通过Accept Language标头重定向并保留URL路径

Question

我正在重新设计我的网站，我希望Apache web服务器像在坦克世界欧洲网站上那样重定向访问者。例如，如果我尝试打开URLhttps://worldoftanks.eu/news/，它会在news/之前添加en/，并用英语打开页面。我现在在根文件夹中的.htaccess文件中有什么：

Options -Indexes
RewriteEngine on
# redirect to Russian section if the visitor has Russian language
RewriteCond %{HTTP:Accept-Language} ^ru [NC]
RewriteRule ^$ /ru/ [L,R=301]
# everyone else should be redirected to the English section
RewriteRule ^$ /en/ [L,R=301]

但只有当访问者开始从网站主页导航时，这才有效。有什么想法吗？

UPD1：我遵循了CBroe在评论中提供的建议，现在我有了这样的东西：

Options -Indexes
RewriteEngine on
# redirect to Russian section if the visitor has Russian language
RewriteCond %{HTTP:Accept-Language} ^(ru|be|uk|kk) [NC]
RewriteCond %{REQUEST_URI} !^/ru/.*$
RewriteRule (.*) /ru/$1 [L,R=301]
# everyone else should be redirected to the English section
RewriteCond %{REQUEST_URI} !^/en/.*$
RewriteRule (.*) /en/$1 [L,R=301]

正如他所提到的，裸线会导致无限重定向，结果是这样的，但导致http://example.com/en/ru/en/ru/en/ru/en/ru/en/ru/重定向出现相应的错误。当我将俄语(或条件中的任何语言(设置为优先级时，就会出现错误，而英语部分工作正常。

UPD2:我尝试过!^/(ru|en)/请求URI重写条件的建议，但也失败了。也许我把它放错了部分？

Options -Indexes
RewriteEngine on
# redirect to Russian section if the visitor has Russian (or any other CIS language) language
RewriteCond %{HTTP:Accept-Language} ^(ru|be|uk|kk) [NC]
RewriteCond %{REQUEST_URI} !^/(ru|en)/
RewriteRule (.*) /ru/$1 [L,R=301]
# everyone else should be redirected to the English section
RewriteCond %{REQUEST_URI} !^/en/.*$
RewriteRule (.*) /en/$1 [L,R=301]

Answer 1

@CBroe获胜！他关于把CCD_；CIS语言"；以及"；其他一切"；部门完成了任务。

Options -Indexes
RewriteEngine on
# redirect to Russian section if the visitor has Russian language
RewriteCond %{HTTP:Accept-Language} ^(ru|be|uk|kk) [NC]
RewriteCond %{REQUEST_URI} !^/(ru|en)/
RewriteRule (.*) /ru/$1 [L,R=301]
# everyone else should be redirected to the English section
RewriteCond %{REQUEST_URI} !^/(ru|en)/
RewriteRule (.*) /en/$1 [L,R=301]