'use client';

import React, { useCallback, useEffect, useState } from 'react';
import {
  History,
  RefreshCw,
  User,
  Calendar,
  FileText,
  ChevronDown,
  ChevronRight,
  Filter,
} from 'lucide-react';
import { PageHeader, Surface, EmptyState } from '@/components/ui';

type Row = {
  id: string;
  tenant_id: string | null;
  tenant_name: string | null;
  user_email: string;
  user_role: string | null;
  entity_type: string;
  entity_id: string | null;
  action: string;
  summary: string;
  detail: Record<string, unknown>;
  source: string | null;
  created_at: string;
};

const ENTITY_LABELS: Record<string, string> = {
  brandbook: 'Zona de marca',
  creative: 'Creatividad',
  calendar: 'Calendario',
  tenant: 'Cliente',
  document: 'Documento',
  enrichment: 'Enriquecimiento',
};

function fmtDate(iso: string): string {
  try {
    return new Intl.DateTimeFormat('es-ES', {
      dateStyle: 'medium',
      timeStyle: 'short',
    }).format(new Date(iso));
  } catch {
    return iso;
  }
}

function entityLabel(t: string): string {
  return ENTITY_LABELS[t] || t;
}

function DetailBlock({ detail }: { detail: Record<string, unknown> }) {
  const changes = Array.isArray(detail.changes)
    ? (detail.changes as { field?: string; from?: unknown; to?: unknown }[])
    : null;
  const fields = Array.isArray(detail.filled_fields)
    ? (detail.filled_fields as string[])
    : null;
  const sources = Array.isArray(detail.sources)
    ? (detail.sources as string[])
    : null;

  if (changes?.length) {
    return (
      <ul className="space-y-1.5 text-xs text-gray-600">
        {changes.map((c, i) => (
          <li
            key={`${c.field}-${i}`}
            className="rounded-lg bg-gray-50 border border-gray-100 px-2.5 py-1.5"
          >
            <span className="font-semibold text-gray-800">{c.field}</span>
            <div className="mt-0.5 grid gap-0.5 sm:grid-cols-2">
              <span className="text-gray-400 line-through break-all">
                {c.from == null || c.from === ''
                  ? '∅'
                  : typeof c.from === 'string'
                    ? c.from
                    : JSON.stringify(c.from)}
              </span>
              <span className="text-emerald-700 break-all">
                {c.to == null || c.to === ''
                  ? '∅'
                  : typeof c.to === 'string'
                    ? c.to
                    : JSON.stringify(c.to)}
              </span>
            </div>
          </li>
        ))}
      </ul>
    );
  }

  if (fields?.length || sources?.length) {
    return (
      <div className="text-xs text-gray-600 space-y-1">
        {sources?.length ? (
          <p>
            <span className="font-medium text-gray-800">Fuentes:</span>{' '}
            {sources.join(', ')}
          </p>
        ) : null}
        {fields?.length ? (
          <p>
            <span className="font-medium text-gray-800">Campos:</span>{' '}
            {fields.join(', ')}
          </p>
        ) : null}
        {typeof detail.note === 'string' ? (
          <p className="text-gray-500">{detail.note}</p>
        ) : null}
      </div>
    );
  }

  const keys = Object.keys(detail || {});
  if (!keys.length) {
    return <p className="text-xs text-gray-400">Sin detalle adicional.</p>;
  }
  return (
    <pre className="text-[11px] text-gray-600 bg-gray-50 border border-gray-100 rounded-lg p-2.5 overflow-x-auto max-h-48">
      {JSON.stringify(detail, null, 2)}
    </pre>
  );
}

export default function ChangeHistoryView({
  isAgency,
  initialTenantId,
}: {
  isAgency: boolean;
  initialTenantId?: string | null;
}) {
  const [rows, setRows] = useState<Row[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [needsMigration, setNeedsMigration] = useState(false);
  const [entityType, setEntityType] = useState('');
  const [portfolioWide, setPortfolioWide] = useState(false);
  const [openId, setOpenId] = useState<string | null>(null);

  const load = useCallback(async () => {
    setLoading(true);
    setError(null);
    try {
      const q = new URLSearchParams();
      q.set('limit', '80');
      if (entityType) q.set('entity_type', entityType);
      if (initialTenantId) q.set('tenant_id', initialTenantId);
      const r = await fetch(`/api/change-history?${q}`, { cache: 'no-store' });
      const j = await r.json();
      if (!r.ok || j.ok === false) {
        setNeedsMigration(Boolean(j.needsMigration));
        setError(j.error || 'No se pudo cargar el historial');
        setRows([]);
        return;
      }
      setNeedsMigration(false);
      setRows(j.rows || []);
      setPortfolioWide(Boolean(j.portfolio_wide));
    } catch (e) {
      setError(e instanceof Error ? e.message : 'Error de red');
      setRows([]);
    } finally {
      setLoading(false);
    }
  }, [entityType, initialTenantId]);

  useEffect(() => {
    void load();
  }, [load]);

  return (
    <div className="space-y-6">
      <PageHeader
        eyebrow="Auditoría"
        title="Historial de cambios"
        description="Usuario, fecha, cambio y detalle de lo que se modifica en el Centro de Mando."
        actions={
          <button
            type="button"
            onClick={() => void load()}
            className="inline-flex items-center gap-2 rounded-lg border border-gray-200 bg-white px-3 py-2 text-sm font-medium text-gray-700 hover:bg-gray-50"
          >
            <RefreshCw className={`w-4 h-4 ${loading ? 'animate-spin' : ''}`} />
            Actualizar
          </button>
        }
      />

