301 Redirect Rules for a Blog Migration - .htaccess

Question

I want to implement 3 redirect rules for a blog migration where each page will be shifted to a sub-folder structure. It currently sits at a sub-domain.
I can't really screw this one up and want to make sure I nail the correct generic rules for the 3 type of existing URLs:
Homepage
Current:
https://blog.lang.example.com
Goal:
https://www.example.com/lang-country/news/
Category
Current:
https://blog.lang.example.com/category/category-name
Goal:
https://www.example.com/lang-country/news/category/category-name
Post
Current:
https://blog.lang.example.com/yyy/mm/dd/article-name
Goal:
https://www.example.com/lang-country/news/yyy/mm/dd/article-name
Is this something you can help?

Answer 1

Unless you have other URLs that you don't want to be redirected then you can do something like what you require with a single redirect near the top of the .htaccess file in the subdomain's document root.
For example:
RewriteEngine On
RewriteCond %{HTTP_HOST} ^blog\.([^.]+)\.example\.com [NC]
RewriteRule (.*) https://www.example.com/%1-country/news/$1 [R,L]
Where %1 is a backreference to the lang subdomain in the requested host.
However, you still have the problem of where country should come from in the target URL, since this is not present in the source URL. You will either need to default this to something or implement some kind of lookup based on the language. This would need server config access (to configure a RewriteMap) if you wanted to do this in .htaccess. Or, you implement this redirect entirely in your server-side script (eg. PHP).
Note that this is currently a 302 (temporary) redirect. Only change this to a 301 (permanent) redirect once you have tested that everything is working OK (if a 301 is required). 301 redirects are cached hard by the browser so can make testing problematic.