from __future__ import annotations

from pathlib import Path
from typing import TYPE_CHECKING, Final

import requests
import sqlalchemy as sql
from dopt_basics.io import combine_route

import delta_barth.logging
from delta_barth import databases as db
from delta_barth.api.common import (
    LoginRequest,
    LoginResponse,
    validate_credentials,
)
from delta_barth.constants import API_CON_TIMEOUT, DB_ECHO
from delta_barth.errors import STATUS_HANDLER
from delta_barth.logging import logger_session as logger
from delta_barth.types import DelBarApiError, Status

if TYPE_CHECKING:
    from delta_barth.types import ApiCredentials, HttpContentHeaders


def validate_path(
    str_path: str,
) -> Path:
    path = Path(str_path).resolve()
    if not path.exists():
        raise FileNotFoundError(f"Provided path >{path}< seems not to exist.")
    elif not path.is_dir():
        raise FileNotFoundError(f"Provided path >{path}< seems not to be a directory.")

    return path


class Session:
    def __init__(
        self,
        base_headers: HttpContentHeaders,
        db_folder: str = "data",
        logging_folder: str = "logs",
    ) -> None:
        self._setup: bool = False
        self._data_path: Path | None = None
        self._db_path: Path | None = None
        self._db_folder = db_folder
        self._db_engine: sql.Engine | None = None
        self._logging_dir: Path | None = None
        self._logging_folder = logging_folder
        self._creds: ApiCredentials | None = None
        self._base_url: str | None = None
        self._headers = base_headers
        self._session_token: str | None = None
        self._logged_in: bool = False

    def setup(self) -> None:
        # at this point: no logging configured
        assert not self._setup, "tried to setup session twice"
        self._setup_logging()
        self._setup_db_management()
        self._setup = True
        logger.info("[SESSION] Setup procedure successful")

    @property
    def data_path(self) -> Path:
        assert self._data_path is not None, "accessed data path not set"
        return self._data_path

    @property
    def db_engine(self) -> sql.Engine:
        assert self._db_engine is not None, "accessed database engine not set"
        return self._db_engine

    @property
    def db_path(self) -> Path:
        if self._db_path is not None and self._setup:
            return self._db_path

        db_root = (self.data_path / self._db_folder).resolve()
        db_path = db_root / "dopt-data.db"
        if not db_root.exists():
            db_root.mkdir(parents=False)
        self._db_path = db_path
        return self._db_path

    def _setup_db_management(self) -> None:
        self._db_engine = db.get_engine(self.db_path, echo=DB_ECHO)
        db.metadata.create_all(self._db_engine)
        logger.info("[SESSION] Successfully setup DB management")

    @property
    def logging_dir(self) -> Path:
        if self._logging_dir is not None and self._setup:
            return self._logging_dir

        logging_dir = self.data_path / self._logging_folder
        if not logging_dir.exists():
            logging_dir.mkdir(parents=False)
        self._logging_dir = logging_dir
        return self._logging_dir

    def _setup_logging(self) -> None:
        delta_barth.logging.setup_logging(self.logging_dir)
        logger.info("[SESSION] Successfully setup logging")

    def disable_logging(self) -> None:
        delta_barth.logging.disable_logging()

    @property
    def creds(self) -> ApiCredentials:
        assert self._creds is not None, "accessed credentials not set"
        return self._creds

    def set_data_path(
        self,
        path: str,
    ):
        self._data_path = validate_path(path)
        self._setup = False

    def set_credentials(
        self,
        username: str,
        password: str,
        database: str,
        mandant: str,
    ) -> None:
        if self.logged_in:
            self.logout()
        self._creds = validate_credentials(
            username=username,
            password=password,
            database=database,
            mandant=mandant,
        )

    @property
    def base_url(self) -> str:
        assert self._base_url is not None, "accessed base URL not set"
        return self._base_url

    def set_base_url(
        self,
        base_url: str,
    ) -> None:
        if self.logged_in:
            self.logout()
        self._base_url = base_url

    @property
    def headers(self) -> HttpContentHeaders:
        return self._headers

    @property
    def session_token(self) -> str | None:
        return self._session_token

