import { SearchableSelect } from '../components/SearchableSelect';
import { useEffect, useMemo, useState } from 'react';
import type { FormEvent } from 'react';
import { Link, useSearchParams } from 'react-router';
import { PermissionGate } from '../auth/PermissionGate';
import { Alert, EmptyState, LoadingBlock, errorMessage } from '../components/Feedback';
import { Icon } from '../components/Icon';
import { useOperationalContext } from '../context/OperationalContext';
import { AssetCenterTabs } from '../features/assets/AssetCenterTabs';
import { AssetHierarchyView } from '../features/assets/AssetHierarchyView';
import {
  assetOperationalStatusLabel,
  assetStatusClass,
  assetStatusLabel,
  ASSET_OPERATIONAL_STATUSES,
  ASSET_STATUSES,
} from '../features/assets/assetPresentation';
import { listAssetTypes } from '../lib/api';
import type {
  AssetInformationStatus,
  AssetOperationalStatus,
  AssetType,
  PageMeta,
} from '../lib/api';
import { listInventory } from '../lib/inventoryBrowserApi';
import type { InventoryListItem, InventoryQuery } from '../lib/inventoryBrowserApi';
import { formatDate } from '../lib/format';

const quickViews = [
  { key: 'all', label: 'Todos' },
  { key: 'validation', label: 'Pendientes de validar' },
  { key: 'location', label: 'Sin ubicación' },
  { key: 'out', label: 'Fuera de servicio' },
] as const;

const structuredTypeCopy: Record<string, { title: string; description: string }> = {
  departamento: {
    title: 'Departamentos',
    description: 'Raíz territorial del Inventario. Cada Departamento contiene sus Áreas.',
  },
  area: {
    title: 'Áreas',
    description: 'Áreas dentro de un Departamento, con sus Empresas operadoras vinculadas.',
  },
  yacimiento: {
    title: 'Yacimientos',
    description: 'Yacimientos pertenecientes a un Área y utilizados para organizar sus Instalaciones.',
  },
  instalacion: {
    title: 'Instalaciones',
    description: 'Instalaciones dentro de un Yacimiento, con clasificación técnica y contexto operativo.',
  },
  subinstalacion: {
    title: 'Subinstalaciones',
    description: 'Subinstalaciones dependientes de una Instalación, último nivel de la estructura.',
  },
};

function structuredPresentation(type: AssetType | undefined) {
  if (!type) return null;
  if (type.operationalRole === 'COMPANY') {
    return {
      title: 'Empresas',
      description: 'Maestro independiente de Empresas operadoras. Se vinculan a una o más Áreas.',
    };
  }
  return structuredTypeCopy[type.code.toLowerCase()] ?? null;
}

export function AssetsPage() {
  const [urlParams, setUrlParams] = useSearchParams();
  const operationalContext = useOperationalContext();
  const [assets, setAssets] = useState<InventoryListItem[]>([]);
  const [types, setTypes] = useState<AssetType[]>([]);
  const [meta, setMeta] = useState<PageMeta>({ page: 1, pageSize: 25, total: 0, totalPages: 0 });
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState('');
  const [advancedOpen, setAdvancedOpen] = useState(false);
  const [draftSearch, setDraftSearch] = useState(urlParams.get('search') ?? '');

  const view = urlParams.get('view') === 'list' ? 'list' : 'hierarchy';
  const quick = (urlParams.get('quick') ?? 'all') as typeof quickViews[number]['key'];
  const search = urlParams.get('search') ?? '';
  const typeId = urlParams.get('typeId') ?? '';
  const rawStatus = urlParams.get('status') ?? '';
  const rawOperationalStatus = urlParams.get('operationalStatus') ?? '';
  const operationalAreaId = operationalContext.areaId || urlParams.get('operationalAreaId') || '';
  const operatorCompanyId = operationalContext.companyId || urlParams.get('operatorCompanyId') || '';
  const status = ASSET_STATUSES.some((item) => item.value === rawStatus) ? rawStatus as AssetInformationStatus : '';
  const operationalStatus = ASSET_OPERATIONAL_STATUSES.some((item) => item.value === rawOperationalStatus) ? rawOperationalStatus as AssetOperationalStatus : '';
  const page = Math.max(1, Number(urlParams.get('page') ?? 1) || 1);
  const needsValidation = quick === 'validation' ? true : undefined;
  const hasGeometry = quick === 'location' ? false : undefined;
  const effectiveOperationalStatus = quick === 'out' ? 'OUT_OF_SERVICE' as AssetOperationalStatus : operationalStatus;
  const selectedType = types.find((type) => type.id === typeId);
  const selectedPresentation = structuredPresentation(selectedType);

