"""
ClickHouse database operations.
"""

import json
import logging
import math
import threading
import time
import clickhouse_connect
from . import config

log = logging.getLogger(__name__)

_client = None
_lock = threading.Lock()
_migrations_applied = False


def get_client():
    global _client
    if _client is None:
        for attempt in range(30):
            try:
                _client = clickhouse_connect.get_client(
                    host=config.CLICKHOUSE_HOST,
                    port=config.CLICKHOUSE_PORT,
                )
                _client.ping()
                log.info("Connected to ClickHouse at %s:%s", config.CLICKHOUSE_HOST, config.CLICKHOUSE_PORT)
                return _client
            except Exception as e:
                log.warning("ClickHouse not ready (attempt %d): %s", attempt + 1, e)
                time.sleep(2)
        raise RuntimeError("Could not connect to ClickHouse")
    return _client


def run_migrations():
    """Run one-time data migrations on startup."""
    global _migrations_applied
    if _migrations_applied:
        return
    client = get_client()
    client.command(
        "CREATE TABLE IF NOT EXISTS _migrations ("
        "  name String, applied_at DateTime DEFAULT now()"
        ") ENGINE = MergeTree() ORDER BY name"
    )
    result = client.query(
        "SELECT count() FROM _migrations WHERE name = 'swap_ac_chairs'"
    )
    if result.result_rows[0][0] == 0:
        log.info("Running migration: swap_ac_chairs")
        client.command(
            "ALTER TABLE games UPDATE "
            "hand_a = hand_c, hand_c = hand_a, "
            "bet_a = bet_c, bet_c = bet_a, "
            "hand_type_a = hand_type_c, hand_type_c = hand_type_a "
            "WHERE 1=1"
        )
        client.insert("_migrations", [["swap_ac_chairs"]], column_names=["name"])
        log.info("Migration swap_ac_chairs applied")
    _migrations_applied = True


def _with_lock(fn):
    """Decorator to serialize all ClickHouse operations."""
    def wrapper(*args, **kwargs):
        with _lock:
            return fn(*args, **kwargs)
    wrapper.__name__ = fn.__name__
    return wrapper


@_with_lock
def insert_game(game: dict):
    """Insert a completed round into the games table."""
    client = get_client()
    client.insert("games",
        [[
            game["game_no"],
            game["winner"],
            game["total_pot"],
            game.get("bet_a", 0),
            game.get("bet_b", 0),
            game.get("bet_c", 0),
            game.get("hand_a", ""),
            game.get("hand_b", ""),
            game.get("hand_c", ""),
            game.get("hand_type_a", 0),
            game.get("hand_type_b", 0),
            game.get("hand_type_c", 0),
            game.get("cards_json", ""),
            game.get("duration_s", 0),
        ]],
        column_names=[
            "game_no", "winner", "total_pot",
            "bet_a", "bet_b", "bet_c",
            "hand_a", "hand_b", "hand_c",
            "hand_type_a", "hand_type_b", "hand_type_c",
            "cards_json", "duration_s",
        ],
    )


@_with_lock
def insert_bet(bet: dict):
    """Insert an individual user bet into the bets table."""
    client = get_client()
    client.insert("bets",
        [[
            bet["game_no"],
            bet["user_id"],
            bet["chair"],
            bet["bet_amount"],
            bet["total_bet"],
        ]],
        column_names=["game_no", "user_id", "chair", "bet_amount", "total_bet"],
    )


@_with_lock
def upsert_user(user: dict):
    """Insert/update a user profile."""
    client = get_client()
    client.insert("users",
        [[
            user["user_id"],
            user.get("nick_name", ""),
            user.get("rich_level", 0),
            user.get("actor_level", 0),
            user.get("gender", 0),
            user.get("consume_total", 0),
            user.get("earn_total", 0),
            user.get("is_actor", 0),
            user.get("portrait", ""),
        ]],
        column_names=[
            "user_id", "nick_name", "rich_level", "actor_level",
            "gender", "consume_total", "earn_total", "is_actor", "portrait",
        ],
    )


@_with_lock
def get_recent_games(n: int = 50) -> list[dict]:
    """Get last N completed games."""
    client = get_client()
    result = client.query(
        "SELECT game_no, winner, total_pot, bet_a, bet_b, bet_c, "
        "hand_a, hand_b, hand_c, hand_type_a, hand_type_b, hand_type_c, "
        "cards_json, duration_s, created_at "
        "FROM games ORDER BY game_no DESC LIMIT {n:UInt32}",
        parameters={"n": n},
    )
    games = []
    for row in result.result_rows:
        games.append({
            "game_no": row[0],
            "winner": row[1],
            "total_pot": row[2],
            "bet_a": row[3],
            "bet_b": row[4],
            "bet_c": row[5],
            "hand_a": row[6],
            "hand_b": row[7],
            "hand_c": row[8],
            "hand_type_a": row[9],
            "hand_type_b": row[10],
            "hand_type_c": row[11],
            "cards_json": row[12],
            "duration_s": row[13],
            "created_at": str(row[14]),
        })
    return games


@_with_lock
def get_leaderboard(n: int = 10) -> list[dict]:
    """
    Get top N users by P&L.
    P&L = sum of winning bets * 1.9 - sum of losing bets.
    With 2.9x fixed payout: win → +1.9x bet, loss → -1.0x bet.
    """
    client = get_client()
    result = client.query(
        """
        SELECT
            b.user_id,
            any(u.nick_name) AS nick_name,
            count() AS total_bets,
            countIf(b.chair = g.winner) AS wins,
            countIf(b.chair != g.winner) AS losses,
            toInt64(sumIf(b.bet_amount, b.chair = g.winner) * 1.9
                  - sumIf(b.bet_amount, b.chair != g.winner)) AS pnl,
            sum(b.bet_amount) AS total_wagered
        FROM bets b
        JOIN games g ON b.game_no = g.game_no
        LEFT JOIN users u ON b.user_id = u.user_id
        GROUP BY b.user_id
        HAVING total_bets >= 3
        ORDER BY pnl DESC
        LIMIT {n:UInt32}
        """,
        parameters={"n": n},
    )
    leaders = []
    for row in result.result_rows:
        leaders.append({
            "user_id": row[0],
            "nick_name": row[1] or str(row[0]),
            "total_bets": row[2],
            "wins": row[3],
            "losses": row[4],
            "pnl": row[5],
            "total_wagered": row[6],
        })
    return leaders


