"""Command line interface for rflink proxy.

Usage:
  rflinkproxy [-v | -vv] [options]
  rflinkproxy (-h | --help)
  rflinkproxy --version

Options:
  --listenport=<port>  Port to listen on [default: 1337]
  --port=<port>        Serial port to connect to [default: /dev/ttyACM0],
                         or TCP port in TCP mode.
  --baud=<baud>        Serial baud rate [default: 57600].
  --host=<host>        TCP mode, connect to host instead of serial port.
  --repeat=<repeat>    How often to repeat a command [default: 1].
  -h --help            Show this screen.
  -v                   Increase verbosity
  --version            Show version.
"""

import asyncio
import logging
import sys
from functools import partial
from importlib.metadata import version
from typing import Any, Callable, Dict, cast

from docopt import docopt
from serial_asyncio_fast import create_serial_connection

from rflink.parser import (
    DELIM,
    PacketHeader,
    decode_packet,
    serialize_packet_id,
    valid_packet,
)
from rflink.protocol import RflinkProtocol

log = logging.getLogger(__name__)

CRLF = b"\r\n"
DEFAULT_RECONNECT_INTERVAL = 10
DEFAULT_SIGNAL_REPETITIONS = 1
CONNECTION_TIMEOUT = 10

clients = []


class ProxyProtocol(RflinkProtocol):
    """Proxy commands received to multiple clients."""

    def __init__(self, *args, raw_callback: Callable = None, **kwargs) -> None:
        """Add proxy specific initialization."""
        super().__init__(*args, **kwargs)
        self.raw_callback = raw_callback

    def handle_raw_packet(self, raw_packet):
        """Parse raw packet string into packet dict."""
        log.debug("got packet: %s", raw_packet)
        packet = None
        try:
            packet = decode_packet(raw_packet)
        except BaseException:
            log.exception("failed to parse packet: %s", packet)

        log.debug("decoded packet: %s", packet)

        if packet:
            if "ok" in packet:
                # handle response packets internally
                log.debug("command response: %s", packet)
                self._last_ack = packet
                self._command_ack.set()
            elif self.raw_callback:
                self.raw_callback(raw_packet)
        else:
            log.warning("no valid packet")


def decode_tx_packet(packet: str) -> dict:
    """Break packet down into primitives, and do basic interpretation.

    >>> decode_packet('20;06;Kaku;ID=41;SWITCH=1;CMD=ON;') == {
    ...     'node': 'gateway',
    ...     'protocol': 'kaku',
    ...     'id': '000041',
    ...     'switch': '1',
    ...     'command': 'on',
    ... }
    True
    """
    node_id, protocol, attrs = packet.split(DELIM, 2)

    data = cast(Dict[str, Any], {"node": PacketHeader(node_id).name})

    data["protocol"] = protocol.lower()

    for i, attr in enumerate(filter(None, attrs.strip(DELIM).split(DELIM))):
        if i == 0:
            data["id"] = attr
        if i == 1:
            data["switch"] = attr
        if i == 2:
            data["command"] = attr

    # correct KaKu device address
    if data.get("protocol", "") == "kaku" and len(data["id"]) != 6:
        data["id"] = "0000" + data["id"]

    return data


class RFLinkProxy:
    """Proxy commands received to multiple clients."""

    def __init__(self, port=None, host=None, baud=57600, loop=None):
        """Initialize class."""
        self.port = port
        self.host = host
        self.baud = baud
        self.loop = loop
        self.protocol = None
        self.transport = None
        self.closing = False

    async def handle_raw_tx_packet(self, writer, raw_packet):
        """Parse raw packet string into packet dict."""
        peer = writer.get_extra_info("peername")
        log.debug(" %s:%s: processing data: %s", peer[0], peer[1], raw_packet)
        packet = None
        try:
            packet = decode_tx_packet(raw_packet)
        except BaseException:
            log.exception(
                " %s:%s: failed to parse packet: %s", peer[0], peer[1], packet
            )

        log.debug(" %s:%s: decoded packet: %s", peer[0], peer[1], packet)
        if self.protocol and packet:
            if ";PING;" not in raw_packet:
                log.info(
                    " %s:%s: forwarding packet %s to RFLink",
                    peer[0],
                    peer[1],
                    raw_packet,
                )
            else:
                log.debug(
                    " %s:%s: forwarding packet %s to RFLink",
                    peer[0],
                    peer[1],
                    raw_packet,
                )
            await self.forward_packet(writer, packet, raw_packet)
        else:
            log.warning(" %s:%s: no valid packet %s", peer[0], peer[1], packet)

