"""数据访问层的基础原语：比赛结果、match→dict、赛季过滤子句。

被 repo 各操作复用；单独成文件，使 repo.py 控制在 200–400 行内。
"""
from __future__ import annotations

from typing import Any, Optional

from sqlalchemy import extract

from .models import Match


def _result(our: int, opp: int) -> str:
    if our > opp:
        return "W"
    if our < opp:
        return "L"
    return "D"


def _match_dict(m: Match) -> dict[str, Any]:
    return {
        "id": m.id,
        "date": m.match_date.isoformat() if m.match_date else "",
        "opponent": m.opponent,
        "home_away": m.home_away,
        "our": m.our_score,
        "opp": m.opp_score,
        "result": _result(m.our_score, m.opp_score),
        "score_str": f"{m.our_score} : {m.opp_score}",
        "note": m.note or "",
        "mvp_locked": bool(getattr(m, "mvp_locked", False)),
        "mvp_user_id": getattr(m, "mvp_user_id", None),
        "mvp2_user_id": getattr(m, "mvp2_user_id", None),
        "dmvp_user_id": getattr(m, "dmvp_user_id", None),
    }


def _season_clause(season: Optional[int]):
    """赛季过滤子句（按 match_date 年份）；season 为 None 时返回 None 表示不过滤。"""
    return extract("year", Match.match_date) == season if season else None


def _season_match_ids(s, season: Optional[int]) -> list[int]:
    q = s.query(Match.id)
    cl = _season_clause(season)
    if cl is not None:
        q = q.filter(cl)
    return [r[0] for r in q.all()]