from json import loads, dumps, JSONDecodeError

from tfw import EventHandlerBase
from tfw.config.logs import logging

from .pipe_io_server import PipeIOServer

LOG = logging.getLogger(__name__)


class PipeIOEventHandler(EventHandlerBase):
    def __init__(self, key, in_pipe_path, out_pipe_path, permissions=0o600):
        super().__init__(key)
        self._pipe_io_server = JSONProxyPipeIOServer(
            in_pipe_path,
            out_pipe_path,
            self.server_connector.send,
            permissions
        )
        self._pipe_io_server.start()

    def cleanup(self):
        self._pipe_io_server.stop()

    def handle_event(self, message):
        try:
            json_bytes = dumps(message).encode()
            self._pipe_io_server.send_message(json_bytes)
        except TypeError:
            LOG.error("Message %s not JSON serializable! Ignoring...", message)



class JSONProxyPipeIOServer(PipeIOServer):
    def __init__(self, in_pipe_path, out_pipe_path, proxy_method, permissions):
        super().__init__(in_pipe_path, out_pipe_path, permissions)
        self.proxy = proxy_method

    def handle_message(self, message):
        try:
            json = loads(message)
            self.proxy(json)
        except JSONDecodeError:
            LOG.error("Invalid JSON received on %s! Ignoring...", self._in_pipe)