"""比赛/联赛查询路由。"""
from __future__ import annotations

from datetime import datetime, timedelta

from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy import func, or_, select
from sqlalchemy.orm import selectinload

from src.api.schemas import MatchListOut, MatchOut, PredictionOut
from src.db.base import AsyncSession, get_db_read
from src.db.models import League, Match, Prediction, Standing

router = APIRouter(prefix="/api/v1", tags=["data"])


def _stats_dict(stats) -> dict | None:
    """把 MatchStats ORM 对象序列化为前端可读的扁平 dict。"""
    if stats is None:
        return None
    return {
        "home_xg": stats.home_xg, "away_xg": stats.away_xg,
        "home_shots": stats.home_shots, "away_shots": stats.away_shots,
        "home_shots_on_target": stats.home_shots_on_target, "away_shots_on_target": stats.away_shots_on_target,
        "home_corners": stats.home_corners, "away_corners": stats.away_corners,
        "home_possession": stats.home_possession,
        "home_yellow_cards": stats.home_yellow_cards, "away_yellow_cards": stats.away_yellow_cards,
        "home_red_cards": stats.home_red_cards, "away_red_cards": stats.away_red_cards,
        "home_big_chances": stats.home_big_chances, "away_big_chances": stats.away_big_chances,
        "home_fouls": stats.home_fouls, "away_fouls": stats.away_fouls,
    }


@router.get("/leagues", response_model=list[dict])
async def list_leagues(db: AsyncSession = Depends(get_db_read)):
    """联赛列表(公开只读,P1-3: 公开站联赛筛选需要;仅返回展示字段)。"""
    stmt = select(League).order_by(League.name)
    result = await db.execute(stmt)
    leagues = result.scalars().all()
    return [{"id": l.id, "code": l.code, "name": l.name, "country": l.country} for l in leagues]


@router.get("/matches", response_model=MatchListOut)
async def list_matches(
    league: str | None = None,
    status: str | None = None,
    date: str | None = None,
    cursor: str | None = None,
    limit: int = Query(50, ge=1, le=100),
    db: AsyncSession = Depends(get_db_read),
):
    """比赛列表(游标分页)。"""
    q = select(Match).options(selectinload(Match.league), selectinload(Match.home_team), selectinload(Match.away_team))

    if cursor:
        try:
            # 用 | 分隔,避免 isoformat 含 _ 时解析失败
            last_date_str, last_id_str = cursor.split("|", 1)
            last_date = datetime.fromisoformat(last_date_str)
            last_id = int(last_id_str)
            # 游标方向必须与排序方向一致:
            # - scheduled(ASC):取「更大」的未开赛场次
            # - 其它(DESC):取「更小」的已赛场次
            if status == "scheduled":
                q = q.where(
                    (Match.match_date > last_date) |
                    ((Match.match_date == last_date) & (Match.id > last_id))
                )
            else:
                q = q.where(
                    (Match.match_date < last_date) |
                    ((Match.match_date == last_date) & (Match.id < last_id))
                )
        except (ValueError, AttributeError):
            pass

    if league:
        stmt = select(League.id).where(League.code == league)
        league_id = (await db.execute(stmt)).scalar_one_or_none()
        if league_id is None:
            return MatchListOut(items=[], next_cursor=None, has_more=False)
        q = q.where(Match.league_id == league_id)

    if status:
        q = q.where(Match.match_status == status)

    if date:
        try:
            d = datetime.strptime(date, "%Y-%m-%d")
        except ValueError:
            raise HTTPException(400, "date 格式应为 YYYY-MM-DD")
        # date 是用户本地日期(默认北京 UTC+8);match_date 存 UTC,需转换:
        # 本地 00:00 (UTC+8) = UTC 前一天 16:00;本地 24:00 = UTC 当天 16:00
        from datetime import timezone as tz_mod
        tz_cn = tz_mod(timedelta(hours=8))
        local_start = d.replace(tzinfo=tz_cn)
        local_end = local_start + timedelta(days=1)
        q = q.where(Match.match_date >= local_start, Match.match_date < local_end)

