import asyncio
import binascii
import libtorrent


NOTIFICATION_MASKS = [
  "error",
  "peer",
  "port_mapping",
  "storage",
  "tracker",
  "debug",
  "status",
  "progress",
  "ip_block",
  "dht",
  "stats",
  "session_log",
  "torrent_log",
  "peer_log",
  "incoming_request",
  "dht_log",
  "dht_operation",
  "port_mapping_log",
  "picker_log",
  "file_progress",
  "piece_progress",
  "upload",
  "block_progress"
]


def get_notification_type(notification) -> str:
    for i, notification_type in enumerate(NOTIFICATION_MASKS):
        if (1 << i) & notification:
            return notification_type
    raise ValueError("unrecognized notification type")


class TorrentHandle:
    def __init__(self, loop, executor, handle):
        self._loop = loop
        self._executor = executor
        self._handle = handle
        self.finished = asyncio.Event(loop=loop)

    def _show_status(self):
        status = self._handle.status()
        if not status.is_seeding:
            print('%.2f%% complete (down: %.1f kB/s up: %.1f kB/s peers: %d) %s' % (
                status.progress * 100, status.download_rate / 1000, status.upload_rate / 1000,
                status.num_peers, status.state))
        elif not self.finished.is_set():
            self.finished.set()
            print("finished!")

    async def status_loop(self):
        while True:
            await self._loop.run_in_executor(
                self._executor, self._show_status
            )
            if self.finished.is_set():
                break
            await asyncio.sleep(1, loop=self._loop)

    async def pause(self):
        await self._loop.run_in_executor(
            self._executor, self._handle.pause
        )

    async def resume(self):
        await self._loop.run_in_executor(
            self._executor, self._handle.resume
        )


class TorrentSession:
    def __init__(self, loop, executor):
        self._loop = loop
        self._executor = executor
        self._session = None
        self._handles = {}

    async def bind(self, interface: str = '0.0.0.0', port: int = 6881):
        settings = {
            'listen_interfaces': f"{interface}:{port}",
            'enable_outgoing_utp': True,
            'enable_incoming_utp': True,
            'enable_outgoing_tcp': True,
            'enable_incoming_tcp': True
        }
        self._session = await self._loop.run_in_executor(
            self._executor, libtorrent.session, settings
        )
        await self._loop.run_in_executor(
            self._executor, self._session.add_dht_router, "router.utorrent.com", 6881
        )
        self._loop.create_task(self.process_alerts())

    def _pop_alerts(self):
        for alert in self._session.pop_alerts():
            print("alert: ", alert)

    async def process_alerts(self):
        while True:
            await self._loop.run_in_executor(
                self._executor, self._pop_alerts
            )
            await asyncio.sleep(1, loop=self._loop)

    async def pause(self):
        state = await self._loop.run_in_executor(
            self._executor, self._session.save_state
        )
        # print(f"state:\n{state}")
        await self._loop.run_in_executor(
            self._executor, self._session.pause
        )

    async def resume(self):
        await self._loop.run_in_executor(
            self._executor, self._session.resume
        )

    def _add_torrent(self, btih: str, download_directory: str):
        self._handles[btih] = TorrentHandle(self._loop, self._executor, self._session.add_torrent(
            {'info_hash': binascii.unhexlify(btih.encode()), 'save_path': download_directory}
        ))

    async def add_torrent(self, btih, download_path):
        await self._loop.run_in_executor(
            self._executor, self._add_torrent, btih, download_path
        )
        self._loop.create_task(self._handles[btih].status_loop())
        await self._handles[btih].finished.wait()


def get_magnet_uri(btih):
    return f"magnet:?xt=urn:btih:{btih}"