"""Utils module providing helper functions around request parameters."""

from typing import Any, Collection

from flask import Request as FlaskRequest
from owsrequest import flask_request
from owsresponse import response, status

from notifications.constants import error
from notifications.constants.header import ORCHARD_USER_ID
from notifications.constants.stream import DEFAULT_USER_FEED, USER_FEEDS


def get_data_params(request: FlaskRequest) -> dict[str, Any]:
    """Parse and return the request body params.

    Args:
        request (Flask.Request): the request object

    Returns:
        dict: containing the body params

    """
    return request.get_json(silent=True, force=True) or {}


def get_header_params(request: FlaskRequest) -> dict[str, str | None]:
    """Parse and return the request header params.

    Args:
        request (Flask.Request): the request object

    Returns:
        dict: containing the header params

    """
    account_type, account_id = flask_request.get_grass_headers(request)

    if account_type and account_id:
        feed_id = '{0}_{1}'.format(account_type, account_id)
    else:
        feed_id = None

    return {ORCHARD_USER_ID: request.headers.get(ORCHARD_USER_ID, None), 'feed_id': feed_id}


def validate_params(params: dict[str, Any], keys: Collection[str]) -> response.Response:
    """Extract and validate a value in params for each keys.

    Args:
        params (dict): the parameters dict
        keys ([str]): the list of required keys

    Returns:
        response.Response: 400 or 200 containing the list of values

    """
    validated_params = []

    for key in keys:
        if key not in params or not params[key]:
            return response.create_error_response(
                status=status.BAD_REQUEST,
                code=error.ERROR_CODE_BAD_REQUEST,
                message=error.ERROR_MESSAGE_MISSING_PARAMETERS,
            )

        validated_params.append(params[key])

    return response.Response(validated_params)


def validate_user_feed_name(request: FlaskRequest) -> response.Response:
    """Extract and validate the user feed name from the query parameters.

    Args:
        request (Flask.Request): the request object

    Returns:
        response.Response: 400 or 200 containing the user feed name

    """
    user_feed_name = request.args.get('user_feed_name', DEFAULT_USER_FEED)

    if user_feed_name and user_feed_name not in USER_FEEDS:
        return response.create_error_response(
            status=status.BAD_REQUEST,
            code=error.ERROR_CODE_BAD_REQUEST,
            message=error.ERROR_MESSAGE_INVALID_USER_FEED_NAME,
        )

    return response.Response(user_feed_name)


def filter_params(**params: Any) -> dict[str, Any]:
    """Remove None values (with keys) from params.

    Args:
        **params: Arbitrary keyword arguments to be filtered.
            Any key with a value of None will be excluded from the result.

    Returns:
        dict[str, Any]: A new dictionary containing only the entries
            from params where the value was not None.

    """
    return {k: v for k, v in params.items() if v is not None}