''' Module that implements OSC '''

import asyncio
import struct

from pytyuosc import packet
#import packet

_DEBUG = True
_TASK = None
_Q = asyncio.Queue()

def __string_to_osc(s: str) -> bytes:
    ''' Convert python string to OSC-string '''
    data = s.encode('ascii')
    to_append = 4 - (len(data) % 4)
    data += b'\0' * to_append
    return data

async def __serve() -> None:
    ''' Task that manages OSC sending '''
    # log
    if _DEBUG:
        print('[I] OSC Client: task is running')
    # task loop
    while True:
        # get value from queue
        val = await _Q.get()
        # stop
        if val == 0:
            break
        # host, port, OSC address and data
        host = val['host']
        port = val['port']
        addr = val['addr']
        data = val['data']
        
        try:
            data_to_send = packet.serialize(addr, data, _DEBUG)
            if data_to_send is None:
                raise Exception()
        except:
            continue

        # send the packet
        trans, prot = await asyncio.get_running_loop().create_datagram_endpoint(
            asyncio.DatagramProtocol,
            remote_addr=(host, port),
            allow_broadcast=True
        )
        try:
            trans.sendto(data_to_send)
            if _DEBUG: print('[I] OSC Client: sent data to %s:%s' % (host, port))
        except:
            if _DEBUG:
                print('[!] OSC Client: failed to send to %s:%s!' % (host, port))
                print('      * address: %s' % addr)
                print('      * data: %s' % data)
        finally:
            trans.close()

    # log
    if _DEBUG:
        print('[I] OSC Client: task is stopped')

async def start() -> None:
    ''' Starts OSC task '''
    global _TASK
    # already started
    if _TASK is not None:
        return
    _TASK = asyncio.create_task(__serve())

async def stop() -> None:
    ''' Stops OSC task '''
    global _TASK
    # not started
    if _TASK is None:
        return
    # stop
    await _Q.put(0)
    await _TASK
    # reset
    _TASK = None

async def send(host: str, port: str, addr: str, values: list) -> None:
    ''' Schedule packet transmission '''
    # not started
    if _TASK is None:
        return
    # create
    d = {
        'host': host,
        'port': port,
        'addr': addr,
        'data': values
    }
    await _Q.put(d)

#
# TEST
#
async def __test__() -> None:
    print('Going to send data to 255.255.255.255:8000')
    await start()
    await send('255.255.255.255', 8000, '/pytyuosc/osc/testing/is/in/progress', ['a', 'b', 1, 2, 3.4, 5.6])
    await stop()
    print('Data must have been sent')

if __name__ == '__main__':
    asyncio.run(__test__())