From 3f36ea25e619dd283e104152a0c32a020ba1060a Mon Sep 17 00:00:00 2001
From: Alexandra Goff <agoff@lsst.org>
Date: Wed, 16 Oct 2024 09:40:52 -0700
Subject: [PATCH] fix: add to robots.txt (#578)

* chore: trigger build

* fix: add to robots.txt
---
 app/[locale]/sitemap.xml/route.ts |  4 ++++
 app/robots.ts                     |  3 +++
 lib/api/sitemap/index.ts          | 16 ++++++++++++++--
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/app/[locale]/sitemap.xml/route.ts b/app/[locale]/sitemap.xml/route.ts
index 7f7aaca5..1114bc61 100644
--- a/app/[locale]/sitemap.xml/route.ts
+++ b/app/[locale]/sitemap.xml/route.ts
@@ -1,6 +1,7 @@
 import { NextRequest, NextResponse } from "next/server";
 import { XMLBuilder } from "fast-xml-parser";
 import {
+  generateAlternateLanguages,
   generateSitemapUrl,
   getSitemapData,
   getSiteMapNewsData,
@@ -15,6 +16,7 @@ export async function GET(
     return {
       loc: generateSitemapUrl(uri, locale),
       lastmod: dateUpdated,
+      "xhtml:link": generateAlternateLanguages(uri, locale),
     };
   });
   const { siteTitle, news } = await getSiteMapNewsData(locale);
@@ -28,6 +30,7 @@ export async function GET(
     const entry = {
       loc: generateSitemapUrl(uri, locale),
       lastmod: dateUpdated,
+      "xhtml:link": generateAlternateLanguages(uri, locale),
     };
 
     if (new Date(date) > recentNewsThreshold) {
@@ -51,6 +54,7 @@ export async function GET(
     },
     urlset: {
       $xmlns: "http://www.sitemaps.org/schemas/sitemap/0.9",
+      "$xmlns:xhtml": "http://www.w3.org/1999/xhtml",
       "$xmlns:news": "http://www.google.com/schemas/sitemap-news/0.9",
       url: pageData.concat(newsData),
     },
diff --git a/app/robots.ts b/app/robots.ts
index fc42c639..f8c06402 100644
--- a/app/robots.ts
+++ b/app/robots.ts
@@ -1,10 +1,13 @@
 import { MetadataRoute } from "next";
 
+const baseUrl = process.env.NEXT_PUBLIC_BASE_URL || "";
+
 export default function robots(): MetadataRoute.Robots {
   return {
     rules: {
       userAgent: "*",
       allow: "/",
     },
+    sitemap: `${baseUrl}/sitemap_index.xml`,
   };
 }
diff --git a/lib/api/sitemap/index.ts b/lib/api/sitemap/index.ts
index 67bbe004..2760be22 100644
--- a/lib/api/sitemap/index.ts
+++ b/lib/api/sitemap/index.ts
@@ -3,7 +3,7 @@ import { getSiteFromLocale } from "@/lib/helpers/site";
 import queryAPI from "@/lib/api/client/query";
 import tags from "@/lib/api/client/tags";
 import { CRAFT_HOMEPAGE_URI } from "@/lib/constants";
-import { fallbackLng } from "@/lib/i18n/settings";
+import { fallbackLng, languages } from "@/lib/i18n/settings";
 
 interface PageMetadata {
   uri: string;
@@ -16,7 +16,7 @@ export const generateSitemapUrl = (
   locale: string,
   preserveLocale = false
 ) => {
-  const segments = uri === CRAFT_HOMEPAGE_URI ? [] : [uri];
+  const segments = uri === CRAFT_HOMEPAGE_URI ? [] : [encodeURIComponent(uri)];
 
   if (preserveLocale || locale !== fallbackLng) {
     segments.unshift(locale);
@@ -27,6 +27,18 @@ export const generateSitemapUrl = (
   return segments.join("/");
 };
 
+export const generateAlternateLanguages = (uri: string, locale: string) => {
+  return languages
+    .filter((language) => language !== locale)
+    .map((language) => {
+      return {
+        $rel: "alternate",
+        $hreflang: language,
+        $href: generateSitemapUrl(uri, language),
+      };
+    }, {});
+};
+
 export const getSiteMapNewsData = async (locale: string) => {
   const site = getSiteFromLocale(locale);