    # 未开赛按日期正序(最近的排最前,便于预测);其余按日期倒序(最新赛果在前)
    if status == "scheduled":
        order = (Match.match_date.asc(), Match.id.asc())
    else:
        order = (Match.match_date.desc(), Match.id.desc())
    rows = (await db.execute(q.order_by(*order).limit(limit + 1))).scalars().all()
    has_more = len(rows) > limit
    rows = rows[:limit]

    items = []
    for m in rows:
        items.append(MatchOut(
            id=m.id,
            league_code=m.league.code if m.league else None,
            season=m.season,
            home_team=m.home_team.name if m.home_team else "?",
            away_team=m.away_team.name if m.away_team else "?",
            home_team_zh=m.home_team.name_zh if m.home_team else None,
            away_team_zh=m.away_team.name_zh if m.away_team else None,
            match_date=m.match_date,
            match_status=m.match_status,
            home_goals=m.home_goals,
            away_goals=m.away_goals,
            match_stage=m.match_stage,
            home_xg=m.stats.home_xg if m.stats else None,
            away_xg=m.stats.away_xg if m.stats else None,
        ))

    next_cursor = None
    if has_more and items:
        last = rows[-1]
        next_cursor = f"{last.match_date.isoformat()}|{last.id}"

    return MatchListOut(items=items, next_cursor=next_cursor, has_more=has_more)


@router.get("/matches/{match_id}", response_model=MatchOut)
async def get_match(match_id: int, db: AsyncSession = Depends(get_db_read)):
    stmt = (
        select(Match)
        .options(
            selectinload(Match.league),
            selectinload(Match.home_team),
            selectinload(Match.away_team),
            selectinload(Match.stats),
        )
        .where(Match.id == match_id)
    )
    m = (await db.execute(stmt)).scalar_one_or_none()
    if m is None:
        raise HTTPException(404, "match not found")
    # 最近预测(倒序,最多 5 条)——复用 PredictionOut 结构,只读,不触发 LLM
    preds = (
        await db.execute(
            select(Prediction)
            .where(Prediction.match_id == match_id)
            .order_by(Prediction.created_at.desc())
            .limit(5)
        )
    ).scalars().all()
    return MatchOut(
        id=m.id,
        league_code=m.league.code if m.league else None,
        season=m.season,
        home_team=m.home_team.name if m.home_team else "?",
        away_team=m.away_team.name if m.away_team else "?",
        home_team_zh=m.home_team.name_zh if m.home_team else None,
        away_team_zh=m.away_team.name_zh if m.away_team else None,
        match_date=m.match_date,
        match_status=m.match_status,
        home_goals=m.home_goals,
        away_goals=m.away_goals,
        match_stage=m.match_stage,
        home_xg=m.stats.home_xg if m.stats else None,
        away_xg=m.stats.away_xg if m.stats else None,
        stats=_stats_dict(m.stats) if m.stats else None,
        recent_predictions=[
            PredictionOut(
                id=p.id, match_id=p.match_id, provider=p.provider, model=p.model,
                prompt_version=p.prompt_version, mode=p.mode or "single",
                pred_home_goals=p.pred_home_goals, pred_away_goals=p.pred_away_goals,
                alt_pred_home_goals=p.alt_pred_home_goals, alt_pred_away_goals=p.alt_pred_away_goals,
                pred_1x2=p.pred_1x2, subjective_confidence=p.subjective_confidence,
                reasoning=p.reasoning, status=p.status or "success",
                agent_outputs=p.agent_outputs, agent_weights=p.agent_weights,
                created_at=p.created_at, actual_home_goals=p.actual_home_goals,
                actual_away_goals=p.actual_away_goals, settled=p.settled,
            )
            for p in preds
        ],
    )


@router.get("/matches/{match_id}/context")
async def match_context(match_id: int, db: AsyncSession = Depends(get_db_read)):
    """比赛上下文(公开只读,P1-2: 公开站详情页需要;不触发 LLM):双方近况 + 历史交锋。

    全部基于现有数据聚合:
      - recent_home / recent客队:该队最近 5 场已完赛(进球/结果)
      - h2h:双方最近 5 次交手
    若数据不足,对应列表为空(前端展示空态)。
    """
    m = (
        await db.execute(
            select(Match)
            .options(selectinload(Match.home_team), selectinload(Match.away_team))
            .where(Match.id == match_id)
        )
    ).scalar_one_or_none()
    if m is None:
        raise HTTPException(404, "match not found")
    home_id = m.home_team_id
    away_id = m.away_team_id

    def _row_to_dict(row):
        return {
            "match_date": row.match_date.isoformat() if row.match_date else None,
            "home_team": row.home_team.name_zh or row.home_team.name if row.home_team else None,
            "away_team": row.away_team.name_zh or row.away_team.name if row.away_team else None,
            "home_goals": row.home_goals,
            "away_goals": row.away_goals,
        }

