"""后台管理:管理区统计、数据完整性分析、数据质量检查。

所有接口需管理员鉴权(require_admin)。路由前缀 /api/v1/admin。
"""
from __future__ import annotations

import logging
from datetime import datetime, timedelta, timezone

from fastapi import APIRouter, Depends
from sqlalchemy import func, select

from src.api.deps import require_admin
from src.db.base import AsyncSession, get_db_read
from src.db.models import DataQualityCheck, IngestFailure, League, Match, MatchStats, Prediction, Standing

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/api/v1/admin", tags=["admin"], dependencies=[Depends(require_admin)])


@router.get("/stats")
async def admin_stats(db: AsyncSession = Depends(get_db_read)):
    """管理区统计(只读):预测次数 + 比赛覆盖。轻量聚合,无 LLM 调用。"""
    day_ago = datetime.now(timezone.utc) - timedelta(days=1)
    week_ago = datetime.now(timezone.utc) - timedelta(days=7)
    r = (
        await db.execute(
            select(
                func.count().label("total"),
                func.count().filter(Prediction.created_at >= day_ago).label("last_24h"),
                func.count().filter(Prediction.created_at >= week_ago).label("last_7d"),
            )
        )
    ).one()
    # F3 修复: 补充真实比赛计数(非 limit=100 近似)
    match_cnt = (await db.execute(select(func.count()).select_from(Match))).scalar() or 0
    finished_cnt = (await db.execute(select(func.count()).where(Match.match_status == "finished"))).scalar() or 0
    stats_cnt = (await db.execute(select(func.count()).select_from(MatchStats))).scalar() or 0
    standings_cnt = (await db.execute(select(func.count()).select_from(Standing))).scalar() or 0
    return {
        "predictions": {"total": r.total, "last_24h": r.last_24h, "last_7d": r.last_7d},
        "matches": {"total": match_cnt, "finished": finished_cnt},
        "stats": {"total": stats_cnt},
        "standings": {"total": standings_cnt},
    }


# ── 数据完整性分析(可视化数据源) ────────────────────────────────


@router.get("/data-completeness")
async def data_completeness(db: AsyncSession = Depends(get_db_read)):
    """按联赛统计数据完整性:比赛覆盖、字段覆盖、积分榜覆盖。

    前端「数据完整性」页据此渲染,回答三个问题:
      1. 数据是否齐全(各联赛比赛/统计/积分榜量级)
      2. 字段是否齐全(每张统计表各字段非空率)
      3. 覆盖是否新鲜(最近一场/最近一次采集)
    """
    from src.data.config import BZZOIRO_LEAGUE_IDS, LEAGUE_NAMES, LEAGUE_COUNTRIES

    out_leagues: list[dict] = []
    for code, bzz_id in BZZOIRO_LEAGUE_IDS.items():
        # 比赛覆盖
        m = (
            await db.execute(
                select(
                    func.count().label("total"),
                    func.count().filter(Match.match_status == "finished").label("finished"),
                    func.count().filter(Match.match_status == "scheduled").label("scheduled"),
                    func.count().filter(Match.source_event_id.is_not(None)).label("with_source_id"),
                    func.max(Match.match_date).label("latest_match"),
                    func.min(Match.match_date).label("earliest_match"),
                )
                .select_from(Match)
                .join(League, League.id == Match.league_id)
                .where(League.code == code)
            )
        ).one()
        # 统计字段覆盖(联表 matches)
        s = (
            await db.execute(
                select(
                    func.count().label("rows"),
                    func.count(MatchStats.home_xg).label("xg"),
                    func.count(MatchStats.home_shots).label("shots"),
                    func.count(MatchStats.home_possession).label("possession"),
                    func.count(MatchStats.home_corners).label("corners"),
                    func.count(MatchStats.home_fouls).label("fouls"),
                    func.count(MatchStats.home_big_chances).label("big_chances"),
                    func.count(MatchStats.home_yellow_cards).label("cards"),
                )
                .select_from(MatchStats)
                .join(Match, Match.id == MatchStats.match_id)
                .join(League, League.id == Match.league_id)
                .where(League.code == code)
            )
        ).one()
        # 积分榜覆盖
        st = (
            await db.execute(
                select(
                    func.count().label("rows"),
                    func.max(Standing.retrieved_at).label("latest_retrieved"),
                )
                .select_from(Standing)
                .join(League, League.id == Standing.league_id)
                .where(League.code == code)
            )
        ).one()