@_with_lock
def get_win_distribution() -> dict:
    """Get win counts per chair + bet rank distribution."""
    client = get_client()
    result = client.query(
        "SELECT winner, count() AS cnt FROM games GROUP BY winner ORDER BY winner"
    )
    dist = {"A": 0, "B": 0, "C": 0}
    for row in result.result_rows:
        chair = config.CHAIRS.get(row[0], "?")
        if chair in dist:
            dist[chair] = row[1]

    # Bet rank distribution: how often the winning chair had high/mid/low bet
    rank_result = client.query(
        """
        SELECT
            countIf(winner_bet >= greatest(bet_a, bet_b, bet_c)) AS high,
            countIf(winner_bet > least(bet_a, bet_b, bet_c)
                AND winner_bet < greatest(bet_a, bet_b, bet_c)) AS mid,
            countIf(winner_bet <= least(bet_a, bet_b, bet_c)) AS low
        FROM (
            SELECT
                bet_a, bet_b, bet_c,
                multiIf(winner = 3, bet_a, winner = 2, bet_b, bet_c) AS winner_bet
            FROM games
            WHERE bet_a + bet_b + bet_c > 0
        )
        """
    )
    bet_rank = {"high": 0, "mid": 0, "low": 0}
    if rank_result.result_rows:
        row = rank_result.result_rows[0]
        bet_rank = {"high": row[0], "mid": row[1], "low": row[2]}

    return {"chairs": dist, "bet_rank": bet_rank}


@_with_lock
def get_user_name(user_id: int) -> str | None:
    """Lookup user nickname from cache."""
    client = get_client()
    result = client.query(
        "SELECT nick_name FROM users WHERE user_id = {uid:UInt64} LIMIT 1",
        parameters={"uid": user_id},
    )
    if result.result_rows:
        return result.result_rows[0][0] or None
    return None


@_with_lock
def get_user_detail(user_id: int) -> dict | None:
    """Get full user profile + session betting stats."""
    client = get_client()
    # Profile
    result = client.query(
        "SELECT user_id, nick_name, rich_level, actor_level, gender, "
        "consume_total, earn_total, is_actor, portrait "
        "FROM users WHERE user_id = {uid:UInt64} LIMIT 1",
        parameters={"uid": user_id},
    )
    if not result.result_rows:
        return None
    row = result.result_rows[0]
    profile = {
        "user_id": row[0],
        "nick_name": row[1],
        "rich_level": row[2],
        "actor_level": row[3],
        "gender": row[4],
        "consume_total": row[5],
        "earn_total": row[6],
        "is_actor": row[7],
        "portrait": row[8],
    }

    # Session betting stats
    stats_result = client.query(
        """
        SELECT
            count() AS total_bets,
            sum(b.bet_amount) AS total_wagered,
            countDistinct(b.game_no) AS rounds_played,
            countIf(b.chair = g.winner) AS wins,
            countIf(b.chair != g.winner) AS losses,
            toInt64(sumIf(b.bet_amount, b.chair = g.winner) * 1.9
                  - sumIf(b.bet_amount, b.chair != g.winner)) AS pnl
        FROM bets b
        LEFT JOIN games g ON b.game_no = g.game_no
        WHERE b.user_id = {uid:UInt64}
        """,
        parameters={"uid": user_id},
    )
    if stats_result.result_rows:
        sr = stats_result.result_rows[0]
        profile["total_bets"] = sr[0]
        profile["total_wagered"] = sr[1]
        profile["rounds_played"] = sr[2]
        profile["wins"] = sr[3]
        profile["losses"] = sr[4]
        profile["pnl"] = sr[5]

    # Recent bets
    bets_result = client.query(
        """
        SELECT b.game_no, b.chair, b.bet_amount, b.total_bet,
               g.winner, b.created_at
        FROM bets b
        LEFT JOIN games g ON b.game_no = g.game_no
        WHERE b.user_id = {uid:UInt64}
        ORDER BY b.created_at DESC
        LIMIT 20
        """,
        parameters={"uid": user_id},
    )
    profile["recent_bets"] = []
    for br in bets_result.result_rows:
        profile["recent_bets"].append({
            "game_no": br[0],
            "chair": br[1],
            "chair_name": config.CHAIRS.get(br[1], "?"),
            "bet_amount": br[2],
            "total_bet": br[3],
            "winner": br[4],
            "won": br[1] == br[4] if br[4] else None,
            "created_at": str(br[5]),
        })

    return profile


@_with_lock
def get_biggest_winner() -> dict | None:
    """Get the single biggest winner by P&L this session."""
    client = get_client()
    result = client.query(
        """
        SELECT
            b.user_id,
            any(u.nick_name) AS nick_name,
            any(u.portrait) AS portrait,
            any(u.rich_level) AS rich_level,
            count() AS total_bets,
            countIf(b.chair = g.winner) AS wins,
            toInt64(sumIf(b.bet_amount, b.chair = g.winner) * 1.9
                  - sumIf(b.bet_amount, b.chair != g.winner)) AS pnl,
            sum(b.bet_amount) AS total_wagered
        FROM bets b
        JOIN games g ON b.game_no = g.game_no
        LEFT JOIN users u ON b.user_id = u.user_id
        GROUP BY b.user_id
        HAVING total_bets >= 3
        ORDER BY pnl DESC
        LIMIT 1
        """
    )
    if result.result_rows:
        row = result.result_rows[0]
        return {
            "user_id": row[0],
            "nick_name": row[1] or str(row[0]),
            "portrait": row[2] or "",
            "rich_level": row[3],
            "total_bets": row[4],
            "wins": row[5],
            "pnl": row[6],
            "total_wagered": row[7],
        }
    return None


