"""
Global track priorities utilities.
"""
import math
from collections import defaultdict
from datetime import date, timedelta
from sqlalchemy import and_, func
from sqlalchemy.orm.query import aliased
from typing import Dict, Iterable

from apollo_main_db.apollo.models import ApolloGlobalTrackPrioritiesHistory, ApolloGlobalTrackPrioritiesHistoryTrack
from src.db.base import session


def get_gtp_history_records(type_id: int, gtp_date: date) -> Iterable:
    """Get GTP history track records.

    Args:
        type_id: GTP list type ID.
        gtp_date: Chosen GTP date.

    Returns:
        GTP history records.

    """
    history_subquery = (
        session.query(func.max(ApolloGlobalTrackPrioritiesHistory.id))
        .filter(ApolloGlobalTrackPrioritiesHistory.type_id == type_id)
        .filter(ApolloGlobalTrackPrioritiesHistory.date <= gtp_date)
        .subquery()
    )

    return (
        session.query(
            ApolloGlobalTrackPrioritiesHistory.date,
            ApolloGlobalTrackPrioritiesHistoryTrack.track_id,
            ApolloGlobalTrackPrioritiesHistoryTrack.isrc,
        )
        .select_from(ApolloGlobalTrackPrioritiesHistory)
        .outerjoin(
            ApolloGlobalTrackPrioritiesHistoryTrack,
            ApolloGlobalTrackPrioritiesHistoryTrack.history_id == ApolloGlobalTrackPrioritiesHistory.id,
        )
        .filter(ApolloGlobalTrackPrioritiesHistory.id == history_subquery)
        .all()
    )


def check_re_entry(gtp_date: date, isrc_list: Iterable[str]):
    """Check what tracks re-entry.

    Args:
        gtp_date: GTP date.
        isrc_list: ISRC list.

    Returns:
        List of re-entered ISRC>

    """
    current_start_date = gtp_date if gtp_date.weekday() == 6 else (gtp_date - timedelta(days=(gtp_date.weekday() + 1)))
    previous_start_date = current_start_date - timedelta(days=7)

    prev_week_history = aliased(ApolloGlobalTrackPrioritiesHistory)
    prev_week_tracks = aliased(ApolloGlobalTrackPrioritiesHistoryTrack)

    prev_week_check = (
        session.query(prev_week_history)
        .join(prev_week_tracks, prev_week_history.id == prev_week_tracks.history_id)
        .filter(prev_week_history.date < current_start_date)
        .filter(prev_week_history.date >= previous_start_date)
        .filter(prev_week_tracks.isrc == ApolloGlobalTrackPrioritiesHistoryTrack.isrc)
        .exists()
    )

    results = (
        session.query(ApolloGlobalTrackPrioritiesHistoryTrack.isrc)
        .distinct()
        .join(
            ApolloGlobalTrackPrioritiesHistory,
            and_(
                ApolloGlobalTrackPrioritiesHistory.id == ApolloGlobalTrackPrioritiesHistoryTrack.history_id,
                ApolloGlobalTrackPrioritiesHistory.date < previous_start_date,
            ),
        )
        .filter(ApolloGlobalTrackPrioritiesHistoryTrack.isrc.in_(isrc_list))
        .filter(~prev_week_check)
        .all()
    )

    return [r[0] for r in results]


def get_gtp_weeks(gtp_date: date, isrc_list: Iterable[str]) -> Dict[str, int]:
    """Get weeks count in GTP by ISRC.

    Args:
        gtp_date: GTP date.
        isrc_list: ISRC list of tracks for gtp_date (it won't work correctly for other ISRC).

    Returns:
        ISRC to weeks count mapping.

    """
    track_dates = (
        session.query(ApolloGlobalTrackPrioritiesHistoryTrack.isrc, ApolloGlobalTrackPrioritiesHistory.date)
        .select_from(ApolloGlobalTrackPrioritiesHistoryTrack)
        .join(
            ApolloGlobalTrackPrioritiesHistory,
            ApolloGlobalTrackPrioritiesHistory.id == ApolloGlobalTrackPrioritiesHistoryTrack.history_id,
        )
        .filter(ApolloGlobalTrackPrioritiesHistoryTrack.isrc.in_(isrc_list))
        .filter(ApolloGlobalTrackPrioritiesHistory.date <= gtp_date)
        .all()
    )

    isrc_dates = defaultdict(list)
    for item in track_dates:
        if item.date.weekday() == 6:
            item_date = item.date + timedelta(days=1)
        else:
            item_date = item.date - timedelta(days=item.date.weekday())
        isrc_dates[item.isrc].append(item_date)

    result = {}
    for isrc, dates in isrc_dates.items():
        dates = sorted(dates, reverse=True)
        max_date = gtp_date
        min_date = max_date
        for _date in dates:
            if (min_date - timedelta(days=7)) > _date:
                break
            min_date = _date
        result[isrc] = (math.floor((max_date - min_date).days / 7) if max_date > min_date else 0) + 1

    return result