import type { components } from '@pipu/api-client';
import { ApiError, unwrap } from '@pipu/core';
import { useInfiniteQuery, useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
import { useEffect, useMemo, useState } from 'react';
import { useTranslation } from 'react-i18next';

import { useSession } from '../../app/session';
import { needsFormatAttention } from '../../features/uploads/files';
import { useErrorText, useFieldError } from '../../shared/lib/errors';
import { formatBytes, formatDateTime, formatDuration } from '../../shared/lib/format';
import { checkIcon, closeIcon, editIcon, refreshIcon } from '../../shared/ui/icons';
import { Button, cx, Dialog, Field, FormError, Icon } from '../../shared/ui/ui';
import s from '../page.module.css';
import { MOVING, QuotaMeter, UploadStatusBadge, useReasonText, type UploadFile, type UploadStatus } from '../uploads/common';
import u from '../uploads/uploads.module.css';

type Meta = components['schemas']['UploadMeta'];
type Settings = components['schemas']['UploadSettings'];

const TABS = {
  review: ['pending_review'],
  failed: ['import_failed'],
  progress: ['uploading', 'processing', 'approved', 'importing'],
  imported: ['imported'],
  declined: ['rejected', 'duplicate', 'invalid', 'withdrawn', 'expired'],
} satisfies Record<string, UploadStatus[]>;
type Tab = keyof typeof TABS;

/** «Очередь на добавление» (docs/uploads.md#8): рассмотрение по пачкам, правка метаданных, массовые решения. */
export function UploadQueuePage() {
  const { t } = useTranslation(['admin', 'common']);
  const session = useSession();
  const queryClient = useQueryClient();
  const errorText = useErrorText();
  const [tab, setTab] = useState<Tab>('review');
  const [onlyPossible, setOnlyPossible] = useState(false);
  const [selected, setSelected] = useState<Set<string>>(new Set());
  const [editing, setEditing] = useState<UploadFile | null>(null);
  const [batchEdit, setBatchEdit] = useState<string | null>(null);
  const [rejecting, setRejecting] = useState(false);

  const list = useInfiniteQuery({
    queryKey: ['admin-uploads', tab, onlyPossible],
    initialPageParam: undefined as string | undefined,
    queryFn: async ({ pageParam }) =>
      unwrap(
        await session.client.GET('/api/v1/admin/uploads', {
          params: {
            query: { status: [...TABS[tab]], possible_duplicate: onlyPossible || undefined, cursor: pageParam, limit: 100 },
          },
        }),
      ),
    getNextPageParam: (p) => p.next_cursor ?? undefined,
    refetchInterval: (q) =>
      q.state.data?.pages.some((p) => p.items.some((it) => MOVING.includes(it.status))) ? 5000 : false,
  });
  const items = useMemo(() => list.data?.pages.flatMap((p) => p.items) ?? [], [list.data]);
  useEffect(() => setSelected(new Set()), [tab, onlyPossible]);

  const refresh = async () => {
    setSelected(new Set());
    await queryClient.invalidateQueries({ queryKey: ['admin-uploads'] });
    await queryClient.invalidateQueries({ queryKey: ['upload-quota'] });
  };
  const review = useMutation({
    mutationFn: async (v: { decision: 'approve' | 'reject'; ids: string[]; reason?: string }) =>
      unwrap(
        await session.client.POST('/api/v1/admin/uploads/review', {
          body: { file_ids: v.ids, decision: v.decision, reason: v.reason },
        }),
      ),
    onSuccess: refresh,
  });
  const retry = useMutation({
    mutationFn: async (id: string) =>
      unwrap(await session.client.POST('/api/v1/admin/uploads/files/{id}/retry', { params: { path: { id } } })),
    onSuccess: refresh,
  });
  const failed = review.data?.items.filter((r) => !r.ok) ?? [];