@_with_lock
def get_analytics(period: str = "all") -> dict:
    """Get all analytics data for a given time period."""
    client = get_client()

    intervals = {
        "1h": "now() - INTERVAL 1 HOUR",
        "6h": "now() - INTERVAL 6 HOUR",
        "24h": "now() - INTERVAL 24 HOUR",
        "7d": "now() - INTERVAL 7 DAY",
    }
    cutoff_expr = intervals.get(period)
    game_where = f"WHERE created_at >= {cutoff_expr}" if cutoff_expr else ""
    bet_where = f"WHERE b.created_at >= {cutoff_expr}" if cutoff_expr else ""

    # 1. Summary stats
    summary_result = client.query(
        f"SELECT count(), sum(total_pot), toInt64(avg(total_pot)) FROM games {game_where}"
    )
    sr = summary_result.result_rows[0] if summary_result.result_rows else (0, 0, 0)
    # Bet counts
    bet_summary = client.query(
        f"SELECT count(), countDistinct(user_id) FROM bets {'WHERE created_at >= ' + cutoff_expr if cutoff_expr else ''}"
    )
    bs = bet_summary.result_rows[0] if bet_summary.result_rows else (0, 0)
    summary = {
        "total_games": sr[0],
        "total_volume": int(sr[1] or 0),
        "avg_pot": int(sr[2] or 0),
        "total_bets_placed": bs[0],
        "unique_bettors": bs[1],
    }

    # 2. Win distribution (chairs + bet rank)
    dist_result = client.query(
        f"SELECT winner, count() AS cnt FROM games {game_where} GROUP BY winner ORDER BY winner"
    )
    chairs_dist = {"A": 0, "B": 0, "C": 0}
    for row in dist_result.result_rows:
        chair = config.CHAIRS.get(row[0], "?")
        if chair in chairs_dist:
            chairs_dist[chair] = row[1]

    rank_result = client.query(
        f"""
        SELECT
            countIf(winner_bet >= greatest(bet_a, bet_b, bet_c)) AS high,
            countIf(winner_bet > least(bet_a, bet_b, bet_c)
                AND winner_bet < greatest(bet_a, bet_b, bet_c)) AS mid,
            countIf(winner_bet <= least(bet_a, bet_b, bet_c)) AS low
        FROM (
            SELECT
                bet_a, bet_b, bet_c,
                multiIf(winner = 3, bet_a, winner = 2, bet_b, bet_c) AS winner_bet
            FROM games
            {game_where + ' AND' if game_where else 'WHERE'} bet_a + bet_b + bet_c > 0
        )
        """
    )
    bet_rank = {"high": 0, "mid": 0, "low": 0}
    if rank_result.result_rows:
        rr = rank_result.result_rows[0]
        bet_rank = {"high": rr[0], "mid": rr[1], "low": rr[2]}

    win_distribution = {"chairs": chairs_dist, "bet_rank": bet_rank}

    # 3. Hand type distribution (winning hand types)
    hand_type_result = client.query(
        f"""
        SELECT hand_type, count() AS cnt FROM (
            SELECT multiIf(winner = 3, hand_type_a, winner = 2, hand_type_b, hand_type_c) AS hand_type
            FROM games
            {game_where}
        )
        WHERE hand_type > 0
        GROUP BY hand_type
        ORDER BY hand_type
        """
    )
    hand_type_distribution = {}
    for row in hand_type_result.result_rows:
        type_name = config.HAND_TYPES.get(row[0], f"Type {row[0]}")
        hand_type_distribution[type_name] = row[1]

    # 4. Leaderboard
    leaderboard_result = client.query(
        f"""
        SELECT
            b.user_id,
            any(u.nick_name) AS nick_name,
            count() AS total_bets,
            countIf(b.chair = g.winner) AS wins,
            countIf(b.chair != g.winner) AS losses,
            toInt64(sumIf(b.bet_amount, b.chair = g.winner) * 1.9
                  - sumIf(b.bet_amount, b.chair != g.winner)) AS pnl,
            sum(b.bet_amount) AS total_wagered
        FROM bets b
        JOIN games g ON b.game_no = g.game_no
        LEFT JOIN users u ON b.user_id = u.user_id
        {bet_where}
        GROUP BY b.user_id
        HAVING total_bets >= 3
        ORDER BY pnl DESC
        LIMIT 20
        """
    )
    leaderboard = []
    for row in leaderboard_result.result_rows:
        leaderboard.append({
            "user_id": row[0],
            "nick_name": row[1] or str(row[0]),
            "total_bets": row[2],
            "wins": row[3],
            "losses": row[4],
            "pnl": row[5],
            "total_wagered": row[6],
        })

    # 5. Hourly volume
    hourly_result = client.query(
        f"""
        SELECT
            toStartOfHour(created_at) AS hour,
            count() AS games,
            sum(total_pot) AS volume
        FROM games
        {game_where}
        GROUP BY hour
        ORDER BY hour
        """
    )
    hourly_volume = []
    for row in hourly_result.result_rows:
        hourly_volume.append({
            "hour": str(row[0]),
            "games": row[1],
            "volume": int(row[2] or 0),
        })

    # 6. Games list
    games_result = client.query(
        f"""
        SELECT game_no, winner, total_pot, bet_a, bet_b, bet_c,
               hand_a, hand_b, hand_c, hand_type_a, hand_type_b, hand_type_c,
               cards_json, duration_s, created_at
        FROM games
        {game_where}
        ORDER BY game_no DESC
        LIMIT 200
        """
    )
    games = []
    for row in games_result.result_rows:
        games.append({
            "game_no": row[0],
            "winner": row[1],
            "total_pot": row[2],
            "bet_a": row[3],
            "bet_b": row[4],
            "bet_c": row[5],
            "hand_a": row[6],
            "hand_b": row[7],
            "hand_c": row[8],
            "hand_type_a": row[9],
            "hand_type_b": row[10],
            "hand_type_c": row[11],
            "cards_json": row[12],
            "duration_s": row[13],
            "created_at": str(row[14]),
        })

    return {
        "summary": summary,
        "win_distribution": win_distribution,
        "hand_type_distribution": hand_type_distribution,
        "leaderboard": leaderboard,
        "hourly_volume": hourly_volume,
        "games": games,
    }


