#!/usr/bin/env python3
# utils.py

from datetime import datetime, date
from typing import List, Optional
from zoneinfo import ZoneInfo

from telegram import ReplyKeyboardMarkup, InlineKeyboardMarkup, InlineKeyboardButton
from config import BTN_ADD, BTN_LIST, BTN_EDIT, BTN_DELETE, BTN_HISTORY, BTN_TZ, BTN_CANCEL, TZ_SUGGESTIONS

# ----------------- UI HELPERS -----------------
def main_menu_kb():
    kb = [
        [BTN_ADD, BTN_LIST],
        [BTN_EDIT, BTN_DELETE],
        [BTN_HISTORY, BTN_TZ]
    ]
    return ReplyKeyboardMarkup(kb, resize_keyboard=True, one_time_keyboard=False)

def tz_keyboard():
    kb = [[tz] for tz in TZ_SUGGESTIONS]
    kb.append(["Ввести вручную"])
    kb.append([BTN_CANCEL])
    return ReplyKeyboardMarkup(kb, one_time_keyboard=True, resize_keyboard=True)

def build_wd_keyboard(wd_sel: set):
    labels = ["Пн", "Вт", "Ср", "Чт", "Пт", "Сб", "Вс"]
    kb = []
    row = []
    for i, lab in enumerate(labels):
        prefix = "✅" if i in wd_sel else "◻️"
        row.append(InlineKeyboardButton(f"{prefix} {lab}", callback_data=f"wd_toggle:{i}"))
        if (i + 1) % 3 == 0:
            kb.append(row)
            row = []
    if row:
        kb.append(row)
    kb.append([
        InlineKeyboardButton("Готово", callback_data="wd_done"),
        InlineKeyboardButton("Отмена", callback_data="wd_cancel")
    ])
    return InlineKeyboardMarkup(kb)

# ----------------- DATA HELPERS -----------------
def parse_hhmm(s: str) -> Optional[str]:
    s = s.strip()
    try:
        dt = datetime.strptime(s, "%H:%M")
        return dt.strftime("%H:%M")
    except ValueError:
        return None

def weekdays_list_to_csv(lst: List[int]) -> str:
    return ",".join(str(i) for i in sorted(set(lst))) if lst else ""

def weekdays_csv_to_list(csv: Optional[str]) -> List[int]:
    if not csv:
        return []
    return [int(x) for x in csv.split(",") if x.isdigit()]

def now_utc() -> datetime:
    return datetime.utcnow()

def utc_str_min(dt: datetime) -> str:
    return dt.strftime("%Y-%m-%d %H:%M")

def utc_str_full(dt: datetime) -> str:
    return dt.strftime("%Y-%m-%d %H:%M:%S")

def localized_now_for_tz(tzname: str) -> datetime:
    try:
        tz = ZoneInfo(tzname)
    except Exception:
        tz = ZoneInfo("UTC")
    return datetime.now(tz)

def local_time_hhmm_for_user(tzname: str, when_utc: datetime) -> str:
    try:
        tz = ZoneInfo(tzname)
    except Exception:
        tz = ZoneInfo("UTC")
    local = when_utc.astimezone(tz)
    return local.strftime("%H:%M")

def user_local_hhmm_to_utc_dt(tzname: str, local_date: date, hhmm: str) -> datetime:
    hour, minute = map(int, hhmm.split(":"))
    local_dt = datetime(local_date.year, local_date.month, local_date.day, hour, minute)
    try:
        tz = ZoneInfo(tzname)
        local_dt = local_dt.replace(tzinfo=tz)
    except Exception:
        tz = ZoneInfo("UTC")
        local_dt = local_dt.replace(tzinfo=tz)
    return local_dt.astimezone(ZoneInfo("UTC")).replace(tzinfo=None)