'use client';

import {
  normalizeAgencyCode,
  pickUtm,
  quote,
  windowStarts,
  yerevanDateKey,
  type Locale,
  type ParamValues,
  type Quote,
} from '@barev/core';
import { formatAmd, formatDateTime, tFromMessages, type Messages } from '@barev/i18n';
import { Icon, Stepper } from '@barev/ui';
import { useEffect, useMemo, useRef, useState, type ReactNode } from 'react';
import type { CleaningConfig } from '../lib/data';

const API = process.env.NEXT_PUBLIC_API_URL ?? 'http://localhost:4000';
const AGENCY_KEY = 'barev.agency';
const TYPES = ['regular', 'general', 'renovation'] as const;

type Errors = Partial<Record<'time' | 'district' | 'street' | 'phone' | 'consent' | 'submit', string>>;

/**
 * Страница /clean (модель qlean.ru): параметры → доп. услуги → время → адрес → контакты.
 * Цена считается в браузере той же функцией quote, что и на сервере. Заявка сразу видна в админке,
 * а человек уходит в бота по ссылке, которая привязывает заявку к его Telegram.
 */
export function CleanForm({ locale, config, messages }: { locale: Locale; config: CleaningConfig; messages: Messages }) {
  const t = useMemo(() => tFromMessages(locale, messages), [locale, messages]);
  const amd = (n: number) => formatAmd(locale, n);

  const fields = config.paramsSchema.fields;
  const intField = (key: string) => {
    const f = fields.find((x) => x.key === key);
    return f?.type === 'int' ? f : { min: 1, max: 6, default: 1 };
  };
  const roomsF = intField('rooms');
  const bathsF = intField('bathrooms');
  const extrasField = fields.find((f) => f.type === 'extras');
  const extrasItems = extrasField?.type === 'extras' ? extrasField.items : [];
  const pricing = config.pricing.kind === 'rooms' ? config.pricing : null;

  const [type, setType] = useState<(typeof TYPES)[number]>('regular');
  const [rooms, setRooms] = useState(Number(roomsF.default ?? 2));
  const [baths, setBaths] = useState(Number(bathsF.default ?? 1));
  const [extras, setExtras] = useState<Record<string, number>>({});
  const params: ParamValues = { cleaningType: type, rooms, bathrooms: baths, extras };
  let q: Quote | null = null;
  try {
    q = quote(config.pricing, params);
  } catch {
    q = null;
  }

  // «сейчас» — только в браузере, иначе список времени разойдётся с серверным рендером
  const [now, setNow] = useState<Date | null>(null);
  useEffect(() => setNow(new Date()), []);
  const durationForWindow = Math.min(q?.durationMinutes ?? 120, config.slotConfig.dayEndMinute - config.slotConfig.dayStartMinute);
  const days = useMemo(() => {
    if (!now) return [];
    return Array.from({ length: config.slotConfig.horizonDays + 1 }, (_, i) => {
      const date = new Date(now.getTime() + i * 86_400_000);
      const dateKey = yerevanDateKey(date);
      return { dateKey, date, starts: windowStarts({ dateKey, config: config.slotConfig, durationMinutes: durationForWindow, now }) };
    });
  }, [now, durationForWindow, config.slotConfig]);
  const [dayKey, setDayKey] = useState<string | null>(null);
  const [time, setTime] = useState<Date | null>(null);
  useEffect(() => {
    if (!dayKey && days.length) setDayKey(days.find((d) => d.starts.length)?.dateKey ?? days[0]!.dateKey);
  }, [days, dayKey]);
  const day = days.find((d) => d.dateKey === dayKey);
  // длительность меняется вместе с параметрами — выбранное время могло перестать помещаться в день
  useEffect(() => {
    if (time && day && !day.starts.some((s) => s.getTime() === time.getTime())) setTime(null);
  }, [day, time]);

  const [district, setDistrict] = useState('');
  const [street, setStreet] = useState('');
  const [note, setNote] = useState('');
  const [phone, setPhone] = useState('');
  const [name, setName] = useState('');
  const [consent, setConsent] = useState(false);
  const [errors, setErrors] = useState<Errors>({});
  const [sending, setSending] = useState(false);
  const [done, setDone] = useState<{ number: number; url: string } | null>(null);

  const setExtra = (code: string, qty: number) =>
    setExtras((prev) => {
      const next = { ...prev };
      if (qty > 0) next[code] = qty;
      else delete next[code];
      return next;
    });

  function validate(): Errors {
    const e: Errors = {};
    if (!time) e.time = t('landing.clean.err.time');
    if (!district) e.district = t('landing.clean.err.district');
    if (street.trim().length < 3) e.street = t('landing.clean.err.street');
    if (!/^\+?\d{8,15}$/.test(phone.replace(/[\s()\-.]/g, ''))) e.phone = t('landing.clean.err.phone');
    if (!consent) e.consent = t('landing.clean.err.consent');
    return e;
  }

