# client_w.py Test poll object's response to two fault conditions under Unix and ESP8266
import usocket as socket
import uasyncio as asyncio
import uselect as select

server_addr = socket.getaddrinfo('192.168.0.35', 8123)[0][-1]
s = socket.socket()
s.connect(server_addr)  # Expect OSError if server down
poller = select.poll()
poller.register(s, select.POLLOUT)
s.setblocking(False)

success = False
async def run():
    global success
    ok = True
    try:
        while ok:
            res = poller.ipoll(10)
            for sock, ev in res:
                if ev & select.POLLOUT:
                    r = sock.send(b'0123456789\n')
                    print(ev, r)  
                    # On ESP8266 if another task closes the socket the poll object
                    # never triggers. uasyncio expects it to trigger with POLLHUP or
                    # (POLLOUT & POLLERR or POLLOUT & POLLHUP)
                    # If server fails gets OSError on both platforms.
                else:  # But on Unix socket closure produces ev == 32
                    print('Terminating event:', ev)  # What is 32??
                    ok = False
                    break
                await asyncio.sleep(1)
            await asyncio.sleep(0)
    except OSError:
        print('Got OSError')  # Happens on ESP8266 if server fails
    success = True  # Detected socket closure or error by OSError or event

async def killer():
    await asyncio.sleep(5)
    print('closing socket')
    s.close()
    for n in range(3, -1, -1):
        print('Shutdown in {}s'.format(n))  # Leave time for response from run()
        await asyncio.sleep(1)
    if success:
        print('Success: detected error/socket closure.')
    else:
        print('Failed to detect error/socket closure.')

loop = asyncio.get_event_loop()
loop.create_task(run())
try:
    loop.run_until_complete(killer())
finally:
    s.close()