"use client";

import Link from "next/link";
import { usePathname } from "next/navigation";
import {
  LayoutDashboard,
  FolderOpen,
  Clock,
  Calendar,
  Brain,
  BarChart3,
  Settings,
  Menu,
  X,
} from "lucide-react";
import { useState, useEffect } from "react";
import { usePermissions } from "@/lib/hooks/usePermissions";

interface NavItem {
  name: string;
  href: string;
  icon: typeof LayoutDashboard;
  permission?: string;
}

const allNavigation: NavItem[] = [
  { name: "Dashboard", href: "/dashboard", icon: LayoutDashboard },
  { name: "Akten", href: "/cases", icon: FolderOpen },
  { name: "Fristen", href: "/fristen", icon: Clock },
  { name: "Termine", href: "/termine", icon: Calendar },
  { name: "Berichte", href: "/berichte", icon: BarChart3 },
  { name: "AI Analyse", href: "/ai/extract", icon: Brain, permission: "ai_extraction" },
  { name: "Einstellungen", href: "/einstellungen", icon: Settings, permission: "manage_settings" },
];

export function Sidebar() {
  const pathname = usePathname();
  const [mobileOpen, setMobileOpen] = useState(false);
  const { can, isLoading: permLoading } = usePermissions();

  const navigation = allNavigation.filter(
    (item) => !item.permission || permLoading || can(item.permission),
  );

  // Close on route change
  useEffect(() => {
    setMobileOpen(false);
  }, [pathname]);

  // Close on escape
  useEffect(() => {
    function onKeyDown(e: KeyboardEvent) {
      if (e.key === "Escape") setMobileOpen(false);
    }
    document.addEventListener("keydown", onKeyDown);
    return () => document.removeEventListener("keydown", onKeyDown);
  }, []);

  const navContent = (
    <>
      <div className="flex h-14 items-center justify-between border-b border-neutral-200 px-4">
        <span className="text-sm font-semibold text-neutral-900">KanzlAI</span>
        <button
          onClick={() => setMobileOpen(false)}
          className="rounded-md p-1 text-neutral-400 transition-colors hover:bg-neutral-100 hover:text-neutral-600 lg:hidden"
          aria-label="Menü schließen"
        >
          <X className="h-4 w-4" />
        </button>
      </div>
      <nav className="flex-1 space-y-0.5 p-2">
        {navigation.map((item) => {
          const isActive =
            pathname === item.href || pathname.startsWith(item.href + "/");
          return (
            <Link
              key={item.href}
              href={item.href}
              className={`flex items-center gap-2.5 rounded-md px-2.5 py-2 text-sm transition-colors ${
                isActive
                  ? "bg-neutral-100 font-medium text-neutral-900"
                  : "text-neutral-600 hover:bg-neutral-50 hover:text-neutral-900"
              }`}
            >
              <item.icon className="h-4 w-4 shrink-0" />
              {item.name}
            </Link>
          );
        })}
      </nav>
    </>
  );

  return (
    <>
      {/* Mobile hamburger button */}
      <button
        onClick={() => setMobileOpen(true)}
        className="fixed left-3 top-3.5 z-40 rounded-md bg-white p-1.5 shadow-sm ring-1 ring-neutral-200 transition-colors hover:bg-neutral-50 lg:hidden"
        aria-label="Menü öffnen"
      >
        <Menu className="h-5 w-5 text-neutral-700" />
      </button>

      {/* Mobile overlay */}
      {mobileOpen && (
        <div
          className="fixed inset-0 z-40 bg-black/20 backdrop-blur-sm lg:hidden"
          onClick={() => setMobileOpen(false)}
        />
      )}

      {/* Mobile sidebar */}
      {mobileOpen && (
        <aside className="animate-slide-in-left fixed inset-y-0 left-0 z-50 flex w-56 flex-col border-r border-neutral-200 bg-white shadow-lg lg:hidden">
          {navContent}
        </aside>
      )}

      {/* Desktop sidebar */}
      <aside className="hidden h-full w-56 flex-col border-r border-neutral-200 bg-white lg:flex">
        {navContent}
      </aside>
    </>
  );
}