import { useEffect, useState } from 'react';
import type { FormEvent } from 'react';
import { Link, useParams } from 'react-router';
import { useAuth } from '../auth/AuthContext';
import { Alert, LoadingBlock, errorMessage } from '../components/Feedback';
import { Icon } from '../components/Icon';
import { SearchableSelect } from '../components/SearchableSelect';
import { formatDate } from '../lib/format';
import {
  addInspectionReportFollowUp,
  getInspectionReportF4,
  inspectionReportGedoPdfDownloadUrl,
  inspectionReportWordDownloadUrl,
  listInspectionReportFollowUps,
  officializeInspectionReport,
  updateInspectionReportNarrative,
} from '../lib/reportWorkflowApi';
import type {
  InspectionReportDetailF4,
  InspectionReportFollowUp,
  InspectionReportFollowUpType,
} from '../lib/reportWorkflowApi';

function names(items: Array<{ name: string }>, empty: string): string {
  return items.length ? items.map((item) => item.name).join(' · ') : empty;
}

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

function reportStatusLabel(status: InspectionReportDetailF4['status']): string {
  if (status === 'WORKING') return 'En preparación';
  if (status === 'OFFICIALIZED') return 'Oficializado en GEDO';
  if (status === 'CANCELLED') return 'Cancelado';
  return 'Legado congelado';
}

function reportStatusClass(status: InspectionReportDetailF4['status']): string {
  if (status === 'OFFICIALIZED') return 'active';
  if (status === 'CANCELLED') return 'danger';
  return 'pending';
}

function followUpLabel(type: InspectionReportFollowUpType): string {
  if (type === 'COMPANY_NOTE') return 'Presentación / nota de empresa';
  if (type === 'COMPANY_DOCUMENT') return 'Documento de empresa';
  if (type === 'INTERNAL_NOTE') return 'Nota interna';
  if (type === 'VERIFICATION') return 'Verificación';
  return 'Otro antecedente';
}

function fileSize(value: number | null): string {
  if (!value || value < 1) return '';
  if (value < 1024) return `${value} B`;
  if (value < 1024 * 1024) return `${Math.round(value / 1024)} KB`;
  return `${(value / (1024 * 1024)).toFixed(1)} MB`;
}

export function ReportDetailPage() {
  const { id } = useParams();
  const { hasPermission } = useAuth();
  const canManage = hasPermission('inspection_reports.generate');
  const [report, setReport] = useState<InspectionReportDetailF4 | null>(null);
  const [followUps, setFollowUps] = useState<InspectionReportFollowUp[]>([]);
  const [loading, setLoading] = useState(true);
  const [working, setWorking] = useState(false);
  const [error, setError] = useState('');
  const [success, setSuccess] = useState('');

  const [executiveSummary, setExecutiveSummary] = useState('');
  const [reportDescription, setReportDescription] = useState('');

  const [gedoIfIdentifier, setGedoIfIdentifier] = useState('');
  const [gedoOfficializedAt, setGedoOfficializedAt] = useState(localDateTime(new Date()));
  const [gedoFile, setGedoFile] = useState<File | null>(null);

  const [followUpType, setFollowUpType] = useState<InspectionReportFollowUpType>('COMPANY_NOTE');
  const [followUpOccurredAt, setFollowUpOccurredAt] = useState(localDateTime(new Date()));
  const [followUpReference, setFollowUpReference] = useState('');
  const [followUpDescription, setFollowUpDescription] = useState('');
  const [followUpFile, setFollowUpFile] = useState<File | null>(null);

  const reload = async () => {
    if (!id) return;
    const [nextReport, nextFollowUps] = await Promise.all([
      getInspectionReportF4(id),
      listInspectionReportFollowUps(id),
    ]);
    setReport(nextReport);
    setFollowUps(nextFollowUps);
    setExecutiveSummary(nextReport.executiveSummary ?? '');
    setReportDescription(nextReport.reportDescription ?? '');
    setGedoIfIdentifier(nextReport.gedoIfIdentifier ?? '');
    if (nextReport.gedoOfficializedAt) {
      setGedoOfficializedAt(localDateTime(new Date(nextReport.gedoOfficializedAt)));
    }
  };

  useEffect(() => {
    if (!id) return;
    setLoading(true);
    setError('');
    reload()
      .catch((requestError) => setError(errorMessage(requestError)))
      .finally(() => setLoading(false));
  }, [id]);

