import {
  LayoutDashboard,
  ClipboardList,
  FileInput,
  Users,
  Building2,
  UsersRound,
  FileText,
  FolderOpen,
  Settings,
  Bell,
  History,
  Mail,
  ListChecks,
  Siren,
  Compass,
  Timer,
  CalendarRange,
  LayoutGrid,
  MapPinned,
  Receipt,
  Download,
  type LucideIcon,
} from "lucide-react";
import type { ModuleKey } from "@/lib/modules";
import type { PlanFeature } from "@/lib/plans";
import type { Permission } from "@/server/rbac";

/**
 * Sidebar-Navigation des Backoffice (src/app/(app)/layout.tsx).
 *
 * Ein Eintrag ist sichtbar, wenn
 *   - sein Modul (falls gesetzt) für den Mandanten aktiv ist UND
 *   - die Session mindestens EINE der `permissions` hat (leer = immer).
 * Das ist reiner Komfort — Seiten und Actions prüfen Modul + Rechte serverseitig selbst.
 *
 * Neue Backoffice-Seite ⇒ hier eintragen; `label` ist ein Schlüssel in messages nav.*.
 * Mobile-Einträge (/m, /m/emergency) gehören NICHT hierher (eigene Mobile-Navigation).
 */
export interface NavItem {
  href: string;
  label: string;
  icon: LucideIcon;
  module?: ModuleKey;
  permissions?: readonly Permission[];
  section: "main" | "admin";
  /** L13: indented sub entry of the preceding item */
  sub?: boolean;
  /** L13: active only on exactly this path (not on sub paths) */
  exact?: boolean;
  /** L17 Pakete: feature without own module that the package tier must include (planning) */
  feature?: PlanFeature;
}

export const NAV_ITEMS: readonly NavItem[] = [
  { href: "/dashboard", label: "dashboard", icon: LayoutDashboard, section: "main" },
  // L13 Planung: top-level entry with sub entries; backoffice (read_all) + team leads (report:approve_team, own crews read-only)
  { href: "/planning", label: "planning", icon: CalendarRange, module: "work_orders", feature: "planning", permissions: ["work_order:read_all", "report:approve_team"], section: "main" },
  { href: "/planning", label: "planningBoard", icon: LayoutGrid, module: "work_orders", feature: "planning", permissions: ["work_order:read_all", "report:approve_team"], section: "main", sub: true, exact: true },
  { href: "/planning/live", label: "planningLive", icon: MapPinned, module: "work_orders", feature: "planning", permissions: ["work_order:read_all", "report:approve_team"], section: "main", sub: true },
  {
    href: "/work-orders",
    label: "workOrders",
    icon: ClipboardList,
    module: "work_orders",
    permissions: ["work_order:read_all", "work_order:read_team"],
    section: "main",
  },
  { href: "/work-orders/time-approvals", label: "timeApprovals", icon: Timer, module: "work_orders", permissions: ["time:approve"], section: "main" },
  { href: "/billing", label: "billing", icon: Receipt, module: "billing", permissions: ["billing:read"], section: "main" }, // L14
  { href: "/work-orders/emergency-review", label: "emergencyReview", icon: Siren, module: "emergency", permissions: ["emergency:review"], section: "main" },
  { href: "/imports", label: "imports", icon: FileInput, module: "imports", permissions: ["import:write"], section: "main" },
  { href: "/customers", label: "customers", icon: Users, module: "customers", permissions: ["customer:read"], section: "main" },
  { href: "/sites", label: "sites", icon: Building2, module: "sites", permissions: ["site:read"], section: "main" },
  { href: "/teams", label: "teams", icon: UsersRound, module: "teams", permissions: ["team:read"], section: "main" },
  { href: "/reports", label: "reports", icon: FileText, module: "reports", permissions: ["report:read"], section: "main" },
  { href: "/documents", label: "documents", icon: FolderOpen, module: "documents", permissions: ["document:read"], section: "main" },
  { href: "/notifications", label: "notifications", icon: Bell, module: "notifications", permissions: ["notification:read"], section: "main" },
  { href: "/settings/order-types", label: "templates", icon: ListChecks, permissions: ["settings:templates"], section: "admin" },
  { href: "/settings", label: "settings", icon: Settings, permissions: ["tenant:manage"], section: "admin" },
  { href: "/settings/email", label: "email", icon: Mail, module: "notifications", permissions: ["tenant:manage"], section: "admin" },
  { href: "/settings/audit", label: "audit", icon: History, permissions: ["audit:read"], section: "admin" },
  { href: "/settings/lotse", label: "lotse", icon: Compass, permissions: ["tenant:manage"], section: "admin" },
  { href: "/settings/export", label: "dataExport", icon: Download, permissions: ["tenant:manage"], section: "admin" }, // L15
];

/**
 * Filtert die Navigation nach aktiven Modulen und Rechten der Session. `disabledModules` = effektiv
 * inaktive Module (L17: abgeschaltet ODER nicht in der Paketstufe), `lockedFeatures` = nicht enthaltene
 * Paket-Features (Planung).
 */
export function visibleNavItems(
  items: readonly NavItem[],
  opts: { disabledModules: ReadonlySet<string>; permissions: readonly string[]; lockedFeatures?: ReadonlySet<string> },
): NavItem[] {
  return items.filter(
    (item) =>
      (!item.module || !opts.disabledModules.has(item.module)) &&
      (!item.feature || !opts.lockedFeatures?.has(item.feature)) &&
      (!item.permissions?.length || item.permissions.some((p) => opts.permissions.includes(p))),
  );
}