"use client";

import { useState } from "react";
import Link from "next/link";
import { usePathname } from "next/navigation";
import { cn } from "@/lib/utils";

const navItems = [
  { label: "Dashboard", href: "/" },
  { label: "Receive", href: "/receive" },
  { label: "Send", href: "/send" },
  { label: "Transfer", href: "/transfer" },
  { label: "Approvals", href: "/approvals" },
  { label: "Activity", href: "/activity" },
  { label: "Settings", href: "/settings" },
];

function NavLink({
  href,
  label,
  isActive,
  onNavigate,
}: {
  href: string;
  label: string;
  isActive: boolean;
  onNavigate?: () => void;
}) {
  return (
    <Link
      href={href}
      onClick={onNavigate}
      className={cn(
        "px-4 py-3 sm:py-4 text-sm font-medium transition-colors border-b-2 whitespace-nowrap",
        isActive
          ? "border-blue-500 text-blue-400 bg-blue-950/30 sm:bg-transparent"
          : "border-transparent text-gray-400 hover:text-gray-200 hover:border-gray-700 hover:bg-gray-800/50 sm:hover:bg-transparent"
      )}
    >
      {label}
    </Link>
  );
}

export function Navigation() {
  const pathname = usePathname();
  const [mobileOpen, setMobileOpen] = useState(false);

  const closeMobile = () => setMobileOpen(false);

  return (
    <nav
      className="bg-gray-900 border-b border-gray-800 shrink-0"
      aria-label="Main navigation"
    >
      <div className="max-w-7xl mx-auto px-4 sm:px-8">
        {/* Mobile: menu toggle + horizontal scroll fallback on sm */}
        <div className="flex items-center justify-between sm:hidden py-2">
          <span className="text-sm text-gray-400">
            {navItems.find((item) => item.href === pathname)?.label ?? "Menu"}
          </span>
          <button
            type="button"
            onClick={() => setMobileOpen((open) => !open)}
            className="px-3 py-2 text-sm font-medium text-gray-200 bg-gray-800 hover:bg-gray-700 rounded-lg transition-colors"
            aria-expanded={mobileOpen}
            aria-controls="mobile-nav-menu"
          >
            {mobileOpen ? "Close" : "Menu"}
          </button>
        </div>

        {/* Desktop nav */}
        <div className="hidden sm:flex items-center gap-2 lg:gap-4 overflow-x-auto">
          {navItems.map((item) => (
            <NavLink
              key={item.href}
              href={item.href}
              label={item.label}
              isActive={pathname === item.href}
            />
          ))}
        </div>

        {/* Mobile dropdown */}
        {mobileOpen && (
          <div
            id="mobile-nav-menu"
            className="sm:hidden flex flex-col border-t border-gray-800"
          >
            {navItems.map((item) => (
              <NavLink
                key={item.href}
                href={item.href}
                label={item.label}
                isActive={pathname === item.href}
                onNavigate={closeMobile}
              />
            ))}
          </div>
        )}
      </div>
    </nav>
  );
}