  // Группировка по пачке: файлы одной загрузки (обычно альбом) рассматриваются вместе.
  const batches = useMemo(() => {
    const m = new Map<string, UploadFile[]>();
    for (const f of items) m.set(f.batch_id, [...(m.get(f.batch_id) ?? []), f]);
    return [...m.values()];
  }, [items]);
  const toggle = (ids: string[], on: boolean) =>
    setSelected((cur) => {
      const next = new Set(cur);
      for (const id of ids) {
        if (on) next.add(id);
        else next.delete(id);
      }
      return next;
    });
  const selectable = tab === 'review' || tab === 'failed';
  const ids = [...selected];

  return (
    <div className={s.page}>
      <div className={s.head}>
        <div>
          <h1>{t('uploads.queue_title')}</h1>
          <p className={s.subtitle}>{t('uploads.queue_subtitle')}</p>
        </div>
        <QuotaMeter />
      </div>
      <div className={s.toolbar}>
        <div className={s.chips} role="group" aria-label={t('uploads.filter')}>
          {(Object.keys(TABS) as Tab[]).map((k) => (
            <button key={k} type="button" className={s.chip} aria-pressed={tab === k} onClick={() => setTab(k)}>
              {t(`uploads.tab_${k}`)}
            </button>
          ))}
        </div>
        <span style={{ flex: 1 }} />
        <label className={u.sub} style={{ display: 'flex', gap: 8, alignItems: 'center' }}>
          <input type="checkbox" checked={onlyPossible} onChange={(e) => setOnlyPossible(e.target.checked)} />
          {t('uploads.only_possible')}
        </label>
      </div>
      <FormError>{(list.error ?? review.error ?? retry.error) ? errorText(list.error ?? review.error ?? retry.error) : null}</FormError>
      {failed.length > 0 && (
        <FormError>{t('uploads.review_failed', { count: failed.length, reason: failed[0]?.error ? errorText(problemError(failed[0].error)) : '' })}</FormError>
      )}
      {list.isSuccess && items.length === 0 && <div className={s.empty}>{t('uploads.queue_empty')}</div>}

      {batches.map((files) => (
        <BatchCard
          key={files[0]!.batch_id}
          files={files}
          selectable={selectable}
          selected={selected}
          onToggle={toggle}
          onEdit={setEditing}
          onEditBatch={setBatchEdit}
          onRetry={(id) => retry.mutate(id)}
        />
      ))}
      {list.hasNextPage && (
        <Button busy={list.isFetchingNextPage} onClick={() => void list.fetchNextPage()}>
          {t('uploads.load_more')}
        </Button>
      )}

      {ids.length > 0 && (
        <div className={u.bulk} role="region" aria-label={t('uploads.bulk')}>
          <span>{t('uploads.selected', { count: ids.length })}</span>
          <span style={{ flex: 1 }} />
          <Button variant="ghost" onClick={() => setSelected(new Set())}>
            {t('common:form.cancel')}
          </Button>
          <Button variant="danger" icon={closeIcon} onClick={() => setRejecting(true)}>
            {t('uploads.reject')}
          </Button>
          {tab === 'review' && (
            <Button variant="primary" icon={checkIcon} busy={review.isPending} onClick={() => review.mutate({ decision: 'approve', ids })}>
              {t('uploads.approve')}
            </Button>
          )}
        </div>
      )}

      {batchEdit && (
        <BatchEditDialog
          batchId={batchEdit}
          onClose={() => setBatchEdit(null)}
          onSaved={() => {
            setBatchEdit(null);
            void refresh();
          }}
        />
      )}

      {editing && (
        <EditDialog
          file={editing}
          onClose={() => setEditing(null)}
          onSaved={() => {
            review.reset();
            void refresh();
          }}
        />
      )}
      {rejecting && (
        <RejectDialog
          count={ids.length}
          busy={review.isPending}
          onClose={() => setRejecting(false)}
          onReject={(reason) => {
            setRejecting(false);
            review.mutate({ decision: 'reject', ids, reason });
          }}
        />
      )}
    </div>
  );
}

