proxy is True:
          proxy = get_proxy(ws_uri)
  
      # Calculate timeouts on the TCP, TLS, and WebSocket handshakes.
      # The TCP and TLS timeouts must be set on the socket, then removed
      # to avoid conflicting with the WebSocket timeout in handshake().
      deadline = Deadline(open_timeout)
  
      if create_connection is None:
          create_connection = ClientConnection
  
      try:
          # Connect socket
  
          if sock is None:
              if unix:
                  sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
                  sock.settimeout(deadline.timeout())
                  assert path is not None  # mypy cannot figure this out
                  sock.connect(path)
              elif proxy is not None:
                  proxy_parsed = parse_proxy(proxy)
                  if proxy_parsed.scheme[:5] == "socks":
                      # Connect to the server through the proxy.
                      sock = connect_socks_proxy(
                          proxy_parsed,
                          ws_uri,
                          deadline,
                          # websockets is consistent with the socket module while
                          # python_socks is consistent across implementations.
                          local_addr=kwargs.pop("source_address", None),
                      )
                  elif proxy_parsed.scheme[:4] == "http":
                      # Validate the proxy_ssl argument.
                      if proxy_parsed.scheme != "https" and proxy_ssl is not None:
                          raise ValueError(
                              "proxy_ssl argument is incompatible with an http:// proxy"
                          )
                      # Connect to the server through the proxy.
                      sock = connect_http_proxy(
                          proxy_parsed,
                          ws_uri,
                          deadline,
                          user_agent_header=user_agent_header,
                          ssl=proxy_ssl,
                          server_hostname=proxy_server_hostname,
                          **kwargs,
                      )
                  else:
                      raise AssertionError("unsupported proxy")
              else:
                  kwargs.setdefault("timeout", deadline.timeout())
                  sock = socket.create_connection(
                      (ws_uri.host, ws_uri.port),
                      **kwargs,
                  )
              sock.settimeout(None)
  
          # Disable Nagle algorithm
  
          if not unix:
              sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, True)
  
          # Initialize TLS wrapper and perform TLS handshake
  
          if ws_uri.secure:
              if ssl is None:
                  ssl = ssl_module.create_default_context()
              if server_hostname is None:
                  server_hostname = ws_uri.host
              sock.settimeout(deadline.timeout())
              if proxy_ssl is None:
                  sock = ssl.wrap_socket(sock, server_hostname=server_hostname)
              else:
                  sock_2 = SSLSSLSocket(sock, ssl, server_hostname=server_hostname)
                  # Let's pretend that sock is a socket, even though it isn't.
                  sock = cast(socket.socket, sock_2)
              sock.settimeout(None)
  
          # Initialize WebSocket protocol
  
          protocol = ClientProtocol(
              ws_uri,
              origin=origin,
              extensions=extensions,
              subprotocols=subprotocols,
              max_size=max_size,
              logger=logger,
          )
  
          # Initialize WebSocket connection
  
          connection = create_connection(
              sock,
              protocol,
              ping_interval=ping_interval,
              ping_timeout=ping_timeout,
              close_timeout=close_timeout,
              max_queue=max_queue,
          )
      except Exception:
          if sock is not None:
              sock.close()
          raise
  
      try:
          connection.handshake(
              additional_headers,
              user_agent_header,
              deadline.timeout(),
          )
      except Exception:
          connection.close_socket()
          connection.recv_events_thread.join()
          raise
  
      connection.start_keepalive()
      return connection
  
  
  def unix_connect(
      path: str | None = None,
      uri: str | None = None,
      **kwargs: Any,
  ) -> ClientConnection:
      """
      Connect to a WebSocket server listening on a Unix socket.
  
      This function accepts the same keyword arguments as :func:`connect`.
  
      It's only available on Unix.
  
      It's mainly useful for debugging servers listening on Unix sockets.
  
      Args:
          path: File system path to the Unix socket.
          uri: URI of the WebSocket server. ``uri`` defaults to
              ``ws://localhost/`` or, when a ``ssl`` is provided, to
              ``wss://localhost/``.
  
      """
      if uri is None:
          # Backwards compatibility: ssl used to be called ssl_context.
          if kwargs.get("ssl") is None and kwargs.get("ssl_context") is None:
              uri = "ws://localhost/"
          else:
              uri = "wss://localhost/"
      return connect(uri=uri, unix=True, path=path, **kwargs)
  
  
  try:
      from python_socks import ProxyType
      from python_socks.sync import Proxy as SocksProxy
  
  except ImportError:
  
      def connect_socks_proxy(
          proxy: Proxy,
          ws_uri: WebSocketURI,
          deadline: Deadline,
          **kwargs: Any,
      ) -> socket.socket:
          raise ImportError("connecting through a SOCKS proxy requires python-socks")
  
  else:
      SOCKS_PROXY_TYPES = {
          "socks5h": ProxyType.SOCKS5,
          "socks5": ProxyType.SOCKS5,
          "socks4a": ProxyType.SOCKS4,
          "socks4": ProxyType.SOCKS4,
      }
  