  useEffect(() => {
    listAssetTypes().then((data) => setTypes(data.filter((type) =>
      type.operationalRole === 'COMPANY'
      || ['departamento','area','yacimiento','instalacion','subinstalacion'].includes(type.code.toLowerCase()),
    ))).catch(() => undefined);
  }, []);

  useEffect(() => {
    if (view !== 'list') return;
    setLoading(true); setError('');
    listInventory({
      page, pageSize: 25, search, typeId, status,
      operationalStatus: effectiveOperationalStatus,
      operationalAreaId, operatorCompanyId, needsValidation, hasGeometry,
    })
      .then((response) => { setAssets(response.data); setMeta(response.meta); })
      .catch((requestError) => setError(errorMessage(requestError)))
      .finally(() => setLoading(false));
  }, [view, page, search, typeId, status, effectiveOperationalStatus, operationalAreaId, operatorCompanyId, needsValidation, hasGeometry]);

  const filters: InventoryQuery = useMemo(() => ({
    search, typeId, status, operationalStatus: effectiveOperationalStatus,
    operationalAreaId, operatorCompanyId, needsValidation, hasGeometry,
  }), [search, typeId, status, effectiveOperationalStatus, operationalAreaId, operatorCompanyId, needsValidation, hasGeometry]);

  const update = (changes: Record<string, string | null>) => {
    const next = new URLSearchParams(urlParams);
    Object.entries(changes).forEach(([key, value]) => value ? next.set(key, value) : next.delete(key));
    next.delete('page'); setUrlParams(next);
  };
  const applySearch = (event: FormEvent) => { event.preventDefault(); update({ search: draftSearch.trim() || null }); };
  const setQuick = (key: string) => update({ quick: key === 'all' ? null : key, operationalStatus: key === 'out' ? null : rawOperationalStatus || null });
  const clearFilters = () => {
    const next = new URLSearchParams();
    if (view === 'list') next.set('view', 'list');
    const parentId=urlParams.get('parentId'); if (parentId) next.set('parentId',parentId);
    setDraftSearch(''); setUrlParams(next);
  };
  const setPage = (value: number) => {
    const next = new URLSearchParams(urlParams);
    value > 1 ? next.set('page', String(value)) : next.delete('page'); setUrlParams(next);
  };
  const advancedActive = Boolean(typeId || status || rawOperationalStatus);
  const sectionTitle = view === 'list' && selectedPresentation ? selectedPresentation.title : 'Inventarios';
  const sectionDescription = view === 'list' && selectedPresentation
    ? selectedPresentation.description
    : 'Empresas y estructura territorial: Departamento → Área → Yacimiento → Instalación → Subinstalación.';

  return <section>
    <div className="page-heading asset-center-heading">
      <div>
        <span className="eyebrow">{selectedPresentation && view === 'list' ? 'INVENTARIOS · SECCIÓN' : 'INVENTARIOS'}</span>
        <h1>{sectionTitle}</h1>
        <p>{sectionDescription}</p>
      </div>
      <div style={{ display: 'flex', gap: 8, flexWrap: 'wrap' }}>
        {selectedPresentation && view === 'list' && <Link className="button secondary" to="/inventarios"><Icon name="layers" />Ver estructura</Link>}
        <PermissionGate permission="assets.create"><Link className="button primary" to="/inventarios/nuevo"><Icon name="plus" />Nuevo registro</Link></PermissionGate>
      </div>
    </div>

