import {useState} from 'react';
import type {LocalPlace} from '@o2o/shared';
import {useSite} from '@site/lib/site-context';
import {naverMapSearchUrl} from '@site/lib/format';
import {PhotoCard} from '../kit/Card';
import {Sheet} from '../paper/Sheet';

const WALK = 80;
const RANGES = [
  {id: 'all', label: '전체', test: () => true},
  {id: 'w5', label: '걸어서 5분 이내', test: (m: number) => m <= 5 * WALK},
  {id: 'w10', label: '걸어서 10분 이내', test: (m: number) => m <= 10 * WALK},
  {id: 'far', label: '걸어서 10분 이상', test: (m: number) => m > 10 * WALK},
] as const;
const FIRST_SPOTS = 6;
const FIRST_EATS = 5;
const HOME_ROWS = 3;

function meters(place: LocalPlace): number {
  if (place.distanceMeters != null) return place.distanceMeters;
  const m = /^([\d.]+)\s*(km|m)$/i.exec((place.distanceText ?? '').trim());
  return m ? Number(m[1]) * (m[2].toLowerCase() === 'km' ? 1000 : 1) : Infinity;
}

const byDistance = (a: LocalPlace, b: LocalPlace) => meters(a) - meters(b);
const inRange = (id: string) => RANGES.find((r) => r.id === id)?.test ?? (() => true);

function RangeTabs({places, value, onChange}: {places: LocalPlace[]; value: string; onChange: (id: string) => void}) {
  const tabs = RANGES.filter((r, i) => {
    const n = places.filter((p) => r.test(meters(p))).length;
    return i === 0 || (n > 0 && n < places.length);
  });
  if (tabs.length < 2) return null;
  return (
    <div className="chips" role="tablist">
      {tabs.map((r) => (
        <button key={r.id} type="button" role="tab" aria-current={r.id === value} onClick={() => onChange(r.id)}>
          {r.label} {places.filter((p) => r.test(meters(p))).length}
        </button>
      ))}
    </div>
  );
}

export function Around() {
  const payload = useSite();
  const {local} = payload;
  const spots = [...local.attractions].sort(byDistance);
  const eats = [...local.restaurants].sort(byDistance);
  const rail = [...spots, ...eats].filter((place) => place.imageUrl).sort(byDistance);
  const [open, setOpen] = useState<LocalPlace | null>(null);
  const [spotRange, setSpotRange] = useState('all');
  const [eatRange, setEatRange] = useState('all');
  const firstSpots = FIRST_SPOTS;
  if (rail.length === 0 && eats.length === 0) return null;

  const shownSpots = spots.filter((p) => inRange(spotRange)(meters(p)));
  const shownEats = eats.filter((p) => inRange(eatRange)(meters(p)));
  const place = (item: LocalPlace, withText = true) => (
    <button key={item.name} type="button" className={item.imageUrl ? 'place' : 'place noph'} onClick={() => setOpen(item)}>
      {item.imageUrl && (
        <span className="ph">
          <img src={item.imageUrl} alt={item.name} loading="lazy" />
        </span>
      )}
      <span className="tx">
        {item.distanceText && <small>{item.distanceText}</small>}
        <b className="nm">{item.name}</b>
        {withText && item.description && <span className="ds">{item.description}</span>}
      </span>
    </button>
  );

  const spot = (item: LocalPlace) => (
    <PhotoCard
      key={item.name}
      image={item.imageUrl}
      title={item.name}
      meta={item.distanceText}
      desc={item.description}
      onClick={() => setOpen(item)}
    />
  );

  return (
    <>
      {rail.length > 0 && (
        <div data-pg="home">
          <section className="wrap" id="around" aria-labelledby="around-heading">
            <p className="label">AROUND</p>
            <h2 id="around-heading">주변 안내</h2>
            <p className="lead">걸어서 닿는 명소와 맛집입니다.</p>
            <div className="guide guide--card">{rail.slice(0, HOME_ROWS).map(spot)}</div>
            <a className="link b-more--c" href="#/area">
              지역 소개에서 모두 보기
            </a>
          </section>
        </div>
      )}

      <div data-pg="area" id="guide">
        {spots.length > 0 && (
          <section className="wrap" id="walk">
            <p className="label">AROUND</p>
            <h2>
              주변 명소 <span className="cnt">{spots.length}곳</span>
            </h2>
            <p className="lead">걸어서 닿는 곳부터 차로 가는 곳까지 묶었습니다.</p>
            <RangeTabs places={spots} value={spotRange} onChange={setSpotRange} />
            <div className="guide guide--card">{shownSpots.slice(0, firstSpots).map(spot)}</div>
            {shownSpots.length > firstSpots && (
              <details className="fold" key={spotRange}>
                <summary className="link">{shownSpots.length - firstSpots}곳 더 보기</summary>
                <div className="guide guide--card">{shownSpots.slice(firstSpots).map(spot)}</div>
              </details>
            )}
          </section>
        )}
        {eats.length > 0 && (
          <section className="wrap" id="eat">
            <p className="label">EAT</p>
            <h2>
              주변 맛집 <span className="cnt">{eats.length}곳</span>
            </h2>
            <RangeTabs places={eats} value={eatRange} onChange={setEatRange} />
            <div className="guide">{shownEats.slice(0, FIRST_EATS).map((item) => place(item, false))}</div>
            {shownEats.length > FIRST_EATS && (
              <details className="fold" key={eatRange}>
                <summary className="link">{shownEats.length - FIRST_EATS}곳 더 보기</summary>
                <div className="guide">{shownEats.slice(FIRST_EATS).map((item) => place(item, false))}</div>
              </details>
            )}
          </section>
        )}
      </div>

      <Sheet open={open != null} onClose={() => setOpen(null)} label={open?.name ?? ''}>
        {open && (
          <>
            {open.imageUrl && <img src={open.imageUrl} alt={open.name} />}
            <h3>{open.name}</h3>
            <p className="meta">{[open.distanceText, open.category].filter(Boolean).join(' · ')}</p>
            {open.description && <p>{open.description}</p>}
            <a
              className="out"
              href={naverMapSearchUrl(open.searchQuery ?? open.name)}
              target="_blank"
              rel="noopener noreferrer"
            >
              네이버에서 보기
            </a>
          </>
        )}
      </Sheet>
    </>
  );
}