"""Чтение данных пользователей для админки (Блок 4.3).

Баланс — контракт ``SUM(bot.money.amount)``; яички — ``SUM(bot.eggs.amount)``.
Подписка на рассылки — отсутствие строки в ``bot.unsubscribe``.
"""

from __future__ import annotations

from typing import Any

from common.db.pool import get_pool

#: Общая часть выборки: агрегаты по сообщениям, деньгам, яичкам и очищениям.
_FROM = """
    FROM bot.tg_users AS tg
        LEFT JOIN bot.de_users AS du ON du.id_user = tg.id_user
        LEFT JOIN bot.titles AS t ON t.id_title = du.id_title
        LEFT JOIN (
            SELECT id_user, count(*) AS cnt, max(dt) AS last_dt
            FROM bot.messages GROUP BY id_user
        ) AS msg ON msg.id_user = tg.id_user
        LEFT JOIN (
            SELECT id_user, sum(amount) AS balance
            FROM bot.money GROUP BY id_user
        ) AS money ON money.id_user = tg.id_user
        LEFT JOIN (
            SELECT id_user, sum(amount) AS eggs
            FROM bot.eggs GROUP BY id_user
        ) AS eggs ON eggs.id_user = tg.id_user
        LEFT JOIN (
            SELECT id_user, count(*) AS cnt, max(dt) AS last_dt
            FROM bot.purifications GROUP BY id_user
        ) AS pur ON pur.id_user = tg.id_user
        LEFT JOIN bot.unsubscribe AS unsub ON unsub.id_user = tg.id_user
"""

_SELECT = """
    SELECT tg.id_user, tg.username, tg.first_name, tg.last_name,
           du.nick, du.lvl, du.expr, du.expr_streak, du.dt_create,
           t.title,
           coalesce(msg.cnt, 0) AS msg_count,
           msg.last_dt AS last_message_at,
           coalesce(money.balance, 0) AS balance,
           coalesce(eggs.eggs, 0) AS eggs,
           coalesce(pur.cnt, 0) AS purification_count,
           pur.last_dt AS last_purification_at,
           (unsub.id_user IS NULL) AS subscribed
"""

#: Колонки, по которым идёт поиск (в порядке подстановки параметров).
_SEARCH_COLUMNS = ("tg.username", "tg.first_name", "tg.last_name", "du.nick")


def _search_clause(term: str) -> tuple[str, list[Any]]:
    """WHERE по нику, username, имени и Telegram-ID."""
    term = term.strip()
    if not term:
        return "", []

    like = f"%{term}%"
    clauses = [f"{column} ILIKE %s" for column in _SEARCH_COLUMNS]
    params: list[Any] = [like] * len(_SEARCH_COLUMNS)

    telegram_id = term.lstrip("@")
    if telegram_id.isdigit():
        clauses.append("tg.id_user = %s")
        params.append(int(telegram_id))

    return " WHERE (" + " OR ".join(clauses) + ")", params


async def count_users(search: str = "") -> int:
    """Сколько пользователей подходит под поиск."""
    where, params = _search_clause(search)
    async with get_pool().connection() as conn:
        cur = await conn.execute("SELECT count(*) AS total " + _FROM + where, tuple(params))
        row = await cur.fetchone()
    return int(row["total"]) if row else 0


async def list_users(search: str = "", *, limit: int = 25, offset: int = 0) -> list[dict[str, Any]]:
    """Страница списка пользователей (с поиском)."""
    where, params = _search_clause(search)
    async with get_pool().connection() as conn:
        cur = await conn.execute(
            _SELECT + _FROM + where + " ORDER BY du.nick NULLS LAST, tg.id_user LIMIT %s OFFSET %s",
            (*params, limit, offset),
        )
        return await cur.fetchall()


async def get_user(user_id: int) -> dict[str, Any] | None:
    """Карточка пользователя со сводными показателями."""
    async with get_pool().connection() as conn:
        cur = await conn.execute(_SELECT + _FROM + " WHERE tg.id_user = %s", (user_id,))
        return await cur.fetchone()


async def money_history(user_id: int, *, limit: int = 10) -> list[dict[str, Any]]:
    """Последние операции по балансу с названием действия."""
    async with get_pool().connection() as conn:
        cur = await conn.execute(
            """
            SELECT m.id_money, m.amount, m.dt_action, a.title AS action
            FROM bot.money AS m
                LEFT JOIN bot.actions AS a ON a.id_action = m.id_action
            WHERE m.id_user = %s
            ORDER BY m.dt_action DESC, m.id_money DESC
            LIMIT %s
            """,
            (user_id, limit),
        )
        return await cur.fetchall()