"use client";

import { usePathname } from "next/navigation";
import { useEffect, useRef, useState } from "react";
import { COOKIE_BAR_ID } from "@/lib/analytics";
import { NAVIGATION_ITEMS } from "@/lib/site-navigation";
import {
  headerOpensWhatsApp,
  type WhatsAppContexts,
  whatsAppSubjectForPath,
} from "@/lib/whatsapp";
import HoverPrefetchLink from "./HoverPrefetchLink";
import { Logo } from "./Logo";
import WhatsAppLink from "./WhatsAppLink";

const MENU_ID = "site-navigation-menu";
const CTA_LABEL = "Falar sobre meu projeto";
/** Fora da home o botão abre o WhatsApp: "Falar sobre meu projeto" é sempre o formulário. */
const WHATSAPP_LABEL = "Chamar no WhatsApp";
/** Ids que ficam inertes com o menu aberto: o conteúdo da página e o rodapé (o id do rodapé vem de app/layout.tsx). */
const INERT_IDS = ["main-content", "site-footer"];
/** A partir do breakpoint xl a barra mostra os links e o menu do celular deixa de existir. */
const DESKTOP_QUERY = "(min-width: 1280px)";

/**
 * Controles que o Tab percorre com o menu aberto: todos os da barra de cookies, quando ela está aberta (o link "Política
 * de privacidade", Aceitar e Recusar; ela vem antes do cabeçalho no layout e não fica inerte), e depois logo, botão do
 * menu, links e botão de contato do painel.
 * A navegação e o botão da barra de desktop ficam de fora (data-menu-trap-skip): estão escondidos no celular.
 */
function menuFocusables(header: HTMLElement) {
  const cookieBar = document.getElementById(COOKIE_BAR_ID);
  const roots = cookieBar ? [cookieBar, header] : [header];
  return roots
    .flatMap((root) =>
      Array.from(
        root.querySelectorAll<HTMLElement>("a[href], button:not([disabled])"),
      ),
    )
    .filter((element) => !element.closest("[data-menu-trap-skip]"));
}

/** Tab (e Shift+Tab) com o menu aberto: o foco dá a volta entre o cabeçalho e a barra de cookies, sem sair para a página inerte. */
function trapTab(event: KeyboardEvent, header: HTMLElement) {
  const focusables = menuFocusables(header);
  const first = focusables[0];
  const last = focusables[focusables.length - 1];
  const [edge, opposite] = event.shiftKey ? [first, last] : [last, first];
  const active = document.activeElement;
  const leaving =
    active === edge || !focusables.some((element) => element === active);
  if (!leaving || !opposite) return;

  event.preventDefault();
  opposite.focus();
}

/**
 * Botão de contato do cabeçalho. Fora da home (serviço, case, /ia, /cases, /servicos e /curriculo) ele abre o WhatsApp
 * já com o assunto da página, com o nome "Chamar no WhatsApp"; na home e nas demais páginas leva ao formulário da home
 * ("Falar sobre meu projeto").
 */
function ContactCta({
  className,
  placement,
  viaWhatsApp,
  subject,
  onNavigate,
}: {
  className: string;
  placement: string;
  viaWhatsApp: boolean;
  subject?: string;
  onNavigate?: () => void;
}) {
  if (viaWhatsApp) {
    return (
      <WhatsAppLink
        className={className}
        service={subject}
        placement={placement}
        onClick={onNavigate}
      >
        {WHATSAPP_LABEL}
      </WhatsAppLink>
    );
  }
  return (
    <HoverPrefetchLink
      href="/#contact"
      className={className}
      onClick={onNavigate}
    >
      {CTA_LABEL}
    </HoverPrefetchLink>
  );
}

export function Header({
  whatsAppContexts,
}: {
  /** Nomes dos serviços e dos cases, montados no servidor (app/layout.tsx), para o WhatsApp falar da página aberta. */
  whatsAppContexts?: WhatsAppContexts;
}) {
  const pathname = usePathname();
  const viaWhatsApp = headerOpensWhatsApp(pathname);
  const subject = whatsAppSubjectForPath(pathname, whatsAppContexts);
  const [mobileMenuOpen, setMobileMenuOpen] = useState(false);
  const [scrolled, setScrolled] = useState(false);
  const headerRef = useRef<HTMLElement>(null);
  const menuButtonRef = useRef<HTMLButtonElement>(null);

