ESPDocs/middleware.js

import createMiddleware from "next-intl/middleware";
import { NextResponse } from "next/server";
import { routing } from "./i18n/routing";
import { ALL_LOCALE_CODES, ENABLED_LOCALES, getLocalizedHref } from "./i18n/links";

const intlMiddleware = createMiddleware(routing);

function parseAcceptLanguage(header) {
	if (!header) return [];
	return header
		.split(",")
		.map((part) => {
			const [langRange, qPart] = part.trim().split(";");
			let q = 1.0;
			if (qPart) {
				const match = qPart.match(/q=([\d.]+)/);
				if (match) {
					const parsed = parseFloat(match[1]);
					if (!isNaN(parsed)) q = parsed;
				}
			}
			return { lang: langRange.trim().toLowerCase(), q };
		})
		.sort((a, b) => b.q - a.q);
}

function matchLocale(lang) {
	if (lang.startsWith("pt")) return "pt";
	if (lang.startsWith("es")) return "es";
	if (lang.startsWith("fr")) return "fr";
	if (lang.startsWith("de")) return "de";
	if (lang.startsWith("zh")) return "zh-CN";
	if (lang.startsWith("en")) return "en";
	return null;
}

function resolveRootLocale(request) {
	const cookieValue = request.cookies.get("NEXT_LOCALE")?.value;
	if (cookieValue && ENABLED_LOCALES.includes(cookieValue)) {
		return cookieValue;
	}
	const acceptLang = request.headers.get("accept-language");
	const parsed = parseAcceptLanguage(acceptLang);
	for (const { lang } of parsed) {
		const matched = matchLocale(lang);
		if (matched && ENABLED_LOCALES.includes(matched)) {
			return matched;
		}
	}
	return ENABLED_LOCALES.includes("en") ? "en" : (ENABLED_LOCALES[0] || "pt");
}

export default function middleware(request) {
	const { pathname, search } = request.nextUrl;

	// Exclusões de caminhos e arquivos estáticos
	if (
		pathname.startsWith("/api") ||
		pathname.startsWith("/_next") ||
		pathname === "/robots.txt" ||
		pathname === "/sitemap.xml" ||
		pathname === "/google21a790a2c23c0ec5.html" ||
		/\.[a-zA-Z0-9]+$/.test(pathname)
	) {
		return NextResponse.next();
	}

	// 1. Raiz: negociação de idioma (307) considerando apenas idiomas ATIVOS
	if (pathname === "/") {
		const targetLocale = resolveRootLocale(request);
		const url = new URL(`/${targetLocale}`, request.url);
		url.search = search;
		const response = NextResponse.redirect(url, 307);
		response.headers.set("Vary", "Accept-Language, Cookie");
		response.headers.set("Cache-Control", "private, no-store");
		return response;
	}

	// 2. Idiomas INATIVOS: prefixos (/es, /fr, /de, /zh-CN etc.)
	// Redirecionam com 307 para o mesmo caminho no idioma fallback (en se ativo, senão pt) quando o slug existir lá.
	const inactiveLocales = ALL_LOCALE_CODES.filter((l) => !ENABLED_LOCALES.includes(l));
	if (inactiveLocales.length > 0) {
		const isInactive = inactiveLocales.some(
			(loc) => pathname === `/${loc}` || pathname.startsWith(`/${loc}/`)
		);
		if (isInactive) {
			const fallbackLocale = ENABLED_LOCALES.includes("en") ? "en" : "pt";
			const targetPath = getLocalizedHref(pathname, fallbackLocale);
			const url = new URL(targetPath, request.url);
			if (search && !targetPath.includes("?")) {
				url.search = search;
			}
			return NextResponse.redirect(url, 307);
		}
	}

	// 3. Livro fora do português para idiomas ATIVOS que não são pt: 404
	const activeNonPt = ENABLED_LOCALES.filter((l) => l !== "pt");
	if (activeNonPt.length > 0) {
		const isBookInOtherActiveLocale = activeNonPt.some(
			(loc) => pathname === `/${loc}/livro` || pathname.startsWith(`/${loc}/livro/`)
		);
		if (isBookInOtherActiveLocale) {
			return new NextResponse(null, { status: 404 });
		}
	}

	// 4. URLs antigas sem prefixo reconhecido: redirecionamento 308 para /pt/<caminho>
	const hasActivePrefix = ENABLED_LOCALES.some(
		(loc) => pathname === `/${loc}` || pathname.startsWith(`/${loc}/`)
	);

	if (!hasActivePrefix) {
		const url = new URL(`/pt${pathname}`, request.url);
		url.search = search;
		return NextResponse.redirect(url, 308);
	}

	// 5. Delegação para o roteamento do next-intl para idiomas ativos
	return intlMiddleware(request);
}

export const config = {
	matcher: [
		"/((?!api|_next|_vercel|.*\\..*|robots\\.txt|sitemap\\.xml|google21a790a2c23c0ec5\\.html).*)",
	],
};