  const saveNarrative = async (event: FormEvent) => {
    event.preventDefault();
    if (!id || report?.status !== 'WORKING') return;
    setWorking(true);
    setError('');
    setSuccess('');
    try {
      await updateInspectionReportNarrative(id, {
        executiveSummary: executiveSummary.trim() || null,
        description: reportDescription.trim() || null,
      });
      await reload();
      setSuccess('Contenido editable del INF actualizado. El Acta fuente y sus Hallazgos no fueron modificados.');
    } catch (requestError) {
      setError(errorMessage(requestError));
    } finally {
      setWorking(false);
    }
  };

  const officialize = async (event: FormEvent) => {
    event.preventDefault();
    if (!id || !gedoFile || !gedoIfIdentifier.trim() || !gedoOfficializedAt) return;
    setWorking(true);
    setError('');
    setSuccess('');
    try {
      await officializeInspectionReport(id, {
        gedoIfIdentifier: gedoIfIdentifier.trim(),
        gedoOfficializedAt: new Date(gedoOfficializedAt).toISOString(),
        file: gedoFile,
      });
      setGedoFile(null);
      await reload();
      setSuccess('IF oficial de GEDO registrado. El PDF y su hash quedaron fijados de forma inmutable.');
    } catch (requestError) {
      setError(errorMessage(requestError));
    } finally {
      setWorking(false);
    }
  };

  const addFollowUp = async (event: FormEvent) => {
    event.preventDefault();
    if (!id || !followUpOccurredAt) return;
    if (!followUpDescription.trim() && !followUpReference.trim() && !followUpFile) return;
    setWorking(true);
    setError('');
    setSuccess('');
    try {
      const next = await addInspectionReportFollowUp(id, {
        type: followUpType,
        occurredAt: new Date(followUpOccurredAt).toISOString(),
        externalReference: followUpReference.trim() || null,
        description: followUpDescription.trim() || null,
        file: followUpFile,
      });
      setFollowUps(next);
      setFollowUpReference('');
      setFollowUpDescription('');
      setFollowUpFile(null);
      setFollowUpOccurredAt(localDateTime(new Date()));
      setSuccess('Antecedente agregado al seguimiento del INF. Los registros anteriores permanecen intactos.');
    } catch (requestError) {
      setError(errorMessage(requestError));
    } finally {
      setWorking(false);
    }
  };

  if (loading) return <LoadingBlock label="Cargando informe…" />;

  return <section>
    <div className="breadcrumb"><Link to="/informes">Informes</Link><span>/</span><span>{report?.code ?? 'Informe'}</span></div>
    <div className="page-heading survey-editor-heading">
      <div><span className="eyebrow">INFORME DE INSPECCIÓN</span><h1>{report?.code ?? 'Informe'}</h1><p>{report ? `Acta ${report.act.code} · generado ${formatDate(report.generatedAt)}` : 'Consulta del informe.'}</p></div>
      {report && <div className="report-status-stack">
        <span className={`status-badge large ${report.wordStatus === 'READY' ? 'active' : report.wordStatus === 'FAILED' ? 'danger' : 'pending'}`}>{report.wordStatus === 'READY' ? 'Word disponible' : report.wordStatus === 'FAILED' ? 'Word con error' : 'Word pendiente'}</span>
        <span className={`status-badge large ${reportStatusClass(report.status)}`}>{reportStatusLabel(report.status)}</span>
      </div>}
    </div>

    {error && <Alert>{error}</Alert>}
    {success && <Alert type="success">{success}</Alert>}

    {report && <>
      <div className="temporal-notice"><Icon name="clipboard" /><p><strong>Un INF corresponde a una sola Acta.</strong> El Word puede editarse durante la preparación del Informe. El Acta sellada y los Hallazgos que contiene permanecen inmutables.</p></div>

