from sqlalchemy import func
from sqlalchemy.orm import Query, Session

from config import config as _config


def get_major_moves(session: Session, client, market: str, start_date: str, end_date: str) -> Query:
    """Get song entities difference between two dates.
    Using this method we can get major moves for tracks inside chart.

    Args:
        session (Session): DB session.
        client: AppleChart object.
        market: str market.
        start_date: str date in format %Y-%m-%d.
        end_date: str date in format %Y-%m-%d.
    """
    query_for_yesterday = client._get_base_query(session, market, end_date).subquery()
    query_for_today = client._get_base_query(session, market, start_date).subquery()
    return (
        session.query(
            query_for_today.c.track_id,
            query_for_today.c.isrc,
            query_for_today.c.track_name,
            query_for_today.c.position,
            query_for_today.c.artist_name,
            (query_for_today.c.position - query_for_yesterday.c.position).label("moves"),
        )
        .join(query_for_yesterday, query_for_yesterday.c.track_id == query_for_today.c.track_id)
        .filter(func.abs(query_for_today.c.position - query_for_yesterday.c.position) >= _config.THRESHOLD_MAJOR_MOVES)
        .group_by(query_for_today.c.track_id)
    )