.htaccess RewriteRule - multiple replacements needed - apache

Question

I'm a photographer, and run a website with thousands of event photos.
Over the years the path to many directories has changed, and, with a new software, the access to individual photos has changed as well.
I get the path changes covered like this (there are many more rules):
RewriteRule ^([0-9]{4})-major-generals-review/?(.*)$ /galleries/trooping-the-colour/$1-major-generals-review/$2 [R=301,NC,L]
RewriteRule ^([0-9]{4})-bcn-challenge/?(.*)$ /galleries/canal-and-waterway-events/$1-bcn-challenge/$2 [R=301,NC,L]
But I also have to replace, on top of the above, access to individual photos.
The "old" form is, to use a concrete example,
2013-bcn-challenge/index.php?`page=11/thumbnails/1305241839185D24543HaraldJoergens_v1.jpg&autoload=1305251137045D25451HaraldJoergens_v1`
and what I need is
galleries/canal-and-waterway-events/2013-bcn-challenge/1305241839185D24543HaraldJoergens_v1-single.php
so there are two replacements needed,
2013-bcn-challenge with /galleries/canal-and-waterway-events/2013-bcn-challenge/
(that part does work), and
index.php?page=11/thumbnails/1305241839185D24543HaraldJoergens_v1.jpg&autoload=1305251137045D25451HaraldJoergens_v1 with
1305241839185D24543HaraldJoergens_v1-single.php
which does not work. My code for the second replacement is
RewriteRule (.*)/index.php?page=[0-9]+/thumbnails/([-_0-9a-zA-Z]+)\.jpg.* $1/$2-single.php [R=301,NC]
on top of the other rules. Unfortunately, it seems to result in an endless loop.
To make matters worse, instead of "/thumbnails/", it could be "/cust_thumbnails/" or "/photos/", and the "autoload" part can be there or not.
Might anyone be able to help me get around the problem? Thanks a lot in advance!
Harald

Answer 1

The problem is that the query string (?page=...) is not part of the request URI, and so cannot be matched in the rewrite pattern.
As such, you will need to check the query string separately:
RewriteCond %{QUERY_STRING} ^page=\d+/((cust_)?thumbnails|photos)/([\w\-]+).jpg [NC]
RewriteRule ^(.*/)?index.php$ /$1%3-single.php? [R=301,NC,L]
Here, we are checking the query string for the presence of page=<num>, cust_thumbnails, thumbnails, photos, and, of course, the name of the photo.
Then, we are redirecting to /<folder-name>/<file-name>-single.php.
Note: In the expression, I have changed [0-9]+ to \d+ and [-_0-9a-zA-Z]+ to [\w\-]+ - these are both shorthand alternatives.