From 62587f18571bcac1cf0c0c4c634e88a166bc512e Mon Sep 17 00:00:00 2001
From: Yohei Yasukawa <yohei@yasslab.jp>
Date: Sat, 18 Jan 2025 13:04:22 +0900
Subject: [PATCH] Enable visitors to switch corresponding EN/JA page if exist

---
 docs/_layouts/post.html | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/docs/_layouts/post.html b/docs/_layouts/post.html
index 40d99bc9..7d9d1798 100644
--- a/docs/_layouts/post.html
+++ b/docs/_layouts/post.html
@@ -26,7 +26,16 @@ <h1 class="post-title" data-aos="fade-up" data-aos-delay="200" data-aos-offset="
     </div>
 
     <p>
-      {{ site.data.translations.link[page.lang] }}: <a href="{{ page.link }}">{{ page.link }}</a>
+      {{ site.data.translations.link[page.lang] }}: <a href="{{ page.link }}">{{ page.link }}</a><br>
+
+      {% assign urls   = site.posts | map: 'url' | sort %}
+      {% assign url_en = page.url | replace_first: page.lang, 'en'  %}
+      {% assign url_ja = page.url | replace_first: page.lang, 'ja'  %}
+      {% if page.lang == 'en' and urls contains url_ja %}
+        {{ site.data.translations.link[page.lang] }}: <a href='{{ url_ja }}'>&raquo; Switch to Japanese</a>
+      {% elsif page.lang == 'ja' and urls contains url_en %}
+	{{ site.data.translations.link[page.lang] }}: <a href='{{ url_en }}'>&raquo; Switch to English</a>
+      {% endif %}
     </p>
     
     <p>