from datetime import datetime as dtp
import errno
import logging
import stat
from queue import SimpleQueue, Empty
from fuse import (
    Operations,
    FuseOSError,
    LoggingMixIn,
    fuse_get_context,
)

from .types import Status

logger = logging.getLogger(__name__)


class StatusFileSystem(Operations, LoggingMixIn):
    """
    Implements a FUSE file system for mapping (ActivityPub, Mastodon, ...) statuses to text files.
    """

    def __init__(self):
        """
        Initialize a new instance of StatusFileSystem, to be used with FUSE.
        """
        self.__queue: SimpleQueue[list[Status]] = SimpleQueue()
        self.__statuses: list[Status] = []
        self.__fd = 0

    def getattr(self, path, fh=None):
        (uid, gid, _) = fuse_get_context()
        if path == "/":
            return {
                "st_mode": (stat.S_IFDIR | 0o700),  # Directory
                "st_nlink": 2,
                "st_uid": uid,
                "st_gid": gid,
            }
        found = next((s for s in self.__statuses if s.id == path[1:]), None)

        if found:
            published_dt = dtp.fromisoformat(found.published)
            pubunix = published_dt.timestamp()
            return {
                "st_mode": (stat.S_IFREG | 0o400),
                "st_size": len(found.content.encode("utf8")),
                "st_nlink": 1,
                "st_uid": uid,
                "st_gid": gid,
                "st_ctime": pubunix,
                "st_mtime": pubunix,
            }
        raise FuseOSError(errno.ENOENT)

    def __update_status_field(self):
        """
        Update the internal statuses list with new statuses from the queue.
        """
        # TODO: Not thread-safe. But no idea what to do about it.
        # Don't set threading to true in FUSE constructor/options.
        try:
            while True:
                statuses = self.__queue.get_nowait()
                self.__statuses.extend(statuses)
        except Empty:
            pass

    def list_dir(self) -> list[str]:
        self.__update_status_field()
        return [s.id for s in self.__statuses]

    def readdir(self, path, fh):
        dir_entries = []
        if path != "/":
            raise FuseOSError(errno.ENOENT)
        dir_entries = [".", ".."]
        dir_entries += self.list_dir()
        return dir_entries

    def add_statuses(self, statuses: list[Status]):
        """
        Add new statuses to the queue.

        Args:
            statuses (list): A list of Status objects to be added.
        """
        self.__queue.put(statuses)

    def open(self, path, flags):  # type: ignore
        self.__fd += 1
        return self.__fd

    def read(self, path, size, offset, fh):  # type: ignore
        found = next(s for s in self.__statuses if s.id == path[1:])

        if found:
            return found.content.encode("utf8")
        raise FuseOSError(errno.ENOENT)