@_with_lock
def get_pattern_analysis() -> dict:
    """Run all pattern analysis queries and return a single dict."""
    client = get_client()

    # 1. Chair win bias
    result = client.query(
        "SELECT winner, count() AS cnt FROM games GROUP BY winner ORDER BY winner"
    )
    chair_wins = {}
    total_games = 0
    for row in result.result_rows:
        chair = config.CHAIRS.get(row[0], "?")
        chair_wins[chair] = row[1]
        total_games += row[1]
    chair_bias = {"total_games": total_games}
    for ch in ("A", "B", "C"):
        wins = chair_wins.get(ch, 0)
        pct = round(wins / total_games * 100, 2) if total_games else 0
        chair_bias[ch] = {"wins": wins, "pct": pct}

    # 2. Bet rank analysis — how often the highest/mid/lowest bet chair wins
    rank_result = client.query("""
        SELECT
            countIf(winner_bet >= greatest(bet_a, bet_b, bet_c)) AS high,
            countIf(winner_bet > least(bet_a, bet_b, bet_c)
                AND winner_bet < greatest(bet_a, bet_b, bet_c)) AS mid,
            countIf(winner_bet <= least(bet_a, bet_b, bet_c)) AS low
        FROM (
            SELECT bet_a, bet_b, bet_c,
                multiIf(winner = 3, bet_a, winner = 2, bet_b, bet_c) AS winner_bet
            FROM games WHERE bet_a + bet_b + bet_c > 0
        )
    """)
    bet_rank = {"high": 0, "mid": 0, "low": 0}
    if rank_result.result_rows:
        r = rank_result.result_rows[0]
        bet_rank = {"high": r[0], "mid": r[1], "low": r[2]}

    # 3. Per-chair bet rank — when chair X has max bet, how often does X win?
    pcr = client.query("""
        SELECT
            countIf(bet_a >= greatest(bet_a, bet_b, bet_c) AND bet_a > 0) AS a_high,
            countIf(bet_a >= greatest(bet_a, bet_b, bet_c) AND bet_a > 0 AND winner = 3) AS a_win,
            countIf(bet_b >= greatest(bet_a, bet_b, bet_c) AND bet_b > 0) AS b_high,
            countIf(bet_b >= greatest(bet_a, bet_b, bet_c) AND bet_b > 0 AND winner = 2) AS b_win,
            countIf(bet_c >= greatest(bet_a, bet_b, bet_c) AND bet_c > 0) AS c_high,
            countIf(bet_c >= greatest(bet_a, bet_b, bet_c) AND bet_c > 0 AND winner = 1) AS c_win
        FROM games WHERE bet_a + bet_b + bet_c > 0
    """)
    per_chair_rank = {}
    if pcr.result_rows:
        r = pcr.result_rows[0]
        for i, ch in enumerate(("A", "B", "C")):
            has = r[i * 2]
            wins = r[i * 2 + 1]
            per_chair_rank[ch] = {
                "has_highest": has, "wins": wins,
                "win_pct": round(wins / has * 100, 2) if has else 0,
            }

    # 4. Hand type distribution by chair (all dealt hands, not just winners)
    ht_result = client.query("""
        SELECT 'A' AS chair, hand_type_a AS ht, count() AS cnt
            FROM games WHERE hand_type_a > 0 GROUP BY ht
        UNION ALL
        SELECT 'B', hand_type_b, count()
            FROM games WHERE hand_type_b > 0 GROUP BY hand_type_b
        UNION ALL
        SELECT 'C', hand_type_c, count()
            FROM games WHERE hand_type_c > 0 GROUP BY hand_type_c
        ORDER BY 1, 2
    """)
    hand_types_by_chair = {"A": {}, "B": {}, "C": {}}
    for row in ht_result.result_rows:
        ch = row[0]
        type_name = config.HAND_TYPES.get(row[1], f"Type {row[1]}")
        hand_types_by_chair[ch][type_name] = row[2]

    # 5. Hand type win rates (winning hand type distribution)
    htw = client.query("""
        SELECT hand_type, count() AS cnt FROM (
            SELECT multiIf(winner = 3, hand_type_a, winner = 2, hand_type_b, hand_type_c) AS hand_type
            FROM games
        ) WHERE hand_type > 0
        GROUP BY hand_type ORDER BY hand_type
    """)
    hand_type_wins = {}
    for row in htw.result_rows:
        type_name = config.HAND_TYPES.get(row[0], f"Type {row[0]}")
        hand_type_wins[type_name] = row[1]

    # 6. Pot size buckets — win rates by pot quartile
    qr = client.query("""
        SELECT
            quantile(0.25)(total_pot) AS q1,
            quantile(0.5)(total_pot) AS q2,
            quantile(0.75)(total_pot) AS q3
        FROM games
    """)
    pot_buckets = {}
    if qr.result_rows:
        q1, q2, q3 = int(qr.result_rows[0][0]), int(qr.result_rows[0][1]), int(qr.result_rows[0][2])
        br = client.query(f"""
            SELECT
                multiIf(
                    total_pot <= {q1}, 'small',
                    total_pot <= {q2}, 'medium',
                    total_pot <= {q3}, 'large',
                    'whale'
                ) AS bucket,
                winner, count() AS cnt
            FROM games GROUP BY bucket, winner
        """)
        for row in br.result_rows:
            bucket, chair_id, cnt = row[0], row[1], row[2]
            chair = config.CHAIRS.get(chair_id, "?")
            if bucket not in pot_buckets:
                pot_buckets[bucket] = {"A": 0, "B": 0, "C": 0, "total": 0}
            pot_buckets[bucket][chair] = cnt
            pot_buckets[bucket]["total"] += cnt
        pot_buckets["_ranges"] = {
            "small": f"0–{q1}", "medium": f"{q1+1}–{q2}",
            "large": f"{q2+1}–{q3}", "whale": f">{q3}",
        }

