# Copyright (c) 2019, Neil Booth
#
# All rights reserved.
#
# The MIT License (MIT)
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


from functools import partial

import websockets

from aiorpcx.curio import spawn
from aiorpcx.session import RPCSession, SessionKind
from aiorpcx.util import NetAddress


__all__ = ('serve_ws', 'connect_ws')


class WSTransport:
    '''Implementation of a websocket transport for session.py.'''

    def __init__(self, websocket, session_factory, kind):
        self.websocket = websocket
        self.kind = kind
        self.session = session_factory(self)
        self.closing = False

    @classmethod
    async def ws_server(cls, session_factory, websocket, _path):
        transport = cls(websocket, session_factory, SessionKind.SERVER)
        await transport.process_messages()

    @classmethod
    async def ws_client(cls, uri, **kwargs):
        session_factory = kwargs.pop('session_factory', RPCSession)
        websocket = await websockets.connect(uri, **kwargs)
        return cls(websocket, session_factory, SessionKind.CLIENT)

    async def recv_message(self):
        message = await self.websocket.recv()
        self.session.data_received(message)
        return message

    async def process_messages(self):
        try:
            await self.session.process_messages(self.recv_message)
        except websockets.ConnectionClosed:
            pass
        finally:
            await self.session.connection_lost()

    # API exposed to session
    async def write(self, framed_message):
        await self.websocket.send(framed_message)

    async def close(self, _force_after=0):
        '''Close the connection and return when closed.'''
        self.closing = True
        await self.websocket.close()

    async def abort(self):
        '''Abort the connection.  For now this just calls close().'''
        self.closing = True
        await self.close()

    def is_closing(self):
        '''Return True if the connection is closing.'''
        return self.closing

    def proxy(self):
        return None

    def remote_address(self):
        result = self.websocket.remote_address
        if result:
            result = NetAddress(*result[:2])
        return result


class WSClient:

    def __init__(self, uri, **kwargs):
        self.uri = uri
        self.session_factory = kwargs.pop('session_factory', RPCSession)
        self.kwargs = kwargs
        self.transport = None
        self.process_messages_task = None

    async def __aenter__(self):
        self.transport = await WSTransport.ws_client(self.uri, **self.kwargs)
        self.process_messages_task = await spawn(self.transport.process_messages())
        return self.transport.session

    async def __aexit__(self, exc_type, exc_value, traceback):
        await self.transport.close()
        assert self.process_messages_task.done()


def serve_ws(session_factory, *args, **kwargs):
    ws_handler = partial(WSTransport.ws_server, session_factory)
    return websockets.serve(ws_handler, *args, **kwargs)


connect_ws = WSClient
