from typing import TypedDict, Union

from flask import current_app
from flask_sqlalchemy import BaseQuery
from sqlalchemy import desc


class PaginationResponse(TypedDict):
    items: list
    max_pages: int


def order_by_column_name(
    query: BaseQuery, model_field: str, order_by_col_name: Union[str, None]
) -> BaseQuery:
    if order_by_col_name is not None:
        if order_by_col_name == "asc":
            query = query.order_by(model_field)
        elif order_by_col_name == "desc":
            query = query.order_by(desc(model_field))

    return query


def paginate_models(page: int, query: BaseQuery, per_page=10) -> PaginationResponse:
    default_page = 1
    if page is not None:
        query = query.paginate(page=page, per_page=per_page, error_out=False)
    else:
        query = query.paginate(page=default_page, per_page=per_page, error_out=False)

    return {"items": query.items, "max_pages": query.pages}


def is_allowed_extensions(filename: str):
    return (
        "." in filename
        and filename.rsplit(".", 1)[1].lower()
        in current_app.config["ALLOWED_EXTENSIONS"]
    )