import logging
import re
from io import BytesIO

from asyncify import asyncify
from cache import AsyncTTL
from cache.key import KEY
from requests import Response
from webdav3.client import Client as WebDAVclient

from .settings import SETTINGS

_logger = logging.getLogger(__name__)


class WebDAV:
    class __WebDAVclient(WebDAVclient):
        def execute_request(
            self,
            action,
            path,
            data=None,
            headers_ext=None,
        ) -> Response:
            res = super().execute_request(action, path, data, headers_ext)

            # the "Content-Length" header can randomly be missing on txt files,
            # this should fix that (probably serverside bug)
            if action == "download" and "Content-Length" not in res.headers:
                res.headers["Content-Length"] = str(len(res.text))

            return res

    _webdav_client = __WebDAVclient(
        {
            "webdav_hostname": SETTINGS.webdav.url,
            "webdav_login": SETTINGS.webdav.username,
            "webdav_password": SETTINGS.webdav.password,
            "disable_check": SETTINGS.webdav.disable_check,
        }
    )

    @classmethod
    @AsyncTTL(
        time_to_live=SETTINGS.webdav.cache_ttl,
        maxsize=SETTINGS.webdav.cache_size,
        skip_args=1,
    )
    async def list_files(
        cls,
        directory: str = "",
        *,
        regex: re.Pattern[str] = re.compile(""),
    ) -> list[str]:
        """
        List files in directory `directory` matching RegEx `regex`
        """

        _logger.debug(f"list_files {directory!r}")
        ls = await asyncify(cls._webdav_client.list)(directory)

        return [f"{directory}/{path}" for path in ls if regex.search(path)]

    @classmethod
    @AsyncTTL(
        time_to_live=SETTINGS.webdav.cache_ttl,
        maxsize=SETTINGS.webdav.cache_size,
        skip_args=1,
    )
    async def exists(cls, path: str) -> bool:
        """
        `True` iff there is a WebDAV resource at `path`
        """

        _logger.debug(f"file_exists {path!r}")
        return await asyncify(cls._webdav_client.check)(path)

    @classmethod
    @(
        _rb_ttl := AsyncTTL(
            time_to_live=SETTINGS.webdav.cache_ttl,
            maxsize=SETTINGS.webdav.cache_size,
            skip_args=1,
        )
    )
    async def read_bytes(cls, path: str) -> bytes:
        """
        Load WebDAV file from `path` as bytes
        """

        _logger.debug(f"read_bytes {path!r}")
        buffer = BytesIO()
        await asyncify(cls._webdav_client.download_from)(buffer, path)
        buffer.seek(0)

        return buffer.read()

    @classmethod
    async def read_str(cls, path: str, encoding="utf-8") -> str:
        """
        Load WebDAV file from `path` as string
        """

        _logger.debug(f"read_str {path!r}")
        return (await cls.read_bytes(path)).decode(encoding=encoding).strip()

    @classmethod
    async def write_bytes(cls, path: str, buffer: bytes) -> None:
        """
        Write bytes from `buffer` into WebDAV file at `path`
        """

        _logger.debug(f"write_bytes {path!r}")
        await asyncify(cls._webdav_client.upload_to)(buffer, path)

        try:
            # hack: zugehörigen Cache-Eintrag entfernen
            # -> AsyncTTL._TTL.__contains__
            del cls._rb_ttl.ttl[KEY((path,), {})]

        except KeyError:
            # Cache-Eintrag existierte nicht
            pass

    @classmethod
    async def write_str(cls, path: str, content: str, encoding="utf-8") -> None:
        """
        Write string from `content` into WebDAV file at `path`
        """

        _logger.debug(f"write_str {path!r}")
        await cls.write_bytes(path, content.encode(encoding=encoding))