'use client';

import { discountFor, quote, type Locale } from '@barev/core';
import { formatAmd, tFromMessages, type Messages } from '@barev/i18n';
import { Stepper } from '@barev/ui';
import { useMemo, useState } from 'react';
import type { CleaningConfig } from '../lib/data';

const TYPES = ['regular', 'general', 'renovation'] as const;

/**
 * Калькулятор экономии с Barev+: цена уборки — функцией quote, как на сервере, скидка — как у участника Barev+.
 * Подписка вычитается из экономии; если выгоды нет, так и пишем и показываем, с какого числа уборок она появится.
 */
export function Savings({ locale, config, monthlyPrice, messages }: { locale: Locale; config: CleaningConfig; monthlyPrice: number; messages: Messages }) {
  const t = useMemo(() => tFromMessages(locale, messages), [locale, messages]);
  const amd = (n: number) => formatAmd(locale, n);
  // стартовый сценарий: генеральная уборка трёшки дважды в месяц — дальше человек подставляет своё
  const [type, setType] = useState<(typeof TYPES)[number]>('general');
  const [rooms, setRooms] = useState(3);
  const [count, setCount] = useState(2);

  const pct = discountFor('BAREV_PLUS', config.categoryDiscountPct);
  const params = { cleaningType: type, rooms, bathrooms: 1 };
  const one = quote(config.pricing, params);
  const oneWithPlus = quote(config.pricing, params, pct);
  const without = one.totalPrice * count;
  const withPlus = oneWithPlus.totalPrice * count + monthlyPrice;
  const save = without - withPlus;
  const perCleaning = one.totalPrice - oneWithPlus.totalPrice;
  // выгода есть, когда скидка за n уборок больше цены подписки: n × perCleaning > monthlyPrice
  const breakeven = perCleaning > 0 ? Math.floor(monthlyPrice / perCleaning) + 1 : null;
  const max = Math.max(without, withPlus);

  return (
    <div className="v5-calc">
      <div className="v5-inputs">
        <div className="v5-seg" role="radiogroup" aria-label={t('params.cleaning.cleaningType.label')}>
          {TYPES.map((v) => (
            <button key={v} type="button" role="radio" aria-checked={type === v} onClick={() => setType(v)}>
              {t(`params.cleaning.cleaningType.${v}`)}
            </button>
          ))}
        </div>
        <div className="v5-row">
          <span>{t('params.cleaning.rooms.label')}</span>
          <Stepper value={rooms} min={1} max={6} onChange={setRooms} decLabel={t('common.decrease')} incLabel={t('common.increase')} />
        </div>
        <div className="v5-row">
          <span>{t('landing.v5.perMonth')}</span>
          <Stepper value={count} min={1} max={8} onChange={setCount} decLabel={t('common.decrease')} incLabel={t('common.increase')} />
        </div>
      </div>

      <div className="v5-result" aria-live="polite">
        <div className="v5-save">
          <span className="v5-save__label">{save > 0 ? t('landing.v5.save') : t('landing.v5.noSave')}</span>
          <span className="v5-save__num">{save > 0 ? amd(save) : '0 ֏'}</span>
          {save > 0 && <span className="v5-save__year">{t('landing.v5.perYear', { amount: amd(save * 12) })}</span>}
        </div>
        <div className="v5-bars">
          <div className="v5-bar">
            <span className="v5-bar__label">{t('landing.v5.without')}</span>
            <span className="v5-bar__track">
              <span className="v5-bar__fill v5-bar__fill--without" style={{ width: `${(without / max) * 100}%` }} />
            </span>
            <span className="v5-bar__num">{amd(without)}</span>
          </div>
          <div className="v5-bar">
            <span className="v5-bar__label">
              {t('landing.v5.with')}
              <small>{t('landing.v5.withNote', { price: amd(monthlyPrice) })}</small>
            </span>
            <span className="v5-bar__track">
              <span className="v5-bar__fill v5-bar__fill--with" style={{ width: `${(withPlus / max) * 100}%` }} />
            </span>
            <span className="v5-bar__num">{amd(withPlus)}</span>
          </div>
        </div>
        {breakeven !== null && (
          <p className="v5-breakeven">{breakeven === 1 ? t('landing.v5.breakevenFirst') : t('landing.v5.breakeven', { count: breakeven })}</p>
        )}
      </div>
    </div>
  );
}