      SOCKS_PROXY_RDNS = {
          "socks5h": True,
          "socks5": False,
          "socks4a": True,
          "socks4": False,
      }
  
      def connect_socks_proxy(
          proxy: Proxy,
          ws_uri: WebSocketURI,
          deadline: Deadline,
          **kwargs: Any,
      ) -> socket.socket:
          """Connect via a SOCKS proxy and return the socket."""
          socks_proxy = SocksProxy(
              SOCKS_PROXY_TYPES[proxy.scheme],
              proxy.host,
              proxy.port,
              proxy.username,
              proxy.password,
              SOCKS_PROXY_RDNS[proxy.scheme],
          )
          kwargs.setdefault("timeout", deadline.timeout())
          # connect() is documented to raise OSError and TimeoutError.
          # Wrap other exceptions in ProxyError, a subclass of InvalidHandshake.
          try:
              return socks_proxy.connect(ws_uri.host, ws_uri.port, **kwargs)
          except (OSError, TimeoutError, socket.timeout):
              raise
          except Exception as exc:
              raise ProxyError("failed to connect to SOCKS proxy") from exc
  
  
  def read_connect_response(sock: socket.socket, deadline: Deadline) -> Response:
      reader = StreamReader()
      parser = Response.parse(
          reader.read_line,
          reader.read_exact,
          reader.read_to_eof,
          proxy=True,
      )
      try:
          while True:
              sock.settimeout(deadline.timeout())
              data = sock.recv(4096)
              if data:
                  reader.feed_data(data)
              else:
                  reader.feed_eof()
              next(parser)
      except StopIteration as exc:
          assert isinstance(exc.value, Response)  # help mypy
          response = exc.value
          if 200 <= response.status_code < 300:
              return response
          else:
              raise InvalidProxyStatus(response)
      except socket.timeout:
          raise TimeoutError("timed out while connecting to HTTP proxy")
      except Exception as exc:
          raise InvalidProxyMessage(
              "did not receive a valid HTTP response from proxy"
          ) from exc
      finally:
          sock.settimeout(None)
  
  
  def connect_http_proxy(
      proxy: Proxy,
      ws_uri: WebSocketURI,
      deadline: Deadline,
      *,
      user_agent_header: str | None = None,
      ssl: ssl_module.SSLContext | None = None,
      server_hostname: str | None = None,
      **kwargs: Any,
  ) -> socket.socket:
      # Connect socket
  
      kwargs.setdefault("timeout", deadline.timeout())
      sock = socket.create_connection((proxy.host, proxy.port), **kwargs)
  
      # Initialize TLS wrapper and perform TLS handshake
  
      if proxy.scheme == "https":
          if ssl is None:
              ssl = ssl_module.create_default_context()
          if server_hostname is None:
              server_hostname = proxy.host
          sock.settimeout(deadline.timeout())
          sock = ssl.wrap_socket(sock, server_hostname=server_hostname)
          sock.settimeout(None)
  
      # Send CONNECT request to the proxy and read response.
  
      sock.sendall(prepare_connect_request(proxy, ws_uri, user_agent_header))
      try:
          read_connect_response(sock, deadline)
      except Exception:
          sock.close()
          raise
  
      return sock
  
  
  T = TypeVar("T")
  F = TypeVar("F", bound=Callable[..., T])
  
  
  class SSLSSLSocket:
      """
      Socket-like object providing TLS-in-TLS.
  
      Only methods that are used by websockets are implemented.
  
      """
  
      recv_bufsize = 65536
  
      def __init__(
          self,
          sock: socket.socket,
          ssl_context: ssl_module.SSLContext,
          server_hostname: str | None = None,
      ) -> None:
          self.incoming = ssl_module.MemoryBIO()
          self.outgoing = ssl_module.MemoryBIO()
          self.ssl_socket = sock
          self.ssl_object = ssl_context.wrap_bio(
              self.incoming,
              self.outgoing,
              server_hostname=server_hostname,
          )
          self.run_io(self.ssl_object.do_handshake)
  
      def run_io(self, func: Callable[..., T], *args: Any) -> T:
          while True:
              want_read = False
              want_write = False
              try:
                  result = func(*args)
              except ssl_module.SSLWantReadError:
                  want_read = True
              except ssl_module.SSLWantWriteError:  # pragma: no cover
                  want_write = True
  
              # Write outgoing data in all cases.
              data = self.outgoing.read()
              if data:
                  self.ssl_socket.sendall(data)
  
              # Read incoming data and retry on SSLWantReadError.
              if want_read:
                  data = self.ssl_socket.recv(self.recv_bufsize)
                  if data:
                      self.incoming.write(data)
                  else:
                      self.incoming.write_eof()
                  continue
              # Retry after writing outgoing data on SSLWantWriteError.
              if want_write:  # pragma: no cover
                  continue
              # Return result if no error happened.
              return result
  
      def recv(self, buflen: int) -> bytes:
          try:
              return self.run_io(self.ssl_object.read, buflen)
          except ssl_module.SSLEOFError:
              return b""  # always ignore ragged EOFs
  
      def send(self, data: BytesLike) -> int:
          return self.run_io(self.ssl_object.write, data)
  
      def sendall(self, data: BytesLike) -> None:
          # adapted from ssl_module.SSLSocket.sendall()
          count = 0
          with memoryview(data) as view, view.cast("B") as byte_view:
              amount = len(byte_view)
              while count < amount:
                  count += self.send(byte_view[count:])
  
      # recv_into(), recvfrom(), recvfrom_into(), sendto(), unwrap(), and the
      # flags argument aren't implemented because websockets doesn't need them.
  
      def __getattr__(self, name: str) -> Any:
          return getattr(self.ssl_socket, name)
  