"""Чтение аналитики из Postgres для админки."""

from __future__ import annotations

import logging
from datetime import UTC, date, datetime, time, timedelta
from typing import Any

from common.analytics.events import ALL_EVENT_TYPES
from common.config import Settings
from common.db.pool import get_pool

logger = logging.getLogger(__name__)

#: Колонки, которые показываем в логах.
EVENT_FIELDS = (
    "event_time",
    "event_type",
    "user_id",
    "username",
    "chat_id",
    "payload",
    "bot_version",
    "prod",
)


def _dates(date_from: str, date_to: str, settings: Settings) -> tuple[date, date]:
    today = datetime.now(settings.tzinfo).date()
    start = datetime.strptime(date_from, "%Y-%m-%d").date() if date_from else today - timedelta(days=6)
    end = datetime.strptime(date_to, "%Y-%m-%d").date() if date_to else today
    return start, end


def _event_bounds(start: date, end: date, settings: Settings) -> tuple[datetime, datetime]:
    start_dt = datetime.combine(start, time.min, tzinfo=settings.tzinfo).astimezone(UTC)
    end_dt = datetime.combine(end + timedelta(days=1), time.min, tzinfo=settings.tzinfo).astimezone(UTC)
    return start_dt, end_dt


def _user_clause(user: str, params: list[Any], column: str = "user_id") -> str:
    user = user.strip()
    if not user:
        return ""
    if user.isdigit():
        params.append(int(user))
        return f" AND {column} = %s"
    params.append(f"%{user}%")
    return " AND username ILIKE %s"


async def fetch_events(
    settings: Settings,
    *,
    event_type: str = "",
    user: str = "",
    date_from: str = "",
    date_to: str = "",
    limit: int = 50,
    offset: int = 0,
) -> tuple[list[dict[str, Any]], int]:
    """Вернуть события и общее количество по фильтрам."""
    start, end = _dates(date_from, date_to, settings)
    start_dt, end_dt = _event_bounds(start, end, settings)

    params: list[Any] = [start_dt, end_dt]
    where = " WHERE event_time >= %s AND event_time < %s"
    if event_type and event_type in ALL_EVENT_TYPES:
        where += " AND event_type = %s"
        params.append(event_type)
    where += _user_clause(user, params)

    async with get_pool().connection() as conn:
        cur = await conn.execute(f"SELECT count(*) AS total FROM analytics.events{where}", tuple(params))
        row = await cur.fetchone()
        total = int(row["total"]) if row else 0

        cur = await conn.execute(
            f"SELECT {', '.join(EVENT_FIELDS)} FROM analytics.events{where}"
            " ORDER BY event_time DESC LIMIT %s OFFSET %s",
            (*params, limit, offset),
        )
        rows = await cur.fetchall()
    return rows, total


async def fetch_messages(
    settings: Settings,
    *,
    user: str = "",
    date_from: str = "",
    date_to: str = "",
    limit: int = 50,
    offset: int = 0,
) -> tuple[list[dict[str, Any]], int]:
    """Вернуть дневные счётчики сообщений и общее количество строк."""
    start, end = _dates(date_from, date_to, settings)

    params: list[Any] = [start, end]
    where = " WHERE day >= %s AND day <= %s"
    where += _user_clause(user, params)

    async with get_pool().connection() as conn:
        cur = await conn.execute(
            f"SELECT count(*) AS total FROM analytics.messages_daily{where}",
            tuple(params),
        )
        row = await cur.fetchone()
        total = int(row["total"]) if row else 0

        cur = await conn.execute(
            f"""
            SELECT day, user_id, username, chat_id, count
            FROM analytics.messages_daily{where}
            ORDER BY day DESC, count DESC
            LIMIT %s OFFSET %s
            """,
            (*params, limit, offset),
        )
        rows = await cur.fetchall()
    return rows, total