    # 主队近况(已完赛,含主/客场)
    home_recent = (
        await db.execute(
            select(Match)
            .where(Match.match_status == "finished", Match.home_team_id == home_id)
            .order_by(Match.match_date.desc())
            .limit(5)
            .options(selectinload(Match.home_team), selectinload(Match.away_team))
        )
    ).scalars().all()

    # 客队近况
    away_recent = (
        await db.execute(
            select(Match)
            .where(Match.match_status == "finished", Match.away_team_id == away_id)
            .order_by(Match.match_date.desc())
            .limit(5)
            .options(selectinload(Match.home_team), selectinload(Match.away_team))
        )
    ).scalars().all()

    # 历史交锋(双方已完赛)
    h2h = (
        await db.execute(
            select(Match)
            .where(
                Match.match_status == "finished",
                or_(
                    (Match.home_team_id == home_id) & (Match.away_team_id == away_id),
                    (Match.home_team_id == away_id) & (Match.away_team_id == home_id),
                ),
            )
            .order_by(Match.match_date.desc())
            .limit(5)
            .options(selectinload(Match.home_team), selectinload(Match.away_team))
        )
    ).scalars().all()

    return {
        "home_recent": [_row_to_dict(r) for r in home_recent],
        "away_recent": [_row_to_dict(r) for r in away_recent],
        "h2h": [_row_to_dict(r) for r in h2h],
    }


@router.get("/standings")
async def list_standings(
    league: str | None = Query(None, description="联赛代码,如 E0;空 = 全部联赛"),
    season: str | None = Query(None, description="赛季标签,如 2026-2027;空 = 各联赛最新赛季"),
    db: AsyncSession = Depends(get_db_read),
):
    """联赛积分榜(只读)。按联赛分组,每张榜按 position 排序。

    season 为空时返回每个联赛最新采集到的赛季榜单(适合前端"查看最新积分榜")。
    """
    # 取每个联赛最新赛季(当 season 为空时)
    latest_seasons: dict[int, str] = {}
    if season is None:
        rows = (
            await db.execute(
                select(Standing.league_id, func.max(Standing.season).label("latest"))
                .group_by(Standing.league_id)
            )
        ).all()
        latest_seasons = {r.league_id: r.latest for r in rows}

    q = (
        select(Standing, League)
        .join(League, League.id == Standing.league_id)
        .order_by(League.name.asc(), Standing.position.asc())
    )
    if league:
        q = q.where(League.code == league)
    if season:
        q = q.where(Standing.season == season)
    else:
        # 多联赛时只保留各联赛最新赛季
        if latest_seasons:
            q = q.where(
                or_(
                    *(
                        (Standing.league_id == lid) & (Standing.season == ls)
                        for lid, ls in latest_seasons.items()
                    )
                )
            )

    rows = (await db.execute(q)).all()

    # 按联赛分组
    grouped: dict[str, dict] = {}
    for standing, lg in rows:
        key = lg.code
        if key not in grouped:
            grouped[key] = {
                "league_code": lg.code,
                "league_name": lg.name,
                "season": standing.season,
                "retrieved_at": standing.retrieved_at.isoformat() if standing.retrieved_at else None,
                "rows": [],
            }
        grouped[key]["rows"].append(
            {
                "position": standing.position,
                "team": standing.team.name_zh or standing.team.name if standing.team else "?",
                "team_en": standing.team.name if standing.team else "?",
                "played": standing.played,
                "won": standing.won,
                "drawn": standing.drawn,
                "lost": standing.lost,
                "goals_for": standing.goals_for,
                "goals_against": standing.goals_against,
                "goal_diff": standing.goal_diff,
                "points": standing.points,
                "xg_for": standing.xg_for,
                "xg_against": standing.xg_against,
                "form": standing.form,
                "zone": standing.zone,
            }
        )
    return {"leagues": list(grouped.values())}