      <Surface className="flex flex-wrap items-center gap-3">
        <Filter className="w-4 h-4 text-gray-400" />
        <label className="text-xs font-medium text-gray-600">Tipo</label>
        <select
          value={entityType}
          onChange={(e) => setEntityType(e.target.value)}
          className="rounded-lg border border-gray-200 bg-white px-3 py-1.5 text-sm text-gray-800"
        >
          <option value="">Todos</option>
          <option value="brandbook">Zona de marca</option>
          <option value="enrichment">Enriquecimiento</option>
          <option value="creative">Creatividades</option>
          <option value="calendar">Calendario</option>
          <option value="tenant">Cliente</option>
        </select>
        {isAgency ? (
          <p className="text-xs text-gray-500 ml-auto">
            {portfolioWide
              ? 'Vista portafolio (todos los clientes)'
              : 'Filtrado por el cliente del contexto'}
          </p>
        ) : null}
      </Surface>

      {needsMigration ? (
        <Surface className="border-amber-200 bg-amber-50">
          <p className="text-sm text-amber-900">
            Falta aplicar la migración SQL{' '}
            <code className="text-xs bg-amber-100 px-1 rounded">
              sql/change_history.sql
            </code>{' '}
            en Supabase. Hasta entonces no se pueden guardar ni listar cambios.
          </p>
        </Surface>
      ) : null}

      {error && !needsMigration ? (
        <Surface className="border-red-200 bg-red-50">
          <p className="text-sm text-red-800">{error}</p>
        </Surface>
      ) : null}

      <Surface padded={false}>
        {loading && !rows.length ? (
          <div className="p-8 text-sm text-gray-500 flex items-center gap-2">
            <RefreshCw className="w-4 h-4 animate-spin" />
            Cargando historial…
          </div>
        ) : !rows.length ? (
          <div className="p-6">
            <EmptyState
              title="Aún no hay cambios registrados"
              description="Cuando guardes Zona de marca, enriquezcas un brandbook u otras acciones instrumentadas, aparecerán aquí."
            />
          </div>
        ) : (
          <ul className="divide-y divide-gray-100">
            {rows.map((row) => {
              const open = openId === row.id;
              return (
                <li key={row.id}>
                  <button
                    type="button"
                    onClick={() => setOpenId(open ? null : row.id)}
                    className="w-full text-left px-4 md:px-5 py-3.5 hover:bg-gray-50/80 transition-colors"
                  >
                    <div className="flex items-start gap-3">
                      <div className="mt-0.5 text-gray-400">
                        {open ? (
                          <ChevronDown className="w-4 h-4" />
                        ) : (
                          <ChevronRight className="w-4 h-4" />
                        )}
                      </div>
                      <div className="min-w-0 flex-1 space-y-1.5">
                        <div className="flex flex-wrap items-center gap-x-3 gap-y-1 text-[11px] text-gray-500">
                          <span className="inline-flex items-center gap-1 font-medium text-gray-700">
                            <User className="w-3 h-3" />
                            {row.user_email}
                            {row.user_role ? (
                              <span className="text-gray-400">
                                · {row.user_role}
                              </span>
                            ) : null}
                          </span>
                          <span className="inline-flex items-center gap-1">
                            <Calendar className="w-3 h-3" />
                            {fmtDate(row.created_at)}
                          </span>
                          {row.tenant_name ? (
                            <span className="rounded-full bg-brand-50 text-brand-700 px-2 py-0.5 font-medium">
                              {row.tenant_name}
                            </span>
                          ) : null}
                          <span className="inline-flex items-center gap-1 rounded-full bg-gray-100 px-2 py-0.5 text-gray-600">
                            <FileText className="w-3 h-3" />
                            {entityLabel(row.entity_type)} · {row.action}
                          </span>
                        </div>
                        <p className="text-sm font-medium text-gray-900">
                          {row.summary}
                        </p>
                      </div>
                      <History className="w-4 h-4 text-gray-300 shrink-0 mt-1" />
                    </div>
                  </button>
                  {open ? (
                    <div className="px-4 md:px-5 pb-4 pl-11 md:pl-12">
                      <DetailBlock detail={row.detail || {}} />
                      {row.source ? (
                        <p className="mt-2 text-[11px] text-gray-400">
                          Origen: {row.source}
                        </p>
                      ) : null}
                    </div>
                  ) : null}
                </li>
              );
            })}
          </ul>
        )}
      </Surface>
    </div>
  );
}