    # 7. Streak analysis — compute in Python from ordered winners
    streak_result = client.query(
        "SELECT winner FROM games ORDER BY game_no ASC"
    )
    winners_list = [config.CHAIRS.get(r[0], "?") for r in streak_result.result_rows]
    streaks = {}
    for ch in ("A", "B", "C"):
        max_s = cur = 0
        for w in winners_list:
            if w == ch:
                cur += 1
                max_s = max(max_s, cur)
            else:
                cur = 0
        # current streak from the end
        current = 0
        for w in reversed(winners_list):
            if w == ch:
                current += 1
            else:
                break
        streaks[ch] = {"max_streak": max_s, "current_streak": current}

    # 8. Hourly patterns — win rates by hour of day
    hr_result = client.query("""
        SELECT toHour(created_at) AS hr, winner, count() AS cnt
        FROM games GROUP BY hr, winner ORDER BY hr, winner
    """)
    hourly = {}
    for row in hr_result.result_rows:
        h = str(row[0])
        chair = config.CHAIRS.get(row[1], "?")
        if h not in hourly:
            hourly[h] = {"A": 0, "B": 0, "C": 0, "total": 0}
        hourly[h][chair] = row[2]
        hourly[h]["total"] += row[2]

    # 9. Recent (last 100) vs overall
    recent = client.query("""
        SELECT winner, count() AS cnt FROM (
            SELECT winner FROM games ORDER BY game_no DESC LIMIT 100
        ) GROUP BY winner
    """)
    recent_dist = {"A": 0, "B": 0, "C": 0}
    recent_total = 0
    for row in recent.result_rows:
        chair = config.CHAIRS.get(row[0], "?")
        if chair in recent_dist:
            recent_dist[chair] = row[1]
            recent_total += row[1]

    return {
        "chair_bias": chair_bias,
        "bet_rank": bet_rank,
        "per_chair_rank": per_chair_rank,
        "hand_types_by_chair": hand_types_by_chair,
        "hand_type_wins": hand_type_wins,
        "pot_buckets": pot_buckets,
        "streaks": streaks,
        "hourly": hourly,
        "recent_vs_all": {
            "recent": {"dist": recent_dist, "total": recent_total},
            "all": {
                "dist": {ch: chair_bias[ch]["wins"] for ch in ("A", "B", "C")},
                "total": total_games,
            },
        },
    }


@_with_lock
def get_hot_cold_players(n: int = 5) -> dict:
    """
    Get players with highest and lowest P&L over their last 10 bets.
    Returns {"hot": [...], "cold": [...]}.
    """
    client = get_client()
    sql = """
        WITH ranked AS (
            SELECT
                b.user_id,
                b.game_no,
                b.chair,
                b.bet_amount,
                g.winner,
                row_number() OVER (PARTITION BY b.user_id ORDER BY b.created_at DESC) AS rn
            FROM bets b
            JOIN games g ON b.game_no = g.game_no
        ),
        last10 AS (
            SELECT * FROM ranked WHERE rn <= 10
        )
        SELECT
            l.user_id,
            any(u.nick_name) AS nick_name,
            count() AS total_bets,
            countIf(l.chair = l.winner) AS wins,
            toInt64(sumIf(l.bet_amount, l.chair = l.winner) * 1.9
                  - sumIf(l.bet_amount, l.chair != l.winner)) AS pnl
        FROM last10 l
        LEFT JOIN users u ON l.user_id = u.user_id
        GROUP BY l.user_id
        HAVING total_bets >= 5
        ORDER BY pnl DESC
    """
    result = client.query(sql)
    all_players = []
    for row in result.result_rows:
        all_players.append({
            "user_id": row[0],
            "nick_name": row[1] or str(row[0]),
            "total_bets": row[2],
            "wins": row[3],
            "pnl": row[4],
        })
    hot = [p for p in all_players if p["pnl"] > 0][:n]
    cold = [p for p in all_players if p["pnl"] < 0][-n:]
    cold.reverse()  # most negative first
    return {"hot": hot, "cold": cold}


# ---------------------------------------------------------------------------
# Prediction helpers (private, called inside the locked main function)
# ---------------------------------------------------------------------------

CHAIR_LABELS = ("A", "B", "C")


def _normal_cdf(x):
    """Abramowitz-Stegun approximation of the standard normal CDF."""
    if x < -8:
        return 0.0
    if x > 8:
        return 1.0
    t = 1.0 / (1.0 + 0.2316419 * abs(x))
    d = 0.3989422804014327  # 1/sqrt(2*pi)
    p = d * math.exp(-x * x / 2.0) * (
        t * (0.319381530 + t * (-0.356563782 + t * (1.781477937 + t * (-1.821255978 + t * 1.330274429))))
    )
    return 1.0 - p if x > 0 else p


def _markov_matrix_1(winners):
    """1st-order Markov transition matrix P(next | last)."""
    counts = {a: {b: 0 for b in CHAIR_LABELS} for a in CHAIR_LABELS}
    for i in range(len(winners) - 1):
        prev, cur = winners[i], winners[i + 1]
        if prev in counts and cur in CHAIR_LABELS:
            counts[prev][cur] += 1
    matrix = {}
    for src in CHAIR_LABELS:
        total = sum(counts[src].values())
        matrix[src] = {dst: round(counts[src][dst] / total, 4) if total else 0 for dst in CHAIR_LABELS}
    return matrix, counts