  async function submit() {
    const e = validate();
    setErrors(e);
    if (Object.keys(e).length) {
      document.querySelector('[data-error="true"]')?.scrollIntoView({ behavior: 'smooth', block: 'center' });
      return;
    }
    setSending(true);
    const search = new URLSearchParams(window.location.search);
    let agency = search.get('a') ? normalizeAgencyCode(search.get('a')!) : null;
    try {
      agency ??= localStorage.getItem(AGENCY_KEY);
    } catch {
      /* приватный режим */
    }
    const utm = pickUtm(search);
    try {
      const res = await fetch(`${API}/trpc/public.cleaningRequest`, {
        method: 'POST',
        headers: { 'content-type': 'application/json' },
        body: JSON.stringify({
          json: {
            params,
            preferredAt: time!.toISOString(),
            districtCode: district,
            addressText: street.trim(),
            note: note.trim() || undefined,
            phone,
            name: name.trim() || undefined,
            locale,
            agency: agency ?? undefined,
            utm: Object.keys(utm).length ? utm : undefined,
            consent: true,
          },
        }),
      });
      const body = (await res.json().catch(() => null)) as {
        result?: { data?: { json?: { number: number; url: string } } };
        error?: { json?: { message?: string; data?: { domainCode?: string | null } } };
      } | null;
      const ok = body?.result?.data?.json;
      if (!ok) {
        const code = body?.error?.json?.data?.domainCode ?? body?.error?.json?.message;
        const known = code && messages[`errors.${code}`];
        setErrors({ submit: known ? t(`errors.${code}`) : t('errors.generic') });
        return;
      }
      setDone(ok);
      window.scrollTo({ top: 0, behavior: 'smooth' });
      // в бота — в той же вкладке: на телефоне откроется приложение Telegram
      setTimeout(() => window.location.assign(ok.url), 900);
    } catch {
      setErrors({ submit: t('landing.clean.err.network') });
    } finally {
      setSending(false);
    }
  }

  const hours = q ? (q.durationMinutes / 60).toLocaleString(locale, { maximumFractionDigits: 1 }) : '…';
  const summaryLine = `${t('params.cleaning.rooms.count', { count: rooms })}, ${t('params.cleaning.bathrooms.count', { count: baths })}`;
  const when = time ? formatDateTime(locale, time, { weekday: 'long', day: 'numeric', month: 'long', hour: '2-digit', minute: '2-digit' }) : null;

  if (done) {
    return (
      <section className="cl-done" aria-live="polite">
        <div className="cl-done__mark">
          <Icon name="check" size={34} strokeWidth={2.6} />
        </div>
        <h1 className="cl-done__title">{t('landing.clean.doneTitle', { number: done.number })}</h1>
        <p className="cl-done__text">{t('landing.clean.doneText')}</p>
        <div className="cl-done__actions">
          <a className="bc-btn cl-btn-pink" href={done.url}>
            {t('landing.clean.doneCta')}
          </a>
          <button type="button" className="bc-btn bc-btn--ghost cl-done__again" onClick={() => window.location.reload()}>
            {t('landing.clean.doneAgain')}
          </button>
        </div>
      </section>
    );
  }

  return (
    <>
      <section className="cl-hero">
        <div className="cl-hero__main">
          <h1 className="cl-title">{t('landing.clean.title')}</h1>
          <p className="cl-sub">{t('landing.clean.sub')}</p>
          <div className="cl-types" role="radiogroup" aria-label={t('params.cleaning.cleaningType.label')}>
            {TYPES.map((v) => (
              <button key={v} type="button" role="radio" aria-checked={type === v} className="cl-type" onClick={() => setType(v)}>
                <span className="cl-type__name">{t(`params.cleaning.cleaningType.${v}`)}</span>
                <span className="cl-type__hint">{t(`params.cleaning.cleaningType.${v}_hint`)}</span>
                {pricing?.tiers[v] && <span className="cl-type__from">{t('common.from', { price: amd(pricing.tiers[v].base) })}</span>}
              </button>
            ))}
          </div>
          <div className="cl-counts">
            <div className="cl-count">
              <span>{t('params.cleaning.rooms.label')}</span>
              <Stepper value={rooms} min={roomsF.min ?? 1} max={roomsF.max ?? 6} onChange={setRooms} decLabel={t('common.decrease')} incLabel={t('common.increase')} />
            </div>
            <div className="cl-count">
              <span>{t('params.cleaning.bathrooms.label')}</span>
              <Stepper value={baths} min={bathsF.min ?? 1} max={bathsF.max ?? 4} onChange={setBaths} decLabel={t('common.decrease')} incLabel={t('common.increase')} />
            </div>
          </div>
        </div>
        <div className="cl-hero__price" aria-live="polite">
          <PriceTicker value={q ? amd(q.totalPrice) : '…'} />
          <div className="cl-duration">
            <Icon name="clock" size={18} />
            {t('landing.clean.duration', { hours })}
          </div>
          {config.categoryDiscountPct > 0 && <div className="cl-plus">{t('landing.clean.plusHint', { pct: config.categoryDiscountPct })}</div>}
        </div>
      </section>

