import type { components } from '@pipu/api-client';
import { unwrap } from '@pipu/core';
import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
import { memo, useCallback, useState } from 'react';
import { useTranslation } from 'react-i18next';
import { useSession, useUser } from '../app/session';
import { useErrorText } from '../shared/lib/errors';
import { Button, Dialog, Field, FormError, Icon } from '../shared/ui/ui';
import { playlistAddIcon } from '../shared/ui/icons';
import s from './catalog.module.css';

export type Playlist = components['schemas']['Playlist'];
export type PlaylistInput = components['schemas']['PlaylistInput'];

export function usePlaylists(enabled = true) {
  const session = useSession();
  return useQuery({ queryKey: ['playlists'], enabled,
    queryFn: async () => unwrap(await session.client.GET('/api/v1/me/playlists')) });
}

export function usePlaylist(id: string, shared = false) {
  const session = useSession();
  const user = useUser();
  return useQuery({ queryKey: shared ? ['shared-playlists', id, user.id] : ['playlists', id], staleTime: 0,
    queryFn: async () => shared
      ? unwrap(await session.client.GET('/api/v1/shared/playlists/{shareId}', { params: { path: { shareId: id } } }))
      : unwrap(await session.client.GET('/api/v1/me/playlists/{id}', { params: { path: { id } } })) });
}

export function playlistInput(p: Playlist): PlaylistInput & { revision: number } {
  return { name: p.name, description: p.description, track_ids: p.tracks.map(t => t.id), revision: p.revision };
}

export function PlaylistEditor({ playlist, trackIds = [], onClose, onSaved }: {
  playlist?: Playlist; trackIds?: string[]; onClose: () => void; onSaved: (p: Playlist) => void;
}) {
  const { t } = useTranslation();
  const session = useSession();
  const cache = useQueryClient();
  const errorText = useErrorText();
  const [original] = useState(playlist);
  const [name, setName] = useState(playlist?.name ?? '');
  const [description, setDescription] = useState(playlist?.description ?? '');
  const save = useMutation({ mutationFn: async () => {
    const body = { name: name.trim(), description, track_ids: original?.tracks.map(t => t.id) ?? trackIds };
    return original
      ? unwrap(await session.client.PUT('/api/v1/me/playlists/{id}', { params: { path: { id: original.id } }, body: { ...body, revision: original.revision } }))
      : unwrap(await session.client.POST('/api/v1/me/playlists', { body }));
  }, onSuccess: p => {
    cache.setQueryData(['playlists', p.id], p);
    void cache.invalidateQueries({ queryKey: ['playlists'] });
    onSaved(p);
  }, onError: () => { void cache.invalidateQueries({ queryKey: ['playlists'] }); } });
  const close = useCallback(() => { if (!save.isPending) onClose(); }, [save.isPending, onClose]);
  return <Dialog title={t(playlist ? 'playlists.edit' : 'playlists.create')} onClose={close}>
    <form onSubmit={e => { e.preventDefault(); if (!save.isPending && name.trim()) save.mutate(); }}>
      <Field label={t('playlists.name')} value={name} onChange={setName} maxLength={120} required autoFocus />
      <Field label={t('playlists.description')} value={description} onChange={setDescription} maxLength={2000} />
      <FormError>{save.error ? errorText(save.error) : null}</FormError>
      <Button variant="primary" type="submit" busy={save.isPending} disabled={!name.trim()}>{t('playlists.save')}</Button>
      <Button variant="ghost" onClick={onClose} disabled={save.isPending}>{t('form.cancel')}</Button>
    </form>
  </Dialog>;
}

/** Mounted only while open, so catalog rows do not each subscribe to the playlist list. */
const PlaylistPicker = memo(function PlaylistPicker({ trackIds, onClose }: { trackIds: string[]; onClose: () => void }) {
  const { t } = useTranslation();
  const session = useSession();
  const cache = useQueryClient();
  const errorText = useErrorText();
  const list = usePlaylists();
  const [create, setCreate] = useState(false);
  const add = useMutation({ mutationFn: async (id: string) => {
    const p = unwrap(await session.client.GET('/api/v1/me/playlists/{id}', { params: { path: { id } } }));
    const body = playlistInput(p);
    body.track_ids = [...new Set([...body.track_ids, ...trackIds])];
    return unwrap(await session.client.PUT('/api/v1/me/playlists/{id}', { params: { path: { id } }, body }));
  }, onSuccess: () => { void cache.invalidateQueries({ queryKey: ['playlists'] }); onClose(); } });
  if (create) return <PlaylistEditor trackIds={trackIds} onClose={() => setCreate(false)} onSaved={onClose} />;
  return <Dialog title={t('playlists.add')} onClose={() => { if (!add.isPending) onClose(); }}>
    <FormError>{list.error || add.error ? errorText(list.error ?? add.error) : null}</FormError>
    {list.isPending && <p role="status">{t('playlists.loading')}</p>}
    {list.isSuccess && list.data.items.length === 0 && <p>{t('playlists.empty')}</p>}
    <div style={{ display: 'grid', gap: 8 }}>
      {list.data?.items.map(p => <Button key={p.id} disabled={add.isPending} onClick={() => add.mutate(p.id)}>{p.name} · {p.track_count}</Button>)}
      <Button variant="primary" disabled={add.isPending} onClick={() => setCreate(true)}>{t('playlists.create')}</Button>
    </div>
  </Dialog>;
});

export function AddToPlaylist({ trackIds, compact = false, className }: { trackIds: string[]; compact?: boolean; className?: string }) {
  const { t } = useTranslation();
  const [selectedIds, setSelectedIds] = useState<string[] | null>(null);
  const close = useCallback(() => setSelectedIds(null), []);
  return <>
    {compact ? <button type="button" className={className ?? s.like} aria-label={t('playlists.add')} title={t('playlists.add')} onClick={() => setSelectedIds([...trackIds])}><Icon src={playlistAddIcon} size={20} /></button>
      : <Button icon={playlistAddIcon} disabled={trackIds.length === 0} onClick={() => setSelectedIds([...trackIds])}>{t('playlists.add')}</Button>}
    {selectedIds && <PlaylistPicker trackIds={selectedIds} onClose={close} />}
  </>;
}