from functools import partial
from typing import Dict, Optional

from server.domains.playlists.tracks import track_in_playlist_is_entry, track_in_playlist_trend_metric
from server.utils.common import add1
from server.utils.mappers.core.getters import getter
from server.utils.mappers.core.mappers import mappers_by_keys, mappers_by_map


def map_positions(item: dict):
    mappers_by_keys(item, ("current", "earliest_position"), none_result=None, f=add1)


def map_trend_metrics(
    item: dict, playlist_map: Optional[Dict[str, dict]] = None, playlist_id_field: str = "playlist_id"
):
    is_personalised = (
        getter(playlist_map[item[playlist_id_field]], key="is_personalised", none_result=False)
        if playlist_map
        else getter(item, key="playlist.is_personalised", none_result=False)
    )
    is_top_track_for_isrc = getter(item, key="is_top_track_for_isrc", none_result=False)

    item["is_entry"] = track_in_playlist_is_entry(
        num_days_on=getter(item, key="num_days_on", none_result=None, f=int),
        is_personalised=is_personalised,
        is_top_track_for_isrc=is_top_track_for_isrc,
    )

    get_trend_metric = partial(
        track_in_playlist_trend_metric, is_personalised=is_personalised, is_top_track_for_isrc=is_top_track_for_isrc
    )

    def get_previous_position(x: Optional[int]) -> Optional[int]:
        x = get_trend_metric(x)
        if x is not None:
            return add1(x)

    mappers_by_map(
        item,
        {
            "trend_change_14_days": {"key_to": "trend"},
            "last_date_change_14_days": {"key_to": "change_position_date_time"},
            "previous_position_change_14_days": {"key_to": "previous", "f": get_previous_position},
        },
        none_result=None,
        f=get_trend_metric,
        remove_key=True,
    )