import { Suspense } from 'react';
import { redirect } from 'next/navigation';
import Link from 'next/link';
import { getServerSession } from '@/lib/auth/getServerSession';
import { PERMISSIONS } from '@/lib/permissions/permissions';
import AccessDenied from '@/components/admin/errors/AccessDenied';
import UnitTypesTable from '@/components/admin/unit-types/UnitTypesTable';
import { UnitTypesTableSkeleton } from '@/components/admin/unit-types/UnitTypeSkeleton';
import { cookies } from 'next/headers';
import { SESSION_COOKIE } from '@/lib/auth/requireAuth';
import { Metadata } from 'next';

export const metadata: Metadata = {
  title: 'Unit Types',
};

// ─── Data fetchers ────────────────────────────────────────────────────────────

async function getInitialUnitTypes(sessionToken: string) {
  try {
    const baseUrl = process.env.NEXT_PUBLIC_APP_URL || 'http://localhost:3000';
    const res = await fetch(`${baseUrl}/api/unit-types?page=1&limit=10`, {
      cache: 'no-store',
      headers: { Authorization: `Bearer ${sessionToken}` },
    });
    if (!res.ok) throw new Error('Failed to fetch unit types');
    const data = await res.json();
    return data.data;
  } catch (error) {
    console.error('Failed to fetch initial unit types:', error);
    return {
      unitTypes: [],
      pagination: { page: 1, limit: 10, total: 0, totalPages: 0 },
    };
  }
}

async function getInitialCounts(sessionToken: string) {
  try {
    const baseUrl = process.env.NEXT_PUBLIC_APP_URL || 'http://localhost:3000';
    const res = await fetch(`${baseUrl}/api/unit-types/counts`, {
      cache: 'no-store',
      headers: { Authorization: `Bearer ${sessionToken}` },
    });
    if (!res.ok) throw new Error('Failed to fetch counts');
    const data = await res.json();
    return data.data as { active: number; deleted: number };
  } catch (error) {
    console.error('Failed to fetch unit type counts:', error);
    return { active: 0, deleted: 0 };
  }
}

// ─── Page content ─────────────────────────────────────────────────────────────

async function UnitTypesContent() {
  const cookieStore = await cookies();
  const sessionId = cookieStore.get(SESSION_COOKIE)?.value;
  if (!sessionId) redirect('/admin/login');

  const session = await getServerSession();
  if (!session) redirect('/admin/login');
  if (!session.permissions.includes(PERMISSIONS.UNIT_TYPES_READ)) return <AccessDenied />;

  const canCreate = session.permissions.includes(PERMISSIONS.UNIT_TYPES_CREATE);
  const canEdit = session.permissions.includes(PERMISSIONS.UNIT_TYPES_UPDATE);
  const canDelete = session.permissions.includes(PERMISSIONS.UNIT_TYPES_DELETE);
  const canBulkDelete = session.permissions.includes(PERMISSIONS.UNIT_TYPES_BULK_DELETE);
  const canViewDeleted = session.permissions.includes(PERMISSIONS.UNIT_TYPES_VIEW_DELETED);
  const canPermanentDelete = session.permissions.includes(PERMISSIONS.UNIT_TYPES_PERMANENT_DELETE);
  const canRestore = session.permissions.includes(PERMISSIONS.UNIT_TYPES_RESTORE);
  const canBulkRestore = session.permissions.includes(PERMISSIONS.UNIT_TYPES_BULK_RESTORE);
  const canViewTimeline = session.permissions.includes(PERMISSIONS.UNIT_TYPES_VIEW_TIMELINE);

  const [initialData, initialCounts] = await Promise.all([
    getInitialUnitTypes(sessionId),
    getInitialCounts(sessionId),
  ]);

  return (
    <>
      <div className="flex flex-wrap justify-between items-center gap-3 mb-6">
        <div>
          <h1 className="text-2xl font-semibold" style={{ color: 'var(--color-text)' }}>
            Unit Types
          </h1>
          <p className="text-sm mt-1" style={{ color: 'var(--color-text-secondary)' }}>
            Manage unit types with multi-language support
          </p>
        </div>

        {canCreate && (
          <Link
            href="/admin/dashboard/system/unit-types/new"
            className="inline-flex items-center gap-2 px-4 py-2 rounded-lg text-sm font-medium transition-all hover:opacity-90"
            style={{ background: 'var(--color-cta)', color: 'white' }}
          >
            <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
              <path d="M12 5v14m-7-7h14"/>
            </svg>
            Add Unit Type
          </Link>
        )}
      </div>

      <UnitTypesTable
        canEdit={canEdit}
        canDelete={canDelete}
        canBulkDelete={canBulkDelete}
        canViewDeleted={canViewDeleted}
        canPermanentDelete={canPermanentDelete}
        canRestore={canRestore}
        canBulkRestore={canBulkRestore}
        canViewTimeline={canViewTimeline}
        initialUnitTypes={initialData}
        initialCounts={initialCounts}
      />
    </>
  );
}

export default async function UnitTypesPage() {
  return (
    <div className="sm:p-6">
      <Suspense fallback={<UnitTypesTableSkeleton />}>
        <UnitTypesContent />
      </Suspense>
    </div>
  );
}