    @property
    def logged_in(self) -> bool:
        return self._logged_in

    def _add_session_token(
        self,
        token: str,
    ) -> None:
        assert self.session_token is None, "tried overwriting existing API session token"
        self._session_token = token
        self._headers.update(DelecoToken=token)
        self._logged_in = True

    def _remove_session_token(self) -> None:
        assert self.session_token is not None, (
            "tried to delete non-existing API session token"
        )
        if "DelecoToken" in self.headers:
            del self._headers["DelecoToken"]
            self._session_token = None
            self._logged_in = False

    def login(
        self,
    ) -> tuple[LoginResponse, Status]:
        ROUTE: Final[str] = "user/login"
        URL: Final = combine_route(self.base_url, ROUTE)

        login_req = LoginRequest(
            userName=self.creds.username,
            password=self.creds.password,
            databaseName=self.creds.database,
            mandantName=self.creds.mandant,
        )
        empty_response = LoginResponse(token="")
        try:
            resp = requests.put(
                URL,
                login_req.model_dump_json(),
                headers=self.headers,  # type: ignore
                timeout=API_CON_TIMEOUT,
            )
        except requests.exceptions.Timeout:  # pragma: no cover
            return empty_response, STATUS_HANDLER.pipe_states.CONNECTION_TIMEOUT
        except requests.exceptions.RequestException:  # pragma: no cover
            return empty_response, STATUS_HANDLER.pipe_states.CONNECTION_ERROR

        response: LoginResponse
        status: Status
        if resp.status_code == 200:
            response = LoginResponse(**resp.json())
            status = STATUS_HANDLER.pipe_states.SUCCESS
            self._add_session_token(response.token)
        else:
            response = empty_response
            err = DelBarApiError(status_code=resp.status_code, **resp.json())
            status = STATUS_HANDLER.api_error(err)

        return response, status

    def logout(
        self,
    ) -> tuple[None, Status]:
        ROUTE: Final[str] = "user/logout"
        URL: Final = combine_route(self.base_url, ROUTE)

        try:
            resp = requests.put(
                URL,
                headers=self.headers,  # type: ignore
                timeout=API_CON_TIMEOUT,
            )
        except requests.exceptions.Timeout:  # pragma: no cover
            return None, STATUS_HANDLER.pipe_states.CONNECTION_TIMEOUT
        except requests.exceptions.RequestException:  # pragma: no cover
            return None, STATUS_HANDLER.pipe_states.CONNECTION_ERROR

        status: Status
        if resp.status_code == 200:
            status = STATUS_HANDLER.SUCCESS
            self._remove_session_token()
        else:
            err = DelBarApiError(status_code=resp.status_code, **resp.json())
            status = STATUS_HANDLER.api_error(err)

        return None, status

    def assert_login(
        self,
    ) -> tuple[LoginResponse, Status]:
        # check if login token is still valid
        # re-login if necessary
        if self.session_token is None:
            return self.login()

        # use known endpoint which requires a valid token in its header
        # evaluate the response to decide if:
        # current token is still valid, token is not valid, other errors occurred
        ROUTE: Final[str] = "verkauf/umsatzprognosedaten"
        URL: Final = combine_route(self.base_url, ROUTE)
        params: dict[str, int] = {"FirmaId": 999999}
        empty_response = LoginResponse(token="")
        try:
            resp = requests.get(
                URL,
                params=params,
                headers=self.headers,  # type: ignore
                timeout=API_CON_TIMEOUT,
            )
        except requests.exceptions.Timeout:  # pragma: no cover
            return empty_response, STATUS_HANDLER.pipe_states.CONNECTION_TIMEOUT
        except requests.exceptions.RequestException:  # pragma: no cover
            return empty_response, STATUS_HANDLER.pipe_states.CONNECTION_ERROR

        response: LoginResponse
        status: Status
        if resp.status_code == 200:
            response = LoginResponse(token=self.session_token)
            status = STATUS_HANDLER.SUCCESS
        elif resp.status_code == 401:
            self._remove_session_token()
            response, status = self.login()
        else:
            response = empty_response
            err = DelBarApiError(status_code=resp.status_code, **resp.json())
            status = STATUS_HANDLER.api_error(err)

        return response, status