def _markov_matrix_2(winners):
    """2nd-order Markov transition matrix P(next | last two)."""
    counts = {}
    for a in CHAIR_LABELS:
        for b in CHAIR_LABELS:
            key = f"{a}{b}"
            counts[key] = {c: 0 for c in CHAIR_LABELS}
    for i in range(len(winners) - 2):
        key = f"{winners[i]}{winners[i+1]}"
        nxt = winners[i + 2]
        if key in counts and nxt in CHAIR_LABELS:
            counts[key][nxt] += 1
    matrix = {}
    for key in counts:
        total = sum(counts[key].values())
        matrix[key] = {dst: round(counts[key][dst] / total, 4) if total else 0 for dst in CHAIR_LABELS}
    return matrix, counts


def _autocorrelation(winners, max_lag=5):
    """Pearson autocorrelation at lags 1..max_lag. Chairs encoded A=0,B=1,C=2."""
    mapping = {"A": 0, "B": 1, "C": 2}
    seq = [mapping.get(w, 0) for w in winners]
    n = len(seq)
    if n < max_lag + 2:
        return [{"lag": i + 1, "r": 0, "significant": False} for i in range(max_lag)]
    mean = sum(seq) / n
    var = sum((x - mean) ** 2 for x in seq)
    results = []
    for lag in range(1, max_lag + 1):
        if var == 0:
            results.append({"lag": lag, "r": 0, "significant": False})
            continue
        cov = sum((seq[i] - mean) * (seq[i + lag] - mean) for i in range(n - lag))
        r = round(cov / var, 4)
        threshold = 1.96 / math.sqrt(n)
        results.append({"lag": lag, "r": r, "significant": abs(r) > threshold})
    return results


def _chi_squared_test(winners):
    """Chi-squared goodness-of-fit for uniform chair distribution (df=2)."""
    n = len(winners)
    if n == 0:
        return {"chi2": 0, "p_value": 1, "significant": False, "counts": {c: 0 for c in CHAIR_LABELS}}
    observed = {c: 0 for c in CHAIR_LABELS}
    for w in winners:
        if w in observed:
            observed[w] += 1
    expected = n / 3.0
    chi2 = sum((observed[c] - expected) ** 2 / expected for c in CHAIR_LABELS)
    p_value = math.exp(-chi2 / 2.0)  # df=2 closed-form
    return {
        "chi2": round(chi2, 4),
        "p_value": round(p_value, 6),
        "significant": p_value < 0.05,
        "counts": observed,
        "expected": round(expected, 1),
    }


def _runs_test(winners):
    """Wald-Wolfowitz runs test for randomness."""
    if len(winners) < 10:
        return {"runs": 0, "z_score": 0, "p_value": 1, "interpretation": "Not enough data"}
    # Count runs (sequences of same chair)
    runs = 1
    for i in range(1, len(winners)):
        if winners[i] != winners[i - 1]:
            runs += 1
    n = len(winners)
    counts = {c: 0 for c in CHAIR_LABELS}
    for w in winners:
        if w in counts:
            counts[w] += 1
    # Expected runs and variance for k categories
    n_vals = [counts[c] for c in CHAIR_LABELS if counts[c] > 0]
    sum_ni2 = sum(ni ** 2 for ni in n_vals)
    expected_runs = 1 + (n * n - sum_ni2) / n
    if n <= 1:
        return {"runs": runs, "z_score": 0, "p_value": 1, "interpretation": "Not enough data"}
    var_num = sum_ni2 * (sum_ni2 + n * n) - 2 * n * sum(ni ** 3 for ni in n_vals) - n ** 3
    var_den = n * n * (n - 1)
    variance = var_num / var_den if var_den > 0 else 1
    if variance <= 0:
        return {"runs": runs, "z_score": 0, "p_value": 1, "interpretation": "Not enough data"}
    z = (runs - expected_runs) / math.sqrt(variance)
    p_value = 2 * (1 - _normal_cdf(abs(z)))
    if p_value < 0.05:
        interpretation = "Too few runs (streaky)" if z < 0 else "Too many runs (alternating)"
    else:
        interpretation = "Random (no significant pattern)"
    return {
        "runs": runs,
        "expected_runs": round(expected_runs, 1),
        "z_score": round(z, 4),
        "p_value": round(p_value, 6),
        "significant": p_value < 0.05,
        "interpretation": interpretation,
    }


def _bayesian_prediction(winners, markov1, markov2):
    """Weighted Bayesian prediction combining 5 signals."""
    if len(winners) < 3:
        return {c: round(1 / 3, 4) for c in CHAIR_LABELS}, {}

    # Signal 1: Base rate (overall frequency) — 20%
    total = len(winners)
    base = {c: winners.count(c) / total for c in CHAIR_LABELS}

    # Signal 2: 1st-order Markov — 30%
    last = winners[-1]
    m1 = markov1.get(last, {c: 1 / 3 for c in CHAIR_LABELS})

    # Signal 3: 2nd-order Markov — 25%
    key2 = f"{winners[-2]}{winners[-1]}"
    m2 = markov2.get(key2, {c: 1 / 3 for c in CHAIR_LABELS})

    # Signal 4: Recent 20-game frequency — 15%
    recent = winners[-20:] if len(winners) >= 20 else winners
    recent_total = len(recent)
    rec = {c: recent.count(c) / recent_total for c in CHAIR_LABELS}

    # Signal 5: Streak momentum/regression — 10%
    streak_chair = winners[-1]
    streak_len = 0
    for w in reversed(winners):
        if w == streak_chair:
            streak_len += 1
        else:
            break
    # Regression to mean: longer streaks → lower probability of continuation
    streak = {}
    for c in CHAIR_LABELS:
        if c == streak_chair:
            streak[c] = max(0.1, 1 / 3 - streak_len * 0.05)
        else:
            streak[c] = 0
    # Normalize streak signal
    s_total = sum(streak.values())
    if s_total > 0:
        streak = {c: streak[c] / s_total for c in CHAIR_LABELS}
    else:
        streak = {c: 1 / 3 for c in CHAIR_LABELS}

    weights = {"base_rate": 0.20, "markov_1": 0.30, "markov_2": 0.25, "recent_20": 0.15, "streak": 0.10}
    signals = {"base_rate": base, "markov_1": m1, "markov_2": m2, "recent_20": rec, "streak": streak}

    combined = {c: 0 for c in CHAIR_LABELS}
    for sig_name, weight in weights.items():
        for c in CHAIR_LABELS:
            combined[c] += weight * signals[sig_name].get(c, 1 / 3)