        stats_rows = s.rows or 0
        pct = lambda n: round(n / stats_rows * 100, 1) if stats_rows else 0.0  # noqa: E731
        out_leagues.append(
            {
                "code": code,
                "name": LEAGUE_NAMES.get(code, code),
                "country": LEAGUE_COUNTRIES.get(code),
                "matches": {
                    "total": m.total or 0,
                    "finished": m.finished or 0,
                    "scheduled": m.scheduled or 0,
                    "with_source_id": m.with_source_id or 0,
                    "earliest_match": m.earliest_match.isoformat() if m.earliest_match else None,
                    "latest_match": m.latest_match.isoformat() if m.latest_match else None,
                },
                "stats": {
                    "rows": stats_rows,
                    "fields": {
                        "xg": {"count": s.xg or 0, "pct": pct(s.xg or 0)},
                        "shots": {"count": s.shots or 0, "pct": pct(s.shots or 0)},
                        "possession": {"count": s.possession or 0, "pct": pct(s.possession or 0)},
                        "corners": {"count": s.corners or 0, "pct": pct(s.corners or 0)},
                        "fouls": {"count": s.fouls or 0, "pct": pct(s.fouls or 0)},
                        "big_chances": {"count": s.big_chances or 0, "pct": pct(s.big_chances or 0)},
                        "cards": {"count": s.cards or 0, "pct": pct(s.cards or 0)},
                    },
                },
                "standings": {
                    "rows": st.rows or 0,
                    "latest_retrieved": st.latest_retrieved.isoformat() if st.latest_retrieved else None,
                },
            }
        )

    # 整体健康信号
    total_finished = sum(l["matches"]["finished"] for l in out_leagues)
    total_stats = sum(l["stats"]["rows"] for l in out_leagues)
    stats_coverage = round(total_stats / total_finished * 100, 1) if total_finished else 0.0
    issues: list[str] = []
    for l in out_leagues:
        if l["matches"]["finished"] == 0:
            issues.append(f"{l['name']}: 无已完赛比赛,请先运行「比赛数据」采集")
        elif l["stats"]["rows"] == 0:
            issues.append(f"{l['name']}: 已完赛 {l['matches']['finished']} 场但无统计回填,请运行「统计回填」采集")
        elif stats_coverage < 80:
            issues.append(f"{l['name']}: 统计覆盖率仅 {stats_coverage}%,建议增量回填")
        if l["standings"]["rows"] == 0:
            issues.append(f"{l['name']}: 无积分榜数据,请运行「积分榜」采集")
    if not issues:
        issues.append("各联赛数据完整度良好")

    return {
        "generated_at": datetime.now(timezone.utc).isoformat(),
        "leagues": out_leagues,
        "totals": {
            "finished_matches": total_finished,
            "stats_rows": total_stats,
            "stats_coverage_pct": stats_coverage,
        },
        "issues": issues,
    }


# ── 数据质量检查 API ────────────────────────────────────────────


@router.get("/data-quality")
async def data_quality_checks(db: AsyncSession = Depends(get_db_read)):
    """数据质量检查结果(只读)。"""
    # 最近的失败记录
    failures = (
        await db.execute(
            select(IngestFailure)
            .where(IngestFailure.status.in_(["pending", "retrying"]))
            .order_by(IngestFailure.created_at.desc())
            .limit(20)
        )
    ).scalars().all()

    # 最近的质量检查
    checks = (
        await db.execute(
            select(DataQualityCheck)
            .order_by(DataQualityCheck.checked_at.desc())
            .limit(20)
        )
    ).scalars().all()

    return {
        "failures": [
            {
                "id": f.id,
                "source": f.source_system,
                "entity_type": f.entity_type,
                "source_record_id": f.source_record_id,
                "error_type": f.error_type,
                "error_detail": f.error_detail,
                "retry_count": f.retry_count,
                "status": f.status,
                "created_at": f.created_at.isoformat() if f.created_at else None,
            }
            for f in failures
        ],
        "checks": [
            {
                "id": c.id,
                "check_name": c.check_name,
                "entity_type": c.entity_type,
                "passed": c.passed,
                "severity": c.severity,
                "detail": c.detail,
                "checked_at": c.checked_at.isoformat() if c.checked_at else None,
            }
            for c in checks
        ],
    }