      <section className="panel report-summary-panel">
        <div className="panel-heading"><div><span className="eyebrow">TRAZABILIDAD DOCUMENTAL</span><h2>{report.code}</h2></div><small className="muted">Versión del Acta: {report.actVersion}</small></div>
        <div className="responsible-summary">
          <div><small>Empresa</small><strong>{names(report.companies, 'Sin asignar')}</strong></div>
          <div><small>Área / Yacimiento</small><strong>{names(report.areas, 'Sin asignar')}</strong></div>
          <div><small>Hallazgos</small><strong>{report.findingCount}</strong></div>
          <div><small>Generado por</small><strong>{report.generatedBy.firstName} {report.generatedBy.lastName}</strong></div>
        </div>
        <div className="report-linked-documents">
          <Link to={`/inspecciones/${report.visitId}`}><span>Inspección</span><strong>{report.visit.code}</strong><Icon name="chevron" /></Link>
          <Link to={`/inspecciones/actas/${report.actId}`}><span>Acta fuente</span><strong>{report.act.code}</strong><small>Contenido inmutable</small><Icon name="chevron" /></Link>
          <Link to={`/hallazgos?search=${encodeURIComponent(report.act.code)}`}><span>Hallazgos del Acta</span><strong>{report.findingCount}</strong><small>Seguimiento técnico</small><Icon name="chevron" /></Link>
        </div>
      </section>

      <section className="panel">
        <div className="panel-heading"><div><span className="eyebrow">WORD EDITABLE</span><h2>Preparación del INF</h2><p className="section-copy">El Inspector puede revisar y ajustar el texto del Informe antes de incorporarlo a GEDO. Esta edición no altera el Acta fuente.</p></div>{report.wordStatus === 'READY' && <a className="button secondary" href={inspectionReportWordDownloadUrl(report.id)}>Descargar Word</a>}</div>
        <form className="form-section" onSubmit={saveNarrative}>
          <label className="field"><span>Resumen ejecutivo</span><textarea rows={4} maxLength={20000} value={executiveSummary} onChange={(event) => setExecutiveSummary(event.target.value)} disabled={!canManage || report.status !== 'WORKING'} placeholder="Resumen ejecutivo del Informe…" /></label>
          <label className="field"><span>Descripción / análisis técnico</span><textarea rows={8} maxLength={50000} value={reportDescription} onChange={(event) => setReportDescription(event.target.value)} disabled={!canManage || report.status !== 'WORKING'} placeholder="Descripción técnica, análisis y consideraciones del Inspector…" /></label>
          {canManage && report.status === 'WORKING' && <div className="form-actions"><button className="button primary" disabled={working}>{working ? 'Guardando…' : 'Guardar contenido del INF'}</button></div>}
          {report.status !== 'WORKING' && <Alert type="info">El contenido editable se cerró al registrar el IF oficial de GEDO.</Alert>}
        </form>
      </section>

      <section className="panel">
        <div className="panel-heading"><div><span className="eyebrow">GEDO</span><h2>Oficialización del Informe</h2><p className="section-copy">Cuando GEDO devuelve el IF y el PDF oficial, ambos se registran en el sistema y pasan a ser la referencia documental institucional.</p></div></div>
        {report.status === 'OFFICIALIZED' ? <>
          <div className="responsible-summary">
            <div><small>Identificador IF</small><strong>{report.gedoIfIdentifier ?? '—'}</strong></div>
            <div><small>Oficializado</small><strong>{formatDate(report.gedoOfficializedAt)}</strong></div>
            <div><small>PDF oficial</small><strong>{report.gedoPdfOriginalName ?? 'Registrado'}</strong></div>
            <div><small>Vencimiento del Acta</small><strong>{formatDate(report.act.deadlineAt)}</strong></div>
          </div>
          {report.gedoPdfOriginalName && <div className="form-actions"><a className="button secondary" href={inspectionReportGedoPdfDownloadUrl(report.id)}>Descargar PDF oficial</a></div>}
          {report.gedoPdfSha256 && <div className="temporal-notice"><Icon name="check" /><p><strong>PDF GEDO fijado.</strong> SHA-256: <code>{report.gedoPdfSha256}</code></p></div>}
        </> : canManage && report.status === 'WORKING' ? <form className="form-section" onSubmit={officialize}>
          <div className="form-grid">
            <label className="field"><span>Identificador IF de GEDO</span><input value={gedoIfIdentifier} onChange={(event) => setGedoIfIdentifier(event.target.value)} required maxLength={255} placeholder="IF-2026-…" /></label>
            <label className="field"><span>Fecha de oficialización</span><input type="datetime-local" value={gedoOfficializedAt} onChange={(event) => setGedoOfficializedAt(event.target.value)} required /></label>
          </div>
          <label className="field"><span>PDF oficial de GEDO</span><input type="file" accept="application/pdf,.pdf" onChange={(event) => setGedoFile(event.target.files?.[0] ?? null)} required /></label>
          <Alert>Esta acción cierra la edición del INF. El IF, la fecha y el hash del PDF oficial quedarán registrados como trazabilidad institucional.</Alert>
          <div className="form-actions"><button className="button primary" disabled={working || !gedoFile || !gedoIfIdentifier.trim()}>{working ? 'Registrando…' : 'Registrar IF y PDF oficial'}</button></div>
        </form> : <Alert type="info">El Informe todavía no está oficializado en GEDO.</Alert>}
      </section>

