import { useState } from "react";
import { Link, NavLink, useLocation } from "react-router";
import {
  Sheet,
  SheetContent,
  SheetHeader,
  SheetTitle,
  SheetTrigger,
} from "~/components/ui/sheet";
import { Button } from "~/components/ui/button";
import { authClient } from "~/lib/auth-client";
import { UserMenu } from "~/components/UserMenu";
import type { RawFlagConfig } from "~/lib/flag-types";
import { HelpCircle, MenuIcon, Settings } from "lucide-react";

const NAV_LINK_CLASS =
  "relative text-sm font-semibold uppercase tracking-wide text-muted-foreground px-3 py-2 transition-colors " +
  "after:content-[''] after:absolute after:bottom-0 after:left-3 after:right-3 after:h-[3px] " +
  "after:scale-x-0 hover:after:scale-x-100 after:transition-transform after:[background:var(--brackt-gradient)]";

function navLinkClass({ isActive }: { isActive: boolean }) {
  return `${NAV_LINK_CLASS}${isActive ? " !text-emerald-400" : ""}`;
}

function mobileNavLinkClass({ isActive }: { isActive: boolean }) {
  return `block px-4 py-2 text-lg font-medium rounded-md transition-colors${isActive ? " text-emerald-400" : " text-muted-foreground"}`;
}

interface NavbarProps {
  isAdmin: boolean;
  currentUser: {
    id: string;
    email: string;
    username: string | null;
    displayName: string | null;
    customAvatarUrl: string | null;
    flagConfig: RawFlagConfig | null;
    avatarType: string | null;
  } | null;
}

export function Navbar({ isAdmin, currentUser }: NavbarProps) {
  const [open, setOpen] = useState(false);
  const location = useLocation();
  const { data: session } = authClient.useSession();

  const signInHref = `/login?redirectTo=${encodeURIComponent(location.pathname)}`;

  const menuUser = currentUser ?? (session ? {
    id: session.user.id,
    email: session.user.email,
    username: null,
    displayName: session.user.name ?? null,
    customAvatarUrl: null,
    flagConfig: null,
    avatarType: null,
  } : null);

  const authSection = menuUser ? (
    <UserMenu
      userId={menuUser.id}
      name={menuUser.username ?? menuUser.displayName}
      email={menuUser.email}
      customAvatarUrl={menuUser.customAvatarUrl}
      flagConfig={menuUser.flagConfig}
      avatarType={menuUser.avatarType}
    />
  ) : (
    <Link to={signInHref}>
      <Button>Sign In</Button>
    </Link>
  );

  return (
    <header className="sticky top-0 z-50 w-full border-b border-border/40 bg-background/95 backdrop-blur supports-[backdrop-filter]:bg-background/60">
      <div className="flex h-16 items-center justify-between px-4 md:px-6 lg:px-8">
        {/* Left: Logo + Nav links */}
        <div className="flex items-center gap-2">
          <Link to="/" className="flex items-center mr-2">
            <img src="/logo.svg" alt="Brackt" className="h-14" />
          </Link>
          <nav aria-label="Main navigation" className="hidden md:flex items-center gap-1">
            {session
              ? <NavLink to="/" end className={navLinkClass}>Dashboard</NavLink>
              : <NavLink to="/" end className={navLinkClass}>Home</NavLink>
            }
            <NavLink to="/how-to-play" className={navLinkClass}>How To Play</NavLink>
            <NavLink to="/sports" className={navLinkClass}>Sports</NavLink>
            <NavLink to="/rules" className={navLinkClass}>Rules</NavLink>
          </nav>
        </div>

        {/* Desktop Right: Support + Admin icons + Auth */}
        <div className="hidden md:flex items-center gap-2">
          <Link
            to="/support"
            className="inline-flex items-center justify-center h-9 w-9 rounded-md text-muted-foreground hover:text-foreground hover:bg-white/5 transition-colors"
            aria-label="Support"
          >
            <HelpCircle className="h-5 w-5" />
          </Link>
          {isAdmin && (
            <Link
              to="/admin"
              className="inline-flex items-center justify-center h-9 w-9 rounded-md text-muted-foreground hover:text-foreground hover:bg-white/5 transition-colors"
              aria-label="Admin"
            >
              <Settings className="h-5 w-5" />
            </Link>
          )}
          {authSection}
        </div>

        {/* Mobile: icons + Auth + Hamburger */}
        <div className="flex md:hidden items-center gap-1">
          <Link
            to="/support"
            className="inline-flex items-center justify-center h-9 w-9 rounded-md text-muted-foreground hover:text-foreground transition-colors"
            aria-label="Support"
          >
            <HelpCircle className="h-5 w-5" />
          </Link>
          {isAdmin && (
            <Link
              to="/admin"
              className="inline-flex items-center justify-center h-9 w-9 rounded-md text-muted-foreground hover:text-foreground transition-colors"
              aria-label="Admin"
            >
              <Settings className="h-5 w-5" />
            </Link>
          )}
          {authSection}

          <Sheet open={open} onOpenChange={setOpen}>
            <SheetTrigger asChild>
              <button
                className="inline-flex items-center justify-center rounded-md text-sm font-medium transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 disabled:pointer-events-none disabled:opacity-50 hover:bg-accent hover:text-accent-foreground h-10 w-10"
                aria-label="Toggle menu"
              >
                <MenuIcon className="h-6 w-6" />
              </button>
            </SheetTrigger>
            <SheetContent side="right" className="w-[300px] sm:w-[400px]">
              <SheetHeader>
                <SheetTitle>Menu</SheetTitle>
              </SheetHeader>
              <nav aria-label="Mobile navigation" className="flex flex-col gap-4 mt-8">
                <NavLink
                  to="/"
                  end
                  className={mobileNavLinkClass}
                  onClick={() => setOpen(false)}
                >
                  {session ? "Dashboard" : "Home"}
                </NavLink>
                <NavLink
                  to="/how-to-play"
                  className={mobileNavLinkClass}
                  onClick={() => setOpen(false)}
                >
                  How To Play
                </NavLink>
                <NavLink
                  to="/sports"
                  className={mobileNavLinkClass}
                  onClick={() => setOpen(false)}
                >
                  Sports
                </NavLink>
                <NavLink
                  to="/rules"
                  className={mobileNavLinkClass}
                  onClick={() => setOpen(false)}
                >
                  Rules
                </NavLink>
              </nav>
            </SheetContent>
          </Sheet>
        </div>
      </div>
    </header>
  );
}