/** Problem из ответа массового решения → объект, понятный useErrorText. */
function problemError(p: components['schemas']['Problem']) {
  return new ApiError(p.status, p.code, p.params ?? {});
}

function BatchCard({
  files,
  selectable,
  selected,
  onToggle,
  onEdit,
  onEditBatch,
  onRetry,
}: {
  files: UploadFile[];
  selectable: boolean;
  selected: Set<string>;
  onToggle: (ids: string[], on: boolean) => void;
  onEdit: (f: UploadFile) => void;
  onEditBatch: (batchId: string) => void;
  onRetry: (id: string) => void;
}) {
  const { t, i18n } = useTranslation('admin');
  const first = files[0]!;
  const ids = files.map((f) => f.id);
  const all = ids.every((id) => selected.has(id));
  const size = files.reduce((n, f) => n + f.size_bytes, 0);
  return (
    <section className={u.batch} aria-label={t('uploads.batch_of', { author: first.author.username })}>
      <div className={u.batchHead}>
        {selectable && (
          <input type="checkbox" aria-label={t('uploads.select_batch')} checked={all} onChange={(e) => onToggle(ids, e.target.checked)} />
        )}
        <b>{first.author.username}</b>
        <span>{formatDateTime(first.created_at, i18n.language)}</span>
        <span>{t('uploads.batch_size', { count: files.length, size: formatBytes(size, i18n.language) })}</span>
        {first.batch_comment && <span className={u.comment}>«{first.batch_comment}»</span>}
        <span style={{ flex: 1 }} />
        {selectable && (
          <Button variant="ghost" onClick={() => onEditBatch(first.batch_id)}>
            {t('uploads.edit_batch')}
          </Button>
        )}
      </div>
      {files.map((f) => (
        <QueueRow
          key={f.id}
          file={f}
          selectable={selectable}
          checked={selected.has(f.id)}
          onCheck={(on) => onToggle([f.id], on)}
          onEdit={() => onEdit(f)}
          onRetry={() => onRetry(f.id)}
        />
      ))}
    </section>
  );
}

function QueueRow({
  file: f,
  selectable,
  checked,
  onCheck,
  onEdit,
  onRetry,
}: {
  file: UploadFile;
  selectable: boolean;
  checked: boolean;
  onCheck: (on: boolean) => void;
  onEdit: () => void;
  onRetry: () => void;
}) {
  const { t, i18n } = useTranslation('admin');
  const reason = useReasonText()(f.status_reason);
  const m = f.metadata;
  const quality = [
    f.format?.toUpperCase(),
    f.bitrate ? `${Math.round(f.bitrate / 1000)} kbps` : null,
    f.sample_rate ? `${(f.sample_rate / 1000).toFixed(1)} kHz` : null,
    f.bit_depth ? `${f.bit_depth} bit` : null,
    f.duration_ms ? formatDuration(f.duration_ms) : null,
    formatBytes(f.size_bytes, i18n.language),
  ]
    .filter(Boolean)
    .join(' · ');
  const editable = f.status === 'pending_review' || f.status === 'import_failed';
  return (
    <div className={u.queueRow}>
      {selectable ? (
        <input type="checkbox" aria-label={t('uploads.select_file', { name: f.original_name })} checked={checked} onChange={(e) => onCheck(e.target.checked)} />
      ) : (
        <span />
      )}
      <div className={u.meta}>
        <span className={u.metaTitle}>{m ? `${m.artist} — ${m.title}` : f.original_name}</span>
        {m && (
          <span className={u.sub}>
            {[m.album, m.year, m.disc && m.disc > 1 ? t('uploads.disc', { n: m.disc }) : null, m.track ? `#${m.track}` : null, m.genre]
              .filter(Boolean)
              .join(' · ')}
            {f.metadata_edited && ` · ${t('uploads.edited')}`}
          </span>
        )}
        <span className={u.sub}>{quality}</span>
        <span className={u.sub} title={f.client_rel_path ?? undefined}>
          {f.client_rel_path ?? f.original_name}
        </span>
      </div>
      <div className={u.meta}>
        <div className={u.flags}>
          <UploadStatusBadge status={f.status} />
          {needsFormatAttention(f.format, f.original_name) && (
            <span className={cx(s.badge, u.tone_warn)} title={t('uploads.format_attention')}>
              {t('uploads.flag_attention')}
            </span>
          )}
          {f.possible_duplicate && <span className={cx(s.badge, u.tone_warn)}>{t('uploads.flag_possible')}</span>}
          {f.quality_upgrade && <span className={cx(s.badge, u.tone_info)}>{t('uploads.flag_quality')}</span>}
          {f.matched_album_id ? (
            <span className={cx(s.badge, u.tone_info)}>{t('uploads.flag_existing_album')}</span>
          ) : (
            m && <span className={cx(s.badge, u.tone_muted)}>{t('uploads.flag_new_album')}</span>
          )}
        </div>
        {f.target_rel_path && <span className={u.target}>{f.target_rel_path}</span>}
        {reason && <span className={f.status === 'pending_review' ? u.warn : u.bad}>{reason}</span>}
        {f.duplicate_level && f.status === 'duplicate' && (
          <span className={u.sub}>{t(`uploads.dup_level_${f.duplicate_level}`)}</span>
        )}
      </div>
      <div className={u.rowActions}>
        {f.stream_url && (
          <audio controls preload="none" src={f.stream_url} aria-label={t('uploads.listen', { name: f.original_name })} />
        )}
        {editable && (
          <Button variant="ghost" aria-label={t('uploads.edit', { name: f.original_name })} onClick={onEdit}>
            <Icon src={editIcon} size={18} />
          </Button>
        )}
        {f.status === 'import_failed' && (
          <Button variant="ghost" icon={refreshIcon} onClick={onRetry}>
            {t('uploads.retry')}
          </Button>
        )}
      </div>
    </div>
  );
}

