import { unwrap } from '@pipu/core';
import { useInfiniteQuery, useMutation, useQueryClient } from '@tanstack/react-query';
import { Link } from '@tanstack/react-router';
import { useState } from 'react';
import { useTranslation } from 'react-i18next';

import { useSession } from '../app/session';
import { TrackList, type Track } from '../entities/catalog';
import { useCollectionCounts } from '../entities/collection';
import { usePlayer } from '../player/context';
import { useErrorText } from '../shared/lib/errors';
import { dislikeFillIcon, historyFillIcon, likeFillIcon, playIcon, shuffleIcon } from '../shared/ui/icons';
import { Button, Dialog, FormError, Icon } from '../shared/ui/ui';
import c from './catalog.module.css';
import s from './page.module.css';

export type CollectionTab = 'history' | 'likes' | 'dislikes';
const TABS: CollectionTab[] = ['history', 'likes', 'dislikes'];

const HERO: Record<CollectionTab, { icon: string; tile: string }> = {
  history: { icon: historyFillIcon, tile: 'linear-gradient(140deg, #35D3FF, #2F80FF 60%, #1B3FA8)' },
  likes: { icon: likeFillIcon, tile: 'linear-gradient(140deg, #5E9BFF, #2F80FF 50%, #7C5CFF)' },
  dislikes: { icon: dislikeFillIcon, tile: 'linear-gradient(140deg, #4A5572, #1A2236)' },
};

export function CollectionPage({ tab }: { tab: CollectionTab }) {
  const { t } = useTranslation();
  const counts = useCollectionCounts();
  const hero = HERO[tab];
  const sub =
    tab === 'likes'
      ? t('collection.sub_likes', { count: counts.likes ?? 0 })
      : t(tab === 'history' ? 'collection.sub_history' : 'collection.sub_dislikes');
  return (
    <div className={s.page}>
      <header className={c.colHero}>
        <span className={c.tile} style={{ background: hero.tile }} aria-hidden>
          <Icon src={hero.icon} size={52} />
        </span>
        <div className={c.heroText}>
          <span className={c.kicker}>{t('collection.title')}</span>
          <h1 className={c.colTitle}>{t(`collection.${tab}`)}</h1>
          <span className={c.heroSub}>{sub}</span>
        </div>
      </header>
      <div className={c.underlineTabs} role="tablist" aria-label={t('collection.title')}>
        {TABS.map((k) => (
          <Link key={k} to={`/collection/${k}`} role="tab" aria-selected={tab === k} className={c.underlineTab}>
            {t(`collection.${k}`)}
          </Link>
        ))}
      </div>
      {tab === 'history' ? <History /> : <Reacted reaction={tab === 'likes' ? 'like' : 'dislike'} />}
    </div>
  );
}

/** Ключ дня в локальном времени: история группируется на клиенте. */
function dayKey(iso: string): string {
  const d = new Date(iso);
  return `${d.getFullYear()}-${d.getMonth()}-${d.getDate()}`;
}

function dayTitle(iso: string, locale: string, t: (k: 'collection.today' | 'collection.yesterday') => string): string {
  const d = new Date(iso);
  const today = new Date();
  const yesterday = new Date(today.getFullYear(), today.getMonth(), today.getDate() - 1);
  if (dayKey(iso) === dayKey(today.toISOString())) return t('collection.today');
  if (dayKey(iso) === dayKey(yesterday.toISOString())) return t('collection.yesterday');
  return new Intl.DateTimeFormat(locale, { day: 'numeric', month: 'long', year: 'numeric' }).format(d);
}

function History() {
  const { t, i18n } = useTranslation();
  const session = useSession();
  const queryClient = useQueryClient();
  const errorText = useErrorText();
  const [confirm, setConfirm] = useState(false);
  const history = useInfiniteQuery({
    queryKey: ['history'],
    initialPageParam: undefined as string | undefined,
    queryFn: async ({ pageParam }) =>
      unwrap(await session.client.GET('/api/v1/me/history', { params: { query: { cursor: pageParam, limit: 100 } } })),
    getNextPageParam: (p) => p.next_cursor ?? undefined,
  });
  const clear = useMutation({
    mutationFn: async () => unwrap(await session.client.DELETE('/api/v1/me/history')),
    onSuccess: () => queryClient.invalidateQueries({ queryKey: ['history'] }),
  });
  const items = history.data?.pages.flatMap((p) => p.items) ?? [];

