"use client";

import Image from "next/image";
import Link from "next/link";
import { useRouter } from "next/navigation";
import { usePathname } from "next/navigation";
import { useEffect, useState } from "react";
import { Moon, Sun } from "lucide-react";
import { useTheme } from "next-themes";
import { DEMO_AUTH_EMAIL_COOKIE, DEMO_AUTH_ROLE_COOKIE } from "@/lib/auth/demoAuth";
import { supabaseBrowser } from "@/lib/supabase/browser";
import { Button } from "@/components/ui/button";
import { cn } from "@/lib/utils";

type NavLink = {
  href: string;
  label: string;
};

const navLinks: NavLink[] = [
  { href: "/courses", label: "Formación Académica" },
  { href: "/case-studies", label: "Casos prácticos" },
  { href: "/practice", label: "Retos" },
  { href: "/eventos", label: "Eventos" },
  { href: "/noticias", label: "Noticias" },
  { href: "/comunidad", label: "Comunidad" },
  { href: "/sobre-acve", label: "Sobre ACVE" },
];

export default function Navbar() {
  const pathname = usePathname();
  const router = useRouter();
  const [userEmail, setUserEmail] = useState<string | null>(null);
  const [isTeacher, setIsTeacher] = useState(false);
  const [mounted, setMounted] = useState(false);
  const { resolvedTheme, setTheme } = useTheme();

  useEffect(() => {
    const client = supabaseBrowser();
    if (!client) {
      const cookieMap = new Map(
        document.cookie
          .split(";")
          .map((entry) => entry.trim())
          .filter(Boolean)
          .map((entry) => {
            const [key, ...rest] = entry.split("=");
            return [key, decodeURIComponent(rest.join("="))] as const;
          }),
      );

      const email = cookieMap.get(DEMO_AUTH_EMAIL_COOKIE) ?? null;
      const role = cookieMap.get(DEMO_AUTH_ROLE_COOKIE) ?? "";
      setUserEmail(email);
      setIsTeacher(role === "teacher");
      return;
    }

    let mounted = true;

    const fetchSession = async () => {
      const {
        data: { user },
      } = await client.auth.getUser();
      if (!mounted) return;
      const email = user?.email ?? null;
      setUserEmail(email);
      if (!user) {
        setIsTeacher(false);
        return;
      }
      try {
        const res = await fetch("/api/auth/session");
        if (!mounted) return;
        const data = await res.json();
        setIsTeacher(data.isTeacher === true);
      } catch {
        if (!mounted) return;
        setIsTeacher(false);
      }
    };

    fetchSession();

    const {
      data: { subscription },
    } = client.auth.onAuthStateChange(() => {
      fetchSession();
    });

    return () => {
      mounted = false;
      subscription.unsubscribe();
    };
  }, []);

  useEffect(() => {
    setMounted(true);
  }, []);

  const handleLogout = async () => {
    const loginSwitchUrl = "/auth/login?switchUser=1&redirectTo=/courses";
    document.cookie = `${DEMO_AUTH_EMAIL_COOKIE}=; path=/; max-age=0`;
    document.cookie = `${DEMO_AUTH_ROLE_COOKIE}=; path=/; max-age=0`;

    const client = supabaseBrowser();
    if (!client) {
      setUserEmail(null);
      setIsTeacher(false);
      router.replace(loginSwitchUrl);
      router.refresh();
      return;
    }

    await client.auth.signOut();
    setUserEmail(null);
    setIsTeacher(false);
    router.replace(loginSwitchUrl);
    router.refresh();
  };

  const isDark = resolvedTheme === "dark";
  const loginHref = userEmail ? "/profile" : "/auth/login";
  const loginLabel = userEmail ? "Mi cuenta" : "Ingresa";

  const isNavActive = (href: string) => {
    return pathname === href || pathname?.startsWith(`${href}/`);
  };

