# Copyright 2014 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.


from mod_pywebsocket import common
from mod_pywebsocket.extensions import PerMessageDeflateExtensionProcessor
from mod_pywebsocket.stream import create_header


def _get_permessage_deflate_extension_processor(request):
    for extension_processor in request.ws_extension_processors:
        if isinstance(extension_processor,
                      PerMessageDeflateExtensionProcessor):
            return extension_processor
    return None


def web_socket_do_extra_handshake(request):
    processor = _get_permessage_deflate_extension_processor(request)
    assert processor is not None
    # Remove extension processors other than
    # PerMessageDeflateExtensionProcessor to avoid conflict.
    request.ws_extension_processors = [processor]


def web_socket_transfer_data(request):
    line = request.ws_stream.receive_message()
    # Hello
    payload = b'\xf2\x48\xcd\xc9\xc9\x07\x00\x00\x00\xff\xff'
    # Strip \x00\x00\xff\xff
    stripped = payload[:-4]

    header = create_header(common.OPCODE_TEXT, len(payload),
        fin=0, rsv1=1, rsv2=0, rsv3=0, mask=False)
    request.ws_stream._write(header + payload)

    header = create_header(common.OPCODE_CONTINUATION, len(stripped),
        fin=1, rsv1=0, rsv2=0, rsv3=0, mask=False)
    request.ws_stream._write(header + stripped)


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