from typing import Callable, Iterable, Optional, Tuple, TextIO, BinaryIO, IO, Union, List
from os import PathLike
from threading import RLock, Condition

import datetime
import logging
import sys

_log_handlers: List[logging.Handler] = []
_log_format = '%(asctime)s - %(name)s - %(levelname)s - %(message)s'

def init_logging(*,
                 level: int = logging.DEBUG,
                 output_file: Union[None, str, PathLike] = None,
                 output_host: Optional[Tuple[str, int]] = None,
                 output_stream: Optional[TextIO] = sys.stdout) -> None:
    """Set up the logging format and outputs.

    level: Logging level (DEBUG)
    output_file: File to write to (None)
    output_host: Tuple of host and port that will receive log datagrams
    """
    global _log_handlers

    _log_handlers = []

    if output_file != None:
        # Create a file handler
        file_handler = logging.FileHandler(output_file)
        _log_handlers.append(file_handler)

    if output_host != None:
        dgram_handler = logging.DatagramHandler(*output_host)
        _log_handlers.append(dgram_handler)

    if output_stream != None:
        console_handler = logging.StreamHandler(output_stream)
        _log_handlers.append(console_handler)

    for h in _log_handlers:
        h.setLevel(level)

    # Default log output
    logging.basicConfig(force=True, level=level, format=_log_format, handlers=_log_handlers)

def logger(*path: Iterable[str]) -> logging.Logger:
    logger = logging.getLogger("door_pi_control")
    for p in path:
        logger = logger.getChild(p)
    return logger

def now() -> datetime.datetime:
    return datetime.datetime.now()

def timestamp() -> str:
    return now().strftime("%Y-%m-%d %H:%M:%S")

class Loggable:
    def _logger(self) -> logging.Logger:
        return logger(type(self).__name__)

class Event:
    def __init__(self, lock = None):
        self._lock = lock if lock != None else RLock()
        self._condition = Condition(self._lock)
        self._subscribers = {}

    def acquire(self, *args):
        return self._condition.acquire(*args)

    def notify(self, *args, **kwargs):
        with self._lock:
            for cv, cb in self._subscribers:
                with cv:
                    if cb:
                        cb(*args, **kwargs)
                    cv.notify()
            self._condition.notify()

    def notify_all(self):
        with self._lock:
            for cv, cb in self._subscribers:
                with cv:
                    if cb:
                        cb()
                    cv.notify_all()
            self._condition.notify_all()

    def subscribe(self, cv: Condition, callback: Callable = None):
        with self._lock:
            self._subscribers[cv] = callback

    def unsubscribe(self, cv: Condition):
        with self._lock:
            if cv in self._subscribers:
                del self._subscribers[cv]

    def wait(self, timeout=None):
        return self._condition.wait(timeout)

    def wait_for(self, predicate, timeout=None):
        return self._condition.wait_for(predicate, timeout)

    def __enter__(self):
        return self._lock.__enter__()

    def __exit__(self, *args):
        self._lock.__exit__()