  const groups: { key: string; title: string; items: typeof items }[] = [];
  for (const it of items) {
    const key = dayKey(it.played_at);
    const last = groups.at(-1);
    if (last?.key === key) last.items.push(it);
    else groups.push({ key, title: dayTitle(it.played_at, i18n.language, t), items: [it] });
  }
  const time = new Intl.DateTimeFormat(i18n.language, { hour: '2-digit', minute: '2-digit' });

  return (
    <>
      {items.length > 0 && (
        <div className={s.toolbar}>
          <span style={{ flex: 1 }} />
          <Button variant="ghost" onClick={() => setConfirm(true)}>
            {t('collection.clear_history')}
          </Button>
        </div>
      )}
      <FormError>{history.error || clear.error ? errorText(history.error ?? clear.error) : null}</FormError>
      {history.isSuccess && items.length === 0 && <div className={s.empty}>{t('collection.empty_history')}</div>}
      {groups.map((g) => (
        <section key={g.key} className={c.section}>
          <h2 className={c.day}>{g.title}</h2>
          <TrackList
            tracks={g.items.map((i) => i.track)}
            showAlbum
            context={{ type: 'history' }}
            lead={(_, i) => time.format(new Date(g.items[i]!.played_at))}
          />
        </section>
      ))}
      {history.hasNextPage && (
        <Button className={s.more} busy={history.isFetchingNextPage} onClick={() => void history.fetchNextPage()}>
          {t('collection.more')}
        </Button>
      )}
      {confirm && (
        <Dialog
          title={t('collection.clear_history')}
          onClose={() => setConfirm(false)}
          footer={
            <>
              <Button variant="ghost" onClick={() => setConfirm(false)}>
                {t('form.cancel')}
              </Button>
              <Button
                variant="danger"
                onClick={() => {
                  setConfirm(false);
                  clear.mutate();
                }}
              >
                {t('collection.clear_history')}
              </Button>
            </>
          }
        >
          <p className={s.note}>{t('collection.clear_confirm')}</p>
        </Dialog>
      )}
    </>
  );
}

function Reacted({ reaction }: { reaction: 'like' | 'dislike' }) {
  const { t } = useTranslation();
  const session = useSession();
  const player = usePlayer();
  const errorText = useErrorText();
  const path = reaction === 'like' ? '/api/v1/me/likes' : '/api/v1/me/dislikes';
  const list = useInfiniteQuery({
    queryKey: [reaction === 'like' ? 'likes' : 'dislikes'],
    initialPageParam: undefined as string | undefined,
    queryFn: async ({ pageParam }) =>
      unwrap(await session.client.GET(path, { params: { query: { cursor: pageParam, limit: 100 } } })),
    getNextPageParam: (p) => p.next_cursor ?? undefined,
  });
  const tracks: Track[] = list.data?.pages.flatMap((p) => p.items.map((i) => i.track)) ?? [];
  const total = list.data?.pages[0]?.total ?? 0;
  const context = { type: 'collection' as const, id: reaction === 'like' ? 'likes' : 'dislikes' };

  return (
    <>
      {reaction === 'like' && tracks.length > 0 && (
        <div className={s.toolbar}>
          <Button variant="primary" className={c.pill} icon={playIcon} onClick={() => player.playList(tracks, 0, context)}>
            {t('collection.play_all')}
          </Button>
          <Button
            className={c.pill}
            icon={shuffleIcon}
            onClick={() => player.playList([...tracks].sort(() => Math.random() - 0.5), 0, context)}
          >
            {t('collection.shuffle')}
          </Button>
          <span className={s.note}>{t('catalog.track_count', { count: total })}</span>
        </div>
      )}
      <FormError>{list.error ? errorText(list.error) : null}</FormError>
      {list.isSuccess && tracks.length === 0 && (
        <div className={s.empty}>{t(reaction === 'like' ? 'collection.empty_likes' : 'collection.empty_dislikes')}</div>
      )}
      {tracks.length > 0 && (
        <TrackList
          tracks={tracks}
          showAlbum
          context={context}
          lead={(_, i) => String(i + 1)}
          disliked={reaction === 'dislike'}
        />
      )}
      {list.hasNextPage && (
        <Button className={s.more} busy={list.isFetchingNextPage} onClick={() => void list.fetchNextPage()}>
          {t('collection.more')}
        </Button>
      )}
    </>
  );
}