    async def forward_packet(self, writer, packet, raw_packet):
        """Forward packet from client to RFLink."""
        peer = writer.get_extra_info("peername")
        log.debug(" %s:%s: forwarding data: %s", peer[0], peer[1], packet)
        if "command" in packet:
            packet_id = serialize_packet_id(packet)
            command = packet["command"]
            ack = await self.protocol.send_command_ack(packet_id, command)
            if ack:
                writer.write("20;00;OK;".encode() + CRLF)
            for _ in range(DEFAULT_SIGNAL_REPETITIONS - 1):
                await self.protocol.send_command_ack(packet_id, command)
        else:
            self.protocol.send_raw_packet(raw_packet)

    async def client_connected_callback(self, reader, writer):
        """Handle connected client."""
        peer = writer.get_extra_info("peername")
        clients.append((reader, writer, peer))
        log.info("Incoming connection from: %s:%s", peer[0], peer[1])
        try:
            while True:
                data = await reader.readline()
                if not data:
                    break
                try:
                    line = data.decode().strip()
                except UnicodeDecodeError:
                    line = "\x00"

                # Workaround for domoticz issue #2816
                if line[-1] != DELIM:
                    line = line + DELIM

                if valid_packet(line):
                    await self.handle_raw_tx_packet(writer, line)
                else:
                    log.warning(
                        " %s:%s: dropping invalid data: '%s'", peer[0], peer[1], line
                    )
                    pass
        except ConnectionResetError:
            pass
        except Exception as e:
            log.exception(e)

        log.info("Disconnected from: %s:%s", peer[0], peer[1])
        writer.close()
        clients.remove((reader, writer, peer))

    def raw_callback(self, raw_packet):
        """Send data to all connected clients."""
        if ";PONG;" not in raw_packet:
            log.info("forwarding packet %s to clients", raw_packet)
        else:
            log.debug("forwarding packet %s to clients", raw_packet)
        writers = [i[1] for i in list(clients)]
        for writer in writers:
            writer.write(str(raw_packet).encode() + CRLF)

    def reconnect(self, exc=None):
        """Schedule reconnect after connection has been unexpectedly lost."""
        # Reset protocol binding before starting reconnect
        self.protocol = None

        if not self.closing:
            log.warning("disconnected from Rflink, reconnecting")
            self.loop.create_task(self.connect())

    async def connect(self):
        """Set up connection and hook it into HA for reconnect/shutdown."""
        import serial

        log.info("Initiating Rflink connection")

        # Rflink create_rflink_connection decides based on the value of host
        # (string or None) if serial or tcp mode should be used

        # Setup protocol
        protocol = partial(
            ProxyProtocol,
            disconnect_callback=self.reconnect,
            raw_callback=self.raw_callback,
            loop=self.loop,
        )

        # Initiate serial/tcp connection to Rflink gateway
        if self.host:
            connection = self.loop.create_connection(protocol, self.host, self.port)
        else:
            connection = create_serial_connection(
                self.loop, protocol, self.port, self.baud
            )

        try:
            if sys.version_info >= (3, 11):
                async with asyncio.timeout(CONNECTION_TIMEOUT):
                    self.transport, self.protocol = await connection
            else:
                import async_timeout

                async with async_timeout.timeout(CONNECTION_TIMEOUT):
                    self.transport, self.protocol = await connection

        except (
            serial.serialutil.SerialException,
            ConnectionRefusedError,
            TimeoutError,
            OSError,
            asyncio.TimeoutError,
        ) as exc:
            reconnect_interval = DEFAULT_RECONNECT_INTERVAL
            log.error(
                "Error connecting to Rflink, reconnecting in %s", reconnect_interval
            )

            self.loop.call_later(reconnect_interval, self.reconnect, exc)
            return

        log.info("Connected to Rflink")


def main(argv=sys.argv[1:], loop=None):
    """Parse argument and setup main program loop."""
    args = docopt(__doc__, argv=argv, version=version("rflink"))

    level = logging.ERROR
    if args["-v"]:
        level = logging.INFO
    if args["-v"] == 2:
        level = logging.DEBUG
    logging.basicConfig(level=level)

    if not loop:
        loop = asyncio.get_event_loop()

    host = args["--host"]
    port = args["--port"]
    baud = args["--baud"]
    listenport = args["--listenport"]

    proxy = RFLinkProxy(port=port, host=host, baud=baud, loop=loop)

    server_coro = asyncio.start_server(
        proxy.client_connected_callback,
        host="",
        port=listenport,
    )

    server = loop.run_until_complete(server_coro)
    addr = server.sockets[0].getsockname()
    log.info("Serving on %s", addr)

    conn_coro = proxy.connect()
    loop.run_until_complete(conn_coro)

    proxy.closing = False
    try:
        loop.run_forever()
    except KeyboardInterrupt:
        proxy.closing = True

        # cleanup server
        server.close()
        loop.run_until_complete(server.wait_closed())

        # cleanup server connections
        writers = [i[1] for i in list(clients)]
        for writer in writers:
            writer.close()
            if sys.version_info >= (3, 7):
                loop.run_until_complete(writer.wait_closed())

        # cleanup RFLink connection
        proxy.transport.close()

    finally:
        loop.close()