    <AssetCenterTabs active={view === 'hierarchy' ? 'navigate' : 'list'} />

    <div className="asset-center-controls">
      <form className="asset-center-search" onSubmit={applySearch}>
        <Icon name="search" />
        <input value={draftSearch} onChange={(event) => setDraftSearch(event.target.value)} placeholder="Buscar por nombre, código o identificación…" />
        <button className="button primary" type="submit">Buscar</button>
      </form>
      <div className="quick-view-row" aria-label="Vistas rápidas">
        {quickViews.map((item) => <button key={item.key} type="button" className={quick === item.key ? 'active' : ''} onClick={() => setQuick(item.key)}>{item.label}</button>)}
        {view === 'list' && <button type="button" className={advancedOpen || advancedActive ? 'advanced active' : 'advanced'} onClick={() => setAdvancedOpen((current) => !current)}>Más filtros</button>}
      </div>
      {view === 'list' && (advancedOpen || advancedActive) && <div className="advanced-filter-panel">
        <label className="field compact-field"><span>Sección</span><SearchableSelect value={typeId} onChange={(event) => update({ typeId: event.target.value || null })}><option value="">Todas las secciones</option>{types.map((type) => <option key={type.id} value={type.id}>{type.operationalRole === 'COMPANY' ? 'Empresas' : structuredTypeCopy[type.code.toLowerCase()]?.title ?? type.name}</option>)}</SearchableSelect></label>
        <label className="field compact-field"><span>Estado del dato</span><SearchableSelect value={status} onChange={(event) => update({ status: event.target.value || null })}><option value="">Todos</option>{ASSET_STATUSES.map((item) => <option key={item.value} value={item.value}>{item.label}</option>)}</SearchableSelect></label>
        <label className="field compact-field"><span>Estado operativo</span><SearchableSelect value={rawOperationalStatus} onChange={(event) => update({ operationalStatus: event.target.value || null, quick: quick === 'out' ? null : quick === 'all' ? null : quick })}><option value="">Todos</option>{ASSET_OPERATIONAL_STATUSES.map((item) => <option key={item.value} value={item.value}>{item.label}</option>)}</SearchableSelect></label>
        <button type="button" className="button text filter-clear" onClick={clearFilters}>Limpiar filtros</button>
      </div>}
    </div>

    {error && <Alert>{error}</Alert>}
    {view === 'hierarchy'
      ? <AssetHierarchyView filters={filters} types={types} />
      : loading
        ? <LoadingBlock label="Cargando Inventarios…" />
        : assets.length === 0
          ? <EmptyState title="Todavía no hay registros" text={selectedPresentation ? `No hay registros cargados en ${selectedPresentation.title}.` : 'La base está lista para comenzar la carga manual desde Departamento.'} />
          : <div className="table-panel compact-assets-table">
            <div className="table-summary"><strong>{meta.total} registro{meta.total === 1 ? '' : 's'}</strong><span>Página {meta.page} de {Math.max(meta.totalPages, 1)}</span></div>
            <div className="table-scroll"><table><thead><tr><th>Registro</th><th>Sección</th><th>Ubicación / Operadora</th><th>Estado</th><th>Actualizado</th><th aria-label="Acciones" /></tr></thead><tbody>
              {assets.map((asset) => <tr key={asset.id}>
                <td><div className="asset-cell"><span className="asset-symbol"><Icon name="layers" size={16} /></span><div><Link to={`/inventarios/${asset.id}`} className="table-primary">{asset.name}</Link><small>{asset.code}{asset.parent ? ` · en ${asset.parent.name}` : ''}</small></div></div></td>
                <td><span className="tag">{asset.type.name}</span></td>
                <td>{asset.operationalArea ? <span><strong className="table-primary">{asset.operationalArea.name}</strong><small className="cell-subtext">{asset.operatorCompany?.name ?? 'Sin operadora vigente'}</small></span> : asset.operatorCompany ? <span>{asset.operatorCompany.name}</span> : <span className="muted">{asset.parent?.name ?? 'Raíz / maestro independiente'}</span>}</td>
                <td><div className="dual-status"><span className={`status-badge ${assetStatusClass(asset.informationStatus)}`}>{assetStatusLabel(asset.informationStatus)}</span><small>{assetOperationalStatusLabel(asset.operationalStatus)}</small></div></td>
                <td>{formatDate(asset.updatedAt)}</td>
                <td className="action-cell"><Link className="icon-button" to={`/inventarios/${asset.id}`} aria-label={`Abrir ${asset.name}`}><Icon name="chevron" /></Link></td>
              </tr>)}
            </tbody></table></div>
            <div className="pagination"><button className="button secondary" disabled={page <= 1} onClick={() => setPage(page - 1)}>Anterior</button><span>{meta.total ? `${(page - 1) * meta.pageSize + 1}–${Math.min(page * meta.pageSize, meta.total)} de ${meta.total}` : '0 resultados'}</span><button className="button secondary" disabled={page >= meta.totalPages} onClick={() => setPage(page + 1)}>Siguiente</button></div>
          </div>}
  </section>;
}