import typing as t

import sqlalchemy as sa

from sarus_statistics.ops.utils import rescale_weights_sql


# pylint: disable=too-many-arguments, too-many-locals
def links(
    session: sa.orm.Session,
    table: sa.sql.FromClause,
    col_name: str,
    user_col: str,
    weight_col: str,
    private_col: str,
    mult_fk: float,
    size_fk: int,
    max_categories: t.Optional[int] = None,
) -> sa.orm.Query:
    if not max_categories:
        max_categories = size_fk

    private_data = session.query(table)
    weighted_data = rescale_weights_sql(
        session,
        private_data.subquery(),
        col_name,
        user_col=user_col,
        private_col=private_col,
        weight_col=weight_col,
        max_multiplicity=mult_fk,
    )
    weighted_col = getattr(weighted_data.c, col_name)

    private_hist = (
        session.query(
            weighted_col.label('data'),
            sa.func.count().label('count_'),
        )
        .group_by(weighted_col)
        .subquery()
    )
    prevalences = session.query(
        private_hist.c.count_.label('data'),
        sa.func.count().label('count_'),
    ).group_by(private_hist.c.count_)

    return t.cast(sa.orm.Query, prevalences)