  return (
    <header className="sticky top-0 z-50 border-b border-border/70 bg-background/90 backdrop-blur supports-[backdrop-filter]:bg-background/70">
      <div className="border-b border-border/60 bg-card/80">
        <div className="mx-auto flex w-full max-w-[1300px] items-center gap-3 px-4 py-2 text-xs text-muted-foreground md:px-6">
          <div className="hidden items-center gap-4 sm:flex">
            <Link className="hover:text-foreground" href="/auth/signup">
              Únete
            </Link>
            <Link className="hover:text-foreground" href={loginHref}>
              {loginLabel}
            </Link>
            <Link className="hover:text-foreground" href="/#footer-contact">
              Contáctanos
            </Link>
          </div>

          <div className="ml-auto flex items-center gap-2">
            <Button
              aria-label={isDark ? "Cambiar a modo claro" : "Cambiar a modo oscuro"}
              className="rounded-full"
              size="icon"
              type="button"
              variant="ghost"
              onClick={() => setTheme(isDark ? "light" : "dark")}
            >
              {mounted && isDark ? <Sun className="h-4 w-4" /> : <Moon className="h-4 w-4" />}
            </Button>

            {userEmail ? (
              <>
                <span className="hidden max-w-44 truncate px-2 text-muted-foreground md:inline-block">{userEmail}</span>
                <Button className="rounded-full" size="sm" variant="outline" asChild>
                  <Link href="/profile">Mi cuenta</Link>
                </Button>
                <Button className="rounded-full" size="sm" type="button" variant="ghost" onClick={handleLogout}>
                  Salir
                </Button>
              </>
            ) : (
              <Button className="rounded-full" size="sm" variant="outline" asChild>
                <Link href="/auth/login">Ingresa</Link>
              </Button>
            )}
          </div>
        </div>
      </div>

      <div className="mx-auto w-full max-w-[1300px] px-4 md:px-6">
        <div className="flex items-center justify-between gap-4 py-4">
          <Link className="flex items-center gap-3" href="/">
            <div className="rounded-xl bg-primary/10 p-1.5 shadow-sm ring-1 ring-primary/20">
              <Image alt="ACVE logo" className="h-10 w-10 rounded-lg object-cover" height={40} src="/images/logo.png" width={40} />
            </div>
            <div className="leading-tight">
              <div className="text-2xl font-bold tracking-tight text-primary md:text-3xl">ACVE Centro de Estudios</div>
              <div className="text-xs text-muted-foreground md:text-sm">Empowering Lawyer one word at a time</div>
            </div>
          </Link>

          <div className="flex items-center gap-2">
            {isTeacher ? (
              <Button className="hidden rounded-full md:inline-flex" size="sm" variant="outline" asChild>
                <Link href="/teacher">Panel docente</Link>
              </Button>
            ) : null}
            <Button className="rounded-full px-5" asChild>
              <Link href="/auth/signup">¡Inscríbete!</Link>
            </Button>
          </div>
        </div>

        <nav className="hidden items-center gap-1 border-t border-border/70 py-3 text-sm lg:flex">
          {navLinks.map((link) => {
            const isActive = isNavActive(link.href);
            return (
              <Button
                key={link.href}
                className={cn("rounded-full px-4 font-semibold", !isActive && "text-muted-foreground hover:text-foreground")}
                variant={isActive ? "default" : "ghost"}
                asChild
              >
                <Link href={link.href}>{link.label}</Link>
              </Button>
            );
          })}
        </nav>

        <nav className="flex gap-2 overflow-x-auto border-t border-border/70 pb-3 pt-2 text-sm lg:hidden">
          {navLinks.map((link) => {
            const isActive = isNavActive(link.href);
            return (
              <Button
                key={link.href}
                className="whitespace-nowrap rounded-full px-4"
                size="sm"
                variant={isActive ? "default" : "outline"}
                asChild
              >
                <Link href={link.href}>{link.label}</Link>
              </Button>
            );
          })}
        </nav>
      </div>
    </header>
  );
}