    # Normalize
    c_total = sum(combined.values())
    if c_total > 0:
        combined = {c: round(combined[c] / c_total, 4) for c in CHAIR_LABELS}

    # Round signal values for output
    signal_detail = {}
    for sig_name, sig_vals in signals.items():
        signal_detail[sig_name] = {
            "weight": weights[sig_name],
            "probs": {c: round(sig_vals.get(c, 0), 4) for c in CHAIR_LABELS},
        }

    return combined, signal_detail


def _card_value_distribution(cards_data):
    """Count of each card value (A–K) per chair."""
    value_names = ["A", "2", "3", "4", "5", "6", "7", "8", "9", "10", "J", "Q", "K"]
    dist = {c: {v: 0 for v in value_names} for c in CHAIR_LABELS}
    for cards_json_str, _ in cards_data:
        try:
            infos = json.loads(cards_json_str)
        except (json.JSONDecodeError, TypeError):
            continue
        for p in infos:
            chair = config.CHAIRS.get(p.get("country"), None)
            if chair not in dist:
                continue
            for card in p.get("cards", []):
                val = config.VALUES.get(card.get("cardValue"), None)
                if val and val in dist[chair]:
                    dist[chair][val] += 1
    return {"labels": value_names, "chairs": dist}


def _face_card_frequency(cards_data):
    """Percentage of face cards (J, Q, K, A) per chair."""
    face_vals = {"J", "Q", "K", "A"}
    face_counts = {c: 0 for c in CHAIR_LABELS}
    total_counts = {c: 0 for c in CHAIR_LABELS}
    for cards_json_str, _ in cards_data:
        try:
            infos = json.loads(cards_json_str)
        except (json.JSONDecodeError, TypeError):
            continue
        for p in infos:
            chair = config.CHAIRS.get(p.get("country"), None)
            if chair not in face_counts:
                continue
            for card in p.get("cards", []):
                val = config.VALUES.get(card.get("cardValue"), None)
                if val:
                    total_counts[chair] += 1
                    if val in face_vals:
                        face_counts[chair] += 1
    result = {}
    for c in CHAIR_LABELS:
        pct = round(face_counts[c] / total_counts[c] * 100, 2) if total_counts[c] else 0
        result[c] = {"face_cards": face_counts[c], "total_cards": total_counts[c], "pct": pct}
    return result


def _suit_distribution(cards_data):
    """Suit counts per chair."""
    suit_names = ["\u2660", "\u2665", "\u2663", "\u2666"]
    dist = {c: {s: 0 for s in suit_names} for c in CHAIR_LABELS}
    for cards_json_str, _ in cards_data:
        try:
            infos = json.loads(cards_json_str)
        except (json.JSONDecodeError, TypeError):
            continue
        for p in infos:
            chair = config.CHAIRS.get(p.get("country"), None)
            if chair not in dist:
                continue
            for card in p.get("cards", []):
                suit = config.SUITS.get(card.get("cardColor"), None)
                if suit and suit in dist[chair]:
                    dist[chair][suit] += 1
    return {"labels": suit_names, "chairs": dist}


def _winning_card_patterns(cards_data):
    """Top 20 individual cards appearing in winning hands."""
    card_counts = {}
    for cards_json_str, winner in cards_data:
        try:
            infos = json.loads(cards_json_str)
        except (json.JSONDecodeError, TypeError):
            continue
        for p in infos:
            chair = config.CHAIRS.get(p.get("country"), None)
            if chair is None:
                continue
            # Check if this chair won: winner is stored as chair_id (1=C, 2=B, 3=A)
            if config.CHAIRS.get(winner) != chair:
                continue
            for card in p.get("cards", []):
                val = config.VALUES.get(card.get("cardValue"), None)
                suit = config.SUITS.get(card.get("cardColor"), None)
                if val and suit:
                    label = f"{val}{suit}"
                    card_counts[label] = card_counts.get(label, 0) + 1
    sorted_cards = sorted(card_counts.items(), key=lambda x: x[1], reverse=True)[:20]
    return [{"card": c, "count": n} for c, n in sorted_cards]


def _backtest_theories(winners):
    """Backtest all prediction theories on historical data."""
    warmup = 30
    if len(winners) <= warmup:
        return {"error": "Not enough data for backtesting"}

    theories = ["base_rate", "markov_1", "markov_2", "recent_20", "streak", "combined"]
    correct = {t: 0 for t in theories}
    total_tested = 0
    rolling = {t: [] for t in theories}  # rolling accuracy over last 200

    for i in range(warmup, len(winners)):
        history = winners[:i]
        actual = winners[i]
        total_tested += 1

        total_h = len(history)
        # Base rate
        base = {c: history.count(c) / total_h for c in CHAIR_LABELS}
        base_pick = max(CHAIR_LABELS, key=lambda c: base[c])

        # Markov-1
        m1, _ = _markov_matrix_1(history)
        last = history[-1]
        m1_probs = m1.get(last, {c: 1 / 3 for c in CHAIR_LABELS})
        m1_pick = max(CHAIR_LABELS, key=lambda c: m1_probs.get(c, 0))

        # Markov-2
        m2, _ = _markov_matrix_2(history)
        key2 = f"{history[-2]}{history[-1]}"
        m2_probs = m2.get(key2, {c: 1 / 3 for c in CHAIR_LABELS})
        m2_pick = max(CHAIR_LABELS, key=lambda c: m2_probs.get(c, 0))

