Question

I’ve always been bad at apache and used very simple solutions. Right now I have built a cms software.. but the .htaccess is starting to be a huge downsize.

I will first explain, how my friendly-urls work and look like. My language-switch is url based and always contains two characters. And it looks like this: stackoverflow.com/en/ this makes the switching really easy and since its url based.. it works well in the SEO terms. Also, if no language-id is set, then the default language will be used (stackoverflow.com/).
There are no page-ids in numbers. I have unique page-ids in text: stackoverflow.com/services.html and for SEO and folder-directories-anti-conflict purposes .html at the end..
For subpages I have “$current_page” and “$parent_page” style variables: stackoverflow.com/services/translating.html Services being the parent and translating being the current page.
Some sample code too (I nerfed it alot, so you don’t think its incomplete):

RewriteRule ^(et|en|fi)\/(.+)\/(.+)\.html  index.php?language=$1&pagelink=$3&parentlink=$2 [L,NC,QSA]

RewriteRule ^(.+)\/(.+)\.html  index.php?language=0&pagelink=$2&parentlink=$1 [L,NC,QSA]
RewriteRule ^(.+)\.html  index.php?language=0&pagelink=$1&parentlink=0 [L,NC,QSA]

How can I make the language-switch part more dynamic?
This method ..^(et|en|fi)\/.. means, that when I set up the cms, I must manually set the languages list. Best bet would be to set it somehow from the cms settings. Because, this way there are no conflicts related to folders. Is it possible global apace variable via php and then display it the .htaccess file? Something like this: ..^(LANGUAGELISTS)\/..? If this isn’t possible, then next best thing would be to match 2 characters in that location and pass it as $_GET['language'].

How can I have unlimited parents dynamically?
Meaning, that the “$parent_page” is not set statically and I have unlimited children, similar to this: stackoverflow.com/services/translating/english/somesubpage.html. If that is possible, then also, how will it be used in the php, with an array?

Bounty edit
First part of the question is basically solved, unless somebody comes up with some php -> apache-array -> .htaccess way.
However, the second part of the question is still not solved. Since this is been the problem with all my projects and could possibly help somebody else in the future, I decided to add bounty to this question.

Answer 1

To answer your first question:
You could use RewriteRule ^([a-zA-Z]{2})([/]?)(.*)$ path/file.php?language=$1
This limits the first string to two characters and passes it on to $_GET['language']

Edit: adding RewriteCond %{REQUEST_FILENAME} !-f
and RewriteCond %{REQUEST_FILENAME} !-d will prevent conflicts with existing directories / files

Second question is much more difficult..

Update:

What Shad and toopay say is a good start in my opinion.
Using explode() to seperate levels and comparing it to the slug is quite simple.
But it’s getting complicated once you want to add flexibility to the script.

function get_URL_items() {
$get_URL_items_url = $_SERVER['REQUEST_URI'];
$get_URL_items_vars = explode("/",$get_URL_items_url);
for ($get_URL_items_i = 0; $get_URL_items_i < count($get_URL_items_vars) ; $get_URL_items_i++) {
    if(strlen(trim($get_URL_items_vars[$get_URL_items_i])) == 0) {
        unset($get_URL_items_vars[$get_URL_items_i]);
    }
}
return $get_URL_items_vars;

Let’s say you you’ve got a website with a sub-section called “Festival” and a database filled with info for 100+ artist and you want your URLs to look like website.com/festival/<artistgenre>/<artistname>/.
You don’t want to create 100+ pages in your CMS so <artistgenre> and <artistname> are some kind of wildcards.

I found it hard to achieve this without a lot of if/else statements like:

$item = get_URL_items();    
if(is_user($item[2]) && is_genre($item[1]) && is_festival($item[0])) {
  // do mysql stuff here
}