/* eslint-disable import/no-unassigned-import */
import dayjs, { type ConfigType } from 'dayjs';
import timezone from 'dayjs/plugin/timezone';
import utc from 'dayjs/plugin/utc';
import 'dayjs/locale/ru';

type DateTime = Exclude<ConfigType, null | undefined>;

if (!dayjs.prototype.tz) {
  dayjs.extend(utc);
  dayjs.extend(timezone);
}

dayjs.locale('ru');

const DEFAULT_TZ = 'Europe/Moscow';

/**
 * Склеивает дату (Date/string) и время (string, HH:mm) в datetime в нужной таймзоне, возвращает ISO строку в UTC
 */
export function combineDateAndTimeToUTC(
  date: DateTime,
  time: string,
  tz: string = DEFAULT_TZ,
): string {
  if (!date || !time) return '';
  const dateString = dayjs(date).format('YYYY-MM-DD');

  return dayjs.tz(`${dateString}T${time}`, tz).utc().toISOString();
}

export function formatDate(datetime: DateTime) {
  return {
    db: () => dayjs(datetime).utc().toISOString(),
    user: (template?: string, tz: string = DEFAULT_TZ) => {
      return dayjs
        .utc(datetime)
        .tz(tz)
        .format(template || 'D MMMM YYYY');
    },
  };
}

export function formatTime(datetime: ConfigType) {
  return {
    db: () => dayjs(datetime).utc().toISOString(),
    user: (tz: string = DEFAULT_TZ) => {
      return dayjs.utc(datetime).tz(tz).format('HH:mm');
    },
  };
}

export function getDateUTCRange(date?: DateTime, tz: string = DEFAULT_TZ) {
  return {
    day: () => {
      const startOfDay = dayjs(date).tz(tz).startOf('day').utc().toISOString();
      const endOfDay = dayjs(date).tz(tz).endOf('day').utc().toISOString();

      return { endOfDay, startOfDay };
    },
    month: () => {
      const startOfMonth = dayjs(date).tz(tz).startOf('month').utc().toISOString();
      const endOfMonth = dayjs(date).tz(tz).endOf('month').utc().toISOString();

      return { endOfMonth, startOfMonth };
    },
  };
}

export function getMinutes(time: string) {
  const [hours = '00', minutes = '00'] = time.split(':');

  return Number.parseInt(hours, 10) * 60 + Number.parseInt(minutes, 10);
}

export function getTimeZoneLabel(tz: string = DEFAULT_TZ): string {
  if (tz === DEFAULT_TZ) return 'МСК';
  const offset = dayjs().tz(tz).format('Z');

  return `GMT${offset}`;
}

export function sumTime(datetime: DateTime, durationMinutes: number) {
  if (!datetime) return '';

  return dayjs(datetime).add(durationMinutes, 'minute').toISOString();
}