  // Trocou a rota: o menu fecha (o cabeçalho vive no layout e não remonta entre as páginas).
  // biome-ignore lint/correctness/useExhaustiveDependencies: pathname só dispara o fechamento a cada página
  useEffect(() => {
    setMobileMenuOpen(false);
  }, [pathname]);

  useEffect(() => {
    let wasScrolled = false;
    const updateScrolled = () => {
      const nextScrolled = window.scrollY > 0;
      if (nextScrolled === wasScrolled) return;
      wasScrolled = nextScrolled;
      setScrolled(nextScrolled);
    };

    updateScrolled();
    window.addEventListener("scroll", updateScrolled, { passive: true });
    return () => window.removeEventListener("scroll", updateScrolled);
  }, []);

  const closeMobileMenu = () => setMobileMenuOpen(false);

  // Menu aberto: o conteúdo e o rodapé ficam inertes, a página não rola, o Tab não sai do cabeçalho e o Esc fecha.
  useEffect(() => {
    const header = headerRef.current;
    const menuButton = menuButtonRef.current;
    if (!mobileMenuOpen || !header || !menuButton) return;

    const root = document.documentElement;
    const inertTargets = INERT_IDS.flatMap((id) => {
      const element = document.getElementById(id);
      return element ? [element] : [];
    });
    for (const element of inertTargets) element.setAttribute("inert", "");
    const previousOverflow = root.style.overflow;
    root.style.overflow = "hidden";

    // Devolve a página ao normal na hora, sem esperar o React: um link do menu para #id precisa achar o destino
    // focável quando o gerenciador de âncoras da home (useHomeFragmentNavigation) tenta focá-lo no clique.
    let released = false;
    const release = () => {
      if (released) return;
      released = true;
      for (const element of inertTargets) element.removeAttribute("inert");
      root.style.overflow = previousOverflow;
    };

    const onKeyDown = (event: KeyboardEvent) => {
      if (event.key === "Tab") return trapTab(event, header);
      if (event.key !== "Escape") return;

      event.preventDefault();
      release();
      setMobileMenuOpen(false);
      menuButton.focus();
    };
    // Na fase de captura da janela, antes do document: roda antes do gerenciador de âncoras da home.
    const onLinkClick = (event: MouseEvent) => {
      const link =
        event.target instanceof Element
          ? event.target.closest("a[href]")
          : null;
      if (link && header.contains(link)) release();
    };
    const desktop = window.matchMedia?.(DESKTOP_QUERY);
    const onViewportChange = (event: MediaQueryListEvent) => {
      if (!event.matches) return;
      release();
      setMobileMenuOpen(false);
    };

    document.addEventListener("keydown", onKeyDown);
    window.addEventListener("click", onLinkClick, true);
    desktop?.addEventListener?.("change", onViewportChange);
    return () => {
      release();
      document.removeEventListener("keydown", onKeyDown);
      window.removeEventListener("click", onLinkClick, true);
      desktop?.removeEventListener?.("change", onViewportChange);
    };
  }, [mobileMenuOpen]);

  return (
    <header
      ref={headerRef}
      className={`site-header fixed inset-x-0 top-0 z-[9000] h-[var(--site-header-height)] w-full border-b px-sp-6 text-[var(--white)] transition-colors duration-200 lg:px-sp-8 xl:px-sp-12 ${
        scrolled
          ? "border-white/12 bg-[var(--ink)]"
          : "border-transparent bg-[var(--ink)]"
      }`}
    >
      <div className="ds-section-shell flex h-full items-center justify-between gap-sp-6">
        <HoverPrefetchLink
          href="/#home"
          aria-label="Evandro.dev.br — início"
          className="flex min-h-11 shrink-0 items-center no-underline"
          onClick={closeMobileMenu}
        >
          <Logo theme="dark" loading="eager" className="w-40 sm:w-44" />
        </HoverPrefetchLink>