@router.post("/data-quality/run")
async def run_data_quality_check(db: AsyncSession = Depends(get_db_read)):
    """手动触发一次数据质量检查。"""
    checks = []

    # 检查1: 已完赛但无统计的比赛
    finished_no_stats = (
        await db.execute(
            select(func.count())
            .select_from(Match)
            .outerjoin(MatchStats, Match.id == MatchStats.match_id)
            .where(Match.match_status == "finished")
            .where(MatchStats.id.is_(None))
        )
    ).scalar() or 0

    checks.append(DataQualityCheck(
        check_name="finished_without_stats",
        entity_type="match",
        actual_value=float(finished_no_stats),
        passed=finished_no_stats == 0,
        severity="warning" if finished_no_stats > 0 else "info",
        detail={"message": f"{finished_no_stats} 场已完赛比赛缺少统计数据"},
    ))

    # 检查2: 积分榜缺失的联赛
    leagues_without_standings = (
        await db.execute(
            select(func.count())
            .select_from(League)
            .outerjoin(Standing, League.id == Standing.league_id)
            .where(Standing.id.is_(None))
        )
    ).scalar() or 0

    checks.append(DataQualityCheck(
        check_name="league_without_standings",
        entity_type="league",
        actual_value=float(leagues_without_standings),
        passed=leagues_without_standings == 0,
        severity="warning" if leagues_without_standings > 0 else "info",
        detail={"message": f"{leagues_without_standings} 个联赛缺少积分榜"},
    ))

    for c in checks:
        db.add(c)
    await db.commit()

    return {"ok": True, "checks": [{"name": c.check_name, "passed": c.passed} for c in checks]}


# ── 近似重名候选(只读,启发式,不做自动合并) ──────────────────────


@router.get("/team-name-duplicates")
async def team_name_duplicates(db: AsyncSession = Depends(get_db_read)):
    """只读列出近似重名候选(大小写变体/子串包含/前缀碰撞)。

    启发式规则(命中任一即列为候选):
      - 大小写变体: lower(name) 相同但 name 不同
      - 子串包含: A 是 B 的子串且 len(A) ≥ 5
      - 前缀碰撞: 前 8 字符相同(忽略大小写)

    仅作排查参考,合并需走人工 SQL(见 docs/05-data.md)。
    """
    teams = (await db.execute(select(Team.id, Team.name))).all()
    by_lower: dict[str, list[dict]] = {}
    for t in teams:
        key = (t.name or "").lower()
        by_lower.setdefault(key, []).append({"id": t.id, "name": t.name})

    groups: list[dict] = []

    # 规则1: 大小写变体(lower 相同但原名不同)
    for key, members in by_lower.items():
        if len(members) > 1:
            groups.append({
                "rule": "case_variant",
                "key": key,
                "members": members,
            })

    # 规则2 & 3: 子串包含 / 前缀碰撞(仅在 lower 名不同的组间比较)
    distinct = [m for members in by_lower.values() for m in members]
    seen_pairs: set[tuple[int, int]] = set()
    for i, a in enumerate(distinct):
        na = (a["name"] or "").lower()
        for b in distinct[i + 1:]:
            nb = (b["name"] or "").lower()
            if na == nb:
                continue  # 已被规则1覆盖
            pair = (min(a["id"], b["id"]), max(a["id"], b["id"]))
            if pair in seen_pairs:
                continue
            hit = None
            if len(na) >= 5 and na in nb:
                hit = "substring"
            elif len(nb) >= 5 and nb in na:
                hit = "substring"
            elif len(na) >= 8 and len(nb) >= 8 and na[:8] == nb[:8]:
                hit = "prefix"
            if hit:
                seen_pairs.add(pair)
                groups.append({
                    "rule": hit,
                    "members": [a, b],
                })

    return {
        "count": len(groups),
        "hint": "命中任一启发式仅表示'可疑',合并前请人工确认是否同一球队",
        "groups": groups,
    }