        # Recent-20
        recent = history[-20:] if len(history) >= 20 else history
        rec = {c: recent.count(c) / len(recent) for c in CHAIR_LABELS}
        rec_pick = max(CHAIR_LABELS, key=lambda c: rec[c])

        # Streak
        streak_chair = history[-1]
        streak_len = 0
        for w in reversed(history):
            if w == streak_chair:
                streak_len += 1
            else:
                break
        streak_probs = {}
        for c in CHAIR_LABELS:
            if c == streak_chair:
                streak_probs[c] = max(0.1, 1 / 3 - streak_len * 0.05)
            else:
                streak_probs[c] = 0
        s_total = sum(streak_probs.values())
        if s_total > 0:
            streak_probs = {c: streak_probs[c] / s_total for c in CHAIR_LABELS}
        else:
            streak_probs = {c: 1 / 3 for c in CHAIR_LABELS}
        streak_pick = max(CHAIR_LABELS, key=lambda c: streak_probs[c])

        # Combined Bayesian
        combined = {c: 0 for c in CHAIR_LABELS}
        weights = {"base_rate": 0.20, "markov_1": 0.30, "markov_2": 0.25, "recent_20": 0.15, "streak": 0.10}
        signals = {"base_rate": base, "markov_1": m1_probs, "markov_2": m2_probs, "recent_20": rec, "streak": streak_probs}
        for sig_name, weight in weights.items():
            for c in CHAIR_LABELS:
                combined[c] += weight * signals[sig_name].get(c, 1 / 3)
        combined_pick = max(CHAIR_LABELS, key=lambda c: combined[c])

        picks = {
            "base_rate": base_pick, "markov_1": m1_pick, "markov_2": m2_pick,
            "recent_20": rec_pick, "streak": streak_pick, "combined": combined_pick,
        }
        for t in theories:
            hit = 1 if picks[t] == actual else 0
            if picks[t] == actual:
                correct[t] += 1
            rolling[t].append(hit)

    accuracy = {t: round(correct[t] / total_tested * 100, 2) if total_tested else 0 for t in theories}

    # Rolling accuracy over last 200 games
    window = 200
    rolling_accuracy = {t: [] for t in theories}
    for t in theories:
        data = rolling[t]
        for j in range(len(data)):
            start = max(0, j - window + 1)
            chunk = data[start:j + 1]
            rolling_accuracy[t].append(round(sum(chunk) / len(chunk) * 100, 2))
    # Only keep last 200 points for the chart
    for t in theories:
        rolling_accuracy[t] = rolling_accuracy[t][-window:]

    return {
        "total_tested": total_tested,
        "accuracy": accuracy,
        "rolling_accuracy": rolling_accuracy,
        "random_baseline": 33.33,
    }


def _last_n_predictions(winners, n=20):
    """Get detailed prediction vs actual for the last N games."""
    warmup = 30
    if len(winners) <= warmup:
        return []
    start = max(warmup, len(winners) - n)
    results = []
    for i in range(start, len(winners)):
        history = winners[:i]
        actual = winners[i]
        m1, _ = _markov_matrix_1(history)
        m2, _ = _markov_matrix_2(history)
        pred, _ = _bayesian_prediction(history, m1, m2)
        predicted = max(CHAIR_LABELS, key=lambda c: pred[c])
        results.append({
            "index": i,
            "predicted": predicted,
            "actual": actual,
            "correct": predicted == actual,
            "probs": {c: round(pred[c], 4) for c in CHAIR_LABELS},
        })
    return results


@_with_lock
def get_prediction_analysis() -> dict:
    """Run all prediction/game-theory analysis and return results."""
    client = get_client()

    # Query 1: Full winner sequence with game numbers
    result = client.query("SELECT game_no, winner FROM games ORDER BY game_no ASC")
    game_nos = [r[0] for r in result.result_rows if config.CHAIRS.get(r[1], "?") in CHAIR_LABELS]
    winners = [config.CHAIRS.get(r[1], "?") for r in result.result_rows]
    winners = [w for w in winners if w in CHAIR_LABELS]  # filter unknowns

    # Query 2: Card data for last 500 games
    cards_result = client.query(
        "SELECT cards_json, winner FROM games WHERE cards_json != '' ORDER BY game_no DESC LIMIT 500"
    )
    cards_data = [(r[0], r[1]) for r in cards_result.result_rows]

    # Markov matrices
    markov1, markov1_counts = _markov_matrix_1(winners)
    markov2, markov2_counts = _markov_matrix_2(winners)

    # Autocorrelation
    autocorrelation = _autocorrelation(winners)

    # Chi-squared test
    chi_squared = _chi_squared_test(winners)

    # Runs test
    runs_test = _runs_test(winners)

    # Bayesian prediction
    prediction, signals = _bayesian_prediction(winners, markov1, markov2)

    # Backtesting
    backtest = _backtest_theories(winners)

    # Last 20 prediction vs actual
    last_20_raw = _last_n_predictions(winners, 20)
    # Attach game_nos to last_20
    for entry in last_20_raw:
        idx = entry["index"]
        entry["game_no"] = game_nos[idx] if idx < len(game_nos) else 0

    # Card analysis
    card_values = _card_value_distribution(cards_data)
    face_cards = _face_card_frequency(cards_data)
    suits = _suit_distribution(cards_data)
    winning_cards = _winning_card_patterns(cards_data)

    return {
        "total_games": len(winners),
        "last_winners": winners[-10:] if len(winners) >= 10 else winners,
        "last_20_predictions": last_20_raw,
        "prediction": prediction,
        "signals": signals,
        "markov1": {"matrix": markov1, "counts": {k: dict(v) for k, v in markov1_counts.items()}},
        "markov2": {"matrix": markov2, "counts": {k: dict(v) for k, v in markov2_counts.items()}},
        "autocorrelation": autocorrelation,
        "chi_squared": chi_squared,
        "runs_test": runs_test,
        "backtest": backtest,
        "card_values": card_values,
        "face_cards": face_cards,
        "suits": suits,
        "winning_cards": winning_cards,
    }