const EMPTY_META: Meta = { artist: '', albumartist: '', album: '', title: '', genre: '', year: null, track: null, disc: null };

function BatchEditDialog({ batchId, onClose, onSaved }: { batchId: string; onClose: () => void; onSaved: () => void }) {
  const { t } = useTranslation(['admin', 'common']);
  const session = useSession();
  const errorText = useErrorText();
  const [artist, setArtist] = useState('');
  const [album, setAlbum] = useState('');
  const [year, setYear] = useState('');
  const [cover, setCover] = useState<string | null | undefined>(undefined);
  const save = useMutation({
    mutationFn: async () =>
      unwrap(
        await session.client.PATCH('/api/v1/admin/uploads/batches/{id}', {
          params: { path: { id: batchId } },
          body: {
            ...(artist.trim() ? { artist: artist.trim() } : {}),
            ...(album.trim() ? { album: album.trim() } : {}),
            ...(year.trim() ? { year: Number.parseInt(year, 10) } : {}),
            ...(cover !== undefined ? { cover_base64: cover } : {}),
          },
        }),
      ),
    onSuccess: onSaved,
  });
  const pickCover = (file: File | undefined) => {
    if (!file) {
      setCover(undefined);
      return;
    }
    const reader = new FileReader();
    reader.onload = () => {
      const data = String(reader.result ?? '');
      const comma = data.indexOf(',');
      setCover(comma >= 0 ? data.slice(comma + 1) : data);
    };
    reader.readAsDataURL(file);
  };
  return (
    <Dialog
      title={t('uploads.batch_edit_title')}
      onClose={onClose}
      footer={
        <>
          <Button variant="ghost" onClick={onClose}>
            {t('common:form.cancel')}
          </Button>
          <Button variant="primary" busy={save.isPending} onClick={() => save.mutate()}>
            {t('uploads.save')}
          </Button>
        </>
      }
    >
      <div className={s.sessions}>
        <p className={s.note}>{t('uploads.batch_edit_hint')}</p>
        <Field label={t('uploads.meta_artist')} value={artist} onChange={setArtist} maxLength={500} />
        <Field label={t('uploads.meta_album')} value={album} onChange={setAlbum} maxLength={500} />
        <Field label={t('uploads.meta_year')} value={year} inputMode="numeric" onChange={setYear} />
        <label className={s.sessions}>
          <span>{t('uploads.batch_cover')}</span>
          <input type="file" accept="image/jpeg,image/png,image/webp" onChange={(e) => pickCover(e.target.files?.[0])} />
        </label>
        <Button variant="ghost" onClick={() => setCover(null)}>
          {t('uploads.batch_cover_clear')}
        </Button>
        <FormError>{save.error ? errorText(save.error) : null}</FormError>
      </div>
    </Dialog>
  );
}