        <nav
          aria-label="Navegação principal"
          data-menu-trap-skip=""
          className="hidden items-center xl:flex"
        >
          <ul className="flex list-none items-center gap-sp-4">
            {NAVIGATION_ITEMS.map((item) => (
              <li key={item.href}>
                <HoverPrefetchLink
                  href={item.href}
                  className="cv-bar inline-flex min-h-11 items-center whitespace-nowrap rounded-sm px-sp-3 font-display text-[15px] font-medium normal-case tracking-normal text-white/80 no-underline [--bar-x:var(--sp-3)] hover:text-white"
                >
                  {item.label}
                </HoverPrefetchLink>
              </li>
            ))}
          </ul>
        </nav>

        <div className="flex shrink-0 items-center">
          <div className="hidden xl:block" data-menu-trap-skip="">
            <ContactCta
              className="cv-fill inline-flex min-h-11 items-center whitespace-nowrap rounded-sm bg-[var(--slash)] px-sp-4 font-display text-[15px] font-semibold normal-case tracking-normal text-[var(--ink)] no-underline"
              placement="header"
              viaWhatsApp={viaWhatsApp}
              subject={subject}
            />
          </div>
          <button
            ref={menuButtonRef}
            type="button"
            className="flex h-11 w-11 flex-col items-center justify-center gap-sp-2 border-none bg-transparent focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-[var(--slash)] focus-visible:ring-offset-2 focus-visible:ring-offset-[var(--ink)] xl:hidden"
            // as linhas têm 2 px (h-0.5) e 8 px de espaço (gap-sp-2): de uma a outra são 10 px, e as de cima e de baixo andam 10 px até o meio, para o X fechar sem torcer
            onClick={() => setMobileMenuOpen(!mobileMenuOpen)}
            aria-controls={mobileMenuOpen ? MENU_ID : undefined}
            aria-label={mobileMenuOpen ? "Fechar menu" : "Abrir menu"}
            aria-expanded={mobileMenuOpen}
          >
            <span
              className={`h-0.5 w-5 bg-white transition-transform duration-300 ${mobileMenuOpen ? "translate-y-[10px] rotate-45" : ""}`}
            />
            <span
              className={`h-0.5 w-5 bg-white transition-opacity duration-300 ${mobileMenuOpen ? "opacity-0" : ""}`}
            />
            <span
              className={`h-0.5 w-5 bg-white transition-transform duration-300 ${mobileMenuOpen ? "-translate-y-[10px] -rotate-45" : ""}`}
            />
          </button>
        </div>
      </div>

      {mobileMenuOpen ? (
        // Tela cheia abaixo da barra, com fundo opaco: o conteúdo da página não aparece por trás dos links.
        // A barra de cookies (fixa, acima do cabeçalho) cobre a base da tela: o espaço dela sobe o botão de contato.
        <div className="ds-enter absolute inset-x-0 top-[var(--site-header-height)] flex h-[calc(100dvh-var(--site-header-height))] flex-col overflow-y-auto overscroll-contain bg-[var(--ink)] px-sp-6 pb-[calc(var(--sp-6)+env(safe-area-inset-bottom)+var(--cookie-bar-height,0px))] [--enter-y:-8px] lg:px-sp-8 xl:hidden">
          <div className="ds-section-shell flex flex-1 flex-col">
            <nav
              id={MENU_ID}
              aria-label="Navegação mobile"
              className="flex flex-1 flex-col"
            >
              <ul className="flex list-none flex-col">
                {NAVIGATION_ITEMS.map((item) => (
                  <li key={item.href} className="border-b border-white/10">
                    <HoverPrefetchLink
                      href={item.href}
                      className="cv-bar flex min-h-14 items-center font-display text-[22px] font-medium normal-case leading-tight tracking-normal text-white/85 no-underline [--bar-y:100%] hover:text-white"
                      onClick={closeMobileMenu}
                    >
                      {item.label}
                    </HoverPrefetchLink>
                  </li>
                ))}
              </ul>
              <div className="mt-auto pt-sp-8">
                <ContactCta
                  className="cv-fill flex min-h-14 w-full items-center justify-center rounded-sm bg-[var(--slash)] px-sp-4 font-display text-[18px] font-semibold normal-case tracking-normal text-[var(--ink)] no-underline"
                  placement="header_menu"
                  viaWhatsApp={viaWhatsApp}
                  subject={subject}
                  onNavigate={closeMobileMenu}
                />
              </div>
            </nav>
          </div>
        </div>
      ) : null}
    </header>
  );
}