import { SearchableSelect } from '../components/SearchableSelect';
import { useEffect, useState } from 'react';
import type { FormEvent } from 'react';
import { Link } from 'react-router';
import { Alert, EmptyState, LoadingBlock, errorMessage } from '../components/Feedback';
import { Icon } from '../components/Icon';
import { AssetCenterTabs } from '../features/assets/AssetCenterTabs';
import { assetStatusLabel, ASSET_STATUSES } from '../features/assets/assetPresentation';
import { AssetVersionDrawer } from '../features/assets/AssetVersionDrawer';
import { assetVersionChangeLabel } from '../features/assets/assetVersionPresentation';
import { getTemporalAsset, listAssetTypes, listTemporalAssets } from '../lib/api';
import type {
  AssetInformationStatus,
  AssetType,
  PageMeta,
  TemporalAssetDetail,
  TemporalAssetSummary,
} from '../lib/api';
import { formatDate } from '../lib/format';

function localDateTime(date: Date): string {
  const local = new Date(date.getTime() - date.getTimezoneOffset() * 60_000);
  return local.toISOString().slice(0, 16);
}

interface TemporalFilters {
  search: string;
  typeId: string;
  status: AssetInformationStatus | '';
}

const emptyFilters: TemporalFilters = { search: '', typeId: '', status: '' };

export function TemporalAssetsPage() {
  const initialDate = new Date();
  const [draftAt, setDraftAt] = useState(localDateTime(initialDate));
  const [at, setAt] = useState(initialDate.toISOString());
  const [draft, setDraft] = useState<TemporalFilters>(emptyFilters);
  const [filters, setFilters] = useState<TemporalFilters>(emptyFilters);
  const [assets, setAssets] = useState<TemporalAssetSummary[]>([]);
  const [types, setTypes] = useState<AssetType[]>([]);
  const [meta, setMeta] = useState<PageMeta>({ page: 1, pageSize: 25, total: 0, totalPages: 0 });
  const [page, setPage] = useState(1);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState('');
  const [detail, setDetail] = useState<TemporalAssetDetail | null>(null);
  const [detailLoading, setDetailLoading] = useState(false);

  useEffect(() => { listAssetTypes().then(setTypes).catch(() => undefined); }, []);
  useEffect(() => {
    setLoading(true); setError('');
    listTemporalAssets({ at, page, pageSize: 25, ...filters })
      .then((response) => { setAssets(response.data); setMeta(response.meta); })
      .catch((requestError) => setError(errorMessage(requestError)))
      .finally(() => setLoading(false));
  }, [at, filters, page]);

  const apply = (event: FormEvent) => {
    event.preventDefault();
    const selected = new Date(draftAt);
    if (Number.isNaN(selected.getTime())) { setError('Seleccioná una fecha y hora válida.'); return; }
    setPage(1);
    setAt(selected.toISOString());
    setFilters({ ...draft, search: draft.search.trim() });
  };
  const reset = () => {
    const now = new Date();
    setDraftAt(localDateTime(now)); setAt(now.toISOString());
    setDraft(emptyFilters); setFilters(emptyFilters); setPage(1);
  };
  const open = async (asset: TemporalAssetSummary) => {
    setDetail(null); setDetailLoading(true); setError('');
    try { setDetail(await getTemporalAsset(asset.assetId, at)); }
    catch (requestError) { setError(errorMessage(requestError)); }
    finally { setDetailLoading(false); }
  };