      <div className="cl-body">
        <div className="cl-steps">
          {pricing && extrasItems.length > 0 && (
            <Block title={t('landing.clean.extrasTitle')} hint={t('landing.clean.extrasHint')}>
              <div className="cl-extras">
                {extrasItems.map((it) => {
                  const p = pricing.extras[it.code];
                  if (!p) return null;
                  const qty = extras[it.code] ?? 0;
                  const single = p.unit === 'service' || it.max === 1;
                  const label = t(`extras.${it.code}.name`);
                  const price = p.unit === 'service' ? amd(p.price) : `${amd(p.price)} ${t(`extras.${it.code}.per`)}`;
                  return single ? (
                    <button key={it.code} type="button" className="cl-extra" aria-pressed={qty > 0} onClick={() => setExtra(it.code, qty > 0 ? 0 : 1)}>
                      <span className="cl-extra__name">{label}</span>
                      <span className="cl-extra__price">{price}</span>
                      <span className="cl-extra__tick" aria-hidden="true">
                        <Icon name={qty > 0 ? 'check' : 'plus'} size={16} strokeWidth={2.6} />
                      </span>
                    </button>
                  ) : (
                    <div key={it.code} className="cl-extra" data-on={qty > 0}>
                      <span className="cl-extra__name">{label}</span>
                      <span className="cl-extra__price">{price}</span>
                      <Stepper value={qty} min={0} max={it.max} onChange={(v) => setExtra(it.code, v)} decLabel={`${t('common.decrease')}: ${label}`} incLabel={`${t('common.increase')}: ${label}`} />
                    </div>
                  );
                })}
              </div>
            </Block>
          )}

          <Block title={t('landing.clean.whenTitle')} hint={t('landing.clean.whenHint')} error={errors.time}>
            <div className="cl-days" role="listbox" aria-label={t('landing.clean.whenTitle')}>
              {days.map((d) => (
                <button
                  key={d.dateKey}
                  type="button"
                  role="option"
                  aria-selected={d.dateKey === dayKey}
                  className="cl-day"
                  disabled={!d.starts.length}
                  onClick={() => setDayKey(d.dateKey)}
                >
                  <span className="cl-day__wd">{formatDateTime(locale, d.date, { weekday: 'short' })}</span>
                  <span className="cl-day__num">{formatDateTime(locale, d.date, { day: 'numeric' })}</span>
                </button>
              ))}
            </div>
            {day && day.starts.length > 0 ? (
              <div className="cl-times">
                {day.starts.map((s) => (
                  <button key={s.toISOString()} type="button" className="cl-time" aria-pressed={time?.getTime() === s.getTime()} onClick={() => setTime(s)}>
                    {formatDateTime(locale, s, { hour: '2-digit', minute: '2-digit' })}
                  </button>
                ))}
              </div>
            ) : (
              day && <p className="cl-muted">{t('landing.clean.noTimes')}</p>
            )}
          </Block>

          <Block title={t('landing.clean.addressTitle')} error={errors.district ?? errors.street}>
            <div className="cl-grid2">
              <label className="bc-field">
                <span className="bc-label">{t('landing.clean.district')}</span>
                <select className="bc-input" value={district} onChange={(e) => setDistrict(e.target.value)} aria-invalid={!!errors.district}>
                  <option value="">{t('landing.clean.districtPlaceholder')}</option>
                  {config.districts.map((d) => (
                    <option key={d} value={d}>
                      {t(`districts.${d}`)}
                    </option>
                  ))}
                </select>
              </label>
              <label className="bc-field">
                <span className="bc-label">{t('landing.clean.street')}</span>
                <input
                  className="bc-input"
                  value={street}
                  maxLength={300}
                  placeholder={t('landing.clean.streetPlaceholder')}
                  autoComplete="street-address"
                  aria-invalid={!!errors.street}
                  onChange={(e) => setStreet(e.target.value)}
                />
              </label>
            </div>
            <label className="bc-field">
              <span className="bc-label">{t('landing.clean.note')}</span>
              <textarea className="bc-input" rows={2} value={note} maxLength={1000} placeholder={t('landing.clean.notePlaceholder')} onChange={(e) => setNote(e.target.value)} />
            </label>
          </Block>