function EditDialog({ file, onClose, onSaved }: { file: UploadFile; onClose: () => void; onSaved: () => void }) {
  const { t } = useTranslation(['admin', 'common']);
  const session = useSession();
  const errorText = useErrorText();
  const fieldError = useFieldError();
  const [m, setM] = useState<Meta>(file.metadata ?? EMPTY_META);
  const [source, setSource] = useState(file.target_source_id ?? '');
  const sources = useQuery({
    queryKey: ['sources'],
    queryFn: async () => unwrap(await session.client.GET('/api/v1/admin/sources')).items,
  });
  const save = useMutation({
    mutationFn: async () =>
      unwrap(
        await session.client.PATCH('/api/v1/admin/uploads/files/{id}', {
          params: { path: { id: file.id } },
          body: { metadata: m, ...(source ? { target_source_id: source } : {}) },
        }),
      ),
    onSuccess: () => {
      onSaved();
      onClose();
    },
  });
  const text = (k: 'artist' | 'albumartist' | 'album' | 'title' | 'genre') => (
    <Field label={t(`uploads.meta_${k}`)} value={m[k]} onChange={(v) => setM({ ...m, [k]: v })} maxLength={500} />
  );
  const num = (k: 'year' | 'track' | 'disc') => (
    <Field
      label={t(`uploads.meta_${k}`)}
      value={m[k] === null ? '' : String(m[k])}
      inputMode="numeric"
      onChange={(v) => setM({ ...m, [k]: v.trim() === '' ? null : Number.parseInt(v, 10) || null })}
    />
  );
  const accepting = sources.data?.filter((x) => x.accepts_uploads) ?? [];
  return (
    <Dialog
      title={t('uploads.edit_title')}
      onClose={onClose}
      footer={
        <>
          <Button variant="ghost" onClick={onClose}>
            {t('common:form.cancel')}
          </Button>
          <Button variant="primary" busy={save.isPending} disabled={!m.artist.trim() || !m.title.trim()} onClick={() => save.mutate()}>
            {t('uploads.save')}
          </Button>
        </>
      }
    >
      <div className={s.sessions}>
        <p className={s.note}>{file.client_rel_path ?? file.original_name}</p>
        <div className={u.grid}>
          {text('artist')}
          {text('albumartist')}
          {text('album')}
          {text('title')}
          {text('genre')}
          {num('year')}
          {num('track')}
          {num('disc')}
        </div>
        <label className={s.sessions}>
          <span>{t('uploads.target_source')}</span>
          <select className={s.select} value={source} onChange={(e) => setSource(e.target.value)}>
            <option value="">{t('uploads.target_default')}</option>
            {accepting.map((x) => (
              <option key={x.id} value={x.id}>
                {x.name}
              </option>
            ))}
          </select>
        </label>
        <p className={s.note}>{t('uploads.tags_note')}</p>
        <FormError>{save.error ? (fieldError(save.error, 'metadata') ?? errorText(save.error)) : null}</FormError>
      </div>
    </Dialog>
  );
}

function RejectDialog({
  count,
  busy,
  onClose,
  onReject,
}: {
  count: number;
  busy: boolean;
  onClose: () => void;
  onReject: (reason: string) => void;
}) {
  const { t } = useTranslation(['admin', 'common']);
  const [reason, setReason] = useState('');
  return (
    <Dialog
      title={t('uploads.reject_title', { count })}
      onClose={onClose}
      footer={
        <>
          <Button variant="ghost" onClick={onClose}>
            {t('common:form.cancel')}
          </Button>
          <Button variant="danger" busy={busy} onClick={() => onReject(reason)}>
            {t('uploads.reject')}
          </Button>
        </>
      }
    >
      <label className={s.sessions}>
        <span>{t('uploads.reject_reason')}</span>
        <textarea className={u.textarea} value={reason} maxLength={1000} onChange={(e) => setReason(e.target.value)} />
      </label>
    </Dialog>
  );
}

const GB = 1024 ** 3;

