"""Тонкая обёртка над Google Sheets через gspread + service account."""
from __future__ import annotations
import threading
from datetime import datetime, timedelta, timezone
from typing import Any
import gspread
from google.oauth2.service_account import Credentials

from .config import get_config

_SCOPES = ["https://www.googleapis.com/auth/spreadsheets"]
_lock = threading.Lock()
_client: gspread.Client | None = None
_book: gspread.Spreadsheet | None = None


def _client_book() -> tuple[gspread.Client, gspread.Spreadsheet]:
    global _client, _book
    with _lock:
        # Если предыдущая попытка частично инициализировалась (auth прошёл, open_by_key упал) —
        # _client есть, _book нет. Нужно повторить open_by_key.
        if _client is None or _book is None:
            try:
                cfg = get_config()
                if _client is None:
                    creds = Credentials.from_service_account_file(cfg.google_credentials_path, scopes=_SCOPES)
                    _client = gspread.authorize(creds)
                _book = _client.open_by_key(cfg.sheet_id)
            except Exception:
                _client = None
                _book = None
                raise
        return _client, _book  # type: ignore


def sheet(name: str) -> gspread.Worksheet:
    _, book = _client_book()
    return book.worksheet(name)


def append_row(name: str, row: list[Any]) -> None:
    sheet(name).append_row(row, value_input_option="USER_ENTERED")


def find_row(sheet_name: str, key_col: str, key_val: Any) -> dict[str, Any] | None:
    """Линейный поиск по колонке-ключу. Возвращает строку как dict или None."""
    s = sheet(sheet_name)
    rows = s.get_all_values()
    if not rows:
        return None
    headers = rows[0]
    if key_col not in headers:
        return None
    idx = headers.index(key_col)
    for r in rows[1:]:
        if len(r) > idx and str(r[idx]).strip() == str(key_val).strip():
            return dict(zip(headers, r + [""] * (len(headers) - len(r))))
    return None


def update_cell_by_key(sheet_name: str, key_col: str, key_val: Any, target_col: str, new_val: Any) -> bool:
    s = sheet(sheet_name)
    rows = s.get_all_values()
    if not rows:
        return False
    headers = rows[0]
    if key_col not in headers or target_col not in headers:
        return False
    key_idx = headers.index(key_col)
    target_idx = headers.index(target_col)
    for i, r in enumerate(rows[1:], start=2):
        if len(r) > key_idx and str(r[key_idx]).strip() == str(key_val).strip():
            s.update_cell(i, target_idx + 1, new_val)
            return True
    return False


def get_setting(key: str) -> str | None:
    row = find_row("Settings", "key", key)
    return (row or {}).get("value")


# === Доменные хелперы ===

def find_user(tg_id: int) -> dict[str, Any] | None:
    if not tg_id:
        return None
    row = find_row("Users", "tg_id", tg_id)
    if not row:
        return None
    full_name = (f"{row.get('first_name', '')} {row.get('last_name', '')}".strip()
                 or row.get("tg_username", ""))
    return {**row, "full_name": full_name}


def get_or_create_user(tg_user: dict[str, Any], start_param: str | None,
                       explicit_role: str | None = None) -> dict[str, Any]:
    cfg = get_config()
    tg_id = tg_user["id"]
    admin_id = cfg.admin_tg_id

    existing = find_user(tg_id)
    now_str = _now_str()

    if existing:
        update_cell_by_key("Users", "tg_id", tg_id, "last_seen_at", now_str)
        # Админ всегда manager
        if tg_id == admin_id and existing.get("role") != "manager":
            update_cell_by_key("Users", "tg_id", tg_id, "role", "manager")
            ensure_admin_manager(tg_user)
            existing["role"] = "manager"
        elif explicit_role and tg_id != admin_id and existing.get("role") != explicit_role:
            update_cell_by_key("Users", "tg_id", tg_id, "role", explicit_role)
            existing["role"] = explicit_role
        return existing

    # Новый пользователь
    role = "client"
    invite_code = ""
    if tg_id == admin_id:
        role = "manager"
    elif explicit_role in ("manager", "client"):
        role = explicit_role
    elif start_param and start_param.startswith("client_inv_"):
        role = "client"
        invite_code = start_param

    append_row("Users", [
        tg_id,
        tg_user.get("username", ""),
        tg_user.get("first_name", ""),
        tg_user.get("last_name", ""),
        role,
        now_str,
        now_str,
        invite_code,
    ])
    if tg_id == admin_id:
        ensure_admin_manager(tg_user)
    return find_user(tg_id) or {}


def ensure_admin_manager(tg_user: dict[str, Any]) -> None:
    tg_id = tg_user["id"]
    if find_row("Managers", "tg_id", tg_id):
        return
    full_name = (f"{tg_user.get('first_name', '')} {tg_user.get('last_name', '')}".strip()
                 or tg_user.get("username", "") or str(tg_id))
    append_row("Managers", [
        tg_id, full_name, "vasrusgen@gmail.com", "",
        "ЗОВ — куратор сети", "Санкт-Петербург",
        True, "active", "", "", 0, 0, 0, "MGR_ADMIN",
    ])


def get_manager_profile(tg_id: int) -> dict[str, Any] | None:
    cfg = get_config()
    row = find_row("Managers", "tg_id", tg_id)
    if not row:
        return None
    is_zov = str(row.get("is_zov_employee", "")).lower() in ("true", "1", "да", "yes")

    last_order = _parse_date(row.get("last_order_date"))
    active_period = int(get_setting("ACTIVE_PERIOD_DAYS") or cfg.active_period_days)
    grace_period = int(get_setting("GRACE_PERIOD_DAYS") or cfg.grace_period_days)

    active_until = None
    status = "lapsed"
    if is_zov:
        status = "active"
    elif last_order:
        active_until = last_order + timedelta(days=active_period)
        grace_until = active_until + timedelta(days=grace_period)
        now = datetime.now(timezone.utc).astimezone()
        if last_order.tzinfo is None:
            now = now.replace(tzinfo=None)
        if now <= active_until:
            status = "active"
        elif now <= grace_until:
            status = "grace"
        else:
            status = "lapsed"

    return {
        **row,
        "is_zov_employee": is_zov,
        "active_until": active_until,
        "status": status,
    }


def get_client_profile(tg_id: int) -> dict[str, Any] | None:
    return find_row("Clients", "tg_id", tg_id)


def log_event(event: str, tg_id: int | None, payload: dict[str, Any] | None = None) -> None:
    import json
    try:
        append_row("Logs", [
            _now_str(), event, tg_id or "",
            json.dumps(payload, ensure_ascii=False) if payload else "",
        ])
    except Exception:
        pass


def _now_str() -> str:
    """ISO-формат для записи в Sheet (gspread не принимает datetime)."""
    return datetime.now(timezone.utc).astimezone().isoformat()


def _parse_date(v: Any) -> datetime | None:
    if not v:
        return None
    if isinstance(v, datetime):
        return v
    s = str(v).strip()
    if not s:
        return None
    for fmt in ("%Y-%m-%d", "%d.%m.%Y", "%Y-%m-%dT%H:%M:%S", "%d.%m.%Y %H:%M:%S"):
        try:
            return datetime.strptime(s, fmt)
        except ValueError:
            continue
    return None