import {
  Award,
  Briefcase,
  CalendarDays,
  ChevronDown,
  ClipboardList,
  LayoutDashboard,
  Shield,
  UserRound,
  Users,
} from "lucide-react";
import { useEffect, useRef, useState, type ComponentType } from "react";
import { NavLink, Outlet, useLocation } from "react-router-dom";

import { useAuth } from "../../auth";

const navItems = [
  { to: "/people", label: "People" },
  { to: "/projects", label: "Projects" },
];

interface ManageItem {
  to: string;
  label: string;
  icon: ComponentType<{ size?: number; className?: string }>;
}

const manageGroups: ManageItem[][] = [
  [
    { to: "/manage", label: "Manage Hub", icon: LayoutDashboard },
  ],
  [
    { to: "/manage/people", label: "People", icon: UserRound },
    { to: "/manage/projects", label: "Projects", icon: ClipboardList },
  ],
  [
    { to: "/manage/roles", label: "Roles", icon: Briefcase },
    { to: "/manage/teams", label: "Teams", icon: Users },
    { to: "/manage/skills", label: "Skills", icon: Award },
  ],
  [
    { to: "/manage/holidays", label: "Holidays", icon: CalendarDays },
    { to: "/manage/users", label: "Users", icon: Shield },
  ],
];

const tailNavItems = [
  { to: "/reports", label: "Reports" },
  { to: "/insights", label: "Insights" },
];

export function Layout() {
  const { logout, user } = useAuth();
  const location = useLocation();
  const [menuOpen, setMenuOpen] = useState(false);
  const [manageOpen, setManageOpen] = useState(false);
  const manageRef = useRef<HTMLDivElement>(null);
  const closeTimer = useRef<number | undefined>(undefined);

  const isManageActive = location.pathname === "/manage" || location.pathname.startsWith("/manage/");

  useEffect(() => {
    setManageOpen(false);
  }, [location.pathname]);

  useEffect(() => {
    if (!menuOpen) return;
    const onClick = (event: MouseEvent) => {
      const target = event.target as HTMLElement;
      if (!target.closest(".topnav-actions")) setMenuOpen(false);
    };
    document.addEventListener("mousedown", onClick);
    return () => document.removeEventListener("mousedown", onClick);
  }, [menuOpen]);

  useEffect(() => {
    if (!manageOpen) return;
    const handler = (event: MouseEvent) => {
      if (manageRef.current && !manageRef.current.contains(event.target as Node)) {
        setManageOpen(false);
      }
    };
    document.addEventListener("mousedown", handler);
    return () => document.removeEventListener("mousedown", handler);
  }, [manageOpen]);

  const openManage = () => {
    if (closeTimer.current) window.clearTimeout(closeTimer.current);
    setManageOpen(true);
  };
  const scheduleCloseManage = () => {
    if (closeTimer.current) window.clearTimeout(closeTimer.current);
    closeTimer.current = window.setTimeout(() => setManageOpen(false), 140);
  };

  return (
    <div className="app-shell">
      <header className="topnav">
        <div className="topnav-brand">
          <div className="brand-mark">R</div>
          <div>
            <strong>Resource Portal</strong>
            <small>Internal IT</small>
          </div>
        </div>

        <nav className="topnav-tabs">
          {navItems.map((item) => (
            <NavLink
              key={item.to}
              to={item.to}
              className={({ isActive }) => `topnav-tab${isActive ? " active" : ""}`}
            >
              {item.label}
            </NavLink>
          ))}

          <div
            className="topnav-dropdown"
            onMouseEnter={openManage}
            onMouseLeave={scheduleCloseManage}
            ref={manageRef}
          >
            <NavLink
              to="/manage"
              end
              className={`topnav-tab${isManageActive ? " active" : ""}`}
              onClick={() => setManageOpen(false)}
            >
              Manage
              <ChevronDown size={14} className="topnav-tab-caret" />
            </NavLink>
            {manageOpen ? (
              <div className="topnav-menu" role="menu">
                {manageGroups.map((group, groupIndex) => (
                  <div className="topnav-menu-group" key={groupIndex}>
                    {group.map((item) => (
                      <NavLink
                        key={item.to}
                        to={item.to}
                        end={item.to === "/manage"}
                        className={({ isActive }) => `topnav-menu-item${isActive ? " active" : ""}`}
                        role="menuitem"
                      >
                        <item.icon size={16} className="topnav-menu-icon" />
                        <span>{item.label}</span>
                      </NavLink>
                    ))}
                  </div>
                ))}
              </div>
            ) : null}
          </div>

          {tailNavItems.map((item) => (
            <NavLink
              key={item.to}
              to={item.to}
              className={({ isActive }) => `topnav-tab${isActive ? " active" : ""}`}
            >
              {item.label}
            </NavLink>
          ))}
        </nav>

        <div className="topnav-actions">
          <button
            aria-haspopup="menu"
            aria-expanded={menuOpen}
            className="user-chip"
            onClick={() => setMenuOpen((open) => !open)}
            type="button"
          >
            <span className="user-avatar">{user?.username?.[0]?.toUpperCase() ?? "?"}</span>
            <span className="user-meta">
              <strong>{user?.username}</strong>
              <small className="badge live">{user?.role}</small>
            </span>
          </button>
          {menuOpen ? (
            <div className="user-menu" role="menu">
              <button
                onClick={() => {
                  setMenuOpen(false);
                  logout();
                }}
                role="menuitem"
                type="button"
              >
                Sign out
              </button>
            </div>
          ) : null}
        </div>
      </header>

      <main className="content">
        <Outlet />
      </main>
    </div>
  );
}