Please can you help me to convert this to nginx

<IfModule mod_rewrite.c>
RewriteEngine on

# If you are having problems or are using VirtualDocumentRoot, uncomment this line and set it to your directory.
# RewriteBase /maindir/
RewriteOptions MaxRedirects=30
RewriteCond %{ENV:REDIRECT_STATUS} 200
RewriteRule .* - [L]


RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d

RewriteRule ^.*$ - [NC,L]

RewriteRule ^index(.*)$ index.php [QSA]
RewriteRule ^chat/.* pages.php [QSA]
RewriteRule ^Songs(.*)$ showcat.php?g=2 [QSA]
RewriteRule ^Jokes(.*)$ showcat.php?g=3 [QSA]
RewriteRule ^Ash3ar(.*)$ showcat.php?g=4 [QSA]
RewriteRule ^iraq/.* showcat.php [QSA]
RewriteRule ^Song/.* sounds.php [QSA]
RewriteRule ^Joke/.* jokes.php [QSA]
RewriteRule ^Poem/.* poems.php [QSA]
RewriteRule ^link/.* advs.php [QSA]
RewriteRule ^search/.* search.php [QSA]
RewriteRule ^adv-conditions(.*)$ ad.php?go=conditions [NC]
RewriteRule ^adv-payments(.*)$ ad.php?go=payments [NC]

RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d

RewriteRule ^.*$ - [NC,L]
RewriteRule ^(?:(.*?)(?:/|$))(.*|$)$ $1.php?r=$2 [QSA]


</IfModule>


<IfModule mod_security.c>
SecFilterEngine Off
SecFilterScanPOST Off
</IfModule>

<IfModule mod_gzip.c>
mod_gzip_on No
</IfModule>