  return <section>
    <div className="page-heading"><div><span className="eyebrow">INVENTARIOS</span><h1>Registros</h1><p>Reconstruí cómo se encontraban los inventarios en una fecha y hora.</p></div><span className="count-pill large">{meta.total} registros</span></div>
    <AssetCenterTabs active="temporal" />
    <div className="temporal-notice"><Icon name="history" /><p><strong>Vista histórica exacta.</strong> Los resultados provienen de snapshots inmutables; no reemplazan ni modifican los datos actuales.</p></div>
    <form className="history-filters panel temporal-filters" onSubmit={apply}>
      <label className="field temporal-date"><span>Fecha y hora de consulta</span><input type="datetime-local" value={draftAt} onChange={(event) => setDraftAt(event.target.value)} required /></label>
      <label className="search-field"><Icon name="search" /><input value={draft.search} onChange={(event) => setDraft((current) => ({ ...current, search: event.target.value }))} placeholder="Código o nombre histórico" /></label>
      <label className="field compact-field"><span>Tipo</span><SearchableSelect value={draft.typeId} onChange={(event) => setDraft((current) => ({ ...current, typeId: event.target.value }))}><option value="">Todos</option>{types.map((type) => <option key={type.id} value={type.id}>{type.name}</option>)}</SearchableSelect></label>
      <label className="field compact-field"><span>Estado</span><SearchableSelect value={draft.status} onChange={(event) => setDraft((current) => ({ ...current, status: event.target.value as AssetInformationStatus | '' }))}><option value="">Todos</option>{ASSET_STATUSES.map((status) => <option key={status.value} value={status.value}>{status.label}</option>)}</SearchableSelect></label>
      <div className="filter-actions"><button className="button text" type="button" onClick={reset}>Volver al presente</button><button className="button primary"><Icon name="history" />Reconstruir</button></div>
    </form>

    <div className="temporal-result-heading"><strong>Inventarios reconstruidos al {formatDate(at)}</strong><span>Las vigencias terminan cuando se registra la versión siguiente.</span></div>
    {error && <Alert>{error}</Alert>}
    {loading ? <LoadingBlock label="Reconstruyendo inventarios…" /> : assets.length === 0 ? <EmptyState title="Sin registros en esa fecha" text="No existen versiones históricas que coincidan con la fecha y los filtros seleccionados." /> : <div className="table-panel temporal-table"><div className="table-summary"><strong>{meta.total} registro{meta.total === 1 ? '' : 's'} reconstruido{meta.total === 1 ? '' : 's'}</strong><span>Página {page} de {Math.max(meta.totalPages, 1)}</span></div><div className="table-scroll"><table><thead><tr><th>Registro histórico</th><th>Tipo</th><th>Estado</th><th>Versión aplicable</th><th>Vigente desde</th><th>Vigente hasta</th><th>Cambio</th><th /></tr></thead><tbody>{assets.map((asset) => <tr key={asset.assetId}><td><Link className="history-asset-link" to={`/inventarios/${asset.assetId}`}><strong>{asset.assetName}</strong><small>{asset.assetCode}</small></Link></td><td><span className="tag">{asset.typeName}</span></td><td>{assetStatusLabel(asset.informationStatus)}</td><td><span className={`version-badge ${asset.isCurrent ? 'current' : ''}`}>v{asset.versionNumber}{asset.isCurrent ? ' · actual' : ''}</span></td><td>{formatDate(asset.occurredAt)}</td><td>{asset.effectiveUntil ? formatDate(asset.effectiveUntil) : 'Continúa vigente'}</td><td>{assetVersionChangeLabel(asset.changeType)}</td><td><button type="button" className="icon-button" onClick={() => open(asset)} aria-label={`Ver versión ${asset.versionNumber}`}><Icon name="chevron" /></button></td></tr>)}</tbody></table></div><div className="pagination"><button type="button" className="button secondary" disabled={page <= 1} onClick={() => setPage(page - 1)}>Anterior</button><span>{meta.total ? `${(page - 1) * meta.pageSize + 1}–${Math.min(page * meta.pageSize, meta.total)} de ${meta.total}` : '0 resultados'}</span><button type="button" className="button secondary" disabled={page >= meta.totalPages} onClick={() => setPage(page + 1)}>Siguiente</button></div></div>}
    {(detailLoading || detail) && <AssetVersionDrawer detail={detail} loading={detailLoading} onClose={() => setDetail(null)} />}
  </section>;
}