          <Block title={t('landing.clean.contactTitle')} error={errors.phone ?? errors.consent}>
            <div className="cl-grid2">
              <label className="bc-field">
                <span className="bc-label">{t('landing.clean.phone')}</span>
                <input
                  className="bc-input"
                  type="tel"
                  inputMode="tel"
                  autoComplete="tel"
                  value={phone}
                  maxLength={30}
                  placeholder="+374 91 123456"
                  aria-invalid={!!errors.phone}
                  aria-describedby="cl-phone-hint"
                  onChange={(e) => setPhone(e.target.value)}
                />
                <span id="cl-phone-hint" className="cl-muted cl-small">
                  {t('landing.clean.phoneHint')}
                </span>
              </label>
              <label className="bc-field">
                <span className="bc-label">{t('landing.clean.name')}</span>
                <input className="bc-input" value={name} maxLength={80} autoComplete="given-name" onChange={(e) => setName(e.target.value)} />
              </label>
            </div>
            <label className="cl-consent">
              <input type="checkbox" checked={consent} onChange={(e) => setConsent(e.target.checked)} aria-invalid={!!errors.consent} />
              <span>
                {t('landing.clean.consent')}.{' '}
                <a href={`/${locale}/privacy`} target="_blank" rel="noopener">
                  {t('landing.clean.privacy')}
                </a>
              </span>
            </label>
          </Block>
        </div>

        <aside className="cl-receipt" aria-label={t('landing.clean.summaryTitle')}>
          <div className="cl-receipt__title">{t('landing.clean.summaryTitle')}</div>
          <div className="cl-line">
            <span>
              {t(`params.cleaning.cleaningType.${type}`)}
              <small>{summaryLine}</small>
            </span>
            <span>{q ? amd(q.servicePrice) : '…'}</span>
          </div>
          {q?.extras.map((l) => (
            <div key={l.code} className="cl-line cl-line--extra">
              <span>
                {t(`extras.${l.code}.name`)}
                {l.qty > 1 ? ` × ${l.qty}` : ''}
              </span>
              <span>{amd(l.amount)}</span>
            </div>
          ))}
          <div className="cl-receipt__rule" />
          <div className="cl-line cl-line--total">
            <span>{t('landing.clean.total')}</span>
            <span>{q ? amd(q.totalPrice) : '…'}</span>
          </div>
          {when && <div className="cl-receipt__when">{when}</div>}
          <button type="button" className="bc-btn bc-btn--block cl-btn-pink" onClick={submit} disabled={sending}>
            {sending ? t('landing.clean.sending') : t('landing.clean.submit')}
          </button>
          {errors.submit && (
            <div className="cl-receipt__error" role="alert">
              {errors.submit}
            </div>
          )}
          <p className="cl-receipt__after">{t('landing.clean.after')}</p>
        </aside>
      </div>

      {/* телефон: итог и кнопка всегда под рукой */}
      <div className="cl-bar">
        <div>
          <div className="cl-bar__total">{q ? amd(q.totalPrice) : '…'}</div>
          <div className="cl-bar__meta">{when ?? t('landing.clean.duration', { hours })}</div>
        </div>
        <button type="button" className="bc-btn cl-btn-pink" onClick={submit} disabled={sending}>
          {sending ? t('landing.clean.sending') : t('landing.clean.submit')}
        </button>
      </div>
    </>
  );
}

function Block({ title, hint, error, children }: { title: string; hint?: string; error?: string; children: ReactNode }) {
  return (
    <section className="cl-block" data-error={!!error}>
      <h2 className="cl-block__title">{title}</h2>
      {hint && <p className="cl-muted cl-block__hint">{hint}</p>}
      {children}
      {error && (
        <div className="bc-error" role="alert">
          {error}
        </div>
      )}
    </section>
  );
}

/** Цена: при изменении старое значение уходит вверх, новое приходит снизу (выключено при reduced motion) */
function PriceTicker({ value }: { value: string }) {
  const [shown, setShown] = useState(value);
  const [prev, setPrev] = useState<string | null>(null);
  const timer = useRef<ReturnType<typeof setTimeout> | null>(null);
  useEffect(() => {
    if (value === shown) return;
    setPrev(shown);
    setShown(value);
    if (timer.current) clearTimeout(timer.current);
    timer.current = setTimeout(() => setPrev(null), 260);
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [value]);
  return (
    <div className="cl-price">
      {prev && (
        <span key={`out-${prev}`} className="cl-price__out" aria-hidden="true">
          {prev}
        </span>
      )}
      <span key={`in-${shown}`} className={prev ? 'cl-price__in' : undefined}>
        {shown}
      </span>
    </div>
  );
}