"use client";

import { usePathname } from "next/navigation";
import Link from "next/link";
import { cn } from "@/lib/utils";
import {
  LayoutDashboard,
  FileText,
  Plus,
  CheckSquare,
  CreditCard,
  History,
  Receipt,
  Users,
  Ship,
  Building2,
  Store,
  Anchor,
  Package,
  Upload,
  MapPin,
  ShoppingCart,
  UserCircle,
  ShieldCheck,
} from "lucide-react";
import type { Role } from "@prisma/client";

interface NavItem {
  href: string;
  label: string;
  icon: React.ElementType;
  roles?: Role[];
}

const NAV_ITEMS: NavItem[] = [
  { href: "/dashboard", label: "Dashboard", icon: LayoutDashboard },
  { href: "/po/new", label: "New PO", icon: Plus, roles: ["TECHNICAL", "MANNING", "MANAGER", "SUPERUSER"] },
  { href: "/my-orders", label: "Closed Purchase Orders", icon: FileText, roles: ["TECHNICAL", "MANNING", "MANAGER", "SUPERUSER"] },
  { href: "/po/import", label: "Import PO", icon: Upload, roles: ["MANAGER", "SUPERUSER"] },
  { href: "/approvals", label: "Approvals", icon: CheckSquare, roles: ["MANAGER", "SUPERUSER"] },
  { href: "/payments", label: "Payments", icon: CreditCard, roles: ["ACCOUNTS"] },
  { href: "/payments/history", label: "Payment History", icon: Receipt, roles: ["ACCOUNTS", "SUPERUSER"] },
  { href: "/history", label: "History", icon: History, roles: ["MANAGER", "SUPERUSER", "AUDITOR", "ADMIN"] },
  { href: "/profile", label: "My Profile", icon: UserCircle },
];

const INVENTORY_ITEMS: NavItem[] = [
  { href: "/inventory/items", label: "Items", icon: Package, roles: ["TECHNICAL", "MANNING", "SUPERUSER"] },
  { href: "/inventory/vendors", label: "Vendors", icon: Store, roles: ["TECHNICAL", "MANNING", "SUPERUSER"] },
  { href: "/inventory/cart", label: "Cart", icon: ShoppingCart, roles: ["TECHNICAL", "MANNING", "SUPERUSER", "MANAGER"] },
  { href: "/admin/vendors", label: "Vendors", icon: Store, roles: ["MANAGER", "ACCOUNTS", "ADMIN"] },
  { href: "/admin/products", label: "Items", icon: Package, roles: ["MANAGER", "ADMIN"] },
  { href: "/admin/vessels", label: "Cost Centres", icon: Ship, roles: ["MANAGER", "ADMIN"] },
  { href: "/admin/sites", label: "Sites", icon: MapPin, roles: ["MANAGER", "ADMIN"] },
];

const ADMIN_ITEMS: NavItem[] = [
  { href: "/admin/users", label: "Users", icon: Users },
  { href: "/admin/superuser-requests", label: "SuperUser Requests", icon: ShieldCheck },
  { href: "/admin/accounts", label: "Accounts", icon: Building2 },
];

export function Sidebar({ userRole }: { userRole: Role }) {
  const pathname = usePathname();
  const isAdmin = userRole === "ADMIN";

  const visible = NAV_ITEMS.filter(
    (item) => !item.roles || item.roles.includes(userRole)
  );
  const visibleInventory = INVENTORY_ITEMS.filter(
    (item) => !item.roles || item.roles.includes(userRole)
  );

  return (
    <aside className="flex h-screen w-60 shrink-0 flex-col border-r border-neutral-200 bg-white">
      <div className="flex h-16 items-center gap-2.5 border-b border-neutral-200 px-4">
        <div className="flex h-8 w-8 items-center justify-center rounded-lg bg-primary-600">
          <Anchor className="h-4 w-4 text-white" />
        </div>
        <span className="text-sm font-semibold text-neutral-900">PPMS</span>
      </div>

      <nav className="flex-1 overflow-y-auto px-3 py-4 space-y-0.5">
        {visible.map((item) => (
          <NavLink key={item.href} item={item} pathname={pathname} />
        ))}

        {visibleInventory.length > 0 && (
          <>
            <div className="pt-4 pb-1 px-3">
              <p className="text-xs font-semibold text-neutral-400 uppercase tracking-wider">Inventory</p>
            </div>
            {visibleInventory.map((item) => (
              <NavLink key={item.href} item={item} pathname={pathname} />
            ))}
          </>
        )}

        {isAdmin && (
          <>
            <div className="pt-4 pb-1 px-3">
              <p className="text-xs font-semibold text-neutral-400 uppercase tracking-wider">Administration</p>
            </div>
            {ADMIN_ITEMS.map((item) => (
              <NavLink key={item.href} item={item} pathname={pathname} />
            ))}
          </>
        )}
      </nav>
    </aside>
  );
}

function NavLink({ item, pathname }: { item: NavItem; pathname: string }) {
  const isActive = pathname === item.href || pathname.startsWith(item.href + "/");
  const Icon = item.icon;

  return (
    <Link
      href={item.href}
      className={cn(
        "flex items-center gap-3 rounded-md px-3 py-2 text-sm font-medium transition-colors",
        isActive
          ? "bg-primary-50 text-primary-700"
          : "text-neutral-600 hover:bg-neutral-100 hover:text-neutral-900"
      )}
    >
      <Icon className="h-4 w-4 shrink-0" />
      {item.label}
    </Link>
  );
}