/** Настройки очереди: общий лимит, лимит на модератора, размер файла, хранилище по умолчанию. */
export function UploadSettingsSection() {
  const { t } = useTranslation(['admin', 'common']);
  const session = useSession();
  const queryClient = useQueryClient();
  const errorText = useErrorText();
  const settings = useQuery({
    queryKey: ['upload-settings'],
    queryFn: async () => unwrap(await session.client.GET('/api/v1/admin/settings/uploads')),
  });
  const sources = useQuery({
    queryKey: ['sources'],
    queryFn: async () => unwrap(await session.client.GET('/api/v1/admin/sources')).items,
  });
  const [form, setForm] = useState<{ queue: string; perUser: string; maxFile: string; source: string; upgrade: boolean } | null>(null);
  useEffect(() => {
    if (settings.data) setForm(toForm(settings.data));
  }, [settings.data]);

  const save = useMutation({
    mutationFn: async () => {
      const f = form!;
      const gb = (v: string) => Math.round(Number.parseFloat(v.replace(',', '.')) * GB);
      return unwrap(
        await session.client.PATCH('/api/v1/admin/settings/uploads', {
          body: {
            queue_limit_bytes: gb(f.queue),
            max_file_bytes: gb(f.maxFile),
            per_user_limit_bytes: f.perUser.trim() ? gb(f.perUser) : null,
            default_source_id: f.source || null,
            allow_quality_upgrade: f.upgrade,
          },
        }),
      );
    },
    onSuccess: async (data) => {
      queryClient.setQueryData(['upload-settings'], data);
      await queryClient.invalidateQueries({ queryKey: ['upload-quota'] });
    },
  });
  if (!form) return null;
  const valid = [form.queue, form.maxFile].every((v) => Number.parseFloat(v.replace(',', '.')) > 0) &&
    (!form.perUser.trim() || Number.parseFloat(form.perUser.replace(',', '.')) > 0);
  const dirty = settings.data ? JSON.stringify(toForm(settings.data)) !== JSON.stringify(form) : false;
  return (
    <section className={s.section}>
      <h2>{t('uploads.settings_title')}</h2>
      <div className={u.settingsGrid}>
        <Field label={t('uploads.set_queue')} value={form.queue} onChange={(v) => setForm({ ...form, queue: v })} inputMode="decimal" />
        <Field
          label={t('uploads.set_per_user')}
          value={form.perUser}
          hint={t('uploads.set_per_user_hint')}
          onChange={(v) => setForm({ ...form, perUser: v })}
          inputMode="decimal"
        />
        <Field label={t('uploads.set_max_file')} value={form.maxFile} onChange={(v) => setForm({ ...form, maxFile: v })} inputMode="decimal" />
        <label>
          <span className={u.settingsLabel}>{t('uploads.set_source')}</span>
          <select className={s.select} value={form.source} onChange={(e) => setForm({ ...form, source: e.target.value })}>
            <option value="">{t('uploads.set_source_auto')}</option>
            {sources.data
              ?.filter((x) => x.accepts_uploads)
              .map((x) => (
                <option key={x.id} value={x.id}>
                  {x.name}
                </option>
              ))}
          </select>
        </label>
        <div>
          <label className={u.settingsCheck}>
            <input type="checkbox" checked={form.upgrade} onChange={(e) => setForm({ ...form, upgrade: e.target.checked })} />
            <span>{t('uploads.set_upgrade')}</span>
          </label>
        </div>
      </div>
      <p className={s.note}>{t('uploads.set_note')}</p>
      <div className={s.toolbar}>
        <span style={{ flex: 1 }} />
        <Button variant="primary" busy={save.isPending} disabled={!dirty || !valid} onClick={() => save.mutate()}>
          {t('uploads.save')}
        </Button>
      </div>
      {save.isSuccess && !dirty && <span className={s.ok}>{t('uploads.saved')}</span>}
      <FormError>{save.error ? errorText(save.error) : null}</FormError>
    </section>
  );
}

function toForm(st: Settings) {
  const gb = (n: number) => String(Math.round((n / GB) * 100) / 100);
  return {
    queue: gb(st.queue_limit_bytes),
    perUser: st.per_user_limit_bytes === null ? '' : gb(st.per_user_limit_bytes),
    maxFile: gb(st.max_file_bytes),
    source: st.default_source_id ?? '',
    upgrade: st.allow_quality_upgrade,
  };
}