from io import BytesIO
from typing import Any, Optional

from pydantic import BaseModel
from tomli import loads as toml_loads
from tomli_w import dump as toml_dump
from webdav3.exceptions import RemoteResourceNotFound

from .async_helpers import run_in_executor
from .dav_common import webdav_resource
from .dav_file import DavFile


class ImageConfig(BaseModel):
    mode: str = "RGB"
    save_params: dict[str, Any] = {
        "format": "JPEG",
        "quality": 85,
    }


class Config(BaseModel):
    ticker_separator: str = " +++ "
    cache_seconds: int = 30

    image: ImageConfig = ImageConfig()

    __instance: Optional["Config"] = None

    @classmethod
    async def get(cls) -> "Config":
        if cls.__instance is not None:
            return cls.__instance

        try:
            dav_file = DavFile("config.txt")

            cls.__instance = cls.parse_obj(
                toml_loads(await dav_file.string)
            )

        except RemoteResourceNotFound:
            cls.__instance = cls()

            @run_in_executor
            def create_conf() -> None:
                buffer = BytesIO()
                toml_dump(
                    cls.__instance.dict(),
                    buffer,
                    multiline_strings=True,
                )

                buffer.seek(0)
                webdav_resource("config.txt").read_from(buffer)

            await create_conf()

        return cls.__instance