      <section className="panel">
        <div className="panel-heading"><div><span className="eyebrow">SEGUIMIENTO DEL INF</span><h2>Presentaciones y antecedentes</h2><p className="section-copy">Las respuestas de empresa, documentos, notas internas y verificaciones se agregan cronológicamente. Nunca reemplazan un antecedente anterior.</p></div><span className="count-pill">{followUps.length}</span></div>

        {followUps.length === 0 ? <div className="inline-empty">Todavía no hay antecedentes posteriores registrados.</div> : <div className="dossier-link-list">
          {[...followUps].reverse().map((item) => <div key={item.id}>
            <div>
              <strong>{followUpLabel(item.type)}</strong>
              <small>{item.description || item.externalReference || item.originalName || 'Sin descripción'}</small>
              {item.originalName && <small>Archivo: {item.originalName}{item.sizeBytes ? ` · ${fileSize(item.sizeBytes)}` : ''}</small>}
            </div>
            <span>{formatDate(item.occurredAt)}{item.externalReference ? ` · ${item.externalReference}` : ''}</span>
          </div>)}
        </div>}

        {canManage && <form className="form-section" onSubmit={addFollowUp}>
          <div><h3>Agregar antecedente</h3><p className="section-copy">Usá este bloque para registrar una nueva presentación sin modificar las anteriores.</p></div>
          <div className="form-grid">
            <label className="field"><span>Tipo</span><SearchableSelect value={followUpType} onChange={(event) => setFollowUpType(event.target.value as InspectionReportFollowUpType)}><option value="COMPANY_NOTE">Presentación / nota de empresa</option><option value="COMPANY_DOCUMENT">Documento de empresa</option><option value="INTERNAL_NOTE">Nota interna</option><option value="VERIFICATION">Verificación</option><option value="OTHER">Otro antecedente</option></SearchableSelect></label>
            <label className="field"><span>Fecha</span><input type="datetime-local" value={followUpOccurredAt} onChange={(event) => setFollowUpOccurredAt(event.target.value)} required /></label>
            <label className="field"><span>Referencia externa <em>opcional</em></span><input value={followUpReference} onChange={(event) => setFollowUpReference(event.target.value)} maxLength={255} placeholder="GEDO, expediente, nota, ticket…" /></label>
          </div>
          <label className="field"><span>Descripción</span><textarea rows={4} maxLength={20000} value={followUpDescription} onChange={(event) => setFollowUpDescription(event.target.value)} placeholder="Contenido o resumen de la presentación…" /></label>
          <label className="field"><span>Archivo <em>opcional</em></span><input type="file" onChange={(event) => setFollowUpFile(event.target.files?.[0] ?? null)} /></label>
          <div className="form-actions"><button className="button primary" disabled={working || (!followUpDescription.trim() && !followUpReference.trim() && !followUpFile)}>{working ? 'Agregando…' : 'Agregar al historial'}</button></div>
        </form>}
      </section>

      <section className="panel report-integrity-panel">
        <div className="panel-heading"><div><span className="eyebrow">INTEGRIDAD</span><h2>Fuente inmutable</h2><p className="section-copy">El INF conserva una copia verificable del Acta sellada que le dio origen.</p></div></div>
        <dl className="report-integrity-list">
          <div><dt>Acta fuente</dt><dd>{report.act.code}</dd></div>
          <div><dt>Hash de cierre del Acta</dt><dd>{report.actClosureSha256}</dd></div>
          <div><dt>Hash de la fuente del INF</dt><dd>{report.frozenSha256}</dd></div>
          <div><dt>Estado del INF</dt><dd>{reportStatusLabel(report.status)}</dd></div>
        </dl>
      </section>
    </>}
  </section>;
}