import asyncio
import os
from asyncio import StreamReader, StreamWriter

def rotate_13( s: str ) -> str:
    ss = ''
    def f( c: str ) -> str:
        return chr( ( ord( c ) + 13 - 97 ) % 26 + 97 )
    for c in s:
        ss += f( c )
    return ss

async def handle_client( reader: StreamReader,
                         writer: StreamWriter ) -> None:
    while True:
        data = await reader.read( 10 )
        if not data:
            break
        response = data.decode( 'utf8' )
        print( 'server received', response )
        msg = rotate_13( response )
        print( 'server sending', msg )
        writer.write( msg.encode( 'utf8' ) )
        await writer.drain()
    print( 'closing connection to server' )
    writer.close()

async def client( msg: str, path: str ) -> str:
    reader, writer = await asyncio.open_unix_connection( path )
    print( "client sending", msg )
    writer.write( msg.encode() )
    if msg == 'world':
        await asyncio.sleep( 1 )

    data_ = await reader.read( 10 )
    data = data_.decode()

    print( "client received", data )
    print( "closing" )
    writer.close()
    return data

async def unix_rot( path: str ) -> list[ str ]:
    server = await asyncio.start_unix_server( handle_client, path )
    data = await asyncio.gather( client( 'hello', path ), client( 'world', path ) )
    server.close()
    await server.wait_closed()
    os.unlink( path )
    return list( data )